Development of Aluminum Drill Pipe in

Development of Aluminum Drill Pipe in

230 Pages · 2000 · 11.82 MB · English

IMPLEMENT RUSSIAN ALUMINUM DRILL PIPE AND The primary advantage of aluminum drill pipe is, of course, a significant in string weight. The pH of the drilling fluid significantly affects the process of ADP corrosion wear.

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IMPLEMENTRUSSIANALUMINUMDRILLPIPEAND RETRACTABLEDRILLINGBITSINTOTHEUSA Volume1:DevelopmentofAluminum DrillPipeinRussia FinalReport TR9923 Preparedfor: MrWilliamJGwilliam FederalEnergyTechnologyCenter USDEPARTMENTOFENERGY Morgantown,WestVirginia PerformedUnderContractNoDEFG2698FT40128 By: AquaticCompany Moscow,Russia and MaurerEngineeringInc 2916WestTCJester Houston,Texas77018 August1999 )$” ‘ ,’ ,,, !:“ c, , ,! , , ,“ \’ : t , , !, !, ,,, ,, —— DISCLAIMER Thisreportwaspreparedasanaccountofworksponsored byanagencyoftheUnitedStatesGovernmentNeither theUnitedStatesGovernmentnoranyagencythereof,nor anyoftheiremployees,makeanywarranty,expressor implied,orassumesanylegalliabilityorresponsibilityfor theaccuracy,completeness,orusefulnessofanY information,apparatus,product,orprocessdisclosed,or representsthatitsusewouldnotinfringeprivatelyowned rightsReferencehereintoanyspecificcommercial product,process,orservicebytradename,trademark, manufacturer,orotherwisedoesnotnecessarilyconstitute orimplyitsendorsement,recommendation,orfavoringby theUnitedStatesGovernmentoranyagencythereofThe viewsandopinionsofauthorsexpressedhereindonot necessarilystateorreflectthoseoftheUnitedStates Governmentoranyagencythereof DISCLAIMER Portionsofthisdocumentmaybeillegible inelectronicimageproductsImagesare producedfromthebestavailableoriginal document Acknowledgements ThisreportsummarizingdevelopmentofaluminumdrillpipeinRussiawas preparedfortheFederalEnergyTechnologyCenterunderDOEGrantNoDEFG26 98FT40128TheassistanceoftheDOEProjectDirector,MrWilliamJGwilliam,is gratefullyacknowledged AquaticCompanypersonnel:DrMichaelGelfgat(ManagerofRussianTeam);Dr VladimirBasovich(ChiefEngineer);ProfGenrikhFain(Consultant);DrAlexander Podrazhansky(Director);MrBorisVygotsky(ChiefDesigner);MsValentina Kholostova(Engineer);andMrBorisVolkovoy(Interpreter) MaurerEngineeringpersonnel:DrWilliamCMaurer(ProjectManager)andMr GregDeskins(ProjectEngineer) ,,s m“,>,,,+ j ii:tu”’u;~ ‘“;:~ :“” N(IVO92000‘ @sT/ ,’ , ,, ,’ ,, ,, ,,>, , >,, ,,,, , ,,,:>J,,$%’ew ,~,,,;~,\ k,wA’ f,, * ,, =: ’ ’ Ill — DevelopmentofAluminumDrillPipeinRussia iv TableofContents ListofFiguresvii ListofTablesix ExecutiveSummaryxi 1 2 3 4INTRODUCTION1 11Background1 12OnshoreApplicationsforADP1 13OffshoreApplicationsforADP2 PROPERTIESOFALUMINUMALLOYS’5 21Advantages/DisadvantagesofSteel,TitaniumandAluminumAlloys5 MaterialSpecificStrength5 ResistancetoAlternatingBendingandDynamicStresses6 CorrosionResistance8 AbrasiveWear9 22GeneralRequirementsforAluminumAlloysforADP9 23ChemicalCompositionandPropertiesofAluminumAlloysusedin RussiaforADP10 24Characteristicsofthe1980TIAlloy12 25CorrosionofADPandMethodsofPrevention 13 ConclusionsRegardingCorrosion78 ADPMANUFACTURINGTECHNOLOGY21 31 32 33 34 35ManufacturingofTubularBilletsUsingPressForming2l MakingPipeThreads23 ColdAssemblyofADP24 HotAssemblyofADP26 SealinganADPPipeThread28 ADPDESIGNSANDAPPLICATIONS31 41 42 ! >’ ,: ~,,, ,’‘ ,’ 1 , “ ,’ , , , > ,, ,—, + ,,, y — GeneralInformation 31 ADPwithInternalandExternalUpsetEnds31 v 43 44 45 46 47 48 49DevelopmentofAluminumDrillPipeinRussia ADPwithProtectionUpset39 IntegralJointADP39 ThickWallADP(ADC)42 ADPforExploratoryDfilling44 AluminumPipesinWorkoverOperations45 TubingfromAluminumAlloys46 PotentialforManufacturingAluminumCasing47 410PotentialforManufacturingAluminumMarineRisers49 5EXPERIENCEWITHADP=53 51ADPOperationattheRigSite53 52DrillPipeWearWhenDrillingUltradeepHoles56 53DrillingProblemsattheKolaSD3Well59 6ASSEMBLINGDRILLSTRINGSFROMADP63 61SpecificsofDrillStringDesign63 62EvaluationofLoadsAppliedtotheDrillStfing65 63DesignParametersandSafeLoadFactorsforADPStrings70 64EnduranceandDurabilityofADP72 65ElongationofanADPDrillString76 66ADPDrillStringsforDirectionalDrillinginWesternSiberia79 67ADPDrillStringsforDrillingUltradeepWells8O 68ADPDrillStringsforDeepwaterStratigraphicDrilling83 7ADPFORVIBRATIONDAMPING 85 8ADPINEXTENDEDREACHDRILLING 87 9ADPINDEEPWATERRISERLESSDRILLING 89 10ECONOMICBENEFITSOFADP 93 11CONCLUSIONS 97 12REFERENCES 99 vi Figure1 Figure2 Figure3 Figure4 Figure5 Figure6 Figure7 Figure8 Figure9DevelopmentofAluminumDrillPipeinRussia ListofFigures ADPwithSteelToolJoint4 RunningDepthsforDrillPipesofVariousMaterials6 BendingStressof146mmDPinVariousHoleSizes7 CorrosionRatewithpHandTemperaturel4 ExtrusionProcessofPipeBilletwithInternalUpsetEndsandThickened Middle 21 ColdAssemblyStandforADPwithSteelToolJoints25 HotAssemblyStandforADPwithSteelTool27 BenchforHotAssemblyofADP27 ADPBeforeandAfterScrewingonSteelToolJoint28 Figure10CompleteADPAssembledUsingHotTechnology28 Figure11ADPswithToolJoints(leftinternalupsetends;middle:externalupset ends;right:protectionupset32 Figure12IntegralJointADP39 Figure13ThickWalledAluminumDrillCollar(ADC)42 Figure14HeavyWallFlutedADC43 Figure15JointsofPinJointandBoxJointADP44 Figure16ADPforWorkoversandCompletions45 Figure17IntegralJointAluminumTubing47 Figure18InternallyFlushADPusedasCasing48 Figure19DesigningAluminumDrillingRiser50 Figure20DragandWearontheKolaSD3(95tripsfrom960010,700m)58 Figure21DistributionofNormalForceinanEllipticalHole66 Figure22DistributionofDragForcesinKolaSD367 Figure23YieldPointofDI6TwithTemperature70 Figure24CreepRateofDI6TwithTemperature71 Figure25CreepRateofD16TAlloyatVariousTemperatures7l Figure26BenchforFatigueTestingofPipeandConnector73 Figure27ST20FatigueTestBench73 Figure28164x9ADPafterFatigueTests74 Figure29FatigueTestResultsofConnections75 Figure30FatigueEnduranceofADPConnection(147mmODPipe;DI6TAlloy)76 Figure31LongTermStrengthofADPwithTemperature77 Figure32BHADesignandResonanceFrequency 86 Figure32BHADesignandResonanceFrequency 88 Figure34BuoyancyFactorsforADP,TDPandSDP 91 Figure35PowerConsumedforPullingADPandSDP 93 Figure36AluminumDrillPipe95 vii , ~,,, ,: “ ,, ,, :, ;i — ,,$,>>:, :<,,;,’ r:,,,,7,: : t%*>! ::,’,?, ’’! —— :*,>,:: [,,,;>++9, ,, ,, ,, ,,< DevelopmentofAluminumDrillPipeinRussia Vlll DevelopmentofAluminumDrillPipeinRussia ListofTables TableESIMechanicalPropertiesofDrillPipeMaterialsxii Table1 Table2 Table3 Table4 Table5 Table6 Table7 Table8 Table9 Table10 Table11 Table12 Table13 Table14 Table15 Table16 Table17 Table18 Table19 Table20 Table21 Table22 Table23 Table24 Table25 Table26 Table27 Table28 Table29 Table30 Table31 Table32 Table33 Table34 Table35 Table36 Table37 Table38 Table39MechanicalPropertiesofMaterialsUsedforManufacturingDrillPipe5 ChemicalCompositionofAluminumAlloysusedforADPll PhysicalandMechanicalPropertiesofAluminumAlloys12 Propertiesofthe1980TIAluminumAlloy13 ADPCorrosionRates(g/m2/hr)inMudTreatedwithReagents16 HeatExposureTimesforDI6TAlloy16 RequirementsforSteelToolJoints3l ADPwithInternalPipeEndUpset(seeFigure11;left)33 ADPwithExternalPipeEndUpset(seeFigure11;middle)34 ADPwithInternalUpset(D16TAlloy)35 ADPwithInternalUpset(1953TIAlloy)36 ADPwithExternalUpset(D16TAlloy)37 ADPwithExternalUpset(1953TIAllOy)38 DimensionsofADPwithProtectionUpset(seeFigure11;right)39 TechnicalCharacteristicsofIntegralJointADP(AlloyD16T)41 TechnicalParametersofHeavyWallADC44 IntegralJointADPforWorkoversandCompletions46 PropertiesofTubingfromAluminumAlloys47 AluminumDrillingRiserCalculationResults50 TorquesforToolJointMakeupwithAntifrictionThreadLubricants53 CoefficientsforADPGeometricalParameters55 AllowableWearofToolJointThreads55 SummaryDataonADPWearandConditionalWorkforKolaSD357 DrillPipeConsumptionforInterval720011,500matKolaSD359 DrillingProblemsforKolaSD3to12,262mDepth6O CausesofDrillStringFailuresforKolaSD36l PropertiesofADPandSteelToolJointMaterials63 DesignParametersofADPforVariousOperatingTemperatures64 DragForcesalongtheDrillString(FieldTestResults)69 SafetyFactors72 TestsofADPThreadConnectionswithDifferentContactPressures74 EnduranceLimitofADP(SteelToolJointThreadedConnection)76 DrillStringAssemblyforWellNo4166(Povhovskaya)79 DrillStringAssemblyforWellNo1057(Povhovskaya)79 KolaUltradeepWellSG3DrillStringDesignat12,000m82 KrivoyRogUltradeepWellSG8DrillStringDesignat5580m82 ADPApplicationforScientificOffshoreDrilling84 TripTime(see)forADPandSDPDrillStrings94 ComparisonofReynoldsAluminumDrillPipe(ADP)andGradeESteel DrillPipe(SDP)96 ix : >, ” ,, ! , ,’ ,, ,“ ~ , e, ,,, ,,/,, ,,— ,, : ,”, ! DevelopmentofAluminumDrillPipeinRussia x ExecutiveSummary ThisreportdescribesthedevelopmentandapplicationofAluminumDrillPipe (ADP)inRussiaAdvantagesofADPforboreholedrillingincludelowspecificgravity, corrosionresistanceinvariousaggressiveenvironments,nonmagnetic,stable mechanicalproperties,andhighmanufacturingefficiency Issuesrelatedtotheuseofaluminumalloysformanufacturingdrillpipebecame anobjectofseriousstudyfordirectional,extendedreach,andhorizontalwells,and ultradeepboreholedrillingFurthermore,extensionofdrillingtooffshoreandtoareas withdifficultenvironmentalconditionsandlimitedinfrastructurerequiredthereductionof transportationcostsofequipmentandmaterialsAlltheseproblemscanbereducedor eliminatedbytheapplicationofADP Background ThefirstexploratorywellswhereADPwasappliedweredrilledintheregionofthe middleVolgain19601962TheseearlyexperimentsshowedthatADPalloweda significantreductionintime,materials,energyandlaborrequirementsInthemid 1960s,ADPwasusedtodrillseveraluitradeepwells,andinthe1970swasgivenwide recognitionforclusterdirectionaldrillinginWesternSiberia ThesuccessfulutilizationofADPindirectionalanddeepdrillingoperations demonstrateditseffectivenessinultradeepscientificboreholeswithhighformation stresses,hightemperaturesandhighlycorrosiveenvironmentsADPhasbeenused fordeepscientificdrilling ~applicationssuchasthe KolaultradeepSG3(12 km;39,400ft),aswell rasinotherultradeep boreholes Morerecently,164mm (646in)diameterpipewas successfullyemployedtodrill rfromthegeotechnicalvessel “Bucentaur,”whichhasa r displacementofonly4470 tonnes(4917tons)DrillingoperationswereperformedintheAtlanticOcean(Voring Basin1993,1997;RockallBank1994)GulfofMexico(MississippiCanyon1995;Green Canyon1996;VioscaKnollarea1996;GardenBanksarea1996),StraitofGibraltar (1995),offshoreJapan(1997),andoffshoreWestAfrica(1998) xi DevelopmentofAluminumDrillPipeinRussia Advantages/Disadvantagesof ADP Theprimaryadvantageofaluminumdrillpipeis,ofcourse,asignificant instringweightTheweightofADPis2to25timeslessthantheweightofreduction asimilar purposesteelstringThisallowsareductionindrillingcrewlabor,aswellasenabling drillingdeeperwellswithagiventypeofrig Thedownholedrillingenvironmentrequirescarefuldesignofdrillstring componentsandselectionofmaterials,especiallyinhostiledrillingapplications(Table ESI)ADPhasdemonstratedseveraladvantagesoverconventionalsteelstrings TableESIMechanicalPropertiesofDrillPipeMaterials MATERIAL DENSITYMODULUSOFSHEARPOISSON’STHERMALSPECIFIC (13/CM3) ELASTICITYMODULUSRATIOEXPANSIONHEAT (104MPA)(104MPA)(1O*/”c)(J/KG“C) SteelAlloys 78521079027 114500 AluminumAlloys 278 7127030226840 TitaniumAllovs 45411042(2884 460 MaterialSpecificStrength Onedimensional(ie,nottapered)ADPstrings allowmaximumsuspendedlengthForexample,auniformsteelstringhasamaximum hangoffdepthofabout8km(26,000fi)AsimilaruniformADPhasahangoffdepthof upto34km(111,000ft) ResistancetoAlternatingBendingandDynamicStresses Alternating bendingstressindrillpipeisproportionaltothemodulusofelasticityofthematerial(all otherfactorsbeingequal)Theirproportionforaluminumpipes,titanium,andsteelis: CorrosionResistance indicatesanadvantagefor(TA:GT:U5=I:I55:296 Corrosionresistanceanalysisforthecandidatematerials titaniumandsteelalloysoveraluminumalloysforthe principaltypesofcorrosionwearHydrogensulfideisanexception,sinceresistanceof aluminumtothismediumishigher CorrosionofADPdependsprimarilyon composition,aggressiveness,andtemperatureofthefluidinwhichthedrillstringis operated,aswellasonexposuretimeThestudyofcorrosionofADPhasledtothe followingconclusions: 1 2ThepHofthedrillingfluidsignificantlyaffectstheprocessofADPcorrosion wearCorrosionisinsignificantinfluidswithapHof7095andrapidly increaseswhenthepHexceeds105 ADPcorrosionisacceleratedathighertemperatures xii DevelopmentofAluminumDrillPipeinRussia 3Anoxidefilmthatformsonpipesurfacesexposedtooxygenprovides reliablecorrosionprotectionforADPHowever,abrasivedrillingfluidswith highsolidscontentcandamagetheoxidefilminareaswithturbulentflow, whichresultsinfastercorrosionofthedrillpipe 4 WhenhighvelocitysalinatedmudwithahighHZScontentisused,ADPhas demonstratedhighresistancefocorrosion,whichindicatesthatADPhas goodpotentialforapplicationinoil,gas,anddrillingmudmedia 5 TheprincipalmethodofprotectingADPfromcorrosionistheadditionof corrosioninhibitorstothemudSodiumpolyphosphateandpotassium basedstabilizinginhibitorsarethemostwidelyused 6 TarcoatingsoftheinternalsurfaceofADPandathickanodecoatingofthe entiresurfaceofthepipeareefficientmeansofADPcorrosionprotection AbrasiveWearIngeneral,ADPwearsmorereadilythansteelortitanium However,givenADP’slowerdensity,normalforcesduetostringtensionare significantlylowerthanwithsteelHence,ADPwearislowerthansteel,allother factorsbeingequalAbrasiveparticlesinthedrillingfluidcirculatedathighspeed insidethedrillpipecausewearoftheirinnerwallsThisprocessismoreseverein transitionzonesalongtheID(drillpipecouplings,couplingtopipezones)dueto turbulenceinthedrillingfluidThisabrasionprocessismoresignificantinADPand lessinsteelandtitanium RussianDrillingPracticeswithADP Threetypesofalloys(D16T,1953TI,andAK4ITI)arecurrentlyusedinRussia formanufacturingADPDI6TbasedADPisthemostwidelyused1953TIalloyis usedforhighstrengthpipecomprisingtheuppersectionofthedrillstringindeepand ultradeepwellsAK4ITIalloyisusedforthermallystableADPcomprisingthebottom sectionofthedrillstringinwellswithtemperaturesover160”C(320”F) SeveraltypesofADParemanufacturedinRussia:ADPwithinternalupsetends, withexternalupsetends,andwithaprotectionupsetinthemiddleofthepipeWall thicknessvariesfrom9to17mm(035to067in);andjointlengthvariesfrom55to 12m(18to39ft)ADPmaybedeliveredaslengths,andwithseparatetooljointsThe tooljointsmayattachedwithastandardtriangularthread(“cold”assembly),orwitha trapezoidalthreadwithataperedstabilizingshoulderusingathermalassemblymethod (“hot”assembly) InRussia,ADPhasbeenusedinexploratorydrillingforover30yearsADPwas originallyintroducedtoreducelaborforcrewsdrillingexploratorywellsinremoteareas, especiallyfortransportingdrillingequipmentLater,ADPbecamewidelyusedinall regionsofexploratorydrilling X111 DevelopmentofAluminumDrillPipeinRussia TheRussianindustrymanufacturesfive drilling: 24mmADPwith45or8Omm wallthicknessand13mlength (095inADPwith0177or0315 inwallthicknessand51inlength) 34mmADPwith65or11Omm walland13or29mlengths (134inADPwith0256or0433 inwallthicknessand43or95ft lengths) 42mmADPwith70or14mm walland43mlength(165inADP with0276or0551inwalland 14143length) 54mmADPwith90or16mm walland44mlength(2’/einADP with0354or0630inwalland 144ftlength) 71mmADPwith8Ommwalland 62mlength(28inADPwith 0315inwalland203f&length)standardsizesofADPforexploratory ComparativetestsofADPandsteelstrings PinJoint Connection invariousregionsunderarangeofgeological (ADPP54)Connection (ADPB65)Joint Pipe and technicalconditions revealedbetter performanceofADPForexample,54mmADP allowedincreasingdrillingdepthby500m(1640 ft)withthesametypeofrigsAlso,rateof= penetrationwas1530%higher,drilledmeterageperrunincreasedby613%,andtrip timewasreducedby1115?40 VibrationDamping Amoreefficientmeansofdampingandcontrollingvibrationinthedrillbit/drill stringsystemcanbedesignedbasedonphysicalandmechanicalpropertiesofdrill pipematerialComparedtosteel,aluminumalloyshaveahighcapacityforabsorbing anddissipatingelasticvibrationalenergy ResearchstudiesperformedinRussia indicatedthatalltypesofADPhaveapproximatelyequalcapacityforabsorbingelastic vibrationalenergyAlso,heavywallADPhasabout50%higherdampingcapacitythan steel ADPwitharticulatedjointshasadampingfactor3035%lowerthanrigidly connectedADP xiv DevelopmentofAluminumDrillPipeinRussia ExtendedReachDrilling Thefiguresummarizesdesignparametersandmaximumdrillstringlengthforthe threetypesofextendedreach(ERD)wellswithADPandsteeldrillstringsInaddition tootheradvantagesofADP, utilizationofADPindrilling ADPforExtem#ed#?eacht3nW’ig ERDwellswillallowlonger boreholeswithoutincreasingHorizontalDisplacement[m) hookloadsordrivecapacityofo1500300045006000750090 therigTypeIwellscanbe drilledwithabout15%longer boreholes,TypeII5%longer,~1500Al andTypeIll50?40longer u g 3000 RiserlessDrillingin alml 10 DeepWatera \H ~ 4500 TypeIII Drillingindeepwater“~ Steel— SiwfeceCasing _IntermediateCas!ng withoutariserpipeismost ~ 6000\ ~ PmductlonLiner oftenconductedfromlow~\ TypeILlmltedbysmng \ capacity drillshipsfor1~500 weightforslidedrlllhg \ TypeIILlmltedbytorquefor\ explorationorscientificstudy rotarydrllllng\ +31uminurn ofoceaniccrustThemain Type111LimitedbyDPstress l bowlpull advantageofADPinthese 9000 applications(ascomparedto steelstrings)isthepotentialtoessentiallyincreasewaterdepthwhileusingthesame lowcapacitydrillshipsForexample,whiledrillinggeotechnicalwellsfrom“Busentaur” and“Bavenit”typedrillingshipsusingsteeldrillpipe,maximumwaterdepthislimitedto about500m(1640ft)Bycomparison,theexperienceoftheAquaticCompanyin drillingfromthesameshipsshowspotentialfordrillingin1500m(4920ft)water depths EconomicBenefits Technicalandeconomicparametersrelatedtodrillingdependcloselyonthe weightofthedrillstringForthesamehookloadcapacityoftherig,cumulativetrip timeoveracompletedrillingoperationisdirectlyproportionaltopowerconsumptionfor theseoperationsAtthesametime,powerconsumptiondependsonweightdistribution betweensectionsofthedrillstringaswellastotalweight Correlationsbetweenbuoyancyfactorsofdrillpipesshowadditionaladvantagesin highermudweightsThebuoyancyfactorforADPin12g/cm3(1Oppg)mudis057, whereasforsteelinthesamemud,buoyancyfactoris085Thismeansthatan aluminumstringin12g/cm3mudisreducedtoalmosthalfitsweightinair,as comparedtoasteelstring,whichisonly15%lighter, xv — — —_ /,,, ,, ,: ,+ ~ —— —— — DevelopmentofAluminumDrillPipeinRussia Analysisoftechnicalandeconomicparametersfordrillinginfieldswithsimilar conditionsandwiththesametypeofdrillingequipmentindicatesthatADP(insteadof steel)reducestriptimebyabout1835Y0 Aiso,aconsiderabledropinpower consumptionfortheseoperationswasobserved HydraulicresistanceofADPisalso1525!40lowerthanofsteeldrillpipedueto specificcharacteristicsofthesurfaceofADPThisleadstolowerhydrauliclosses, higherdrillingefficiency,andlowercosts Conclusions TheexperienceofRussianengineersandscientistsindesigning,manufacturing, andusingADPinavarietyofdrillingconditionsclearlydemonstratesthetremendous potentialofADPItishopedthatthesignificantbenefitsenjoyedhistoricallyinRussia’s drillingindustrywithADPmightbesharedbythedrillingcommunityworldwide , xvi 1Introduction 11 Background Aluminumalloysareoneoftoday’smostimportantandefficientconstruction materialsTheyarewidelyusedinavarietyofindustriesAluminumalloyspossessa numberofphysicalandmechanicalpropertiesthatsurpassthoseofsteel,whichis traditionallyusedformanufacturingdrillpipesfortheoilindustryTheseproperties includelowspecificgravity, goodcorrosionresistancein various aggressiveenviron ments,theyarenonmagnetic, havestablemechanical properties,andexhibithigh efficiencyunderpressureand duringmanufacturing Issuesrelatedtotheuse ofaluminumalloysfor manufacturingdrillpipebecame anobjectofseriousstudyfor directional, extendedreach, andhorizontalwells,andultra deepboreholedrillingFurther more,extensionofdrillingto offshoreandtoareaswith difficultenvironmentalcondi ,,; , ‘“~ ,’ Figure1AluminumDrillPipe (withoutandwithSteelToolJoint) tionsandlimitedinfrastructurerequiredthereductionoftransportationcostsof equipmentandmaterials Alltheseproblemscanbereducedoreliminatedbythe applicationofaluminumdrillpipe(ADP)(Figure1) 12OnshoreApplicationsforADP ThefirstexploratorywellswhereADPwasappliedweredrilledintheregionofthe middleVolgain19601962TheseearlyexperimentsshowedthatADPalloweda significantreductionintime,materials,energyandlaborrequirementsInthemid 1960s,ADPwasusedtodrillseveralultradeepwells,andinthe1970swasgivenwide recognitionforclusterdirectionaldrillinginWesternSiberia ThesuccessfulutilizationofADPindirectionalanddeepdrillingoperations demonstrateditseffectivenessinultradeepscientificboreholeswithhighformation stresses,hightemperaturesandhighlycorrosiveenvironments 1 ,,— — m, —yrmm* ‘,,,,,4W,, VT ~ ,,,, DevelopmentofAluminumDrillPipeinRussia UltradeepScientificBoreholes ADPhasbeenusedfordeepscientificdrillingapplicationssuchastheKola ultradeepSG3(12km;39,400II),Krivorozhskaya(55km;18,000ft),Saatlinskaya (85km;27,900ft),Uralskaya(6km;19,700ft),aswellasotherultradeepboreholes Dri//StringfortheKo/aSG3(19701993)TheKolaultradeepborehole,withan 8Yzinopenholeatadepthof12,000m,wasdrilledwithacombinationdrillstring including5YAinADPwithwallthicknessof11,13,15and17mm(0433,0512,0591 and0669in)ThesepipeswereproducedfromalloysofgradesAK4TI,DI6Tand 1953Equivalentdurabilityfordifferentcrosssectionsofthedrillstringwasprovidedby utilizationofpipeswithdifferentwallthickness Applyingpipesmanufacturedfrom differentalloysguaranteedstablestrengthpropertiesfortemperaturesrangingfrom20° to220”C(68°to428”F) DrillStringforKrivorozhskayaSG8(19847997)Significantexperiencewas gainedwith65&inADPwhiledrillingtheKrivorozhskayaSG8toadepthof5432m (17,822ft)Inadditiontotheadvantagesmentionedabove,excellentresultswere achievedinhydraulicsthroughtheuseofinternallyflushpipe RecentDri//ingOperationsinRussia(19937997)About2500tonnesofstandard ADPhavebeensuppliedmonthlytoRussiandrillingcompaniesADPwasanimportant partofthemostcomprehensivevolumeofdirectionaldrillingoperationsinWestSiberia atabout3millionmetersperyear(98millionft/yr) 13OffshoreApplicationsforADP At/anticOcean(1991)Pipesofaluminumalloyweredesignedforthedeepwater scientificdrillingprogram(19851990)inconjunctionwiththeconstructionofthedrilling vessel“Nauka”fortheUSSRAcademyofSciencesA73km(24,000ft)ADPstring andan11km(36,100ft)ADP/SDP(steeldrillpipe)combinationstringweredesigned D16T,1953and1933aluminumalloyswerechosenasthethreemostefFicientalloy typesfordrillstringdevelopmentspecificallyforoperationinthemarineenvironment Thefirstoffshoretestsofthesepipeprototypeswerecarriedoutin1991fromthe geotechnicalvessel“Bavenit”intheAtlanticOceanSeveralscientificboreholeswere drilledattheseamountsJoscfin,AmperandGorrindgeMaximumwaterdepthwas212 m(696ft)andboreholedepthwas50m(164ft)DrillingwithADPshowedexcellent workability TheseandotherstudiesledtothedevelopmentofadeepwaterADPdrillstring forusefromrelativelysmallgeotechnicaldrillingvessels DeepWaferProjects(19931998)Pipesof164mm(646in)diametermadeof the1953alloyhavebeensuccessfullyemployedtodrillfromthegeotechnicalvessel “Bucentaur,”whichwas similartothe abovementioned“Bavenit”withadisplacementof 2 DevelopmentofAluminumDrillPipeinRussia only4470tonnesDrillingoperationswerepetiormedinareasoftheAtlanticOcean (VoringBasin1993,1997;RockallBank1994)GulfofMexico(MississippiCanyon 1995;GreenCanyon1996;VioscaKnollarea1996;GardenBanksarea1996), GibraltarStrait(1995),Japanoffshore(1997),andWestAfricaoffshore(1998) Noapparentsignsofpipecorrosionhavebeennotedafterfouryearsof exploitationAdrillstringlengthof19815m(6500ft)wasachievedwithadrillingrig liftingcapacityofonlyupto40tonnesTheprojectedpotentiallengthofastringmade ofthesetypesofpipesforriserlessdrilling(seeChapter9)couldreach30004000m (980013,100ft) 3 , ,, “” ~, , , , , ,: ,,, , , ,, —, ,, ,,, , , ,J CC,,,,,, ),, ,J,,, :, 3,, ,, ,, , , , , ! , , ,, ,, + ’,, , rMATERIALDENSITYMODULUSOFSHEARPOISSON’S COEFFICIENTSPECIFIC (GICM3)ELASTICITYMODULUSRATIO OFTHERMALHEAT (104MPA)(104MPA)ExPANslON(J/KG“C) (lo*/”c) SteelAlloys78521079027 114500 AluminumAlloys2787127030226 840 TKaniumAlloys4541104202884 460 MaterialSpecificStrength Drillstringweightisafunctionofdrillpipematerialdensity,itssize/shapefactor, andlengthWeightofadrillstringdictateslevelsofnominalstressesthatstretchthe stringwhileintheholeMaterialspecificstrengthisusedtoevaluatethefeasibilityof usingvariousmaterialsfordrillpipemanufacturingMaterialspecificstrengthisthe ratioofyieldpointandmaterialspecificweight I=s~,~/ym(21) where: s 0,2= yieldpointofthematerial 5 DevelopmentofAluminumDrillPipeinRussia ‘Ym= materialspecificweight MaterialspecificstrengthismeasuredinunitsoflengthItcharacterizesmaximum lengthofa onedimensionaldrillstringhanginginairwhenlevelsofstressatthepoint ofsuspensionreachthemaximum yieldpointofthematerial Thefactthatadrillstring suspendedindrillingfluidbecomes lighterthroughbuoyancymustbe taken intoaccountwhenthe calculationisperformed Thus, includingasafetyfactor(n),specific strengthiscalculatedusing: s 1=0’2(22) n(~m–Yl) wherex=mudspecificgravity Figure2showspotentiallengths ofonedimensional(thatis, not tapered)drillstringsinwellswithdrill mud Theshadedareasindicate allowablelengthsofdrillstringsmade ofeachtypeofalloyTheselengths arecalculatedaccountingforpotential variationofthematerialyieldpointand drillingfluidspecificgravity(1020 g/cm3)36 32 28 24 20 4 0 200400 6008001000 MinimumYieldPoint(MPa) OnedimensionalADPstrings allow maximumsuspended lengthFigure2RunningDepthsfor Drill Therefore, basedonthis parameter,PipesofVariousMaterials aluminumalloysarethebestoption fordrill pipeconstruction ResistancetoAlternatingBendingandDynamicStresses Themostimportantparametersfordrillpipematerialaremodulusofelasticity(E) andshearmodulus(G),whichsignificantlyaffectsthestressedconditionofadrillstring Whenadrillstringisrotatedinthehole,itundergoesalternatingbendingstresses: Sb=X2 Edf (23) 4L; 6 DevelopmentofAluminumDrillPipeinRussia where: d=drillpipediameter f=bendingdeflection Lo=lengthofabendingstringaxishalfwave Withafewminorapproximations,itispossibletoconcludethatalternating bendingstressesofdrillpipeareproportionaltothemodulusofelasticityofthematerial (allotherfactorsbeingequal)Theirproportionforaluminumpipes(ADP),titanium (TDP),andsteel(SDP)is: a*:a~:O~=l:l55:296 Figure3showstheresultsofbendingstresscalculationsusingEquation23for ADP,TDP,andSDPatvariousratiosbetweendiametersofpipeandborehole Thedynamictensionstress duetosettingheavydrillstringon theelevatororpowerslipsduring atripiscalculatedusing: rEy~ SD=v”—(24) q where: v=drillpipetrippingspeed fl=unitweightofdrillpipe z Dynamicstressesduringm trippingoperationsare proportionalto~/q(allother factorsbeingequal)Their proportionfordrillpipematerials (ADP,TDP,SDP)is:1:16:29 Whenthedrillstringfailsduringa ,,, , ,,, , ,, !“ ,, , ,, , ,, ,, — — : 03 042 (754066 DrillstringODIBoreholeID Figure3BendingStressof146mm (5%in)DPinVariousHoleSizes trippingoperation,thelowerpartofthestringfallsdowntheholeThefollowingformula isusedtocalculatetheultimatedynamicstressinthepipethatfallsdownfromheight /?,fordeterminingthedegreeofdeformationofthelostinholesection(ie,thefish): J 6Eh sD=yml l+— yml’ where/=lengthofthedrillstringsectionlostinhole 7(25) DevelopmentofAluminumDrillPipeinRussia Sincedrillpipematerialswithlowerelasticmodulihave,asarule,lowerspecific weightsy~,itispossibletoconcludethatdynamicstressofastringwithlowerEisalso lowerwhenthestringimpactsthebottom Thefollowingformulaisusedtocalculateeffectivedynamictorsionstressfor caseswhenadrillbit,BHAcomponentordrillstringwedgesinthehole: J md Gy ~D=—— 2q (26) where: G=shearmodulusofdrillpipematerial m=RPM Consequently,forthesameRPManddrillpipediameter,thesestressesforADP, TDP,andSDPwillbeinthesameproportionas rGym —,ie, 1:16:29 !7 Duringoperationstounstickthedrillstring,thestringtorsionangleisusedto controltorqueTorsionangleiscalculatedusingthefollowingformula: ML,, _— ‘0–GIP (27) where: M=torque L~~=lengthofdrillstringfromthebottomholetothestuckpoint I =polarmomentofinertiaofthepipesection Drillstringtorsionangleisinverselyproportionaltoshearmodulusofthedrillpipe material Theseobservationsleadtotheconclusionthatbothmodulusofelasticityand shearmodulusgivealuminumalloysindisputableadvantagesoversteelandtitanium alloys CorrosionResistance Corrosiveagentsaffectdrillpipematerialsintheboreholeandonthesurface Uniformattack,pittingcorrosion,isolatedcorrosion,intercrystallinecorrosion,aswellas laminatingcorrosion,canallaffectdrillpipesUniformattackresultsinfastwearofdrill pipe,decreasingits’bearingstrengthandleadingtoearlypipefailureIsolated, intercrystalline,andlaminatingcorrosionarethemostcritical 8 DevelopmentofAluminumDrillPipeinRussia Corrosionresistanceanalysisforthevariouscandidatematerialsindicatesan advantagefortitaniumandsteelalloysoveraluminumalloysfortheprincipaltypesof corrosionwearHydrogensulfideisanexception,sinceresistanceofaluminumtothis mediumishigher AbrasiveWear Frictionbetweenthedrillpipeandtheboreholeorcasingwallresultsinabrasive wearThiswearisafunctionofthesurfacehardnessofthepipematerial,friction distance,rockabrasiveproperties,normalforce,andthelubricatingpropertiesofthe drillingfluid BrinellhardnessofaluminumalloysusedforADPis120140HBr,andis1520 timeslowerthansurfacehardnessofSDPTherefore,ADPwearsmorereadilythan SDPandTDP,allotherfactorsbeingequalHowever,givenADP’slowerweight, normalforceduetostringtensionissignificantlylowerthanthatofSDPHence,ADP wearislowerthanSDP,allotherfactorsbeingequal Abrasiveparticlesinthedrillingfluidcirculatedathighspeedinsidethedrillpipe causewearoftheirinnerwallsThisprocessismoreintensiveintransitionzonesalong theID(drillpipecouplings,couplingtopipezones)duetoturbulenceinthedrillingfluid ThisprocessismoreintenseinADPandlessintenseinSDPandTDP 22GeneralRequirementsforAluminumAlloysforADP Threetypesofalloys(D16T,1953TI,andAK4ITI)arecurrentlyusedinRussia formanufacturingADPDI6TbasedADPisthemostwidelyused1953TIalloyis usedforhighstrengthADPcomprisingtheuppersectionofadrillstringindeepand ultradeepwellsTensileloadsinthesewellsexceedoperatingcapacityofDI6Tbased drillpipeAK4ITIalloyisusedforthermallystableADPcomprisingthebottom sectionofadrillstringinwellswithtemperaturesover160”C(320”F) Ofthesethreealloys,AK4ITIisusedformanufacturingADPforhigh temperaturewellsThisalloyisusedspecificallyforthermallystablepipes,and involvesarathercomplexprocessofpipepressingMoreover,thealloy’sresistanceto fatiguedamageandcorrosionarequitesimilartoDI6T ADPbasedonthealloysDI6Tand1953TIhasincreasedinpopularityThese alloysweredesignedtakingintoaccountthespecificconditionsofwelldrillingDrill pipeswithhighstaticstrengtharenotrequiredbycomparativelyshallowofwells However,highlevelsofalternatingdynamicstressesinthedrillstringplacespecial requirementsonphysicalandmechanicalparametersofalloystoensurereliableADP Amongtheseparametersare:durability,sensitivitytostressconcentrations,longitudinal andlateralplasticity,andhighcorrosionresistance 9 ,,,, \“ ,, , \ !,’ , , , —~ ,, , , , ,,, ,> ,,,,, >!, , , J,,,,1, :, ~ DevelopmentofAluminumDrillPipeinRussia Itisextremelyimportantthatthematerialselectedfordrillpipehascertain technologicalpropertieswhichenablemanufacturingpipeswithvariablecrosssections alongthelengthThisisnecessaryforimplementingoptimumgeometricparameters, whichinturnwillensurehighstructuralintegrityofADPandpreventmetallurgical defects(castingandpressingcracks,highsegregationzones,etc) AlloysDI6Tand1953TIbothhavecertainadvantagesanddisadvantagesFor example,alloyDI6Thasrequiredlevelsofstaticanddynamiccharacteristics,andis highlyadaptableforeficientmanufacturing;however,itexhibitslowcorrosion resistanceinseawater Alloy1953TIhashighstaticstrengthandrelativelyhighcorrosionresistance However,ADPmadeofthisalloyfailstoensuresatisfactoryparametersofdurability duetohighdissemination,relativelylowductility,significantanisotropyofpropertiesin lateralandlongitudinaldirections,andhighsensitivitytovariousstressconcentrators 23Chemical inRussiaCompositionandPropertiesofAluminumAlloysused forADP Allcommercialaluminumalloysaregroupedintosystems,withinwhichtypical physicalandmechanicalpropertiesdependonbasicalloyingelementsGenerally, basicpropertiesofonesystemofalloysdependontheirphasecomposition Thereare13systemsofaluminumalloysusedaroundtheworldFollowing thealuminumalloysofthreesystemsthatareusedinRussiafor pipes: DI6T–ofthesystemA1CuMg AK4ITIofthesystemA1CuMgSiFe l 1953TI –ofthesystemA1ZnMg Table2showsthechemicalcompositionofthesealloysmanufacturingare drill 1o DevelopmentofAluminumDrillPipeinRussia Table2ChemicalCompositionofAluminumAlloysusedforADP GRADEOFALLOYALLOYSYSTEMBASICADDITtVESMmIMPURITIES (%)(%) D16TA1CuMgCu3849Fe05 Mg1218Si05 Mn0309Zn03 Ti01 Ni01 other01 AK4ITIA1CuMgSiFeCU1925Zn03 Mg1418Mn02 Fe0308other01 Ni0813 Si0814 Tiupto 01 1953TIA1ZnMgZn5560Fe02 Mg2430Si02 Cu0408other01 Mn0103 Cr0102 Tilmto 01 AlloysofthesystemA1CuMgaremostwidelyused,wrought,andthermally hardenableBesidesADPmanufacturing,theyarewidelyusedformanufacturingload carryingstructuresofcriticalimportanceintheaviationandspaceindustries, shipbuilding,etc PropertiesofalloysinthesystemA1CuMgSiFewithaddednickelaresimilarto alloysofthesystemA1CuMgAthightemperatures,duetopresenceofphaseswith NiandFe,thesealloyshavelowerlossofstrengththanthealloyswithoutthese additives AlloysofthesystemA1ZnMgwithdifferentcontentofalloyingelementsarethe bestformanufacturingdrillpipesThistypeofalloyhas30%higheryieldpointas comparedwithalloysofthefirsttwosystems Table3summarizesthephysicaland mechanicalpropertiesofthesealloys 11 ,,, “’ ~,, , ,$ , ,, 4 , , , > : — ,, DevelopmentofAluminumDrillPipeinRussia Table3PhysicalandMechanicalPropertiesofAluminumAlloys PARAMETERUNITS GRADEOFALLOY D16T1953TI AK4IT1 Yieldpoint(SOz)minMPa 330490 350 Tensilestrength(SJminMPa 450540410 HardnessHBr 120120130130 Normalstrain(8) %117 12 Reductionofarea %2015 26 Specificgravityg/cm3 2828 28 ModulusofelasticityMPa EX105 072070 073 G 0260275 0275 Poisson’sratio 033031031 CoefficientofthermalIl”c 225238 238 expansionx106 Maxoperatingtemperature “c 160110 220 24Characteristicsofthe1980TIAlloy Asaresultoftheconversionofthemilitary/industrialcomplexinRussia, informationbecameavailableonaluminumalloyswidelyusedinspecialpurpose submarineequipmentPreviouslythisinformationwasclassifiedastopsecret,andwas unavailablefordevelopmentofgeneralpurposeindustrialproducts Forexample,weobtainedinformationonthealloy1980TI(anA1ZnMgsystem), whichwasdevelopedfortargetuseindurablesubmarineequipmentOptimizationof chemicalcompositionandheattreatmentofthisalloy(quenchingandtwostageaging) ensuredstrengthofdeformedintermediateproducts,includingpressedpipeswith guaranteed yieldpointS0,Z>350MPa(51ksi)andhighcorrosionresistanceinseawater Deformedintermediateproducts(extrudedpipes,pressedproducts)fromthe1980TI alloyarewidelyusedinthemilitarymetallurgicalindustry Relatively systemare:littleisknownaboutthe1980TIalloyTheprimaryalloyelementsinthe Zn–4O4870;Mg–2O2670;Mn–0305% Informationaboutotheralloycomponentsisstillrestricted Accordingtotheavailabledata,the1980TIalloyhasahighfatiguelimit(ie,not lessthantheDI6Talloy)Itstechnologicalpropertiesaresuticienttoensurerequired geometricalparametersofADPandhighoutputofqualityproductsThejointstock companySameko(inthecityofSamara)producesalltypesofroundbilletsforADP fromvariousalloysIthasexperienceinmanufacturinglongroundbilletsfrom1980TI alloyforthemilitaty 12 DevelopmentofAluminumDrillPipeinRussia Table4presentstheavailableinformationaboutmechanical,fatigue,and corrosionresistancepropertiesof1980TIalloy Table4Propertiesofthe1980TIAluminumAlloy ALLOY 1980TITYPEOF INTERMED PRODUCT 290770 mm extruded pipeMECHANICALPROPE = 400350 (alongthefibers) 370300 (tangential direction) TIES (“:) 90 FATIGUE STRENGTH S,(MPA) Circularbendof smoothlyshaped testspecimen basedon2107 cycles S,=112123 Consolebendofa smoothlyshaped testspecimen basedon107 cycles s, =107 CORROSIONRESISTANCE 1 GENERAL CORROSION Depthof penetration 005mm/year Rate I t’ , ,, : ,,,, , ,, , ,, !“ !’,’ :, , ,, ,, ,’ , ,, , ,,,/! ,, >,, — —,f,,,!>, , :,:::*,M, ;, ,”,:: $:>, :, ,,,,, , 0015g/m2”hr CORROSION CRACKING Not observed Informationaboutthe1980TIfamilyofaluminumalloystentativelysuggeststhat itsmosteffectiveapplication,ascomparedtootherknownalloys,isfordrillingwells whencorrosionisofconcern 25CorrosionofADPandMethodsofPrevention CorrosionofADPisdefinedthroughacomplexseriesofphysicalandmechanical characteristicsThesecharacteristicsdirectlydeterminebasicparametersforthe electrochemicalprocessesthataffectdrillpipesinaggressivemediatypicalofwell drillingandoilandgasproductionoperationsCorrosionmayalsoattackandweardrill pipeswhentheyarestoredundercertainconditions DrillpipecorrosionisquitediverseinnatureSeveraltypesofcorrosionare observedwithdrillpipesincluding1)generalcorrosion,2)layercorrosion,3) intergrannularcorrosion,4)contactcorrosion,and5)corrosioncrackingThespecific typeofcorrosiondependsonthepipematerialandcomposition,levelofcorrosion, durationofcorrosionattack,stressconditionsandoperatingtemperature Severalfactors–differentpropertiesofaluminumalloysusedfordrillpipes,and diversityoftemperatures,timeperiodsofexposure,andforcesthataffectadrillstringin operation– requireasystemsapproachtodevelopmentoftechnicalrecommendations regardingmethodstoprotectpipesfromcorrosion 13 DevelopmentofAluminumDrillPipeinRussia Resultsfromvarioussurveysandstudiesindicatedthataluminumoxidefilmisthe mainelementofcorrosionprotectionofaluminumalloysThefilmisformedonapipe surfacethatisexposedtooxygen 9 1071 z?pHMechanicalactivityisveryimportantfor developmentofcorrosionprocessesforADP Hydrogenevolutioncorrosionofaluminumis observedinaqueousmediaMoreover,afterthe processhasstopped,dehydrogenationcontinues foralongtimeatadecreasingrate Electrochemicalprocessesaremoreintensein pipesaffectedbyhydrocorrosion Studiesofwearofaluminumalloysinvarious drillingfluidsindicatethatcorrosionprocessesare relativelyslowanddonotstronglydependonthe pHofthefluidifthepHremainsbetween7095, butsignificantlyacceleratewhenpHexceeds105 (Figure4) Figure 4CorrosionRatewith pHand Temperature(1=waterat20”C;2=water at50”C;3=5°ANaClat20°C;4=5%NaCl at50”C;3=5?10NaClat90”C)Therefore,whenADPsareused,thepHof drillingfluidstreatedwithalkalinechemicalsmust becarefullycontrolledpHmustnotexceed95 100InhibitorsmustbeusedifthepHofalime drillingmudis1213Somedrillingmudviscosity reducers(stabilizingagents)widelyusedformud treatmentproduceaninhibitingeffectoncorrosion ofaluminum Amongthemarespentsulfite alcoholliquor,waterglass,andpolyphosphates Whenaddedtoaclaydrillingmudata concentrationof0250350A,theseslow corrosionofaluminumat2080”C(68176”F)by 4080% Increasesinmudtemperatureresultinfastercorrosion(VCO,)ofaluminumalloys Thecorrosionrateat40°Cina3?40NaClsolutionisabout05g/m2hr,whereasat80°C therateincreasesto065g/m2hrCorrosionrateinasolutionwith05%sodaashat 40°Cis11g/m2hr;at80°Citincreasesto18g/m2hrV~,significantlyincreasesin solutionscontaininghighlevelsofmagnesiumchlorideThisisprobablyduetohigher levelsofelectrolyticdissociation Thewholespectrumoferosionfactors,notjustindividualcomponentsofthe drillingfluid,affecttherateofaluminumcorrosioninclaymudsForexample,chlorides acceleratecorrosionbecausetheoxidefilmhasbeendamagedearlierduetofriction betweenthepipeandboreholewalls,aswellastheerosiveeffectofabrasiveparticles 14 DevelopmentofAluminumDrillPipeinRussia inthedrillingfluidThevelocityofthedrillingfluidcirculatedinside requiredtocleantheholereaches57m/see(1623ft/see)thedrillpipeand Theoxidefilmintransitionareasonthepipewallsisalwaysdamagedbyturbulent flowandabrasiveparticlesinthedrillingfluidElectrodepotentialindamagedzonesof pipeis122V,comparedtonondamagedzonesat055Vandtosteeljointsscrewed ondrillpipesat025VTherefore,zoneswithdamagedoxidefilmonADPwillbehave asaneffectiveanodeandwillcorrodeintensivelyChloridesandotherhalogenides destroytheprotectivefilmonaluminumalloysCorrosionresistanceofaluminumin thesesolutionsisreducedHydrolysisofchloridesattemperaturesabove6080°Cis alsoimportantfortheseprocessesWhenpHofamediumisreduced,corrosionrate increasesCorrosionrateofADPisveryhighwhendrillingthroughmagnesiumsalts withhighbottomholetemperatures Asarule,corrosiondoesnotpenetrateverydeeplyandnormallyaffects0312 mm(00120047in)ofthepipewallAtthesametime,newlayersofthepipeare exposedtocorrosionasaresultofcorrodedzonesscalingoff,whichleadstofaster pipewearinsomecases,deepercorrosionwearoccursinzonesofturbulentflowofa drillingfluid(zoneswithrapidchangeofpipeOD)Thiswearmayresultinlower strengthofthemainsectionofthepipe InformationrelatedtocorrosionratesofDI6TalloyADPindrillingfluidwithNaCl, CaClz,FeSOd,andotherchemicalsusedfortreatmentofdrillmudisshowninTable5 Thesedataclearlyindicatethatincreasesintemperatureresultinintensiveandhigh ratecorrosionofDI6TaluminumalloyindrillingfluidswithNaCl,CaClz,andFeS04 Thefastestcorrosionindrillingfluidswiththesefirsttwochemicalsisobservedat80”C CarboxymethylcelluloseandIigninalkalineessentiallydonotaffectcorrosionwearof ADPoperatedat80120”C 15 ,’‘: ~ ‘, , ! ,,,’ > ,, —— ,, ? ,>,, ,:, — DevelopmentofAluminumDrillPipeinRussia Table5ADPCorrosionRates(g/m2/hr)inMudTreatedwithReagents REAGENTCONCTEMPERATURE~C) (%) 204080 120 NaCl30008001200250019 50009001200220013 100007000900150005 150006000900040006 20 00030006 00020001 CaC1210011001100260024 20002001200290025 30002001200290028 FeSOd10002000800270037 2 00110013 00430051 30013001900510054 “KSSB10000100010 30 000010002 50000020002 80000100020002 “UschR”1000700100 2 000600100 30004 000700 KMC10008 001200030002 20004002100280001 30003003100110001 Pittingcorrosionofaluminumandmostofitsalloysinseawaterisobservedonlyat relativelylowtemperatures(58°C)Pittingcorrosionisnotobservedinwarmwater (2530°C) Themostintensivecorrosionoccursduringtheinitial2530daysofoperation, afterwhichtherateisreducedThissuggeststhatADPcanbeusedinoffshore operationswithoutanyspecialprotectionfromcorrosion Intercrystallinecorrosionrepresentstheprincipaldangerforreliableapplicationof ADPsinceitdoesnotchangetheappearanceofthepipe,butsignificantlydecreases theabilitytowithstandloads,especiallydynamicloadsContinuousexposuretoheat greatlyaffectssusceptibilityofnaturallyagedpipestointercrystallinecorrosionTable6 presentsdataonminimumexposuretimeforDI6Talloyatarangeoftemperatures, afterwhichitissusceptibletointercrystallinecorrosion Table6HeatExposureTimesforD16TAlloy TemperaturePC) 9095100 110120130 140150160 170 1 Exposure(hr) 30050158 211 05033 025 16 DevelopmentofAluminumDrillPipeinRussia WhenADPisequippedwithsteeltooljointsandthereisanelectrolyte(ie,drilling fluid)inthewell,avoitaiccoupleisformedbetweenthepipebodyandtooljointThis leadstocontact(galvanic)corrosionSignificantexperiencerunningADPwithtool jointsindicatesthatwearfromcontactcorrosionisinsignificantSurveysofADPsthat wereinoperationfor67yearsandinspectionsofthreadedconnectionsandthepipe bodyadjacenttoatooljoint,showedanabsenceofcorrosionwearforthedrillpipein contactwiththetooljoint StudiesconductedinRussiaandabroadrevealedlowersusceptibilitytocorrosion withADPinaggressiveoilandgasmediawithhydrogensulfideascomparedtosteel drillpipesAlso,steeltooljointsonADPwerefoundtobemoreresistanttocorrosionin fluidswithhydrogensulfideThereasonisthataluminumalloysprovide electrochemicalprotectionundertheseconditions Aninterestingpracticalapplicationisfromstudiesofaluminumalloycorrosionina flowingelectrolytecontainingsulfurandabrasiveparticlesThestudiesconfirmthat hydrogensulfidereducessusceptibilityofaluminumalloystopittingcorrosionA3?/o solutionofNaCl(pH=40)with2g/literHZSwasusedastheelectrolyteinthese studiesTheprocessofaluminumdissolutioninthiselectrolytewas23timesless rapid,whereasdissolutionofsteelwas152timesmorerapidTheseresultsindicatea potentialadvantageforusingaluminumalloysasapipematerialwhenahighvelocity salinatedmudwithhighHZSiscirculated OneoftheprincipalmethodsofprotectingADPfromcorrosionistoaddinhibitors tothemudInhibitorsusedforADPprotectionofcoursemustnotdegradethe theologicalcharacteristicsandpropertiesofthemudsystem Anumberofmudstabilizers,particularlysodiumpolyphosphateandpotassium, produceaninhibitingeffectoncorrosionofADPinmudwithalkalineWaterglass, condensedspentsulfitealcoholliquor,etccanbeusedasinhibitorsinalkalinefluids Potassiumbichromate,widelyusedasadrillingmudthermalstabilizer,isan efficientnonorganiccorrosioninhibitorforaluminumalloysSmallamountsof potassiumbichromate(052?40)significantlyreducecorrosionwearofaluminumalloys CoatingofinternalADPsurfacesisanefFicientmethodofsurfaceprotectionfrom corrosionanderosionwearinaggressivemediaOperationofpipeswithinternal coatingsshowedasubstantialincreaseintheirdurabilityandlowerhydrauliclossesin fluidscirculatedthroughthepipesThesecoatingsallowoperatingADPwithawider rangeofdrillingfluidsandminimizingthecorrosiveeffectofmudremaininginthepipes duringstorageaftertheoperationDeeporthickanodecoatingsonADPsurfacesare amostpromisingmethodofprotectionfromcorrosionwear Anexampleofan anodeoxidefilmsTheanodecoatingistitaniumandmolybdenumalloy5070pm processtakesplaceinasulfuricacidelectrolyteat23A/dm2 17 , ,, — , &,4——— DevelopmentofAluminumDrillPipeinRussia currentdensityInthesamebaththefilmissimultaneouslysaturatedwithtitaniumor molybdenumAnticorrosioncharacteristicsofADPwithananodecoatingalloyedwith titaniumareclosetothoseofpipesconstructedoftitaniumalloysTheseare specificallyrecommendedformediawithhighchloridecontentPipeswithanodefilms withmolybdenumalloyshavehighanticorrosionpropertiesinhighlysalinatedmuds withlargeproportionsofdissolvedoxygen Layercorrosionhasbeenobservedinpipesstoredforextendedperiods,aswell asinpipesretiredfromoperationandmovedtostoragefacilities,particularlyincoastal areasLayercorrosionisparticularlyintensivewhenthepipeswerenotcleanedfrom mudafterbeenpulledoutoftheholeBeforedrillpipesarestored,theyshouldbe washedwithfreshwatertoreducecorrosionwearduringstorageItisrecommendedto putalayerofgreaseonpipesurfaceswhenthepipesaretobestoredincoastalareas ConclusionsRegardingCorrosion AnalysisofcorrosionwearofADPandmethodsofpreventionleadtothefollowing conclusions: 1 2 3 4 5 6 7CorrosionofADPdependsprimarilyoncomposition,aggressiveness,and temperatureofthefluidinwhichthedrillstringisoperated,aswellason exposuretime ThepHofthedrillingfluidsignificantlyaffectstheprocessofADPcorrosion wearADPcorrosionwearisinsignificantinfluidswithpH7095andrapidly increaseswhenpHexceeds105 ADPcorrosionisacceleratedathighertemperatures Anoxidefilmformedonpipesurfacesexposedtooxygenprovidesreliable corrosionprotectionforADPAbrasivedrillingfluidswithhighsolidscontent damagetheoxidefilminareaswithturbulentflow,whichresultsinfasterdrill pipecorrosion Increasedtemperatureofthedrillingfluid,prinlarilyinfluidswithchlorides, leadstointensecorrosionwearofADP WhenhighvelocitysalinatedmudwithahighcontentofH2Sisused,ADP hasdemonstratedhighresistancetocorrosionundertheseconditions,which meansADPhasgoodpotentialforapplicationinoil,gas,anddrillingmud media TheprincipalmethodofprotectingADPfromcorrosionistheuseofcorrosion inhibitorsaddedtothemudSodiumpolyphosphateandpotassiumbased stabilizinginhibitorsarethemostwidelyused 18 DevelopmentofAluminumDrillPipeinRussia 8 TarcoatingsoftheinternalsurfaceofADPandthickanodecoatingofthe entiresurfaceofthepipeareefficientmeansofADPcorrosionprotection 9Aluminumalloys1980TIand1953TIarethemostcorrosionresistantamong alloysusedforADPmanufacturingTherefore,pipesfromthesealloysare mostwidelyusedinoffshoredrillingADPfromDI6Talloyisrecommended fordrillingoilandgaswellswithhighconcentrationsofHZS 19 ,,, : “, :’, ,, , , ,, !’ ,, ,, ‘, , ,: , — , ’ ,! — DevelopmentofAluminumDrillPipeinRussia 20 3ADPManufacturingTechnology 31ManufacturingofTubularBilletsUsingPressForming Tubularbilletsforsteeldrillpipes,casing,andtubingaremanufacturedbyrolling Afteraholeispiercedintheoriginalingot,itisrolledonatubularmilltoobtainthe desireddiameterRequiredfinishingoperationsareperformedafterrollingiscomplete Theseoperationsincludeupsettingofpreheatedendsonahorizontalforgingmachine, makingpipethreads,weldingontooljoints,etcRollinghasalimitednumberof technologicaloperationsanddoesnotallowmakinganirregularsectionofapipewith upsetends Thedirecthydraulic extrusiontechniqueisusedfor manufacturingADPAhollow cylinder ingotmadeby semicontinuouscastingisused foranoriginalbilletThesizeof anoriginalingotdependsonthe sizeandtypeofthepipetobe manufacturedPriortoextrusion, 1014mm(039055in)ofthe IDandODoftheoriginalbillet areturnedofftoremovecasting defectsfromthesurfacesTo eliminatestructuralheterogen eity, thebilletundergoes homogenizationinaspecial furnaceTheingotisheatedto thetemperatureofintermetallic phasevolubility(460490”C;860 914°F)andisheldthereuntila diffusionprocessofintermetallic elementsdissolutioniscom pleted(1216hr)Afterwards, homogenizedingotsarecooled downforextrusionto380420”C forpipeswithaninternalend upset,andto400420”Cfor pipeswithanexternalendupset Aheatedingotisplacedina chamberofahydraulicpressfor extrusion : ,, , “ : ,, , ,, ,“ ,,, ,, , ,: — ,’,: ,,,:< ,>i:’c, ;>,,c,,, ,, +,, 1’ ! , $ ,,t’+, Y 2345 ExtrudingUpsetEnd eBody Body ExtrudingUpsetEnd Figure 5 ExtrusionProcessofPipeBilletwithInternal UpsetEndsandThickenedMiddle 21 DevelopmentofAluminumDrillPipeinRussia Figure5showsaprocessdiagramforextrudingapipelength(tubularbillet)with internalupsetendsandaprotectionupsetinthemiddle 1 2 3 4 5Theextrusionprocessiscompletedinthefollowingorder: Afrontendconsistingofastepneedlewithadiameterthatdependsonthe IDofthemanufacturedsectionofthepipeissetupinapiercingdieAfront upsetendisthenextruded(Figure5a) Whiletheextrusionprocesscontinues,thestepneedleisslowlymoved forwarduntiltheclearancebetweenitandapiercingdieisminimum(Figure 5b)Thistravelofthestepneedleallowsformingasmoothtransitionzone betweentheupsetandmainbodyofthepipe Thestepneedleisstoppedinthisposition(Figure5b)andthemainbodyof thepipeisextrudeduptoabeginningofatransitionzonetoaprotection upset Whilethestepneedlecontinuestomoveforward(Figure5c),metalflows aroundtheneedleheadlocatedoutsidethepiercingdieAsaresult,wallsof thepipebecomethicker,sincetheODofthepipeincreasesandtheIDdoes notchangeDuringthisoperation,thetransitionzoneandtheprotection upsetareformed Theotherhalfofthepipeisextrudedwithsequentiallyrepeatedoperations4, 3,2,1asthestepneedletravelsbackAtransitionzoneandthemainbody ofthepipeareformed(Figure5d),alongwithatransitionzoneandthe secondupsetend(Figure5e) Differentshapesofthestepneedlearerequiredforextrusionofpipeswith externalupsetendsHowever,theextrusionprocessitselfissimilartothatforforming theprotectionupset(operation4) Theextrusionprocessallowsmanufacturingpipeswithhelicalbeadingofthe externalsurfaceHelicalbeadingisformedasaresultoffrictionforceswhenthemetal isflowingthroughdiespositionedatacertainangletothelongitudinalaxisofextrusion ThisiswidelyusedinmanufacturingADPwithhigherwallthicknessfordrillcollars Lengthsareextrudedinspecialhydraulicpressmachines73to102mm(2%to 4in)ODpipesareextrudedat40,000kN(4500tons);114to170mm(4%to67in) ODat60,000kN(6750tons)Extrusionspeeddependsonthetypeofaluminumalloy andvarieswithintherange1835m/min(59115ftlmin) Aftertheextrusionprocessiscompleted,tubularbilletsaremovedintoahorizontal quenchingfurnace,whereitisevenlyheatedto490~2°Candheldatthistemperature for70minutesTwentypipesaretreatedtogetherinthequenchingfurnaceOnepipe 22 DevelopmentofAluminumDrillPipeinRussia ismovedfromthefurnaceevery35minintoahorizontaltankwithwaterflowing towardthedescendingpipeWaterisappliedtobothinternalandexternalsurfaces 002O04~0potassiumorsodiumbichromateorchromateisaddedtothewaterused forhardening,tomakepipesmoreresistanttosurfacecorrosion Afterquenching,pipesmadeofalloysthatrequireartificialaging(1953,Ak4, 1980)areadditionallyheatedto170200°Cfor812hoursDuringhardening,pipe billetsundergosignificanttemperaturedeformationTherefore,directlyafterhardening (butnotlaterthanafter12hours)pipesaremovedtoalevelingmachinefor straighteningbytensionAfterstraightening,thepermanentdeformationofpipeswith internalupsetendsmustbel3?t0,andforpipeswithexternalupsetends23Y0The designedaxialforceofthelevelingmachineisupto6000kN Thestraighteningprocessnotonlyeliminateslongitudinalcurvatureofthemain bodyofapipe,butessentiallyimprovesitsstress/strainpropertiesbymechanical hardeningofthepipesurface,asaresultofplasticdeformationsAdditional straighteningoftheupsetendsisdoneinspecialdiesonbendingpressesAfterthe finalleveling,pipesareinspectedvisuallyandwithspecialinstrumentsonahorizontal controlplateandaremovedtoanassemblyshopThere,pipethreadsaremadeand tooljointsarescrewedontothepipes 32MakingPipeThreads Thetechniqueofmakingthreadsonpipebilletsfromaluminumalloysisin principlethesameasforsteeldrillpipeProcessparameters(RPMandfeed)are, however,slightlydifferent 1 2 3 4 5, 6Belowisatypicalsequenceforpipethreading: Thepipeissetinahollowspindleofapipethreadingmachineandthefree pipeendsitsonarest OvalityoftheprocessedpipeendischeckedItsmustnotexceedtO2mm Pipeendiscutandaconeforathreadisturned AplaingaugeandaflatfeelerareusedtochecktheconeturningAllowable conedeviationis+03/02mm Aspecialthreadingcutterwith60°threadingangleisusedtocutathread with46passesat255rpm Aspecifiedallowanceisleftforthelastpasstomakerequireddensityof threadThenaspecialthreadchaserwith1:16conicityisusedtofinishthe thread 23 , ,, ! ,, ! ,, , ‘, , > ,, — —— 6 , ’> :!,, _— DevelopmentofAluminumDrillPipeinRussia 7 Threadtightnessischeckedwithaplaingageandathreadgage 8A protectionringisputonthethread 9Next,theotherpipeendisthreaded Computercontrolledpipethreadingmachinesareusedtocutthreadsondrill pipesWhenTTtypetrapezoidalthreadswithastabilizingshoulderarecut,itmustbe takenintoaccountthat,unliketriangletypetaperthreads,itsconjugationwhenpipes aremadeupgoesalongtheinsidethreaddiameterandnotalongthemiddlethread diameterInthiscasedeviationofangleofthreadandofthreadpitchdoesnotaffect axialthreadtightness Plainringgagesareusedtocheckconicityoftheoutsidethreaddiameterand accuracyofthepipestabilizingshoulderAplainringgageisputonathreadedend andclearanceismeasuredusingafeelergage Theremustnotbeanyclearanceat thewider endofapin,andatthethinnerenditmustnotexceed008mmAplainring gageisalsousedtochecktheODofthestabilizingshoulderThedistancebetween themeasurementplaneofthegageandafaceofthepipeendmustbe96*2mm Theplainringgageisalsousedtocheckconicityofthestabilizingshoulder Clearancebetweenthebigandsmalldiametersoftheconicalpinandthegagemust notexceed006mmThreadringgageswithcompleteandbrokenprofilesareusedto checkthethreadIDAfterthreadgagesarescrewedonasfaraspossible,their measurementplanemustcoincidewiththepipeendfacewithin*2Omm Thesamethreadingmachinesareusedtocutcoarsetooljointthreadsonintegral jointADPThesurfaceofthepinandboxthrustfacemustbesmoothandallowtight makeupThedistancebetweenthethrustfaceofanypinandboxmadeupwithout additionaltorqueappliedmustnotexceed2mmQualityoftooljointthreadsisalso controlledusingplainandthreadgages 33ColdAssemblyofADP ADPswithinternalupsetendsandODSof64129mm(2%5in)arefittedwith steeltooljointsusingthe“coldassembly”method,withrequiredtorqueappliedThese pipesaremostlyusedfordrillingshallowwells(253km;82009800ft)wherehigh tensileloadsandtorquesarenotappliedStandardtriangularthreadedpipeswithsteel tooljointsareconnectedusingepoxyresinbasedselfhardeningsealingcompounds AspecialstandwasdesignedtoassembleADPusingthecoldassemblymethod (Figure6) Thefollowingequipmentisinstalledinthefrontofthestand:a25kWelectrical motorat730rpm(1),awormgearreducer(2),andafronthead(3)Allthisequipment 24 ,,, DevelopmentofAluminumDrillPipeinRussia< , ismountedonone frameAgearreducer reducesrotaryspeedto 610rpm Thefront headissetonthekey ofthereduceroutput shaft[tclampsoneof atooljointelements whenitisconnectedto adrillpipeThefront headchuckandthe backheadchuckhave oneshapedandtwo plaindiesthathold element6ofthetool joint(pin,box)and preventitsrotation duringtheassembly processTherearpart ofthestandismounted onarailcarriageBy D 1 l 1electricengine4pipe 2 reductiongear 5backheadclamp 5tlonthead 6 tooljoint pin(left) andbox traveling onrails,‘the Figure6ColdAssemblyStandforADPwithSteelToolJoints carriagecompensatesforI , thereduceddistancebetweenthetooljoints,simultaneouslyscrewingonbothendsof,, thepipe,whichenablesassemblingpipesofvariouslengthsThecarriagewheels, haveflangesthatpreventitfromoverturningasaresultoftippingforcesTorque,, sensorsareinstaIledattherearofthestandTheyallowcontrollingtorqueduringthe assemblyprocessThestanddriveisautomaticallyshutdownwhentorquereachesa presetlevel Priortoassembly,threadsofdrillpipesandtooljointsarethoroughlycleaned, rinsed,anddegreasedAnepoxybasedselfhardeningcompoundisputononethird thelengthofpipesthreadsfromthesmallerdiameterendoftheconeTooljointsare thenmanuallyscrewedontothepipeSelectionoftooljointspriortoassemblyisbased onspecificthreadparameters,andisdesignedtoensuretherequiredtightnessThe pipewithconnectedtooljointsissetonthestand,andthetooljoints(pin,box)are grippedbythecorrespondingchucks Thechucksholdsectionsofthetooljoints beyondthethreadsThenthemotorisstartedWhenthetorquerisestothesetlimit, themotorisautomaticallyshutdownAsetofreplaceablechucksisusedatthestand toallowtheassemblyofvariousstandardsizesofpipe ThiscoldassemblymethodofADPfabricationhasthefollowingdrawbacksthat restrictitsapplicationformanufacturingdrillpipesfordeepandcriticalwells: lowresistancetofatiguefailureofthepipethreadconnection 25 DevelopmentofAluminumDrillPipeinRussia possibilityofadditionalrotationduringanoperationofatooljoint connectedtoapipeasaresultofhightorque lowreliabilityofconnectionpressureintegrity potentialforformationofaluminumandsteelcoldweldingzonesdueto torqueappliedduringtheassemblyprocessThisreducesgeneral strengthandmightleadtofailureduringoperation 34HotAssemblyofADP The“hotassembly”method,widelyusedforassemblingSDP,allowsthermal expansionofthetooljointbyheatingittoaspecifictemperaturetoensurerequired tightnessofthethreadconnectionAnumberoffactorshavelimitedtheutilizationof existinghotassemblytechnologytoattachsteeltooljointstoADP: WhenanADPisincontactwithaheatedsteeltooljoint,itquickly becomeshotandexpandsbecauseofitssignificantthermalconductivity andhighthermalexpansionfactorThispreventsfreeaxialfitofthetool jointwhileitisscrewedonandmakesitimpossibletoachievethe requiredtightness Strengthcharacteristicsofthepipematerial(yieldpoint)decreasewhen temperatureisincreased,whichmayresultinexcesshoopstressabove theyieldpointduringconnectionandplasticdeformationThisinturn maypreventcontactpressuresinthethreadcouplefromreachingthe requiredlevelWhilecooling,diameterofthepipewillshrinkmorethan thatofthesteeltooljointduetodifferentthermalexpansioncoefficients forsteelandaluminumThiswillleadtGlowactualcontactpressuresand lowoperationalreliabilityoftheconnection Overheatingathreadedpipeendmayresultinlowstress/strainproperties ofanaluminumalloyThisisduetoadecreaseinstrengthcharacteristics withhightemperatureaswellaspatilalnegationofthealloythermal treatment Researchevaluatingwhetherathermalfieldcouldbemaintainedduringhot assemblyofADPwithsteeltooljointsindicatedthatthedisadvantagesofhotassembly canbecompletelyeliminatedbyforcedcoolingoftheconnectionduringtheprocessof assembly Otherexperimentalworkonhotassemblytechnologyledtoaproperprocedurefor theassemblyprocessthatcouldmakehighqualityandreliableconnectionsbetween ADPandsteeljointsusingacmetaperedthreadswithataperedstabilizingbelt(shrink seal)AspecialstandwasdesignedtoimplementthistechniqueFigure7presents theprincipaloperationaldiagram 26 DevelopmentofAluminumDrillPipeinRussia 1I I >\ II 1supportrokrs2 pipebillet 3 majordiameterfittingand clampingmechanism 4driverollers 5 externalmolirmchamber 6helicalguideway 7 too!ioint(pinorbox)8hollowshaft 9driveoffeeding 10driveofscrewingon 11maximaltonguesltttch 12reductioncoilheater 13indicatinggaugeoftool jointtemperamre 14internalcodingchamber Figure7HotAssemblyStandforADPwithSteelTool Figure8showsthe workstanddesignedfor screwingasteeltooljoint ontoADPusing“hot technology” Figure9showsADP beforeandaftersteeltool jointsareattached Figure10showsthe finishedproduct:ADP assembledwithsteeltool jointsusinghotassembly technology The hotassembly method isusedto assembleallADPwith externalupsetends,as I Figure8BenchforHotAssemblyofADP In$L I wellas147to170mmADr WIIIi[ I 27 ~ —> ,,,,, ,, _ — DevelopmentofAluminumDrillPipeinRussia internalupset endsusedin 7 drillingdeepandultradeep wells withcomplicated geologicalconditions Long termexperienceinwellsdrilled with hotassembledADP includingtheKolskayaultra deepwell(includingextreme loadingofthedrillstring) showedindisputableadvan tagesof thismethod OperationalreliabilityofADP significantlyincreased,which resultedinalargedropinthe numberoffailuresdueto fatiguebreakageofthe_ pipethreadconnection I Figure9ADPBeforeandAfterScrewingonSteelToolJoint 35SealinganADPPipeThread AfterADPisassembledwithatooljoint,itmustbepressuretightwhenusedina drillingoperation AdditionalsealingisnotrequiredwhenatrapezoidalTTtypepipe threadwithaconicalstabilizingshoulderisused,andiftheconnectionismadeusing thehotassemblymethod(seeprevioussection)BecauseresistanceintheTTtype threadoccursalongtheIDofthethread(notthemiddlediameter)andthehot assemblymethodensurestightnessinboththethreadandtheconicalstabilizing shoulder,pressureintegrityofthepipethreadconnectionisguaranteed Whenastandard triangularthreadisused, theconnectionhastwo longhelicalpassages throughthethreads,one along thecutand roundedcrestofthe thread,andthesecond alongthebottomofthe threadIntheseconnect ions,evenhighcontact pressuresonthemating surfaces generated during theassembly process,cannotensure thatleakagewillnotFigure10CompleteADPAssembledUsingHotTechnology 28 DevelopmentofAluminumDrillPipeinRussia occurathighmudpressuresandvariableloadsThepipethreadconnectionmaystay pressuretightinpracticeoveralongperiodoftimeifthescrewpassagesareproperly filledwithathreadcompoundthathashighviscosity,adhesion,andhighchemical resistancewhichpreventsitfrombeingdestroyedanddisplacedbythemudwhile drilling ExperiencewithADPfittedwithatriangularthreadindicatesthatepoxybased compoundsareabletoefficientlysealthepipethreadThesecompoundsspread evenlyduringtheassemblyprocessoverthesurfaceofthethreadconnectionAfter curing,theyturnintoatough,impermeablebodywithhighadhesiontometal, resistancetochemicals,andstrengthundervariableloadsThecuredcompound becomesintegralwiththejoint/threadconnection US1isthemostwidelyusedsealingcompoundUS1includesacompound composedofresin,plasticizedwithpolyetherandthiokol,andanextenderthat increasesthesealingabilityofthecompound,whichconsistsofamixtureofgraphite, lead,andzinc/copperpowdersThecompoundcuresatdifferentratesdependingon temperature CompletepolymerizationofUS1compoundat51O°Ctakesplacein about45hours;at20°Cin2hoursand20minutes;at30°Cin1hourand40minutes; at50°Cin30minutes Priortothesealantbeingapplied,thethreadisproperlycleaned,washed,and degreasedThejointsealantisspreadonthepipethreadandevenlydistributedover thesurfacefromthesmalldiametersideontwothirdsofthethreadlengthAfterthe sealanthasbeenputonthethread,thepipeandtooljointarescrewedtogether Duringthisoperationthecompoundevenlyspreadsoverallfilletsofthethread connectionTheexcesssealantissqueezedoutintoataperedboreofthetooljoint fromthelargethreaddiameterside Fortygramsofsealantarerequiredtosealeachthreadconnectionof73to114 mm (27/8to 4’Xin)ADPand60garerequiredfor129to170mm(5to67in)ADP 29 ,, ,,,, , “,”, , , , ,, L’ J,,’ ,’” ,: —— —, r ,,, ,,, ,,:,’,/,,\,,,,,> !r,, ,,, , c ,, , ,,,, DevelopmentofAluminumDrillPipeinRussia 30 4ADPDesignsandApplications 41GeneralInformation IndustrialmanufacturingofvariousstandardsizesofADPcameaboutasaresult ofanumberoffactors,suchasthevarietyofgeologicalandtechnicalconditionsof drilling,theabilitytomanufacturepipesofvariouslengthsanddiametersfrom aluminumalloysusingthehotextrusionmethod,aswellasalargeamountofscientific researchandengineeringworkADPdrillpipesallowdrillingwellsforavarietyof purposes Since1980,designsandsizesofADPmostwidelyusedindrillingare manufacturedinRussiainaccordancewiththestatestandard(GOST2378679) CurrentlytheinternationalstandardforADP,“AluminumAlloyDrillPipeForPetroleum AndNaturalGasWells:Specification”(1S015546),isalmostcompletedBasedonthe Russianstandard(GOST2378679),thefollowingtypesofADParemanufactured: ADPwithinternalupsetends,withexternalupsetends,andwithaprotectionupsetin themiddleofthepipeWallthicknessvariesfrom9to17mm(035to067in);length variesfrom55to12m(18to39ft),dependingonthetypeandspecificationADP maybedeliveredaslengths,andwithscrewedontooljointsThetooljointsmaybe screwedonastandardtriangularthreadwiththerequiredtorqueapplied(“cold” assembly),andonatrapezoidalthreadwithataperedstabilizingshoulderusinga thermalassemblingmethod(“hot”assembly) Table7summarizesthebasicrequirementsandmechanicalcharacteristicsofa materialforsteeltooljoints Table7RequirementsforSteelToolJoints CHARACTERISTICUNITSREQUIREMENT Tensilestrength,SN/mm*880min Yieldstrength,S,2(02%N/mm*735min offsetmethod) Elongationafterfracture,A%13min (seenote)(LO=565dFO) Impactstrength,KCV(21”C)J/m*685103min BrinellhardnessHB280340 Note:If othergaugelengths areused,thecorrespondingelongationvaluesshallbeobtainedin accordancewith/S02566Incasesofdispute,gaugelength,LO=565~(FOinitialcross sectionalarea) 42ADPwithInternalandExternalUpsetEnds Figure11presentsADPdesignswithinternal(left),externalupsetends(middle) andprotectionupset(right)Tables8and9summarizetheirdimensions 31 , , ,, ,“ ,, , , , , ! —,,,,,,,, >v,! 1>, —~ ,IA ,, i, ,’ DevelopmentofAluminumDrillPipeinRussia 1C I ) LLl t C 1 lu t c 1 IQl FigureIlADPswithToolJoints(left:internalupsetends;middle: externalupsetends;right:protectionupset ADPmanufacturedfromtwotypesofalloys,DI6Tand1953TI,weremostwidely usedindrillingTable10summarizestechnicalparametersforADPwithinternalupset endsfromD16Talloy,andTable11from1953TIalloy Table12showstechnicalparametersofADPwithexternalupsetendsfromDI6T alloy,andTable13from1953TIalloy 32 DESCRIPTION 1 PipelenathL 2Pipebodvxsection 3 Wallthickness: G H 4Upsetlengthends: boxside1 Dinside–J 5Nominaldiameten A B F 6lDjointD CDjointC BoxmemberK PinmemberM 7Openenddisplacement 8Capacitv 9ThreadconnectiontvpeTable8ADPwithInternalPipeEndUpset(seeFigure11;left) PIPEPIPEPIPE UNITS 27/8” 3?4”41/16” (73MM)~ ~ mm 930094009500 cm218122,5263 mm 999 161615 mm 2003001000 200200250 mm 73 90103 557285 415873 mm 4158 70 901081206 200215285 220240285 1/m 204328347 1/m2375407567 z~8 “Req 3%’’Req3?4”IFPIPEPIPEPIPEPIPE 4%”5,, 58” 58’ (I08MM)(129MM) JJ47MM)(147MM)= 9500 12400’12400’12400’ 280 408‘470547 4 PIPE 58”b 147MM~ 12400’~ 622 3 — s 9 1111 13 15; ‘t71717 17 17 2 s =l= 108129 90107 74 95 7095 1206155 285325 285300 37524 636899 3?4”IFNC50 =l= 147 147 125’121 113 113 110110 178178 350350 350350 612649 12271149 5%”FH5?4”FH 5 1075 5%”FH Pipelengthsrangefrom9000to12,000mm(295to394ft) ,, ,,,’,,4>, Table9ADPwithExternalPipeEndUpset(seeFigure11;middle) b)PI PIPEPIPEPIPEPIPE DEsCRlpTlON UNITS~1/81t 5?4”6?4” (35/@ (131MM)(140MM)(164MM)(168MM) 1 PipelenathLmm 9000900090009000 2 Pipebodvxsectioncm24825184438542 3 Wallthickness:mm G13013090110 H210330200200 4 Upsetlengthends:mm boxside11400140014001400 PinsideJ14001400250250 5 Nominaldiameter:mm A131140164168 B105114146146 E146/132(cone)147/140186186 6 IDjointDmm105 110127127 ODjointC178178203203 BoxmemberK350350320320 PinmemberM350350320320 7 Threadconnectiontvpe5%”FH5%”FH f35~11 FH6516”FH Table10ADPwithInternalUpset(D16TAlloy) PIPE ~,, (129MM) DESCRIPTIONUNITS PIPE 27/’11PIPE 3%”PIPE 41/16” (103MM)PIPE 4%’ (108 MM) PIPE 58” (147 MM) PIPE 58” (147 MM) PIPE 58” (147X15) (73MM)(90 MM) kN I1lAxialload I Maxoperate(085SU) 1730 2030 500 600 650 845720 870775 1000 1120 1460 1290 1680 1500 1950 kNm 409 487 464 552523 615 71 85125 149158 188 190 22630,5 36,3 I Maxoperating I MPa 290295240 % 47043,0 295 I Ipressure I 4MaxoperatinginternalMPa 540500 384 370 375 330 pressure 5 Approxweightofkg 20462306I2567 53,0714 874978 1736 kglm 140 89165 10418,6 207 118 131 I inair57 3,676 4892 58 103 65 47547I62,2 cm2181225263280408 I ,,,,, ,, — nl I IIII I fl I II II —1AIIII I1 I 1 OIC9Sulco I 36 1 I Table12ADPwithExternalUpset(D16TAlloy) ! — 1 2 3 4 5 6 7DESCRIPTION Axialload Maxoperate(085SU) Maxallowed (SU) Torque Maxoperating Maxallowable Maxoperatingexternal pressure Maxoperatinginternal messure Approxweightof one pipe(withjoint) Unitweight: inair inwater PipebodycrosssectionPIPE UNITS2T~ll (73MM) kN 500 600 kNm 71 85 MPa 470 MPa 540 kg 53,0 kglm 5,7 36 cm2181PIPE 3%” (90 MM) 650 845 125 149 430 50,0 714 7,6 48 225PIPE 41/16“ (103 MM) 720 870PIPE 4%” (108 MM) 775 1000PIPEPIPE PIPEPIPE 5,, 58”58”58” (129 MM) (147MM) (147MM) (147X15) ~ m II I I I* 158190305409 464523% 188226363487552615 $ s * 3 29529,029524,0 32039,0 s q 384 370375330390 43,0s m *, a 87497817362046 23062567 :, g 92 10314016518620,7 g 58 6589104118131 3“ 26,328,040,847547622 ,,,’>,, ,,, ,, , , ,, Table13ADPwithExternalUpset(1953TIAlloy) DESCRlpTIONUNITS 1 Axialload kN Maxoperating(085 SU) Maxallowed(SU) 2Torque kNm L a Maxoperating 1 Max allowed 3MaxoperatingcollapseMPa 4MaxoperatingburstMPa 5Approxweightofkg onepipe(withjoint) 6Unitweight:kglm inair inwater PIPEPIPEPIPEPIPE 51/”11 I 5X’ I 6%” I fj5/fU (131MM)(140MM) (164 MM)(168MM) 209021571900 2350 2450253822502750 720 I 750 I 610 I 780 850880720920 I 350380260330 530560400490 1880195017002100 209215189233 139146128 157 DevelopmentofAluminumDrillPipeinRussia 43ADPwithProtectionUpset SeveralstandardsizesofADParemanufacturedwithaprotectionupsetinthe middleofthepipetoprotectthemainbodyfromwearandtoincreasepipestrength Figure11(right)showsaschematicofADPwithaprotectionupset,andTable14 summarizespipegeometry Table14DimensionsofADPwithProtectionUpset(seeFigure‘11;right) MAINPIPEPROTECTIONWALLTHICKNESS(MM)TAPERLENGTHPROTECTIONI BODYODUPSETOD(MM)UPSETLENGTH (A) (MM)(P)(MM)END PIPEPROTECTIONBoxPINSIDE(MM) UPSETBODYuPsETSIDE (J) (H)(G)(1) 12915017112151300250300 14717217112351300250300 16819720112551300250300 ADPwithaprotectionupsethasbeenmostwidelyusedindrillingdirectionaland horizontalwellsThismodificationhasproventobeefficientforprotectingcasing stringsfromgalling 44IntegralJointADP Specificphysicalandmechanicalpropertiesofaluminumalloys(suchaslow surfacehardnessandthepotentialtobedrilledouteasily)allowedthedevelopmentof anewpipedesign,thesocalledintegraljointpipeThesepipesdonothavesteeltool joints,and,hence,theydonothavepipethreadsforconnectionwithtooljointsA coarsejointthreadcutontheinternalorexternalupsetendsconnectsthepipesField experiencewiththesepipeswith51AinFHjointthreadindicatedthat,withinthe allowablerangeoftorque,thesetypesofconnectionsareabletowithstand140160 makeupsandbreakoutsConsideringthatpipesarefabricatedwithextendedupset ends,recutting(repairing)ajointthreaddoesnotpresentanydifficulty Figure12showsthedesignoftheintegraljointADPTable15presentstechnical parametersofthesepipes I_,,,, 4 a r_, S d G I I IFigure12IntegralJointADPI ,! , ,, +“ , ,, 4 —— ,_ —___ ,, ,, ,, , +,,,,0 , ,,,&f ,? ,’ ,,, 39 2 DevelopmentofAluminumDrillPipeinRussia Integraljointpipesarewidelyusedindrillingdirectionalandhorizontalwells,as wellasforrunningcasinglineronthedrillstring Whiledrillingdirectionalandhorizontalwells,theboreholepositionmustbe continuouslymonitoredIntegraljointADPsareusedforthelowersectionofthedrill stringforthispurposeThenonmagneticpropertiesofthesepipesandabsenceof steeltooljointsallowdriftsurveysdirectlythroughthedrillstringusinggeophysical methods,whichreducestimeforthisoperation IntegraljointADPsarealsousedforthelowersectionofthedrillstringwhile runningcasinglinersincomplicatedboreholeswithhighriskofdrillstringstickingwhile cementingduetocemententeringtheannulusacrossfromthedrillpipeIncaseofa failure,integraljointADPareeasilydrilledout,thusreducingtimerequiredforrecovery ofthehole 40 ,,, ” , ,! , , , ! ,, , ,, ‘ 1 ,,, ,’ ~, ,, ,L >\L, ~ DevelopmentofAluminumDrillPipeinRussia mmC9Q Oclowcum Oc U91cmm O)csNm madw OcLnlrcowNC md xl cd 41 —— — DevelopmentofAluminumDrillPipeinRussia 45ThickWallADP(ADC) HeavywallADC(AluminumDrillCollars)aremanufacturedwithintegraljointsor withsteeltooljointsJustlikestandardintegraljointADP,heavywallintegraljointADC maybeusedfordrillingdirectionalandhorizontalwellsfordriftsurveysthroughthedrill stringInaddition,thesepipesareusedinBHAsforasmoothertransitioninrigidity fromdrillcollarstodrillpipesFigure13showsthedesignofanintegraljointheavy wallADC L=u=J””” +’+=kd‘“ I Figure13ThickWalledAluminum DrillCollar(ADC) I FlutedorspiralgrooveddrillcollarsarewidelyusedindrillingpracticeDuring theirapplication,theareaoftheirsurfaceincontactwiththeboreholewallsissmaller thanwithstandarddrillcollars,whilediametricclearancebetweentheboreholewalls andtheoutsidesurfaceofthepipesremainsthesameorisevenlargerThisfactis instrumentalinloweringtheriskofstickingthelowersectionofthedrillstringdueto differentialpressure(differencebehveentheformationpressureandthehydrostaticwell pressure),aswellasinstabilizingtheBHAattheholebottomSpiralgrooveddrill collars,whichcreateturbulenceinthemudflow,allowcontrolofthereturnflowinthe annulusThisallowsincreasedbottomholecleaningfromdrillcuttingsandincreases drillingefficiency 42 ,,,,! ;, ,,, DevelopmentofAluminumDrillPipeinRussia Spiralgroovesontheexternalsurfaceofsteeldrillcollars(DC)aremachinedon speciallyequippedmachinetoolsThemachiningmethodhasrelativelylowefficiency andleadstohighcostsforflutedDCSpiralgroovescanbeformedonheavywallADC duringtheextrusionprocess,withouttheneedformachiningDieconfigurationand speedofthepiercingstubmandrelduringtheextrusionprocesscontroltheformationof desiredgrooveparameters(numberofgrooves,screwpitch,helixelevationangle,etc) Figure14showsthedesignofaheavywallflutedADC & Figure14HeavyWallFlutedADC ThejointthreadofanintegralheavywallADCiscutonthecorrespondingupset endsForanassembledheavywallADC,twotypesofthreadsarecutonthepipe: triangularthreadsfor“cold”assemblywithsteeltooljoints,andtrapezoidalthreadsfor “hot”assembly FieldoperationswithheavywallADCbythecompaniesSamaraneftand Mangyshlakneftshowedhighefficiencythatincludedthefollowing: Paramagneticpropertiesofthepipes Highvibrationdamping BHAstabilization DecreasednumberofBHAsstuckduetofluteddesign Turbulenceinthemudduetofluteddesign IssuesrelatedtothehighdampingabilityofADPandheavywallADCwillbe describedinasectionbelow Table16summarizestechnicalparametersofheavywallADC 43 —— ——— — DevelopmentofAluminumDrillPipeinRussia Table16TechnicalParametersofHeavyWallADC Pipedimensions(mm)146x80159x80180x92 Elevatorgroovediameter(mm)129140 146 Pipeholecrosssectionalarea(cmz)502502 676 Pipebodyaxialmomentofinertia(cm’)202829354767 Pipebodypolarsectionmodulusoftheelevator359481 512 Unitmassofpipebody(kg/m)3241 51 Allowabletensionload(safetyfactor=12)14502150 2500 CriticallengthwhenADCloseslongitudinalstability underownweight(m)2226 34 Recommendedtorqueforassemblingonepiece connections(kNm)151925 46ADPforExploratoryDrilling InRussia,ADPhasbeenusedin exploratorydrillingforover30years OriginallyADPwasintroducedtoreducelabor fordrillingcrewsfordrillingexploratorywellsin remote,hardtoreachareas,especiallyduring transportationofdrillingequipmentLater, ADPbecamewidelyusedinallregionsof exploratorydrilling TheweightofADPshownabovefor exploratorydrillingis2to25timeslessthan theweightofsimilarpurposeSDPThis allowedareductionindrillingcrewlabor,as wellasdrillingdeeperwellswiththesametype rigs Figure15showstwotypesofADPused inexploratorydrilling:1)withpin(ADPP)and 2)box(ADPB)joints Theindustrymanufacturesfivestandard sizesofADPforexplorato~drilling: 24mmADPwith45mmand 8Ommwallthicknessand13m length(095inADPwith0177 and0315inwallthicknessand 51inlength) 44 Pin Drill Pipe HalfPin PinJoint Connection (ADPP54)Box~oint Connection (ADPB65) Figure15JointsofPinJoint andBoxJointADP Joint Pipe DevelopmentofAluminumDrillPipeinRussia 34mmADPwith65mmand11Ommwalland13and29mlengths (134inADPwith0256and0433inwailthicknessand43and95ft lengths) l 42mmADPwith70rnmand14mmwalland43mlength(165inADP‘ with0276and0551inwalland141ftlength) 54mmADPwith9Ommand16mmwalland44mlength(2ViiinADP with0354and0630inwalland144ftlength) l 71mmADPwith8Ommwalland62mlength(28inADPwith0315 inwalland203ftlength) ComparativetestsofADPandSDPinvariousregionsundervariousgeological andtechnicaldrillingconditionsrevealedbetterperformanceofADPForexample, utilizationofADPP54allowedincreasingdrillingdepthof500mwiththesametypeof rigsAlso,rateofpenetrationwas1530%higher,drilledmeterageperrunincreased by613!!40,andtrippingtimewasreducedby1115% ThemaximumwelldepthdrilledwithADPP71was3000m(9842ft) 47AluminumPipesinWorkoverOperations WellworkoversincludeavarietyofoperationsOperationstocorrectproblemsare themostcrucialandtimeconsumingTheseincludereleasingandremovingcollapsed tubing,stalledsubmersiblepumps,packers,cable,etcTheseoperationsnormally requireseveraltripsofthedrillstring,whichleadstoanincreaseintrippingtimeIn wellswith22002500mTD,trippingoperationsnormallytake3050?40ofthetotaltime ofaworkoverThisalsoresultsinhighconsumptionoffuelandlubricants,drillline, brakeshoes,aswellasincreasedrigmaintenancetimeAddressingfailuresrelatedto stuckdownholeequipmentrequiresmobilizationofpullingunitswithcapacity significantlyhigherthantheweightofthedrillstring,consideringdragWorkovers includeasignificantnumberofproductioncasingpatchingoperations SpecialADPforwellworkoverandcompletionwasdevelopedandutilized,based onananalysisofworkoveroperationsandADPmanufacturingtechnologyFigure16 showstheseintegraljointpipes;Table17givestheirtechnicalparameters Bo~Elev~torGroovePip~BodyPin \ \, ,, , , , , > , $ , , , ~;, ,, , ’/ ,/ ,, !, ,,— I Figure16ADPforWorkoversandCompletions I 45 DevelopmentofAluminumDrillPipeinRussia Table17IntegralJointADPforWorkoversandCompletions PIPEPROPERTIESPIPEDIMENSIONS 95x9I08X8 OD (mm)95108 Pipelength(mm)90009000 Pipebodywallthickness(mm)9080 Outsidegroovediameter(mm) onBoxside7489 onPinside90102 IDofupsetends(mm)4256 Unitmass(kg/m)7892 TensileLoad(kN) Allowable650900 Limit7801080 Torque,(Nm) Allowable750013200 Limit900015800 Internalpressure(MPa) Allowable520405 Limit625490 Typeoftooljointthread2718Reg31/2Reg UtilizationofthesepipesbythecompaniesSamaraneft,Yuganskneftegaz,and Nizhnevartovskneftegazshoweda2to3folddecreaseintimeforoperations,as comparedtoSDPinsimilarconditionsThecostoftheworkoverswasalsolowerby 2030Y0 48TubingfromAluminumAlloys Tubingiswidelyusedintheoilandgasindustryforvariousoperationsrelatedto completion,production,wellworkoversanddownholerepair,andwellstimulationA diversityoffunctionsperformedbythetubingstringresultsinavarietyofappliedforces Theprincipalforcesaffectingtubinginoperationincludeaxialforcethatstretchesa stringunderitsownweight,andexternalandinternalpressuresAtubingstringisalso exposedtobendingforcesindirectionalintervalsofaborehole,dragforcesthatresist axialmovementofthestring,andtemperatureloadsfromvariationoffluidtemperatures intheborehole Atubingstringinthewellisexposedtoaggressivemediathatmaychange compositionovertime ThisaffectsreliabilityanddurabilityoftubingSincespecific strengthandcorrosionresistancearecriticalparametersforselectionofmaterialfor tubing,utilizationofaluminumalloysisquitepromisingMaximumlengthofauniform ADPtubingstringfitsoperationalrequirementsofthedeepestoilwellsTheweightof thesestringsinawellis34timeslowerthantheweightofasteelpipestringwiththe 46 DevelopmentofAluminumDrillPipeinRussia samesafetyfactorTherefore,hookloadcapacityanddrivecapacityofmobile workoverrigsmaybecorrespondinglyreduced ,Aluminumpipeshavelowerhydraulicresistancethansteelpipesduetolower roughnessoftheinternalsurfaceandreducedfrictionfactorTransportationcostof tubingfromaluminumalloysissignificantlylower,especiallywhiledeliveringpipesto inaccessibleareasTheseadvantageswereinstrumentalinthedevelopmentinRussia ofstandardassemblytubingfromaluminumalloyswithinternalupsetendsandtool jointsTable18summarizestheirparameters E (%) 60 73 89 102 114 114 Table18PropertiesofTubing WALLI TOOLJOINTIUNITMASS THICKNESSWITHTOOL (fdM)(::)JOINT (KGIM) 673295 7 89428 7107 525 75 121666 8 132766 85 132817 “omAluminumAlloys SHEARING I ALLOWABLEPRESSURE LOADOF (MPA) “THREAD tINTERNAL I‘EXTERNAL (KN) 196560 520 296520 450 360435 390 410400 380 495390 385 495415 385 IntegraljointaluminumtubingwithinternalflushendsishighlypromisingFigure 17showstubingdesign ThistubingiswidelyusedinWesternSiberiainwellswith highflowrates ‘TTKI=31N I ILIII 1 Figure 17 IntegralJointAluminumTubing ,, ,,, ,, , ,, ,, _ ,>~ , , — 49PotentialforManufacturingAluminumCasing PracticalexperiencehasshownthatintegraljointADPcanbeeasilydrilledout (similartoamediumhardrock)Thisfeaturecanbeusedfordevelopingdrillable casingliners Thesewouldbecapableofreliablyisolatingproblemintervalsina boreholeThen,whiledrillingthroughthenextprobleminterval,thelinersetabovecan bedrilledouttokeepthesamediameterofboreholeAfterthewholeintervalhasbeen drilledthrough,anewlinercanberuntoisolateit 47 DevelopmentofAluminumDrillPipeinRussia ThisideawastestedbySamaraneftwhiledrillingadeepwellA250mm(98in) integraljointaluminumlinerwith10mm(039in)wallswassetat26503450mThe drillstringmadeabout150tripsthroughthelinerwithoutanyvisibledamagetoit SimilarworkwasdonebyBashneftwheninapilottrial220mm(866in)aluminum casingpipewasset Drillablealuminumlinerscanreducelostcirculation,water,oil,andgasshows, andefficientlyeliminateothercomplicationswhiledrilling AluminumalloysarenotaffectedbyhydrogensulfideCurrentproblemswith ensuringreliabilityofsteelcasingexposedtohydrogensulfide,andthedeficiencyand highcostofspecialsteelalloysforpipesruninaggressivemediawithhydrogensulfide, promptworktocontinueonthedevelopmentofcasingfromaluminumalloysthatare speciallyselectedfortheseharshoperatingconditions Researcheffortsareaimedatresolvingthefollowingproblems: Theelasticmodulusofaluminumalloysis3timeslowerthansteelThis factorreducescasingresistancetocollapsepressureThisshouldbe takenintoaccountwhiledevelopinganewpipedesign CorrosionofaluminumalloysisrelativelyintenseinmediawithapH>95 Therefore,theeffectofacementslurrycontactingaluminumcasingmust beanalyzedSpecialprotectivemeasuresmustbedeveloped,ifdeemed necessary ARussiancompany(Samaraneft)hashad longtermexperiencewiththefirstaluminum productionstringIntegraljointADPwith internalflushendswasusedforcasing168 mmpipeswith1lmmwallsand185mm externalupsetendsmanufacturedfromDI6T alloy(Figure18),wereruninwellNo134with a1376mTMDA1195mstring(118joints) wassetat451240mDuringassemblyofthe string,thepipesthreadconnectionswere sealedwithanepoxybasedselfcuring compoundPriortorunning,fourlayersofa bakeliteandepoxycompoundwereappliedto thepipes Afterthestringwassetand cemented,itwaspressuretestedto143MPa Thewellflowedinitiallyat25m3/dayThenit wastransferredtoartificialliftproductionwith anelectricsubmersiblepumprunonasteel tubingstring , I Figure18InternallyFlush ADP usedasCasing !, 48 DevelopmentofAluminumDrillPipeinRussia Sincethattime,thepumphasbeenpulledover15timesforrepairThestring assembledfromintegraljointADPhasbeeninoperationforover10yearswithoutany failures Thisexperienceindicatesthenecessityofintensiveresearchanddesignworkto developandusealuminumcasingThesepipesshouldbeappliedinwellswith hydrogensulfideAlso,theyshouldbeusedinwellslocatedininaccessibleareas,with lowcapacityrigs,aswellasindrillingwildcatandexploratorywells 410PotentialforManufacturingAluminumMarineRkers TheexperiencegainedinADPdesign,fabricationandexploitationtestifytothe possibilityofusingthe1953alloyfortubularsforvariouspurposesintheoffshore environmentItnowappearstobepossibletoextrapolatefromthatexperienceandto considerdesigningaluminumrisersTheseriserscouldbeseveralkilometerslong Experiencegainedbythemarine,militaryandaerospaceindustries(whichrecently becameavailable)confirmsthataluminumtubesof20inODandgreatercanbe fabricatedbyextrusion TheideatodevelopaluminumrisersfortheBaikalLakeScientificDrillingProject (BDP)originatedintheStateenterprise“Nedra”inYaroslavl,RussiaThe500m (1640ft)longprototyperiserof9%indiameterwasfabricatedin1995and successfullydeployedin1998Itwasmadeupof9m(295ft)longpipesmadeof DI6Talloywith240mm(945in)OD,220mm(866in)IDandexternalupsetsto 270mm(1063in)ODTheupsetsallowthepipestobeconnecteddirectlywithout usingsteeltooljointsTheresultingweightinairoftherisertubesis25kg/m(168Ib/ft) (weightinwater16kg/m;107lb/ft) Thepreliminaryanalysismadein1995showedthatthedesignandfabricationofa slimriser245300mm(96118in)diameterand34km(984213,123)inlengthis feasibleusingexistingRussiantechnologyThesecalculationsbroughttheideato introducealuminumtubesasapotentialmaterialforproductionrisersalongwithsteel andtitaniumAproposalforincludingaluminumtubesmadeofD16Tor1953alloys waspresentedtotheISOworkinggroupontheStandard“DesignofRisersforFloating ProductionSystemsandTensionLegPlatforms”Themajorconcernhereisthelong termcorrosionandfatiguedurabilityofaluminumpipes,whichcanbeevaluatedonthe basisofspecialexperimentalstudiesonly Thenextlogicalstepwasananalysisofaluminumdrillingrisers(ADR)Sucha studywasconductedin19971998TheprogramRISOPTwasusedtoevaluateADR deploymentattheCamposBasinoffshoreBrazil(2700mwaterdepth)(example1)and offshoreJapaninthePacificOcean(4000mwaterdepth)(example2)Theriser consideredwasofstandarddesign:19in(485mm)IDwithfiveauxiliarylines(choke andkill,booster,twohydraulic)All pipeswereto be madeofaluminumalloyssimilar to1953TIandallconnectorsaresteelNobuoyancyelementshavebeenused 49 DevelopmentofAluminumDrillPipeinRussia Resultsofoptimization oftheADRmainpipewallthicknessarepresentedinTable 19andFigure19Themainpipewallthicknessforthreerisersectionswascalculated basedonasafetyfactornotlessthen165atallrisercrosssectionsThisvaluewas determinedonthebasisofAPIrecommendations(15timesyieldstrengthplus1070 additionalbecausebendingstressesarepresent)Themanufacturingofaluminum pipeswiththesecalculateddimensionsaswellascompleteADRsectionsdevelopment appearsviable Table19AluminumDrillingRiserCalculationResults EXAMPLEMUDRISER SECTIONLENGTH(M)RISERSECTIONMAINPIPEWALL NUMBERDENSITYTHICKNESS(MM) (KGIM3) LOWERMIDDLEUPPERLOWERMIDDLE UPPER 12000 6701690 340310245 275 ~2 15505102380 1110245220 275 — — I — — — I A 3 wxs?7N7 / \7/NAY I Figure19DesigningAluminumDrillingRiser I 50 DevelopmentofAluminumDrillPipeinRussia TheanticipatedbenefitsofapplyingADRintheoffshoreenvironmentincludethe following: Less totalrisersystemweight Lesstime forriserassembly/disassembly l Potentialtoreachgreaterwaterdepthswiththesameplatformsandrig equipment 51 , ,,, ,> ,, , , ,, ~, , , — _ ,,,>,> ,, ,,, DevelopmentofAluminumDrillPipeinRussia 52 5ExperiencewithADP 51ADPOperationattheRigSite ThetechniquesforrunningADPattherigsiteareanimportantelementintotal drillpipeoperations Thereliabilityanddurabilityofadrillstringisimpactedbythe qualityoftheoperationWhenreceivedatthedrillingsite,jointsofADPareassembled intoadrillstringinstrictconformitywiththedesigncalculationsusedtodetermineits configuration SpecialattentionshouldbegiventothetooljointthreadsofdrillpipesWorking andidleconnectionsshouldbeswitchedevery4050tripstoensureuniformwearThis canbeaccomplishedbyunscrewingtheupperpipeofthedrillpipestandduringthe nexttrip,andbyunscrewingidleconnectionsThesamesequenceofoperations shouldbeobservedduringdownholetrips Tooljointsaremadeupbyapplyingtorquetothespecifiedvalueforeachjoint typeRecommendedtorqueswiththeapplicationofthreadlubricantsaregivenin Table20 Table20TorquesforToolJointMakeupwithAntifrictionThreadLubricants TOOLJOINTTHREADTYPERECOMMENDEDTORQUE (KNM) Z147(5%FH)260285(1921xl03ftlb) Z171 (65A FH)350370(2627x103t%lb) Operationofapipestringwithlengthexceeding500m(1640ft)requiresnotonly replacementofworkingjointsinonedrillpipestandbutalsochangingthedrillstand arrangementoftheentirestring,againtoensureuniformwearofeachjoint ItisnecessarytoaddmudintothedrillstringtoavoidcollapsingADPwhen trippinginwhiledrillingwithheavymudsoratgreaterdepthsTheheightofthedrilling mudcolumnrequiredinsidethestringisdeterminedbytheformula: h=HmP/~ (51) where: H= n= P= 71=thetripdepthofthedrillstring pipesafetyfactor maximumoutsidepressure densityofmud 53 ,, ,,, , ,, , ,, ~, ’” , ,, ,! ,, : ,,,~ ~ DevelopmentofAluminumDrillPipeinRussia IfthedrillstringisconstructedofADPmadeofvariousalloys,therecommended temperaturelimitsfortheiroperationasspecifiedaboveshouldbestrictlyobserved Strings consistingofdrillpipeswitt are usedforsimilarpipetypes)should whereaxialloadsarehighest ContinuousmonitoringofmudpHhighinitialyieldpoints(whendifferentalloys beplacedintheuppersectionofdrillstring nustbeperformedtoensurethepHremains withintherange6595IfpHisnotwithinthisrange,corrosionofaluminumalloys sharplyincreases Whendownholeproblemsariseandadditionalloadsmustbeappliedtothedrill string,itisnecessarytokeeptrackofloaddynamicsandtodocumentthepeakvalue Aftertheproblemiseliminated,thejointsofpipeinwhichthestressesexceededthe allowablevalues(085SOZ)areidentifiedCarefulinspectionofpipesurfaces,tooljoints andthreadsshouldbeperformedforpipesfromthesesetsInthoseproblemsituations forwhichtorqueexceedsthenominallimit,itisadvisabletocheckthreaded connectionsformatchingofmarksontooljointsandpipes [ncaseswhenADPremainsintheholeformorethan500hourswithoutdrilling mudcirculation,itisnecessarytotakeintoaccounttheexposureofeverypipejointto criticaltemperaturesAfterremovalfromtheborehole,thesejointsarewithdrawnfrom theoperation,andonelowerpipeofeachtypeandsizeistakenfortestingTestsare neededtodetermineyield,strength,relativeextensionandtorquetoshiftthenipple andboxinapipethreadedconnectionValuesrecordedinthetestsshouldbe comparedwithcertifiedperformancedata Attherigsite,behaviorofthegeometricalshapeandtheconditionofdrillpipes andtooljointsareregularlyinspectedTheinspectionincludesmeasuringtooljoint nipple/boxshoulderclearanceThisclearanceisthegapbetweenthenippleandbox shouldersinapositionoftaperedsurfacecontactwithoutrotation ThepipeODischeckedinthemiddleandatthepipefixtureontheslipsThe arithmeticmeanvalueoftwodiametermeasurementstakenperpendiculartoone anothershouldbeusedaspipeODforcalculations PrincipalparametersforADPduringoperationsareestimatedbyintroducing correctionfactorsasrelatedtonewpipesThesefactors,giveninTable21,dependon thewearvalueofpipes,ie,theweargrade TocalculatethestrengthcharacteristicsofADP,geometricalparameters(cross section,momentofinertia,sectionmodulusandpolarsectionmodulus)were determinedaccordingtopipecertificationdataTheseparametersarechangingduring thepipe’slifeduetowearAccordingtoexperimentalinvestigationsofwearfeatures, coefficients(Kl;Kz;KS;KQ)forthemaingeometricalparametersweredefinedThe valuesofthesecoefficientsdependonpipewallthicknessoronweargrade 54 DevelopmentofAluminumDrillPipeinRussia DWearGrade oWearGrade nWearGrade t4DP TYPE 14711 14713 14715 14717 1649 16811 — l– II–nowear(newpipe) wearof10tol5%ofnominalwallthickness wearmorethen15%ofnominalwallthickness Table21Coe~cientsforADPGeometricalParameters ADP WEAR GRADE II Ill II III II Ill II 1[1 II Ill II Ill NoteCROSS SECTION, K, 080 078 083 081 078 076 079 078 078 076 081 FACTORFOR MOMENTOF INERTIA,K2 088 087 090 088 086 084 088 085 086 084 089 CalCUlatiOn SECTION MODULUS,K3 086 084 088 087 085 083 087 084 085 083 086 084 078087 orADP1,wearclassfactorsK,=K2=K3=K4=10POLARSECTION MODULUS,K4 087 085 088 087 085 083 087 085 085 083 087 085 Thevalueofshoulderclearanceisusedtomonitortheconditionofthetooljoint threadofdrillpipesRegularinspectionisperformedafterevery5060trips(make up/breakout)ForcaseswhentheclearanceexceedsthevaluespecifiedinTable22, thepipesarewithdrawnfromoperationforthreadrepairPipewallthicknessand threadconnections(pipeandjoint)arecheckedforfatiguecracksbyaportableNDE system, Table22AllowableWearofToolJointThreads ADPTYPETOOLJOINTTHREADMmNOOFTURNSTOMwNIPPLEAND Box CODEMAKEUPCONNECTIONSHOULDERCLEARANCE FORGRADESBEFOREMAKEUPFOR GRADES(MM) IIII II ADP147x11,13,15,17Z147(5%”FH) 6253394 33 ADP164x9,168x11Z171(6?4”FH) 6253394 33 ADPwhileinserviceisexposedtoabrasivewearcausedbyfrictionbetweenthe drillstringandtheboreholewallsduringrotationanddisplacementduringroundtrip operationsHydraabrasivewearislikelyduringboreholedrillingwithheavyweight mudsInaddition,ADPhasshownthatwearmayoccurontheoutersutiaceinthe areasincontactwiththeslipsAsarule,maximumODwearisobservedinthemiddle sectionandintheareacontactedbytheslipsThewearcrosssectionisdistributed nonuniformlyovertheperimeterandrevealsaneccentricpattern 551 —— —— DevelopmentofAluminumDrillPipeinRussia ADPsaredividedintothreeclassesformatchingwithsuitableoperationsPipes ofclassIandIIarerecommendedforturbineandrotarydrillingPipesofclassIllare recommendedforturbinedrillingofshallowboreholesinnoncomplicated environments 52DrillPipeWearWhenDrillingUltradeepHoles Thedrillstringmayincludeabout1000jointsofdrillpipewhenboreholedepths reach12,000m(39,000ft)Allpipesareassembledintodrillpipestandsofthreepipes about36m(118ft)longbeforethedrillstringismadeup Allpipesaredividedintosetsforinspectingtheirphysicalcondition,for replacementwithinonetypesections,toassignthemformeasurementsandrepair,to placethemintooperation,etcEachsetconsistsofsevendrillpipestandsandhasa lengthofapproximately250m(820ft)ADPoperationtimeiscalculatedforeachset Wearforthefullsetisdeterminedastheaveragevalueofinspectionresultsforall pipesintheset [ntheKolaSD3ultradeep well,wearofdrillpipeODforacompletesetofdrill pipes(approximately250m)isestimateddependingondragforcesalongthesetand thepositionofthesetwithinthedrillstring Suchanapproachincludesloadswhich affectthesetatagivenmomentanddeterminingthelateralforceandrouteoftheset alongtheborehole Ai=XLi(Fip+ Fir) (52) where: Ai= conditionalworkofdragforcesaccomplishedbythesetduringtrip“i” Li =positionofthesetintheboreholefromtherotarytable(km) Fip,Fir= dragforcesactingalongthelengthofthesetduringtheroundtrip operations(kN) Experimentalstudiesconductedduringregularinspectionsofdrillstringsets confirmedtheexistenceofacorrelationbetweenthedrillpipeexteriorsurfacewearand theconditionalworkThisdependencehasaparabolicshape: 8i=aA~+bAi+c (53) wherea,b,careconstantfactorsforthegivenboreholewithallowanceforitsdesign, radialsizes,spatialposition,etcThus,wearofthesetcouldbeestimatedbasedon calculationofthe“workoftheset”SummarydataontheADPsetsincludingwearand conditionalworkduringtheKolaSD3withintheinterval720010,700m(theborehole wascaseddownto2000m)areshowninTable23Figure20showsthe“workofdrag forces–ADPwear”correlationintheinterval96001C,700m 56 — SET# (FROM BOTM) 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 — *A DevelopmentofAluminumDrillPipeinRussia Table23ADPWearandConditionalWorkforKolaSD3 (interval720010,700m) INTERVAL72007700M Set position (km) (see note) 75 725 70 675 65 625 60 575 55 525 50 475 45 425 40 375 35 325 30 275 25 225 20100TRIPS) Conditional workof dragforces (103kNkm) 600 870 980 1687 1950 2310 2520 2587 2690 2992 2900 2897 2880 2760 2640 2475 2380 2372 2220 2090 1925 1800 1620Relative wear (%) 11 12 12 26 31 34 38 46 53 60 62 54 54 52 50 43 41 36 24 22 20 16 12 — te:The ADP“setposition” INTERVAL85009200M Set position (km) (see note) 875 85 825 80 775 75 725 70 675 65 625 60 575 550 525 50 475 45 425 40 375 350 325 30 275 25 225 thedi: 120TRIPS) ConditionalRelative ,, , , , ,“ ~ , ,“ ,, — — —, ,,,(,*,, , :>!~,, f,,, ,,, : ,,’:,?,, ,! ,,/ >, ,, —— workofdrag forces (103kNkm) 1680 1938 2170 3840 4929 5760 5829 5964 6399 7020 7050 6984 6900 6798 6678 6600 6440 6264 6018 5856 5715 5544 5304 5112 4884 4530 4158wear (%) 28 32 34 43 48 59 73 106 122 135 130 126 120 114 110 112 108 95 87 82 63 56 48 39 28 26 21 mcebetweenthe~ 57 INTERVAL960010,700M Set position (km) (see note) 100 975 95 925 90 875 85 825 80 775 750 725 70 675 65 625 60 575 55 525 50 475 45 425 40 375 35 325 30 275 25 225 20 — !midpt (95TRIPS) Conditional workofdrag forces (103kNkm) 1805 2130 2527 3603 4446 5486 5572 5956 6156 6773 6626 6543 6517 6412 6260 6234 6213 6173 6061 5885 5842 5776 5660 5491 5396 5272 5087 4816 4474 4154 3847 3506 3116 ?fandrigiRelative wear (%) — 32 38 46 58 65 82 91 96 98 101 103 97 95 86 82 80 74 71 67 62 56 52 50 46 41 39 32 28 24 22 20 19 18 or DevelopmentofAluminumDrillPipeinRussia SetL,~~ number II 1 10,E 2 3 4 5““9)o 6 7 8 8,0‘“ 9 10‘ 11 12“ FR 13‘7,0 14 15“ 16‘ 176,0 18‘ 19‘ 20“ 21‘51o 22‘ ~3 24‘ 25’J>o 26 27“ 28 29“3,0 30‘ 31‘ 32‘ 332,(P 100“ 200300 401 500 600700800900 kN LI 246$1012 141618km N 100200300400 500600 700x103kN,krn 81 1,0 2,03,04,05,06,07,0~8)09,0~ Figure20DragandWearontheKolaSD3(95tripsfrom960010700m)(FP= averagedrag pullingout; FR=averagedrag runnin9in;Li=PiPesettravelPer trip;Ai=workofdragforcefor95trips;81=wear for95 tnPs) 58 DevelopmentofAluminumDrillPipeinRussia Thistypeofapproachwasusedtodeterminethedrillpipewearrate,the frequencyandsequenceofNDEmethods,techniquestoarrangethesetswithinthe drillstringtoensureuniformwear,etc TheusageofdrillpipesattheKolaSD3revealedproportionatewearalong aluminumandsteelpipesatthesegreatdepthsThedrillstringconfigurationatthe KolaSD3consistedmainlyofADPOnlyinsignificantsections–thesection immediatelyabovethebit(120150m;394492ft)andtheuppermost500600m (16401969ft)–wereequippedwithsteelpipesduetotechnologicalspecificsand safetyconcernsThemainreasonforonsiterejectionofdrillpipesiswearofthetool jointthreadZ147(5%FH):Duetothiswearthesepipeswererejectedfromoperation andtransferredtootherlesscriticalboreholesDataondrillpipeconsumptionand reasonsforrejectionfromtheinterval720011,500mattheKolaSD3areshownin Table24 Table24DrillPipeConsumptionforInterval720011,500matKolaSD3 DESCRIPTION ADP used: meters tons Rejectedortransferredtolower grade: a)Tooljointthreadwear meters tons b)DrillpipeorTJbodywear: meters tons c)Erosion(m) Averagedrillpipeoperationtime (runs) Drillpipeconsumed/meter penetration(kg) ADP147 (D16T) 19200 306 4922 77 9644 153 4434 291 72,, ,,, ,,,, , , ,, , ,, ,, ~, , ,,, ,, , ,,,,+, ADP147 (1953TI) 15100 256 15100 256 367 60 Ez!IIzz T 5900 7700 89 252 5900 89 250 209 — 1550 50 6150 202 470 593 53DrillingProblemsattheKolaSD3Well AlldrillingproblemswhichoccurredwhiledrillingtheKolaSD3ultradeepwellcan bedividedintothefollowingbasictypes: 1BHAsticking 2 Breakageofthedrillstring 3Breakageandlossofdrillingtoolelementsinthehole 59 DevelopmentofAluminumDrillPipeinRussia 4Loggingcablefailure Table25listsstatisticaldataondrillingproblemsattheKolaSD3 Table25DrillingProblemsforKolaSD3to12,262mDepth DRILLINGPROBLEMSAND COMPLICATIONS 1BHAsticking 2 3 4 5 6 Drillstringcomponentfailure Bitcomponentfailure BHAcomponentfailure Loggingcablebreakage Other(increasinginclination angle,unsuccessful sidetrack,etc) ITotal NUMBER OF FAILURES 140 27 112 72 8 5 364%OFALL FAILURES 385 74 307 198 22 14 100CONSUMEDFOR SIDETRACKING/ BYPASSING DAYS% 1016 433 21 206 1724 , 59 25 12 148 100 EXTENTOF SIDETRACK (M) 8359 2373 62 764 11766 DatainTable25aregivenforalltypesofdrillingproblemsthatoccurredatKola SD3withintheintervalof012,066m(drilling,tripping,reaming,bypassholedrilling, etc)Mostproblemscouldberesolvedinlessthan5daysBHAstickingwas eliminatedbyapplyingtensiononthedrillstringuptopermissiblevaluesorbyusing jarsFragmentsofthedrillingtoolelementswereremovedwithmagneticbitextractors; thelostBHAelementswerefishedwithtapsandbellsocketsForonlytwelvecases relatedtoBHAstickinganddrillstringbreakagewasitimpossibletoresolvethe problembytraditionalmethodsTheseproblemswereresolvedbysidetrackingand drillingbypassholesThetotallengthofbypassholeswas11,766m AmajorityofproblemsandcomplicationswerecausedbyBHAsticking(140 events)Therewerecaseswhenthetensionappliedtothedrillstringinthecourseof addressingtheproblemexceededthepermissiblevalues(above085S,2)andtheload reachedultimatevaluesAsarule,thisresultedinadditionalproblemscausedbydrill stringfailureBreakagegenerallyoccurredwithintheintervalof94009800mandmost likelywasconnectedwithastrongtendencyforcavernstoforminthiszone,causing notonlytensionbutbendingloadstoactonthedrillstringUsingafishingtaporabell socketwasnotpracticaleveninasinglecase Duetosignificantsizeofthecaverns, thetopoftheemergencystringdeviated,soallattemptstofixitwithafishingtoolwere unsuccessfulTheonlymethodforovercomingthesedoubleproblems(stickingand breakingatthesametime)wassidetracking Drillstringelementbreakagemadeupaninsignificantportionofthetotalnumber ofproblems(only27events)However,consideringthecomplicationsinherentinthese typesofproblems,thecostoftheirresolutionwithbypassdrillingarehighThedetails ondrillstringproblemsaresummarizedinTable26 60 DevelopmentofAluminumDrillPipeinRussia Table26CausesofDrillStringFailuresforKolaSD3 REASONSFORFAILURENUMBEROF % FAILURES 1 Fatiguefailureoftooljointthread5%FH622% 2Breakingoftooljointbody(ofpoorqualityproduction)31I% 3Breakingofdrillpipebodyinsectionwithhighestload12 44% (loadexceedinglimit) 4Fatiguefailureofpipethread(standardtriangularthread)4 15’% 5Unscrewingofpipesintooljointthread(ofpoorquality2 8% production) 1, AAn, Ananalysisoftheprimarycausesofdrillstringproblemsledtotheconclusionthat itispossibletominimizelosttimeforresolvingtheseproblemsFirstly,itisnecessaiy tonotethatafterreplacementofatriangularpipethread(toconnectaluminumpipe bodytosteeltooljoint)byanacmethread,onethemostfrequentproblemsrelatedto drillstringelements,ie,fatiguefailureatthepipethread,waseliminated(seeitem4, Table26)Toreducetimelostduetofailureinthesteeljointthreadbecauseoffatigue ormanufacturingdefects(seeitems1,2,5),itiscriticaltomaintainastrictscheduleof toolinspectionbothwithinstrumentsandnondestructiveevaluationinthecourseof acceptanceandintermediatechecks Pullingonastuckstringwithatensionloadabovetheallowablelimitisabsolutely forbiddenasabasicmethodforunstickingtheBHAHowever,notknowingtheactual dragforcesalongthedrillstringcanresultinloadingthecriticalstringsectionsbeyond theprescribedlimitsDrillstringbreakageisasureconsequenceofthisapproach accompaniedbyanattendantvarietyofcomplications 61 ,’ , ,, , , ,, ,, ’” , , , ,,,; rr7 , >>!, ,, +>,!<>, , ! T ,% $ ,,,~ , — DevelopmentofAluminumDrillPipeinRussia 62 6AssemblingDrillStringsfromADP 61SpecificsofDrillStringDesign Thestudyofmaterialstobeusedfordrillpipeproductionrequirestheapplication oftheconceptofspecificstrength,whichexpressestheratioofyieldpointtospecific weightSpecificstrengthofamaterialcanbeexpressedintermsoflengthand,inits applicationtothedrillstring,definesthemaximumlengthofasinglesizedrillstring hunginairwherethestressesduetosuspensionareequaltotheyieldpointofthe materialMaximumlengthofasinglesizedrillstringisdeterminednotonlybythe strengthofthedrillpipematerialbutalsobythedifferenceinspecificweightsofthe pipematerialanddrillingmud Comparisonofdrillpipesofvariousmaterialsbasedonthisparametershowsthat thelongeststringofasinglesizedrillstringismanufacturedofADPInactualdrilling operations,thelowersectionsofthedrillstringmayhavelongtermexposuretohigh temperatures,whichdeterioratesthestrengthofthedrillpipematerialand, consequently,restrictspenetrationdepthThisconsiderationnecessitatesthechoiceof highlythermoresistivealloysforthebottompartofadrillstringandthedevelopmentof correspondingmethodsforanalysisandoperation Thestudyledtotheselectionofthreealuminumalloysfordrillpipemanufacturing: DI6T,AK4ITIand1953TIThesealloysnotonlymeettherequirementsofdrilling operationsbutarealsoeasytoproduce,whichallowedmassproductionofpipeswith variablediametersalongthelength Table27presentsphysicalandmechanical propertiesofADPandsteeltooljointmaterialsundernormaltemperatures Table27PropertiesofADPandSteelToolJointMaterials I 1 2 3 4 5 6 7 8 9 10 ,, , , , , ,“ ,, ,, , ,’ , ~Tensilestrength,notlessthan HardnessHBr120 Elongation0/011 Percentagereductionofarea%20 Specificgravityg/cm328 ModulusofelasticityMPax105 E072 G 026 Poisson’sratio033 Thermalexpansioncoefficientl/cOxlo+225 MaxallowoperatingtemperatureI“CI160 63 PIPE IPIPE t (1953 TI)IAK4ITI* +EEE t 120 240TOOLJNT (40KHN) 735 880 277340 11 45 785 21 081 03 DevelopmentofAluminumDrillPipeinRussia Thephysicalandmechanicalpropertiesofaluminumalloysessentiallydependon temperature,loadconditionsanddurationofexposureADPofhighstrengthalloy 1953TIisespeciallysensitivetohightemperaturesAt11O°C(230°F),theplasticityof thisalloyisrelativelylowItisrecommendedtouseADPfrom1953TIalloyintheupper sectionsofthedrillstringwhere,attemperaturesbelow11O°C,itshighstrengthwillbe ofadvantageindrillstringswithhighstaticloads PipesofDI6Talloyarecharacterizedbythehighestplasticityascomparedto otheralloys[tisreasonabletousethemwithinthetemperaturerange11O160°C(230 320”FItisrecommendedtouseADPoftheAK4ITIalloyifthetemperatureexceeds 160°C Experimentalstudiesandlongtermoperationalexperienceshowthatthreemajor temperaturezonescanbeidentifiedforADPInthefirstzone,mechanicalproperties arerelativelystableandthedesignstrengthfactorshouldbetakenasequaltothe materialyieldpointat20”C(whichisconventionallytakenforthedesignofdrillstrings) Withincreasedoperatingtemperature,materialstrengthpropertiesarenoticeably reduced,withoperationtimebeinganimportantfactorWithinthiszone,theyieldpoint determinedafter500hoursexposuretothegiventemperatureisusedasthemajor designparameter Thetimespanof500hoursischosentoprovideforalongterm exposureofADPintheboreholeduringdrillingproblems incasethecriticaltemperatureofADPisexceeded,thelatteraccumulatesplastic deformationsunderthecombinedloadexposureThisresultsinstructuralchanges andpossibledestructionofthepipeunderloadsconsiderablylowerthanthose calculatedusingyieldpointatthesametemperatureOperationofADPwithinthis temperaturezonerequirestheuseofprolongedstrengthlimitsofthematerialasthe majordesignparameter Table28illustratesADPdesignofvarioustypesofalloyschosenfordrillstring sectionsundervariousoperatingtemperatures Table28DesignParametersofADPforVariousOperatingTemperatures DESIGNPARAMETER RANGEOFTEMPERATUREFORALLOY(“C) I D16TAK4ITI1953TI Yieldpointafter500hoursexposureto operatingtemperature 12014514016090115 Prolongedtensilestrengthunder operatingtemperaturebasedon500 145200160200 hoursexposure Oneofthemostimportantoperationalparametersofadrillstringistheendurance limitofitsthreadconnectionsandtheirdurabilityinthezoneoflimitedendurance Fatiguecracksthatappearasaresultofalternatingbendingstressesareoneofthe maincausesofdrillstringfailures 64 DevelopmentofAluminumDrillPipeinRussia ExperimentaldataonthedurabilityandendurancelimitofADPconnectionsbased onlaboratorytestsareusedfordrillstringdesignThesamedataareusedfor optimizingthedesignofthepipeconnectionoptimalandestimationoftheirstress deformationstate Aspecialsoftwarepackagefordesignandcalculationofdrillstringsforultradeep boreholedrillingwasdevelopedbasedonanalyticalandexperimentalstudiesIn additiontostaticdesigncomputationsforthedrillstring,itincludesspecificprograms forevaluationofelasticstringstretchwithallowancefortemperature;estimationof powerconsumptionforroundtripoperations;dragforcedistributionalongthestring; longtermstrengthassessment,etc StaticanalysisofdrillstringsconstructedfromADPiscarriedoutforthreemain technologicalsituations:theprocessofmechanicaldrillingandboreholereaming; trippingoperations;andeliminationofproblemsandcomplicationsMethodsof designingdrillstringsforcyclicdurabilityunderperiodicbendingandprolongedstrength undernonstationaryloadingmodeswerealsodeveloped 62EvaluationofLoadsAppliedtotheDrillString Toimprovetheoperationalreliabilityofadrillstring,itisextremelyimportantto accuratelyknowtheloadsactingineachsectionThisallowsverifyingthedesignand lowerstheriskofemergencycausedbycomponentfailuresduetotheloadsexceeding thelevelpermittedbytheoperationalconditions Drillstringcalculationsnormallytakeintoaccountadditionalloadsarisingfrom frictionforcesbetweenthedrillstringandboreholeAtthesametime,specific conditionsofultradeepboreholedrillingincrystallinerocksalsorequiretakingaccount ofthedragforcesThesearedeterminedbythewedgingeffectoccurringwhenthedrill stringmovesalonganellipticcrosssectionoftheboreholeorinitscurvedintervals ExperimentalstudiesintheKolaultradeepboreholeat12,000m(39,370ft) showedthatdragforcescontributeover60%ofthedrillstringweightThefriction force,F~,,comprisesabout35%ofthetotaldragforceandisstronglydependentonthe levelofthenormalforce,Fn,andthefrictioncoefficient,f,ofthedrillstringcomponents againsttheboreholewalls,whichisrelatedtoweightofthedrillstring,Iithological compositionofthesection,andlubricatingpropertiesofthedrillingmud Ff,=fxFn (61) Underrelativelytypicalfieldconditions(alargevolumeofdrillingmudcirculatingin theborehole,considerablesolidsinthemud,andanineffectiverigcleaningsystem),it isratherproblematictosignificantlydecreasethefrictioncoefficientbyincreasingthe lubricatingcapabilityofthedrillingmud Evenwhenitwaspossibletoreducethe frictioncoefficientto025030byappropriatetreatments,thedragforcedependenton 65 DevelopmentofAluminumDrillPipeinRussia thefrictionforceshasbeenseentoreach520to550kN(117to124tip),which comprised2835%oftheweightofthedrillstringinthedrillingmudConsequently,the firststeptowardreducingthedragforcesdeterminedbyfrictionforces,istoreducethe radialnormalloadsbydecreasingtheweightofthedrillstring Theleaststudiedproblemistheeffectofacavernousboreholeofellipticalcross sectiononthedragforceInvestigationscarriedoutintheKolaultradeepborehole showedthatthemajoraxisoftheellipseessentiallycoincideswiththedirectional deviationInthiscasethenormalforce,Fn,determinedasafunctionoftheweightof thedrillstring,canbedividedintotwocomponentsinaccordancewiththepointof contactbetweenthestringcomponentandtheboreholewallThisresultsinthe generationoflateralforcescausingastickingeffectwhichformsadditionaldragforce, F~,hinderingdrillstringmotion(Figure21) F,=k,Fn=(Fnicos~) where: k,=coefficientwhichaccountsfortheboreholecrosssectional(62) shape ~=halfangleofthedrillingtoolcontactintheboreholecrosssection [twasexperimentallyshownthatthedragforcerelatedtothestickingeffectduring stringmotioninanellipticalborehole reached31 YO ofthetotaldragforceand ~=k~~=“ amountedto450to460kN(101to130Cosp kip) foranopenholelengthover10,000 m(32,800ft) ItispossibletoreducethedragP, forcerelatedtotheboreholecross sectionalshapebyreducingtheradial normalforcesThisispossibleby:— 1)decreasingtheweightofthedrill string;or 2)narrowingthecontactanglein P =0j3 =7080° theboreholecrosssections k,=lk,=2,22,5 Thefirstapproachappearstobe preferable,sincenarrowingthecontactangle ~ Figure21DistributionofNormal intheboreholeisonlypossiblewhenthe boreholeisspeciallyreamedtonominalsize withinthecorrespondingintervalsThisisacomplextechnologicalprocedurewhich takesadditionaltimeandcost 66 DevelopmentofAluminumDrillPipeinRussia Theinfluenceofthe3Ddeviationoftheboreholeonthedragforce,Fj,is determinedbythetotalcontactanglealongtheboreholeanddependsonthevalueof thenormalforcesonindividualboreholeintervalsandthe3DtrajectoryThedragforce isnegativelyaffectedbyboreholeintervalswithextensivechangesinthe3Dtrajectory Theadditionalnormalforceagainsttheboreholewall,Fn,whichformsthedrag forcewhenthestring followingexpression: Fn=kql where: k= q= r=movesalongacurvedborehole,canbedeterminedfromthe (63) dimensionlesscoefficientcharacterizingtheperiodofcrookedborehole intervals(k=15) weightofaunitlengthofdrillstringinthedrillingmud reciprocaloftheboreholedeviationradiusintheintervalunderconsideration (r=I/R) Toreducethedragforcedeterminedbythe3Ddeviationoftheborehole,itis necessarytoattempttominimizethenumberofdoglegsReductionofthedrillstring unitweightishelpfulaswell Thisapproachtodragforceevaluationcanbevalidatedbyacomparisonbetween thedragforceswhilepullingoutthedrillstringintwoboreholesoftheKolaSD3 (Figure22) Thefirstborehole (borehole1inFigure 22)hadadepthof 12,066m,casingstring setdepthof2000m, withopenboreholefor theremainderDrag forcehaditsmaximum valueof1560kNduring theextremeloadingof thedrillstringwhile pullingoutofthe bottom Inthecased intervalto2000m,the dragforce distribution waslinearandonly dependedon the frictionforces,F~,Asfar Fjcomponents [email protected]— A 1500” 1400’] 1300 i3D245rnm ~~sing 1200‘ 11oo 1000 900 800“ 700 600“ 500 1 40C ~ looI i I1I1 I1 11I, 1 1000 20003000400050006000700080009000100001100012000 Figure22DistributionofDragForcesinKolaSD3 astheboreholewasverticalandcased,therewerenoFfand 67 ,, ,, ,,,, ,,, DevelopmentofAluminumDrillPipeinRussia Withintheintervalfrom2000to5500m,thedragforcedistributionwas approximatelylinearThisfactcanbeattributedtoarelativelyweakinfluenceofFtand Fjsincethelowerboreholewallwastreatedbythepipetooljointsduringtheextensive trippingoperations,thecontactanglehadaminimumvalue,andthemaximum borehoieinclinationwas3to4° Withintheinterval5500to12,066m,thedragforcedistributionbecameparabolic, withthemaximumincrementnearthebottomhole[nthatinterval,allthreecomponents (F~,,F,andFj)contributedtothedragforce Sincetheboreholewascavernousand hadanellipsoidalcrosssectionthroughouttheinterval,andtheinclinationangle exceeded25°nearthebottom,thedragforcewascomprisedmostlyofF~andFj Thesecondborehole(borehole2inFigure22)was12,260mdeepithadbeen reamedandcasedbya245mm(965in)stringtoadepthof8770m,whichresulted insubstantialchangesinthedragforcedistributionalongtheborehole Theboreholeintervalwithalineardragforcedistributionincreasedfrom2000to 8770m,whichcoincideswiththecasedintervalwithouttheF~componentThe incrementofthedragforcewasslightlygreateronthatintervalcomparedtothefirst borehole,whichcanbeexplainedbytheinfluenceofthe3Dpositionofthecasing string Ontheopenboreholeinterval877012,260mwherethedragforceincludedall threecomponents(F~,,F~andFj),thedragforcedistributionischaracterizedasinthe firstboreholeCasingtheboreholereducedthetotaldragforceby600kNTheir absolutevalueswereequalto960kNatcomparableboreholedepths Theanalysisofchangesinthedragforcedistributioninthetwoboreholesofthe Kolaultradeepboreholevalidatedtheapproachfortheevaluationofthecontributionsof F~,,F~andFjtothetotaldragforceappliedtothedrillstringConsiderationoftheactual loadsalongthewholestringlengthallowedamorequalifieddrillstringcalculation, whichincreaseditsoperationalreliability Thisproposedprocedureiscomplexforpracticalimplementationbecauseofthe lackofreliabledataaboutthefrictioncoefficientforthestring/boreholecontact,the stringcontactangleintheboreholesection,andthespatialparametersoftheborehole Duetothis,amethodfor“pullingthrough”thedrillstringwhilepullingitoutwas developedtodeterminethedragforcedistributionalongtheboreholewithdepthand taketheforcesintoconsiderationtoevaluatethestress/strainstateofthedrillstring TheessenceofthemethodisthefollowingLetF~l,F~2f~nbethedragforces measuredasthehookloadreadingsfordifferentstringlengths(whenpullingoutthe first,second,thirddrillpipestands,etc)ThedragforceatdepthLis: FC=(G,–G~)/qP 68(64) where: G~= G~= ~= P=DevelopmentofAluminumDrillPipeinRussia hookloadaccordingtotheweightindicator tacklesystemweight tacklesystemefficiencyforpullingout; calculatedweightofthestringcorrectedforitsbuoyantweightinthedrilling (65) mud Then,thefollowingdragforceincrementwilloccurontheboreholeinterval betweenthefirstandthesecondmeasurements: AF,=FL1FU=[(GL,GT)/qP,][(GUGT)/qP2]= (GL,GM)/q(PIP,) Andonthenextintervals: AFZ=(GW–G~~)/q(Pz–P,); AFn=(G~n–G~(n+lJ/q(Pn–P(n+l))(66) Thedragforceincrementsateachmeasurementstepareusedtoconstructaplot ofthedragforcedistributionalongthewholestringTheplotisusedtoevaluatethe stressedstateondifferentsectionsofthedrillstringTheshorterthemeasurement step,thehighertheaccuracyofthedragforcedistribution Theaccuracyofthistypeofmethodfordragforcemeasurementalongthedrill stringwascheckedexperimentallywiththehelpofselfcontainedboreholerecorders whichwereinstalledatvariousdepthsandregisteredthestretchofthedrillstand dependingontheloadappliedExperimentaldataaresummarizedinTable29 Table29DragForcesalongtheDrillString(FieldTestResults) RECORDERSTRING STRINGRECORDED< COEFFICIENTACTUAL DRAGFORCE (KN) DEPTH LENGTHWEIGHTDRILLPIPEOFSTRETCHLOADAT (M)BELOW BELOWSTRETCHDURINGTESTED ATTESTEDAT RECORDERRECORDER(MM)CALIBRATIONPIPE PIPESTAND (M)HOOK (KN)(KN/MM)(KN) 1028959012861270 1752230 9401020 2295 8323109412801461870 780820 4304 631481411501261450 640 560 6584 40345356901521050 520 470 Theseresultsshowagoodconvergence(errorbelow10YO)indeterminingthe dragforcedistributionalongthedrillstringandprovedthepotentialforusingthe“pull through”methodforactualaxialloadstobetakenintoaccountinthedrillstring analysis 69 ,, , ,, , , , ,, ,, , ’” ,,,, , ,’, ,, ,, ! /,!,,,, ? ,, ’,, —— DevelopmentofAluminumDrillPipeinRussia 63DesignParametersandSafeLoadFactorsforADPStrings Operationalparametersofdrillpipesdependontheirdesignandmaterial propertiesConventionalyieldstrengthofthepipematerial(S02)at20°C(68°F)isthe maincriterionforthestaticdesignofdrillstringsThefollowingstrengthcriteriaare usedfordrillstringoperationunderhightemperatures: l Conventionalyieldstrengthofthematerialatoperatingtemperature Materialcreepstrength,whichdependsonplasticstrainresultingfrom staticloadduringaperiodoftime Longtermstrength,definedasultimatestressduringaspecifiedtime periodandtemperatureatwhichthepipecollapses Anumberofresearchstudieswereperformedtoevaluateapplicabilityofthe criteriamentionedaboveincalculationsforADPstringdesignFlatspecimenscutout fromthemainbodyofADPalongtheaxiswereusedinthestudiesThestudies indicatedthatyieldstrengthoftheDI6Talloydidnotchangewithinthetemperature rangeof20120”C Furtherincreasesintemperatureleadtoarapiddropinyield strengthAt180°C,itisabout70?40oftheinitialvalue(Figure23) Thus,utilizationofyield strengthasthemaincriterion fordesignislimitedtotherange ofstabletemperatures Operationaldurabilityof drillpipesdependsonthelevel oftheirfailurehazard,rather thanondeformationsaccumu latedduringtheiroperation Therefore,itisapparentlymore expedienttousecreepstrength orlongtermstrengthasthe mainstrengthcriterion Figures24and25show the resultsof testsfor determining correlation betweenthecreeprateofDI6T 20/70 1(7(714” ?80 Temperature(°C) Figure23 YieldPointofDI6TwithTemperature (1=05hn2=12hH3=100hr;4=500hr) alloyandtemperatureandalevelofappliedstressThediagramsclearlyindicatethat whenthelevelofstressisbelowconventionalyieldstrengthofthematerial,critical creeprate(>0002Y0perhour)occursattemperaturesabove140°C(284°F) Therefore,longtermstrengthshouldbeusedasadesigncriterionofstrengthforDI6T alloyatoperatingtemperaturesabove140°C 70 DevelopmentofAluminumDrillPipeinRussia Similarstudieswereperformedfor?~ the1953TIandAK41TIalloysGeneral trendscorrelatingcreeprateand_ temperatureremainedunchangedfor~7&0 [email protected]°Cisacritical‘w temperature forthe1953TIalloy~~~ UltimatelongtermstrengthshouldbeS usedincalculationsofstrengthfor~ temperaturesabove10O°CThecritical~‘~a temperatureforAK4IYIis220°C~ Testsandstudiesperformedledtothe g7JU establishmentofthefollowingcriteriato beusedincalculationsofADPstring %0 designs: L l materialyieldstrengthat 20°Cisassumedforyield strengthintherangeof temperaturestability ,, ‘1 Figure24CreepRateofDI6T withTemperature cmaterialyieldstrengthat operatingtemperatureafter500hoursfortemperaturerangesofmaterial thermalfailure longtermstrengthatoperatingtemperatureandaspecifiedtimeperiod,, fortemperaturesabovethecriticaltemperatureatwhichirreversible, plasticdeformationsoccur Safetyfactorisanimportantdesign parameterthatreflectsoperational characteristicsandreliabilityofthedrill stringThefollowingformulaisusedfor~ calculatingsafetyfacto~ g n=S~/SjM (67)~ z where: s;= allowableserviceabilityofdrill pipematerial s,= stressintensityinaspecific sectionofthestring Conventionalyieldstrengthofa material(S2)isusedasaserviceability parameter(S:)fornormalstaticdesign /II If{ CY02=creeprateunder yieldstrength I 256 1 1I I I 1 ;246810 CreepRate(103%Jhr) Figure25CreepRateofDI6TAlloy atVariousTemperatures 71 + ,,,,,!;,,,/,> !, “,> ! DevelopmentofAluminumDrillPipeinRussia calculationsofadrillstringSafeloadfactorsdependonthetypeofwellanddrilling method(Table30) Table30SafetyFactors DRILLINGMODEHOLETYPE VERTICALERD Rotary14515 Turbodrill135‘14 64EnduranceandDurabilityofADP Rotationofadrillstringinslantedintervalsaroundabentaxiswhiledrillingresults inalternatingbendingstresses6080?40ofdrillstringfailuresresultfromfatiguefailure ofpipeandtooljointthreadsThesefailuresoccurduetoalternatingbendingstresses thatleadtoformationandpropagationoffatiguecracksintherootofthethread Thefatiguestrengthlimitofapipethreadconnectionisoneofthecriticaloperating parametersfordrillpipesFatiguestrengthlimitoftheconnectionisthemaximumlevel ofstressthattheconnectioncanbearwithoutfailurewhenaspecifiednumberof alternatingloadcyclesareapplied Thestudiesindicatedthatpipeconnectionfatigueanddurabilityparameterscan beobjectivelydeterminedonlyinbenchtestsoffullscalespecimensunderconditions thatarerepresentativeofactualdrillingloads Moststudiesoffatigueparametersusetestbencheswithconsolealternating bendingloadsappliedtofullscalespecimens Thesebenchesperfectlyimitatedrill pipeconnectionloadsinwellsTheyhaveasimpledesignandarecapableofcreating stableloadingparametersFigure26showsaschematicdiagramoftheST20bench Figure27presentsaphotographofthebench 72 DevelopmentofAluminumDrillPipeinRussia 213 4 1 ,, ,, Figure26BenchforFatigueTestingofPipeandConnector (1=testspecimen;2=suppo~3=loadingunit;4=drive;5=foundation) Figure28showsspecimensofADP 164x9aftertestingtofailureontheST20 bench Anupgradedbench(modelST50M) allowsdeterminingdurabilityandfatigue parametersoftestspecimensathigh temperature Thebenchhasheating blocksforheatingthespecimensOne blockisputinsideaspecimen,andthe threeotherinsidecylindricalspacesonthe benchfrontpanel Thisarrangement allowsformingauniformthermalfield withinthethreadconnectionzonesduring thetestBelowareparametersfortheST 50Mbench: Diameter(mm) specimens 64182 tooljoints 64206 Vibrationamplitudeerror(%)25 Lengthofspecimen(mm)<3000 Testtemperature(“C) 20250Figure27ST20FatigueTestBench Timerequiredtoreachtestconditionsat250”C(hr)6 73 DevelopmentofAluminumDrillPipeinRussia Maximumvariationintemperature (%)25 Abasictestprotocolforfullscale specimensofADPconnections includes107cyclesofloadreversal Thisallowstestresultswithrequired accuracy TheST20benchwasusedina largenumberoftestsandstudiesfor evaluatingtheeffectproducedby conventionalspecificcontactpressure affectingthepipetojointthread connectionondurabilityandfatigue parametersoftheconnectionFigure 29presentsresultsoffatiguetestsof 73,114,and147mmADPthread connectionswithdifferentcontact pressuresappliedtothesurfaceof connectedthreadsduringmakeup Table31presentstheresultsofthese tests Table31TestsofADPThreadConnectionswithDifferentContactPressures CONVENTIONALCONTACTPRESSURESOFADPENDURANCELIMIT(MPA)OFCONNECTIONSFOR THREADCONNECTION (MPA) 6080575347 4060504437 204045 Testresultsrevealedalineartendencybetweenfatiguestrengthoftheconnection andconventionalcontactpressureUltimatecontactpressurewasalsodetermined Contactpressureabovetheultimatelimitresultsinconsiderabledecreaseofcycle strengthFortheabovegivenstandardsizesofADP,thisparameterisabout80MPa Table31indicateshigherdurabilityofthreadedconnectionsofsmallerdiameters andhighercontactpressuresuptoacertainlimitThiscanbeexplainedbylower relativedisplacementoftheconjugatedelementsandhigherintegrityoftheconnection athighercontactpressuresWhencontactpressuresexceedaspecifiedlimit,plastic 74 I DevelopmentofAluminumDrillPipeinRussia ADP73withZL90Tool Joint go 6!7 70 60 50 40 30 2G’ ADP114withZSh146Tool Joint 8 6 4 2 [email protected]#[email protected] 6870 NumberofCycles(Nx106) Figure29FatigueTestResultsofConnections (1=2040MPacontactpressure;2=4060;3=6080;4=>80) deformationoccursintheconjugatedpairThisleadstolowerplasticityreserveofthe pipematerialasaresu!tofstrainhardening,whichpromotesformationandpropagation offatiguecracks FatiguetestswerepetiormedontheST20benchforfullscalespecimensof147 mm(58in)widelyusedADPfromvariousaluminumalloyswithZL(triangular),and 75 _;____— , !,,,?,,,,+,, ‘ DevelopmentofAluminumDrillPipeinRussia ZLK(trapezoidalwithataperedstabilizingshoulder)threadconnectionsTable32 showstheresultsofthesetests Table32EnduranceLimitofADP(SteelToolJointThreadedConnection) ObjectTestedPipeBodyAlloyGradeEndurance OD(mm)Limit(MPa) 1Pipebody147D16T110 2Connectionwithtriangulartapered147D16T47 threadatcalculatedtorque 3Connectionwithtriangulartapered1471953TI 40 threadatcalculatedtorque 4Connectionwithspecialtooljoint147D16T64 (acmetaperedthreadprofileand sealshrink) 5Connectionwithspecialtooljoint147AK4ITI 70 (acmetaperedthreadprofileand sealshrink) Note: atestpatternof107cycleswith 650cycles perminuteat 20°C wasusedtoobtainfatiguelimits Figures30and31showfatiguecurvesforconnectionsof147mmADPfrom DI6T&d1953TIalloyswithZL builtaftertestsontheST50M benchThetestsresults indicatethatanincreaseintest temperatureleadstoconsid erablereductionofconnection durabilityintheendurance strengthandfatiguelimitzone Forexample,thefatiguelimit forADPfromDI6Talloywith ZLtypeconnectionsat160”Cis onethirdofthefatiguelimitat 20”C Slightlybetterresults wereobtainedforZLKtype connectionsmadeupusingthe hotassemblymethodThese connectionsarerecommended for operationsathigh temperatures 65ElongationofanADP DrillString andZLKthreadconnectionsathightemperatures, 90ZL172 Tool Joint 704 50 10 —m s’ ZLK178 ToolJoint 1%r( $0– 80– 70“ (* uo 30III,200, III OIZ3~5678910 NumberofCycles(Nx106) Cettaindrillingoperationsrequire Figure30FatigueEnduranceofADP determiningtheexactpositionofthe Connection(147mm OD Pipe;DI6TAlloy) drillstringinthewell,whichincludes / 76 DevelopmentofAluminumDrillPipeinRussia calculationof itselastic elongationNormally,SDPwith weightsandelasticitiesdifferent fromADParesetinthelower sectionsofthestringtocreate additionalweightonthedrillbit andallowsmoothtransitionof rigidityfromBHAtoADPIn addition,adrillstringcanbe assembledfromsectionsof ADPwithdifferentweightsand dimensionsAdrillstringina wellisexposedtoavarietyof temperaturesElongationmod uliofpipematerialdecreaseat hightemperature, whereas thermalexpansioncoefficients increaseAllthesefactorsmust betakenfullyintoaccountwhile calculatingelasticelongationof combinedstrings Thefollowingformulais usedtocalculateaggregate elasticelongationofacombi nationdrillstringinawell: where: Alk~= Alk~= A!k~= m= ,, ,, , , > ,“ ,, ,, ,’” —: ————,,7— >, ~~, ,,,, ,,,, ,, ~~ ~+, +’ 4*:,: ,+: ,3 ,,? ,,, two AlloysD16Tand1953TI t 220 780 1400 700 z &60 c Alloy AK41TI %JO*, 0 2600 4 780‘ n I 700240°C——— 60 040 80720760 Zdu24Q Time (hr) Figure31LongTermStrengthof ADPwithTemperature (68) AL= ~(Alk+Al~,+Al~~) k=l elongationofthek*sectionofadrillstringduetoitsownweight thermalelongationofthekhsectionofadrillstring elongationofthek*sectionundertheweightofthesectionbelowandthe BHA numberofsections Theelasticelongationofthenthsectionunderitsownweightofacombineddrill stringiscalculatedaccordingtotheformula: l;qk(l–pl/pm) Alk,= 2EmFp(69) where: 77 1,= qk= PI= Pm= Em= FP=DevelopmentofAluminumDrillPipeinRussia lengthofthekthsection,definedasthesumofitsdrillpipesasmeasuredat thesurface reducedmassofunitpipeofthesection drillingmuddensity reduceddensityofdrillpipematerialforthatsection,accountingfordensity oftooljointmaterial elasticitymodulusofdrillpipematerial crosssectionalareaofthesection Thermalelongationofthenlhsection,neglectingthethermallinearexpansion coefficient: where: am= n=AL= ~(L:– L:,) linearexpansioncoefficientofmaterialthegivensectionpipe; wellgeothermalgradient;(610) L~;L~qdefinethewellintervalcorrespondingtotheupperandlowerlimitsofthe section Thethermalelongationformultidiameterorsinglediameterdrillstrings assembledexclusivelyfromADPcalculatedforthewholestringwithlengthLis: Al==nL2a~112 (611) Thefollowingformulaisusedforcalculatingthekthsectionelasticelongationunder theweightofsectionsbelowand 41, Alti=— E~FP — theBHA: (612) wherepk=tensileforceappliedtothelowerpartofthesection,calculatedby: Pk=Q“(l–Pl/P~)+~qiZi(l–Pl/P)(613) izk+l where: Q=BHAweight PBHA=reduceddensityoftheBHA Elasticelongationisaffected bytheforcesthatresistdrillstringaxialmovement, andtheirdistributioninthewellForcesthatopposedrillstringweightduetodrag occurwhilethestringisbeingrundown,leadingtoadecreaseofelasticelongation 78 DevelopmentofAluminumDrillPipeinRussia Equation612canbeusedtocalculatereducedelasticelongationinthiscaseWhen thedrillstringispulledout,axialresistanceforcescauseadditionalelasticelongation Thiselongationiscalculatedusingtheformula: (614) where: P Fb= axialdragappliedtothelowerpartofthekthsection Additionalelasticelongationcausedbyforcesresistingdrillstringaxialmovement inaborehole,mustbeaddedtofullelasticelongationofthedrillstringwhenitispulled outandsubtractedwhenitisrunin 66ADPDrillStringsforDirectionalDrillinginWesternSiberia ADPwaswidelyusedbythecompanyYuganskneftegaz(asubsidiaryof Glavtyumenneftegaz)fordrillingdirectionalwellsinWesternSiberiaTables33and34 showexamplesofdrillstringassembliesforthistypeofwelldrilledonturbines Table33DrillStringAssemblyforWellNo4166(Povhovskaya) PlannedDepth:2800mActualDepth:2808m VerticalDepth:2675mDeviation:530m DRtLLSTRING ASSEMBLY SECTIONLENGTHMEASUREDDEPTH 1 (M) (M) BHA2626 DC17824 50 ADP147XI12474 SDPI27x9465539 ADP147XI122692808 4 Table34DrillStringAssemblyforWellNo1057(Povhovskaya) PlannedDepth:2800mActualDepth:2870m VerticalDepth:2745mDeviation:732m DRILLSTRINGASSEMBLY SECTIONLENGTHMEASUREDDEPTH (M) (M) BHA2626 DC17826 52 ADP147XI124 76 SDPI27x9475551 ADP147XI123192870, ,,, , , , , , , ,— ,, ,,+ , — 79 DevelopmentofAluminumDrillPipeinRussia Whiledrillingthesewells,significantattentionwasgiventoreducingADP consumptionpermeterbyusingadvancedoperationalmethods,improvingthequality ofthepipes,andintroducingasubstantiatednormofpipeconsumptionThese measuresallowedextendingtheoperationalperiodofasetofADP(2200m)beforethe firstserviceofthetooljointthreadsto55,00060,000m(180,000197,000ft)drilledAt thesametime,whentooljointthreadsweresentforrepair,ADPparametersallowed furtheroperationForexample,theaveragepipewallthicknesswas105mm comparedtotheminimumallowable8mm;averageODofthetooljointswas171mm comparedtoanallowablelimitof166mm Afterthetooljointthreadswererepaired,thetestpipesetsweresenttofurther operationTheircumulativepenetrationreached100,000m(328,000ft)beforethe pipeswereconsideredunusableAtthispoint,minimumthicknessofthepipemain bodywas92mm,andtheaveragevalueremainedintherange98mmto103mm AveragespecificoperationalwearofthemainbodyofADPfordirectionalwell drillingwithturbinesbyYuganskneftegazleadtotheconclusionthatitispossibleto increaseADPoperationallifeto175,000190,000m(574,000623,000ft)providedtheir applicationisoptimizedandsteeltooljointsarerepairedandreplacedasnecessary 67ADPDrillStringsforDrillingUltradeepWells Drillingultradeepwellsintroducesspecificoperatingconditionsforthedrillstring thatsignificantlyimpactoperatingparametersfordrillpipesandconnectionsThe uppersectionsofthedrillstringareexposedtoconsiderablestatictensileandtorsion loadsduetotheweightofthestringandforcesthatresistaxialmovementandrotation Closertothebottom,absolutevaluesofstaticloadsaredecreasing,whilevariable bendingloadsareincreasing Operationofthelowersectionsofthedrillstringis additionallycomplicatedbylongexposuretohightemperaturesInthegeneralcase, temperature,load,andtimecomponentsareunevenlydistributedalongthestringThis distributiondependsonacombinationofgeologicalandoperationaldrillingparameters Thesefactorsmustbetakenintoaccountwhiledevelopingadesignandoperatinga drillstring Adrillstringina10,000mwellisexposedtothehigheststresswhileitisliftedup fromthebottomandthefirst56drillpipestandsarepulledoutCalculationofstatic tensilestrengthisthemainelementofdesignofadrillstringforultradeepwellsTables 35and36showexamplesofthesetypesofcalculationsfortheKolskayaSG3 ultradeepwell(12,000m)andKrivorozhskayaSG8(5580m) ThedrillstringassemblyfortheKolskayaSG3istypicalofassembliesusedin ultradeepdrillingconditions Table35showsthatADPfromthreealloyswasused whiledrillingSG3,dependingonthetensileloadsandtemperaturedistributionADP oftheAK4IThightemperaturealloywasusedforthelowersectionsofthestring,and ADPfromthe1953Thighstrengthalloyfortheuppersections150mofSDPwas 80 DevelopmentofAluminumDrillPipeinRussia installeddirectlyabovetheBHAforasmoothertransitioninrigidityfromthedrillcollars toADPAsectionofSDPwasinstalledintheupperpartofthedrillstringtoensureits strengthuniformity,aswellassafeoperationincaseofabreakintheADPUniformity ofstrengthwasachievedbyensuringequalsafeloadsforallsectionsofthestringIn theexampleabovethissafeloadwas560570kN 81 ,, > : , , !’ ,, , , ~’”,“, ,, ,,, ,:,{ ,+,,,, ,>:,> ,,, :: ,:!, ,:,!?,, ,,,J ,,,, ,, ,, , DevelopmentofAluminumDrillPipeinRussia 82 DevelopmentofAluminumDrillPipeinRussia 68ADPDrillStringsforDeepwaterStratigraphicDrilling Extensivedevelopmentofnaturalresourcesdepositedindeepwaterzoneson continentalshelves,aswellasstudiesofoceaniccrustgeologicalstructureusing deepwaterstratigraphicwelldrilling,prescribespecificrequirementsfordevelopmentof equipmentandtechnologyforthesecomplexandcriticaloperationsThedrillstringis animportantelementindeepwaterdrillingItsupportsacomplexcombinationofstatic anddynamicloads: 1Tensileloadsinastringunderitsownweighttakingaccountofbuoyancyin seawater 2 Bendingmomentsthatresultfromdrillshipoffset(horizontalmotion,pitching androlling) 3, Reactiveforcescausedbyoperatingthebitanddownholemudmotor 4Lateralloadsfromseawatercurrentswhoseparametersvarywithdepth 5Dynamicforcesasaresultofdrillshipheave 6Torsionloadsduetodrillbitrotationbythepowerswivel(rotarymachine) Theseloadsdeterminetension,bendingandtorsionstressesthataffectadrillstring whiledrillingoffshorestratigraphicwellsfromadrillship Acombinationofthesestressesproducescombinedstressstatesinvarious sectionsofthestringAtthesametime,staticcomponentsofstressstateanddynamic componentsresultingfromrotationofthestring,shipmovements,andcurrents,leadto unbalancedcyclicloadsThisresultsinaccumulationoffatiguedamage,whichis aggravatedbycorrosionprocessesinseawater StudiesperformedindicatedthatADPisthemostreliableandefficientdrillpipefor deepwaterdrillingconditions Atthesametime,aluminumalloysforADPmusthave highresistancetofatiguefailurefromalternatingbendingstressaswellascorrosion resistanceinseawater In19851990intheUSSR,alargeamountofresearchanddesignworkleadto thedevelopmentandconstructionof“Nauka”(“Science”),ashipfordeepwater stratigraphicwelldrillingUniqueequipmentandtechnologyforoffshorestratigraphic drillingandsurveyingoperationsweredevelopedunderthisprogramDevelopments includednew146mminternalflushADPthatwassuccessfullytestedandiscurrently usedindrillingdeepwaterwellsfromlowtonnagedrillships(“Busentavr”or“Bavenit” type,etc)Table37showsexamplesofadrillstringassemblyfrominternalflushADP asusedon“Nauka” 83 DevelopmentofAluminumDrillPipeinRussia Table37ADPApplicationforScientificOffshoreDrilling DrillStringDesignforProject‘NaukaD/S” DRILLSTRINGASSEMBLY “~MEASUREDDEPTH(M) BHA 100100 ADP168x9 164x924003500 168X1112504750 172x1312506000 SDP168X1113507350 DRILLSTRINGASSEMBLY SECTIONLENGTH(M)MEASUREDDEPTH(M) / BHA100100 ADP164x951505250 168X1113006550 172x1310007550 SDP168X1114008950 DRILLSTRINGASSEMBLYSECTIONLENGTH(M)MEASUREDDEPTH(M)! 100100 45004600 13005900 8506750 15308280 I IDRILLSTRINGASSEMBLYSECTIONLENGTH(M)MEASUREDDEPTH(M) BHA100100 I SDP168x910001100 ADP164x945005600 168X1115007100 172x1312508350 ISDP168X111700 10,500 DRILLSTRINGASSEMBLY SECTIONLENGTH(M)MEASUREDDEPTH(M) BHA100100 SDP168x910001100 ADP 164x9 39005000 168X1115006500 i172x1312507750 Cnn 4/2044 * 7nn aAQl 84 7ADPforVibrationDamping Wavestravelthroughthedrillstringduringdrillingoperationsandaregenerated bylongitudinal,lateral,andtorsionalvibrationofdownholemudmotorsandpulsationof drillingmudDistributionanddampingofvibrationinthedrillstringarebothcomplexin nature,anddependonphysicalandmechanicalpropertiesofthepipematerial,length ofthestring,pipedimensions,geologicalandoperationalparameters,propertiesofthe drillingfluid,typeofbitanddownholemotor,etcBasicparametersdefiningvibration processesinthedrillstringaredifficulttodetermineusinganalyticalmethodsduetothe largenumberoffactorsaffectingtheseprocesses Varioustypesofbottomholebumperassembliesareusedindrillingpracticeto dampvibrationofthedrillbitCommondrawbacksintheirapplicationincludealimited rangeofamplitude/frequencycharacteristicsandlowoperationalreliability Amoreefficientmeansofdampingandcontrollingvibrationprocessesinthedrill bit/drilIstringsystemisdesignedtotakeadvantageofcertainphysicalandmechanical propertiesofdrillpipematerialComparedtosteel,aluminumalloyshaveahigh capacityforabsorbinganddissipatingelasticvibrationalenergyResearchstudies performedbyspecialistsfromtheTyumenIndustrialInstituteindicatedthatalltypesof ADPhaveapproximatelyequalcapacityforabsorbingelasticvibrationalenergyAlso, heavywallADPhasabout50%higherdampingcapacitythanSDPADPwith articulatedjointshasadampingfactor3035?10lowerthanrigidlyconnectedADP Thissuggeststhatvibrationdampingismoreextensiveinthebottomsectionof thedrillstringsetonthebottomthaninthestretchedsectionsofthestring Thus,acontrolledwiderangeofamplitude/frequencycharacteristicscanbe formedbyvaryingposition,length,andotherdimensionalparametersofsectionswithin thedrillstring Inadditiontoreducingvibration,thereisapossibilitytouseelastic vibrationalenergytoincreaseefficiencyofrockcrushingwhiledrilling,ie,tocontrol BHAvibrationlevels ThisconceptwastestedbythecompanySamaraneftwhiledrilling18wells1580 1630mdeeponturbineswithoutSDP75150m(246492ft)longADPswith180x90 mmheavywallswereusedtocreateaxialloadsintheBHAWhiledrillingthesewells anaverageincreaseinpenetrationperbitof24%wasrecordedascomparedtosimilar wellsdrilledwithSDP StudiesconductedbyVNIIBT(AllRussiaScientificandResearchInstituteof DrillingEquipmentandTechnology)showedthatspecialBHAswithADPforseparating vibrationwavesgeneratedatthebottommustbeusedtoincreasedrillingefficiency Reflectionoflongitudinalvibrationwaveswasobservedintheareasoftransitionfrom SDPtoADPThestudieswerepetformedinfieldsoperatedbyTatneft,wherea325 85 1 , , , $“ ,, ,, , +, ,,, , ,: ,~!,z ;,: c ),/ (, , ’ <, , DevelopmentofAluminumDrillPipeinRussia mm(128in)sectionofSDPwasusedwiththeBHASectionlengthwasthreefourths ofalongitudinalvibrationwavelengthgeneratedbythebitonahighspeedturbineat normaldrillingconditionsOthersectionsofthedrillstringwereADPAsaresultof operationofthistypeofBHA,parametersofmechanicaldrillingincreasedby2027% duetoutilizationofenergyreflectedinlongitudinalvibrationwaves StudiesperformedbyspecialistsfromtheOilInstituteinlvanoFrankovskallowed evaluationoftheeffectofthepositionofADPsectionsonamplitude/frequency characteristicsofdrillstringvibrationAccordingtostudyresults,withinthefrequency rangeof46Hz(whichcorrespondsto80120RPMatthebit),adrillstringwithanADP sectionhas1118timeslowerrigiditythanacompleteSDPstringThisallowsan increaseinstringRPMwithoutadditionalriskofdrillpipeorconnectionfailure Moreover,thisfeaturecontributestomoreefficientuseofbitcapacityAnADPsection ofsufficientlengthincludedinthedrillstringassembly(intermsofthedynamiceffect onvibration)isequivalenttoanuppervibrationdampenerItreducesvibration interferenceindrillstringsectionsbelowandabovetheADP,andmakesmechanical drillingmoreefficient TestsandstudiesonwellsinWesternSiberiadeterminedvaluesofahigh frequencycomponentofvibrationcausedbyimpactofbitteethonthebottomholeFor rocksanddrillingparametersinWesternSiberiathisvalueis5080Hz,whereasthe lowfrequencycomponentfrom longitudinalhelicalmovement 140 ofthedrillstringisabout1419 HzThesedatawereusedto 120 calculate the resonance frequencyoftheBHAusedin Western SiberiaThis$’00 frequencyinthedrillbiffdrill~ stringsystemremainedintheg&7 rangeof2060Hz ~ 60 Figure32showsthe: resultsofresonancefrequency : 40 calculationsforBHAswithSDP,g DC,andheavywallADPThe#~0 BHAswithADCSareseento providetherequiredfrequency range [email protected]&~ BHA length,m [ Figure32BHADesignandResonanceFrequency 86 8ADPinExtendedReachDrilling Recentyearshavewitnessedextensiveworldwideactivitydrillingdirectionalwells withextendedreachhorizontalintervals(ERDwells)Thesewellsaredrilledduring explorationanddevelopmentofoilandgasfieldsincontinentalshelfzonesInsome cases,thesetypesofwellscanbedrilledmoreeffectivelyfromanonshoreareausing directionaldrilling Thesamedrillingtechniqueiswidelyusedfordrillinghorizontal intervalsinproductivehorizonstoincreaseoilandgasrecovery BasedondepthandlengthofERDboreholes,threetypesofwellsareusually described(Figure33): TypeI TypeII–shallowwells(TVD=15002000m;49006600ft)withhighlyextended horizontalintervalsThereisonlyalimitedpossibilityofusingstring weighttotransferweighttothebit,whichlimitsthelengthofthese boreholesThislimitationisduetohighlevelofresistance(drag) affectingmovementofthestringinhorizontalintervals mediumdepthdirectionalwells(TVD=30003500m;980011,500ft) withahighangleofdeviation(50600)Themaximumborehole extensionlengthinthistypeofwelldependsprimarilyonmaximum torquecapacityofthedrillstringandrigdrive,whichislimitedbyhigh dragontherotatingdrillstringinthehole TypeIll–deepdirectionalwells(TVD=50006000m;16,40019,700ft)with30 40°deviationfromverticalThemainfactorlimitingboreholeextension lengthinthesewellsisthemaximumtensionloadinthedrillstring whenitispickedupfromthebottomandthefirstfewjointsarepulled outThislimitationisalsoduetohighdragforces ThetableshownwithinFigure33summarizesdesignparametersandmaximum drillstringlengthforthethreetypesofERDwellsforADPandSDPcasesInaddition totheadvantagesofADPcomparedtoSDPenumeratedinthisreport,utilizationof ADPindrillingERDwellswillallowdrillingalongerboreholewithoutincreasinghook loadsordrivecapacityoftherigTypeIwellswillhavea15%longerborehole,TypeII 59f0longer,andType[1150?40longer 87 DevelopmentofAluminumDrillPipeinRussia o 1500 30004500600075009000m z SJAI m ~ o1 0“ >t z5 n ‘A[ + E o 0 0 m1 Tednieal characteristics ODPipe wallthickness Unitweightinair Muddensity Unitweightinmud Maximaldrillstring lengthbysafetyfactor 1,6 *400mofStD\ \ \ \ \ \ \ TypeIlimitationonstringweightbyslidingdrilling TypeIIlimitationontorquebyrotarydrilling TypeHI–limitationonDPstressbyoverpulling \ \ \= x!x:dw$?%(l))~cl \ —ProductionLiner \ I \ i \ \ “,A[ ERD,Holetypes Mes TypeI(Shallow)TypeII(Intermediate)meHIpeep) stDPI /@p* stDPADPstDP ADP mm140168/140168168140168/140 t I 111, J (168x1O)areusedinupperpartofdrillstring Figure33ComparisonofSteelandAluminum DPforERDApplications 88 9ADPinDeepwaterRiserlessDrilling Deepwaterdrillingwithoutariserpipeismostoftenconductedfromlowcapacity drillshipsforpurposesofexplorationorscientificstudyofoceaniccrustThemain advantageofADPintheseapplications(ascomparedtoSDP)isthepossibilityto essentiallyincreasewaterdepthwhileusingthesamelowcapacitydrillshipsFor example,whiledrillinggeotechnicalwellsfrom“Busentaur”and“Bavenit”typedrilling shipsusingSDP,maximumwaterdepthislimitedtoabout500mBycomparison,the experienceoftheAQUATICCompanywithdrillingfromthesameshipsshowspotential fordrillingin1500m(4920ft)waterdepths Deepwaterriserlessdrillingiscomplicatedprimarilybyhighvelocitycurrents(over 1m/see;33ftkec)resultingin: Vortexinducedlateralvibrationofthedrillstringinacurrenthomogeneous overthewholedepth Significantincreaseindragcoefficientforavibratingdrillstring(upto24 28)Foranonvibratingdrillstringthiscoefficientis1213 Uncontrolledoffsetofthedrillingvesselasaresultofhighvelocitycurrent andwindspeed Thesenegativefactorsleadtosignificantbendingofthedrillstringaxis,which resultsinhighbendingstressesandfrequentfailuresofthedrillstringwhiledrilling, tripping,makingaconnection,etc Thesedisadvantageswerepartiallyeliminatedwhiledrillingfromthe“Bavenit” drillingvesselintheStraitofGibraltarwithupto2m/see(66ft/see)currentvelocities Aropewascoiledaroundthedrillpipesaccordingtoaspecifiedpatterntoeliminate vibrationcausedbytrailingvotilcesinthecurrent Thisenabledrandomizingwave generationanddevelopmentofwakevortices,andslightlyreducedtheleveloflateral vibration Toreducethelevelofbendingstressinthedrillstringincontactwiththedrillship moonpool,abumperframewasinstalledinthelatter Introductionofanadditional pointofsupportintheupperpartofadrillstringallowedmoreevendistributionof bendingstressesbetweenthepowerswivel,spider,andbumperframe A specialcomputerprogram (BURNPAS)wasdevelopedtocontrolstress/strain stateofthedrillstringwhilethevesselismovedbycurrentsinrapidlychanging hydrologicconditions Thisallowedcalculatingadequatedisplacementofthevessel aroundthewell,andmaintainingasafeloadfactorforthedrillstringwithinrequired limits 89 ,, ,, , ,, ,, , ,, , ,, , ,, ‘t:, ,, :’,, , ‘,’,, ,+, (,!J, S ,,,,~ ,‘ >A%’ ,, r:I ,,,, , h, DevelopmentofAluminumDrillPipeinRussia FurtherresearchandstudiesbytheAQUATICCompanywereaimedat developingtechnologyfordeepwaterriserlessdrillinginhighvelocitycurrentsThe studieswereperformedundervariouscontractsandresultedindevelopmentof technicalsolutions,including: 1 2 3 4 withInstallingfairingsonthedrillstring,whichcompletelyeliminatesvortex inducedvibrationandreducesthedragcoefficientonthedrillpipeto0305 Asaresultoftheanalysisofhydrofoilprofiles,afairingdesignwith2224 elongationwasrecommendedThedesignincludesstabilizersinstalledon thefairingtailsat45° Shapingtheseabedframechannel,whichformedanadditionalpointof supportandallowedmoreevendistributionofbendingstressesbetweenthe wellheadandframe Intentionaloffsetandmaintenanceofvesselpositiontoefficientlydistribute bendingstressesbetweenthe upper(swivel/spider/bumperframe)andthe lower(wellhead/seabedframe)pointsofthedrillstring Thegeneral objectiveofvesseldisplacementistoequalizesafeloadfactorsintheupper andthelowerpointsofthedrillstringThisisachievedbydisplacingthe vesselforadistanceofupto710%ofthewaterdepthinadirectionopposite thedominatingcurrent Developmentofaspecialcomputerprogramforanalyzingstressandstrain stateofthedrillstringtoassistoffshoredrillinginhighvelocitycurrentsThis includedupgradingtheoriginalBURNPASsoftwareThelatestversions BURN9andBURN10allowcalculatingdrillstringdesignfordrilling,tripping, andwellspuddingoperationsTheprogramassistsinselectingoptimum(for maximumsafeloadfactor)displacementofavesselaboutawellfora specifiedpatternofcurrentdistributionwithdepthTheprogramisalsoused forcalculatingoptimumparametersofabumperframe(diameterofopening anddistancetothespider)andaseabedframe(heightandconicity)BURN 10softwarewasusedtosubstantiatethepossibilityofdrillingwithADPin 1920m(6300ft)ofwaterwestoftheHebridesinahighvelocitylinear current(13m/see(43ftlsec)atthesurface,05m/see(16ft/see)atthe seafloor) Theresearchworkandstudiesdemonstratedthepossibilityofriserlessdrilling thistypeofhighvelocitycurrentwithadrillstringsafeloadfactorofatleast15, providedfairingelementsareinstalledonthedrillstring(exceptforthelower150m) Thedragcoefficientoffairingelementsisabout04Thebumperframehasa09m openingandisinstalled7mfromthespiderThevesselispurposelydisplacedfrom thewellby150m(492ft)(77Y0ofwaterdepth)againstthecurrent 90 DevelopmentofAluminumDrillPipeinRussia Thelatestsoftware(DBUR)usescontinuousinformationfromcurrentvelocity sensors,andallowscalculatingandvisualizingonthecomputerdisplayareasofvessel displacementfromthewellduetodrillstringbendingwhiledrilling 91 ,, ,,, ,, , ,, , , ,, ,, ,,,r — DevelopmentofAluminumDrillPipeinRussia 92 10EconomicBenefitsofADP Technicalandeconomicparametersrelatedtodrillingdependontheweightofthe drillstringForthesamehookloadcapacityoftherig,cumulativetriptimeoveracomplete drillingoperationisdirectlyproportionaltopowerconsumptionfortheseoperationsAtthe sametime,powerconsumptiondependsonweightdistributionbetweensectionsofthedrill stringaswellastotalweight Drillstringweightisafunctionofdensityofthedrillpipematerial,itsdimensions,and welldepthSinceadrillstringoperatesinawellnormallyfilledwithdrillingmud,buoyancy forcesimpactoperationsbyreducingtheweightofthedrillstringThefollowingcoefficient isusedtocalculatethisweightreduction: K= (Pm ‘PI)/P~ (lo1) wherepmandp,aredensitiesofthepipematerialandmud Figure34showscorrelationsbetweenbuoyancyfactor(weightreductioncoefficient) ofdrillpipesfromaluminumalloys(line1),titanium(line2),andsteel(line3)andmud densityBuoyancyfactorforADPin12g/cm3mudis057,whereasforSDPinthesame mudbuoyancyfactoris085Thismeansthat reducedtoalmosthalfitsweightinair,as comparedtoasteelstring,whichis‘only 15%lighter Anumberofspecialfieldtestswere performedtoevaluatetangibletechnical andeconomicadvantagesofADPThe testsdeterminedmoreexactvaluesfor decreasesintimethatmightbeexpected forcertaintrippingoperationsafter replacingSDPwithADPSimilardrilling rigsoperatedbySamaraneftwithsimilar mechanicalequipmentwereusedforthe tests Table38showsasummaryof thesetestsanaluminumstringin12g/cm3mudis Ut ~z~lo ~z~q~~ Z(!720 EquivalentCirculatingDensity(g/m3) Figure34BuoyancyFactorsfor ADP,TDPandSDP Y3 , ‘, , , ! _ y ~,, J,, ,,,i,,,,,,,,,<,,, ,;?,A, ,,/ , ,’$ , , ,’ ,, DevelopmentofAluminumDrillPipeinRussia Table38TripTime(see)forADPandSDPDrillStrings SDPADP REEVING ALINEREEVINGALINE(3x4)AVERAGE ATIME MODEOFOPERATION(5x6)WITH HOLEHOLEHOLEHOLEHOLE SDPADP ADP 51189181 185190 PullingOutofHole 2ndspeed10896726596891089673 416 3rdspeed657433428429657430 227 4tispeed497455298281288457289 168 Landdrillpipeat3622 3029282929 0 slips Unloadelevator,358297194 210217327207127 lowerandbreakout pipestand Removepipestand5359766061566610 fromtackleblock Total+1108 RunninginHole Pulloutofunload307304223266242305244 61 elevator Releasefromslips1415 111413 01 Runin248207159191193227181 46 Landonelevator523724 27324541 04 Insertstandintackle65475756655759 02 block Totalil1() UtilizationofADPleadstoasignificantlylowerpowerconsumptionfortripping operations Figure35presentstypicaldrawworkspowerconsumptioncurvesperdrillpipestand atvariousspeedsforthesamedrawworkspullingoutSDPandADPstringsThearea enclosedbythedrivepowercurveshowspowerconsumptionforpullingoutonejointofan ADPstringTheaveragepowerareaforADPisalmosthalfthatforSDP Figure35alsoshowsthatADPstringswerepulledoutfasterAnalysisoftechnical andeconomicparametersfordrillinginfieldswithsimilarconditionsandwiththesame typeofdrillingequipmentindicatesthatADP(insteadofSDP)reducestriptimebyabout 1835Y0 Also,aconsiderabledropinpowerconsumptionfortheseoperationswas observed 94 DevelopmentofAluminumDrillPipeinRussia Liftingof1! I1: I1! vacant i i i! elevator [ Figure35PowerConsumedforPullingADPandSDP ThereisnodoubtthatutilizationofADPwhiledrillingsavesmaterialresourcesand time,inlightofthefactthatconsumptionoffuelandlubricants,drillingline,brakeshoes, andsparesforrigliftingequipmentisproportionaltopowerconsumption HydraulicresistanceofADPisalso1525%lowerthanofSDPduetospecific characteristicsoftheADPsurfaceThisleadstolowerhydrauliclossesandhigherdrilling efficiency ThetechnologicalandeconomicadvantagesofADPdescribedinthissectioncanbe supplementedwithcomparativetechnicalparametersforastandardrangeofADP manufacturedbytheReynoldscompanyandSDPofAPIcategoryEstrengthTable39 presentsdataforADPfrom2024T6alloywhichissimilartotheRussianDI6Talloyin compositionandmechanicalproperties Table39showsthatADPfromthisalloy outperformscategoryEstrengthSDPofsimilarsize 95 —,— , ,, ,, : ,,’,,,~,,~,,,,,,,f Table39ComparisonofReynoldsAluminumDrillPipe(ADP)andGradeESteelDrillPipe(SDP) PIPEDIAMETER(MM)g DRILLPiPEPROPERTIES 7389102 114127140‘$ ADP SDPADPSDPADPSDPADPSDPADPSDPADPSDPs OD(mm)85173094089,010671016116811431308127014431397,3 ID(mm)5465466807028338489149721041108611881214!l ~ Wallthickness(mm)15292130941178412,7861339212792q ODtoolioint(mm)10481048120712071461146115561556‘1778177817831783~ Unit~ipeweiqhtwith toolioint(ka/m)s t Inair110163117207 144232160266205318215s 348~ ~ [nmudfl2dcm36713872175 90d96103225 132269139295 I Inmud17dcm351127551627118279209 1042501092743 Loadcapacitv(kN)c1 Y Allowabletensionlimit12669731348123314231296169614982006179621381985~ Ultimateload156613521725170318111798215720792552249727282747~ Torsionlimitfor215159286266339338 475446 64459176872,7~ stress=~, 02 (kNm)3 Colla~selimit(MPa)996911849778690626689573653556 56,8489 g Burstlimit for13061563130513068451024839929786698679815 g, n) 11Conclusions 1 2 3 4 5 *AlargevolumeofscientificR&DperformedinRussiaresultedinthedevelopment, manufactureandwideutilizationofaluminumdrillpipe(ADP)Thesepipesare currentlyusedinmostdrillingoperationsforoilandgaswellsinRussiaTheyare alsousedindrillingdirectionalwells,offshorewells,andallultradeepwells ThetechnologicalandeconomicbenefitsofapplyingADPwereinstrumentalin expandingthesphereofADPusageinexploratorydrillingItisnowusedas tubing,inwellworkoversanddownholerepairs,forinfieldserviceanddistribution lines,etcWorkhasalsobeeninitiatedforevaluatingthepotentialforaluminum alloysforrisersfordeepwaterdrillingandcasing ThegreatestbenefitsofADPareobservedinwellsover3000m(9843ft)TMD Thedeeperthewellis,thehigherthepercentageoftimespenttrippingtoreplace wornbitsetc,ratherthanactualdrillingAtthesametime,resolvingdrilling problemsandfishingoperationsbecomemorecomplicatedUsingADPinsteadof SDP(steeldrillpipe)undertheseconditionsyieldsimprovedresults Drillingoffshoreexploratoryanddevelopmentwellsonthecontinentalshelf involvesanumberofuniquetechnicalproblemsInsomecases,thesewellscan bedrilledmoreeticientlyfromanonshoreareausingdirectionaldrillingADPwith highresistancetoalternatingbendingstressandcorrosionshowsgood performanceandenablesdrillingERDwellswithlongerextendedreachintervals Drillstringweightis directlyproportional towelldepth,which oftenrequiresusing rigswithhigherhook loadcapacityand,so itmayseem,pipes withhigherstrength However,highspeci ficstrength(ie,ratio ofmaterialstrength tospecificweight)is moreimportantThis suggeststhatADPs aremostefficientin thiscase I Figure 36 AluminumDrillPipe I 97 ,, 6 The DevelopmentofAluminumDrillPipeinRussia Lower,nothigher,rigidityofthedrillstringisrequiredwhiledrillingdirectional, horizontal,andhighlydeviatedwellsWithoutchangingpipedimensions,lower rigiditycanbeachievedonlybyusingpipematerialswithlowerelasticitymoduli Thiswillleadtoaproportionaldecreaseinbendingstressandnormalforcethat pressesthedrillstringagainsttheboreholeAsaconsequence,torqueanddrag arealsoreducedADPhassignificantlylowerelasticitymodulusthanSDP,which makesADPevenmoreefficient experienceofRussianengineersandscientistsindesigning,manufacturing,and usingADPinavarietyofdrillingconditions,alongwithstudiesperformedforevaluating operationalreliabilityandprospectsforapplication,clearlydemonstratethetremendous potentialofADPItishopedthatthesignificantbenefitsenjoyedhistoricallyinRussia’s drillingindustrywithADPmightbesharedbythedrillingcommunityworldwide 98 12References 1Akgun,F,Maidla,E,Basovich,V,andGelfgat,M,1998:“WhyNotUseAluminum inDrilling?”lADC/SPE47823,presentedatAsiaPacificDrillingConferenceheldin Jakarta,Indonesia,September79 2Basovich,V,Gelfgat,M,Akgun,FandMaidla,E,1998:“AluminumApplicationin Drillingj”SPE49957,presentedatAsiaPacificOilandGasConferenceand ExhibitionheldinPerth,Australia,October1214 3Fine,G,Basovich,V,Pisarnitsky,A,Jemetz,B,Mazurova,L,Gelfgat,M,1995: “AluminiumAlloysforOffshoreDrillingSystems,”OMAE95482,Copenhagen 4Fine,G,Shtamburg,V,Daneiiants,S,1990:“OilFieldLightAlloyDrillpipes,” Publishedby“Nedra”,Moscow,222pp 5Gelfgat,M,Basovich,V,1999:“AluminumTubularinDeepWaterDrilling Application,”presentedattheETCE’9975tiEnergyTechnologyConferenceand Exhibition,Houston,Texas,February 6Gelfgat,M,Podrazhansky,A,Geise,J,andPaff,G,1997:“StratigraphyDrillingin DeepWaterwithAluminumDrillPipeApplication,”SPE37597 7“KolaUltradeepScientificResultsandResearchExperience,”Publishedby “Technoneftegaz,”Moscow,1998,260pp 99 ,,/, ‘,, , , , ,, ,J,<’,,, <, , ,~,:~:,ti% + c>, ~1 ,, ,: = , ,, ,, DevelopmentofAluminumDrillPipeinRussia 1oo IMPLEMENTRUSSIANALUMINUMDRILLPIPEAND RETRACTABLEDRILLINGBITSINTOTHEUSA Volume11:DevelopmentofRetractable DrillBitsinRussia FinalReport TR9924 Preparedfor: MrWilliamJGwilliam FederalEnergyTechnologyCenter USDEPARTMENTOFENERGY Morgantown,WestVirginia PerFormedUnderContractNoDEFG2698FT40128 By: AquaticCompany Moscow,Russia and MaurerEngineeringInc 2916WestTCJester Houston,Texas77018 August1999 ,! (k ‘x ,, , ‘,, , ,, ,, ——,,, J~,,,,;% ~zT7TT%,, ,:J:, ,,!,$, ,&>;:::> %;,3, >; $ ,4J,,,_,}, 2q~ ,——_, Acknowledgements ThisreportsummarizingthedevelopmentofretractablebittechnologyinRussia waspreparedfortheFederalEnergyTechnologyCenterunderDOEGrantNoDE FG2698FT40128TheassistanceoftheDOEProjectDirector,MrWilliamJGwilliam, isgratefullyacknowledged AquaticCompanypersonnel:DrMichaelGeifgat(ManagerofRussianTeam); MrRudolfSAlikin(ChiefDesigner);DrYakovAGelfgat(Consultant);MrDavid1 Indrupskiy(Consultant);MsValentinaKholostova(Engineer);MsElmiraMPogosyan (Assistant);andMrBorisVolkovoy(Interpreter) MaurerEngineeringpersonnel:DrWilliamCMaurer(ProjectManager)andMr GregDeskins(ProjectEngineer) Ill ,, , ‘,, ,, , , ,, ,, , ,’ !,”, ,, ,, — , ,, , ,,rm~ rr r” —— — DevelopmentofRetractableDrillBitsinRussia iv TableofContents ListofFiguresvii ListofTablesix ExecutiveSummaryxi 1 2 3 4 5INTRODUCTION1 HISTORICALREVIEW=mmmm3 21DevelopmentsOutsideRussia3 22DevelopmentsintheUSSR5 23RecentDevelopmentsinRussia 8 DESIGNOFRBs11 31GeneralRequirementsandClassification 11 32RBComponents12 33RetractingMechanism l4 34RBOperation l8 35ReviewofRussianPatentsl8 RBMANUFACTURINGTECHNOLOGY 25 41 42 43 44 45ManufacturingRBBitLegsandCones25 ManufacturingTechnologyforThreeConeAssemblies29 ManufacturingRetractingMechanismsforRBsandReamers31 ManufacturingDefectsandTheirImpact 32 DesignsofCommercialRBs 34 BitsUsedwithDHMs 34 RBsforRotaryDril/ingDesignedbyM/NHGP37 DRILLINGWITHRBs 39 51DrillString 39 52DrillingOperations 4o 53TrippingOperations41 54CoringOperations43 55FishingOperations43 v ,, ,, , , — DevelopmentofRetractableDrillBitsinRussia 6RBTESTSANDFIELDAPPLICATIONS45 61FirstTestIntervalsDrilledwith12inRB(19481956)45 62TestBoreholesDrilledwith10inRB(19571964)49 63OilFieldTestingandCommercialDrilling(19651971)54 64FieldTestsofDrillingwithCasing57 65ScientificDrillingExpedience58 66OffshoreStratigraphicDrilling65 67BenchTestsforODP66 68DemonstrationofRBatMaurerEngineeringInc72 7 UNDERREAMERS75 71 introduction75 72FieldofApplication75 73DesignsofExpandableUnderreamers76 74RRBUnderreamerApplications83 RRBOperationsbyGrozneilDrillingandProductionCompany83 RRBOperationsbyPrikaspiiburneftDrillingCompany87 RRBOperationsbyAzneftDrillingandProductionCompany91 SummaryofRRBOperations9f 8APPLICATIONSFORRBTECHNOLOGY93 9BIBLIOGRAPHY95 vi Figure1 Figure2 Figure3 Figure4 Figure5 Figure6 Figure7 Figure8 Figure9 Figure10 Figure11 Figure12 Figure13 Figure14 Figure15 Figure16 Figure17 Figure18 Figure19 Figure20 Figure21 Figure22 Figure23 Figure24 Figure25 Figure26 Figure27 Figure28 Figure29 Figure30 Figure31 Figure32 Figure33 Figure34 Figure35 Figure36DevelopmentofRetractableDrillBitsinRussia ListofFigures RetractableBit 1 ThreeConeHarleyRB 3 FourConeWalkerRB 3 SyulRetractableReamerwithPilotBit 4 TwoConeBitwithMonolithicHead(BDType) 6 TwoPistonRBD2PVIO 6 TwoConeRBDRB 7 ThreeConeBodylessRB(Type3DR) 7 RetractingMechanism l3 Cone/BitAssemblyDRB248S 25 PrimayControlDevice 28 SecondaryControlDevice 28 MachiningSequenceforShortLeg 3o ControlDeviceforThreeConeAssemblies 31 RBforRotaryDtiliing37 RBDVR6I51 38 SteelPipewithWeldedToolJoints 39 AluminumDrillPipe 39 BHAwithRBandDownholeMotor 4o DroppingRBDownHole 41 PullingOutRetrievableTool 42 PullingRetrievableToolbyReverseCirculation 43 SteppedBit(1948) 45 TurbodrillSealAssembly 45 RetractableToolswithPilotReamers 46 RBBD312 47 CasingwithSpecialToolJoints 48 RBAssembly 49 PerforatedPupJoint 5o RBRunsperDay 51 FourConeRB4DV295 57 RB4DV295ConeAssembly 57 RetractingMechanism3DR220 58 RBConeAssembly3DR217K 59 AdvancedRetractingMechanism3DR220 62 PhysicalandMechanicalPropertiesofRocksversusDrillBitTypes65 ,, , ,, ,”,, , <, ,,,4 : ,, , ,, <,T” , ——= vii DevelopmentofRetractableDrillBitsinRussia Figure37TRB300OperationalSchematic67 Figure38TriconeRBTRB3007l Figure39RBTRB300ConeAssemblies7l Figure40RBinTestStandforDemonstrationinHouston72 Figure41RBDrillingTestsinHouston73 Figure42TypeRRARetrievableUnderreamer77 Figure43TypeRRBRetrievableUnderreamer77 Figure44TypeRRVRetrievableUnderreamer78 Figure45TypicalCasingProgramforReamingOperation79 Figure46TypeRRB215Underreamer8l Figure47PartialCaliperLogfromWellno20atTengiz89 Figure48RetractableBitAssembly93 VIII DevelopmentofRetractableDrillBitsinRussia ListofTables Table1TypicalRBProblemsandEffectsonOperation 33 Table2StandardDesignsandSizesofRBs 34 Table3ConeAssembliesofRBs 35 Table4 RBRetractingMechanisms 36 Table5NumberofExtraTripsper100BitRunsDuetoFailureofRBs52 Table6ComparisonofRB(Well19)andConventionalTricone(Well20)52 Table7ComparisonofRB(Well3)andConventionalTriconeBit(Well1)in DvoyenskayaField 53 Table8ComparisonofConventionalandRBsinKvasnikovskaiaField54 Table9AveragePenetrationperRBRun 55 Table10ComparisonofRBstoBestConventionalBits 56 Table11BitPerformanceinPodolskoKashirkyHorizon 56 Table12RBTestsinSputnikSD3(197475) 59 Table13RBTestsinSputnikSD3(197778) 6l Table14Resultswith3DR217KRBinSputnikSD3 62 Table15BitPerformanceinHardQuartzite(KrivoyRogSD8) 63 Table16ResultswithRB3DR217KinKrivoyRogSD8 63 Table17Resultswith3DR317KinOffshoreScientificDrilling(1991)64 Table18Resultswith3DR317KinOffshoreStratigraphicDrilling(1993)66 Table19DimensionsofRRBUnderreamers 8O Table20RRBUnderreamerApplicationRecommendations 80 Table21OperatingParametersforRRBUnderreamers 83 Table22PerformanceofRRB295/345UnderreamersinOctyabrskayano23885 Table23PerformanceofRRB243/285UnderreamersinVariousWells86 Table24PerformanceofRRB295/345inTengizno20 88 Table25PerformanceofRRB215/255SinTengizWells 90 Table26PerformanceofRRB215/255SinTengizno113 90 ix , , ,,, ,, , , ,: ,: >7!,, ~>,~ 7 ;!,,,,~<<><,,,,~,,<,,,,,<,,;,>,,:, ! >, :yn,$,~$ f,~J, ——— DevelopmentofRetractableDrillBitsinRussia x ExecutiveSummary Thisreportdescribesthedevelopmentof RetractableBits(RBs)fordrillingwithouttheneedtotrip thedrillstringthathasbeenongoinginRussiaduring thepast50years,includingthelatestresearchandfield applicationsinoffshorestratigraphicdrillingprojects Thepotentialtodrillwithfewertripsofthedrillstring significantlyaffectstheprocessofboreholeconstruc tion,sidetracking,aswellasworkoversOtherbenefits ofRBsinclude: 1Continuouscirculationoftheboreholeduring theRBoperationalcycle(runin/drill/puHout) 2Toolsforavarietyofoperations(eg,drilling, coring,milling)canberuninturnwithout pullingthedrillstring 3,Theabilitytologtheboreholewithoutpulling thedrillstring 4Reductionofrigcrewworkloads Background Methodstodrillwithoutpullingthedrillstringwere firstdevelopedandappliedatthebeginningofthe20th centuryDrillingsystemsconsistingofRBsand downhoiemotorswereproposedin1902Great interestinRBswasdisplayedintheUSA,wherethefirst designsofrockconeRBswerepatentedbeforeWorld WarII ThefirstRussianfieldexperimentsonturbodriliing withRBstookplaceintheearly1930sMajoreffortson drillingwithRBswereinitiatedin1948bytwogroupsof engineersandscientistsOnegroupworkedon turbodrilling/downholemotorswithRBs;theother developedrotaryRBsSignificantfieldexperiencehas sincebeenaccumulatedwithbothsystems xi RBinRunningPosition + h! FishingNeck r ToqueandWOB Latch(Retracted) Downhole Motor L~DrillPipeorCasing Expandable Mechanism (Retracted) ~RetractedBii RBinDrillingPosition kosing ToqueandWOB ~ReactionLatch Downhole Motor ‘,’ Shaft , llil Expandable Mechanism All’ RadialBearing ~ ~RetractableBit DevelopmentofRetractableDrillBitsinRussia FieldExperience DrillingorrockdestructionwithRBsissimilartoconventionalturbinedrilling,and isaffectedbyacombinationofbasictechnicalparameters:WOB,mudcirculationrate, andturbine~motorRPMRPMdependsonWOB,mud circulatingrate,rockphysicalproperties,andbittype Originally,directdrivehydraulicturbineswithoperating speedsof500600RPMwereusedwithRBsBecauseof thehighspeeds,durabilityofbitbearingswasverylow Later,lowRPMdownholemotors(DHMs)wereappliedFor example,agearreducerturbineandscrewDHMat120200 RPMweredevelopedtoworkwith220mm(87in)RBs ActualWOBfora220mmbitwasbelow12tonnes(26,460 lb)at7080MPa(10001160psi)pressuredropina retractabletool From1965to1971,26exploratoryanddevelopment boreholes25003000m(82009800ft)deepweredrilled duringtheprocessofcommercialtestingattheExperimental TurbodrillingDepartmentofPOSaratovneftegas(Production Amalgamation)ThetotalfootagedrilledbyRBswasnearly 41,000m(134,500ft)Mostfootagewasdrilledundervery complicatedgeologicalconditionsgasandwatershows, unstableformations,cavingtendencies,etc ConclusionsrelatedtodrillingatPOSaratovneftegas include: 1 Inareaswherehighdurabilityrockbitsareusedfor standarddrillingatlowRPM,drillingwithRBswith increasedRPMholdspromise 2Comparedtohighperformance,lowRPMrotarydrilling, RBswithDHMsareverycompetitiveundercertain geologicalandtechnicalconditions 3 Astechnologicalimprovementsresultinincreasesin footageperbitruninstandarddrilling,theefficiencyof drillingwithretractablesystemswilldependontherate ofpenetrationincreasewithRBsandanydecreasein footageperbitduetoshorterRBlife xii DevelopmentofRetractableDrillBitsinRussia ItwasalsoconcludedthattherearespecificapplicationsforRBtechnologythat canbehighlyefficientirrespectiveofRBdrillingperformance: l Drillinguniqueultradeepwells l Drillingextendedreachdirectionalboreholeswithcomplicatedprofiles withhighanglesofinclinationincludinghorizontal l Drillingwithcasingandleavingitintheboreholeasasurfaceor intermediatecasingstring Underbalanceddrilling AnotherresultofcommercialtestingofRBswasthedevelopmentofasimilar methodforcoringinhardcrystallinerocksTheadvancedcontinuouscoringsystem wasdesignedforultradeepboreholeapplicationsaspartofanationalprogram “InvestigationoftheEarth’sCrustandUltraDeepDrilling”Thecalculationsshowed that,whendrillingbelow7000m(22,970ft)(correspondingtothesecondstageofthe KolaSD3ultradeepborehole),thismethodwouldbesubstantiallymoreeffectivethan alternativesystems ThreeconeRBswererecentlyusedinthestratigraphicdrillingprojectofIKU PetroleumResearch(Norway)in1993ThiswasthefirstfieldtestoftheComplete CoringSystemindeepwaterenvironmentsWaterdepthwasabout1500m(4921ft), andwelldepthintherangeof150200mTotalfootageforreaminginintervals composedofconsolidatedsandstonewas363m(119ft)inthreerunswithanaverage penetrationrateof27m/hr(89ft/hr)Whilespuddingthetestborehole,theRBdrilled 102m(33ft)inclaywithanaveragepenetrationrateof136m/hr(45ft/hr)RBswith DHMswereconsideredasthebestmethodtospudboreholeswithoutaseabedframe toguidetheBHAifsoftsedimentswerenotoverlyinghardrocks Additionalfieldexperienceisdescribedindetailinthebodyofthisreport CommercialRBSystems AcompleteBHAfordrillingwithoutpullingthedrillstringincludestheRB,aDHM (eg,aturbodrillwithalandingunit),andatorqueandWOBreactionmechanismwitha fishingneckontopTableESIpresentsstandarddesignsandsizesofretractabledrill bits XIII DevelopmentofRetractableDrillBitsinRussia TableESIStandardDesignsandSizesofRBs BIT ~IDOFIDMARKINGOFDRILLBITS~~ SIZEEXPANDING SOFTMEDIUMTOHARDHARDDRILLINGTRANSPORT MECHANISM ROCKROCKROCKPOSITION POSITION TwoDRBI9’DRB29”S220134 conebitDRB2220DRB29’SZ Three3DR2203DR217S3DR217K217134 #9 conebit3DR220S3DR220134 3DR220SZ2170K ReamerRVAI217RVA1217134 w/pilot217020 DRB3IoDRB3DRB3IO”SDRB3 248154 Two10“MDRB3IO“ST10“T conebitDRB248DRB248S(020)248154 #1oDRB248SZ(030)DRB DRB248ST(040) 248T(070) Three3DRI2483DR248S3DR248T248154 conebitM3DR22483DR248SZ 3DR248ST #12Four4DV4DV295020295203 conebit295010 RetractableUnderreamers BasedonbroadexperienceinRBresearch,developmentandfieldapplication,‘ relatedtechnologiesforunderreamingwerealsodevelopedWelldesignsbasedon Z275 —i Operating Transport minimalclearances betweencasing/linersbecame commonpracticeComplicatedgeologicalconditions requiredthatfiveorsixcasingstringsberunwithatotal welldepthofabout6000m(19,690ft)Underreamer applicationsimprovedthequalityofwellconstructionand producedlargesavingsbecauseoflowerdrillingmudand casingvolumes,highratesofpenetrationandrelatively lowrequirementsfordrillingrigcapacityMorethan 100,000m(328,000ft)ofintervalswereunderreamedin 1970s1980sInthe1980s,thecostimpactinvarious regionswas820rubles/meterreamed Thehighestefficiencyisachievedbyintegrating expandableunderreamersinthewellforreamingintervals forseveralcasingstringsThebestperformanceisfor reamingintervalswithsoftformations;penetrationrate whilereamingintervalsinsoftformationsis410times higherthanpenetrationratewhiledrilling RetractableUnderreamer xiv DevelopmentofRetractableDrillBitsinRussia Penetrationrateforreamingintervalsinhardformationsishigher(1525times) thanpenetrationratewhiledrillingthepilothole ApplicationsforRBSystems BasedonfieldexperienceinRussiaandtheformerSovietUnion,avarietyof drillingapplicationsderivesignificantbenefitsfromtheapplicationofRBtechnology Themostpromisingapplicationsare: 1DrillingwithCasing–thisismostpromisingtrendforthesecosteffective technologiesforthenextcentury 2UltralongBoreholes–RBscouldprovidesignificantreductionsintriptime, andallowbetterwellcontrolandboreholestabilityin10to15km(33,000to 49,000ft)wells 3ScientificDrilling–RBsprovideuniqueopportunitiesforcontinuouscoring andloggingoperationsinalltypesofgeologicalconditions,bothonshore andoffshore 4GeothermalDrilling–drillingwithRBsallowscosteffectivedeepgeother maldrillinginhardcrystalline,hotformations xv ,, ,,, ,, ,, ‘ $: “ , ,’ ,, , ,, ,, ,,, , ,~,, !! ,*, ,0% + ,,’ ,, DevelopmentofRetractableDrillBitsinRussia xvi 1Introduction Subsequentwiththehistoricaldevelopmentofrotarydrillingtechnologiesand increasingboreholedepths,engineersdevelopedconceptstodecreasedrillstringtrip timestochangewornbitsDevelopmentofabitthatcouldberundownandpulledout ofthewellinsidethecasingordrillpipebywirelineorbycirculatingthedrillingmud, wasseenasasolutionwithgreatpromise Themainfeatureofthistypeofbitwouldbethe abilitytoadopttwodifferentconfigurations:1)an operatingpositionfordrillingformationatthebottomof theholeand2)atransportconfigurationformoving throughthedrillstringThistypeoftechnologyis referredtoasaRetractableBit(RB)(Figure1)These toolsprovidethepotentialtodrillwithoutpullingpipe, whichsignificantlyaffectstheprocessofborehoie constructionoroneofitsintervalsOtherbenefitsof RBsinclude: 1Continuouscirculationoftheboreholeduring theRBoperationalcycle:runningin/drilling/ pullingout 2Changetoadifferentpurposetool(eg,drill ing,coring,milling)withoutpullingdrillpipe 3 Loggingwithoutpullingpipe 4Reductionofdrillingrigcrewworkload Atthesametime,thetraditionalmethodofbit rotationbythedrillstringand/ordownholemotor(DHM) ismaintainedNotsurprisingly,theadvantages , ’1 Figure1RetractableBit achievedwithRBsrequireadditionalinvestment[nadditiontoamorecomplicatedbit, specialorinternalflushjointdrillpipeswithlargerdiameter(ascomparedtostandard drillpipe)shouldbeusedActually,thisrequirementintroducesanewapplicationofRB technologywithsignificantpotential–runningcasingsimultaneouswithdrilling(“casing whiledrilling”)Unfortunately,thequalityofstandardcasingpipesandparticularlytypes ofthreadconnectionsdidnotallowusingthemfordrillingwithoutpullingpipe, especiallyinhardformationsNevertheless,thisareaofRBapplicationcouldbeoneof themajortasksforfutureresearch,becauseitcouldbringrevolutionarychangestothe entiredrillingprocess 1 —— ,,,,’ >1 %< , 1~~,, ,,,, f s, <,, =, ,, ‘,:,> ,< 7—— DevelopmentofRetractableDrillBitsinRussia ThisreportdescribesthedevelopmentofRBdesignsfordrillingwithDHMs withoutpullingpipeinRussiaduringthepast50years,includingthelatestresearch andfieldapplicationsinoffshorestratigraphicdrillingprojectsThisallowsestimating, withdueregardforcurrentmechanicalengineeringachievements,thepotentialfor usingR13andrelatedtechnologiesinmoderndrillingprojectsBesidesdrillingwith casing,theseincluderiserlessdrilling,geothermaldrilling,andoffshorescientific drilling , 2 2HistoricalReview 21DevelopmentsOutsideRussia Thefirstprojectsincorporatingmethodsofdrilling withoutpullingpipeoccurredatthebeginningof20th centuryDrillingmethodsincludingRBsandDHMswere proposedin1902AttemptsweremadeallerWorldWarI withthismethodinPoland,andalittlelaterinFrance (1928)Overthesameperiod(1920s1930s),great interestinRBswasdisplayedintheUSABitdesignswith retractablebladesperformedworsethanstandardtwo bladedragdrillbits(“fishtail”bits)Inthe1930s,three conerockbitswereintroducedandbecametheprincipal typeofrockdestructiontoolThefirstdesignsofrockcone RBswerepatentedintheUSAbeforeWorldWarII ThethreeconeHarleybit(Figure2)ischaracterized bythreeseparatedlegswithcones,which,inthetransport position,aredisplacedalongtheheight,formingagarland ThefourconeWalkerbit(Figure3)hasfourcones, whichwereconfiguredwhentransportinginagarlandIn * (ATransportPosltlon,BOperatingtheoperating position,the conepairsare mountedat twolevels,and AB thepair”of conesdrilling thecentralof m theholeis LPosition;CCutterSection) slightlyahead of~heperipheralpairofcones Thecommonfeatureofthesecone rockbitsisthetransmissionofoperatingbit loadsfromthedrillpipeshoedirectlytothe legsThelatterischaracteristicofRBs designedforrotarydrillingRBsfor operatingwithDHMsrequireseparationof rotatinglegsfromthefixedstringshoe ThefirstdesignsofconerockRBsforuse withDHMsweredevelopedbasedona 5 DevelopmentofRetractableDrillBitsinRussia retractablereamerwithapilotbitAmongtheseistheSyulbit (Figure4)Thelegswithconesareretractedundertheactionof flatspringsThereactionwiththebottomholeinducesamoment whichturnsupthelegsAbandoningtheapproachofbitload transmissiontothelegsdirectlybytheshoerequiredexpandable elementstobeintroduced,whichundertheactionofanaxial springgoesintotheshoebore CarterOilCompanymadeseveralfieldtestsbasedontwo typesof248mm(9%in)diameterRBswithspecial178mm(7 m)diameterpipesin1957Thebitshadfourcones,arrangedin transportpositionbypairsattwolevelsIntheoperatingposition, allfourconesaremountedonthesamelevel,withtwodrillingthe centralpartofthehole,andtheothertwotheperipheralpartIn theotherbittherewerethreecones,arrangedinthetransport positionasagarlandIntheoperatingposition,theconesare mountedasinastandardthreeconerockbitAtdepthsupto 500m(1640ft),theydrilled350m(1148ft)withfourconebits and128m(420ft)withthreeconebitsHughesToolCompany acquiredalicensetomanufacturethesebits,alongwiththeright tointroducedesignchanges Inthe1960s,investigationsontheuseofRBsinoceanic scientificdrillingbeganwiththeMoholprojectandtheDeepSea DrillingProject(DSDP) InthesecondphaseoftheMoholprojectaprototype retractablediamondbitforcoringwasdeveloped(stageAreport “DownholeDrillingTools”VOI40300)Ananalysisofthe possibleuseofasimilarbitfortheDSDPwascarriedoutin1968 (Engineering Study:“Methods toPenetrateHardFormations in DeepOceanBasins,” IPODTechnicalReportno2)Itwas concludedthatitwasnotexpedienttodevelopretractablecone rockbitsbecauseitwouldhavebeennecessarytoexchangethe M drillpipesontheGlomarChallengerdrillshipwithlargerdiameter pipesTheretractablediamondbitwasrecommendedforsupplywiththeaimto expandthepotentialforcoringinhardformationsTheseproposalshavenotyetbeen realized ItwasannouncedrecentlythattheTESCOCorporationinCalgary,Canada, acquiredthepatentrightstoa“DrillingwithCasing”methodandtoolsin1995The USApatent(no5,197,553witharelatedpatentno5,271,472)describesmethodsand assembliesfordrillingwiththecasingstringinsteadofdrillstringusingretrievable drillingandMWDassemblies Theretrievablebitiswellknowninprincipleasthe expandablereamerwithpilotbitADHMcouldbepartoftheassemblyResultsofthe 4 firstfielddrillingDevelopmentofRetractableDrillBitsinRussia testwerepresentedattheSPE/lADCconferenceinAmsterdam, February1999AtestwascompletedattheTESCOR&DcenterinCalgaryin1998 3040ftofboreholeweredrilledwiththreedifferentcasingstrings:9Y&incasingtol50ft depth, 75/8h casinguntil575feetand5Y%incasingwasusedtoTDTESCOis pursuingfurtherdevelopmentsinthisarea 22DevelopmentsintheUSSR ThefirstfieldexperimentsonturbodrillingwithRBwerecarriedoutinBakuinthe early1930sWorkondrillingtechniqueswithoutpullingpipewasresumedin1945 MajoreffortsondrillingtechnologywithRBsstartedin1948andwereconductedbytwo groupsofengineersandscientistsOnegroup,leadbyGeorgyiBarshay,wasworking onturbodrillingwithRBs;theother,leadbyYakovKershenbaum,developedrotary RBsSince1953,allresearchanddevelopmentworkondrillingwithoutpullingpipe withturbodrillswascarriedoutintheAllUnionDrillingTechniquesResearchInstitute (theVNIIBTinRussian)TheRussianauthorsofthepresentreportwereVNIIBT employeesholdingseniorengineeringpositionsinthegroupdevelopingtechnologies fordrillingwithoutpullingpipe,whichwasleadbyBarshayatthistimeTheseR&D effortscanbedividedintoseveralstages: A,Developmentofdrillingtechnologywith12inbits(19481956)including: l Designingthefirstretractabletool TestingofRBsfordrillingseparateintervalsofboreholeatdepthsupto 1500m(4921ft) B Developmentof10inbits(19571964): l SeriesproductionofRBsandturbodrillswithretrievablerotorsfordrilling withoutpullingpipe WorkingouttrippingoperationswithRBs l Drillingthefirsttestboreholesof2100mandthen2800m(9186ft)depth CCommercialuseofdrillingwithoutpullingpipe(19651971): Testsandindustrialdrillingofboreholesof25003000m(82009800ft) depths l Masteringdrillingtechnology l Developmentofspecialretractabletoolsfortroubleshootingandproblem avoidance l ImprovingRBandturbodrilldesigns Improvingtrippingoperationswithretrievabletools D,Developmentofdrillingtechnologywith9inbits(19671975): 5 , , , ,, , , ,“ — ,,, , ,J,~, ,,,,,,,, , ,,,:’ , , ,,,,, , —ZT?7 —— — DevelopmentofRetractableDrillBitsinRussia l CommercialdesignsofRBandturbodrillswithretrievablerotor l Developmentofaretractabletoolforcoring l Positivedisplacementmotor(PDM)andspecialtorquereactionlatch development l Fieldtestsofdiamonddrillingtechniqueswithturbodrillswithretrievable rotors l Drillingofexploratory m i boreholesupto2800m (9186ft)depth DevelopmentofRBdesignswas carriedoutalongthefollowingtrends: a) b) c) d) r Figure5Two ConeBitwith MonolithicHead (BDType) e)Stepbit(19491952)–three conepilotbitandtwocone expandablereamer SteeringbittypeBD(1953 1964) –twoconebitwith singlepiecedrillhead(Figure 5) TwopistonbittypeD2PV4 (19591968)twoconebitwith separatelegs,andinternal systemofmovablecomponents inthemechanism(Figure6) BodylessbitoftypeDRB (1966)–twoconebitwith externalsystemofmovable componentsinthemechanism (Figure7) Threeconebodylessbittype3DR(1969)–external movablesystemfeaturestwoholdersforlegswith conesandspecialarrangementsforproperbittransfer sequence(Figure8) 6 DevelopmentofRetractableDrillBitsinRussia Retracting Mechanisni’ [+Barrel ~CoIlet1 Oneresultofcommercialtestingofdrilling withoutpullingpipeintheUSSRwasthe developmentofasimilarmethodforcoringin hardcrystallinerocksTheadvanced continuouscoringsystemwasdesignedfor ultradeepboreholeapplicationsaspartofa nationalprogram“InvestigationoftheEarth’s CrustandUltraDeepDrilling” The calculationsshowedthat,whendrillingbelow 7000m(22,970ft)(correspondingtothe ml secondstageoftheKolaSD3borehole),this methodwouldbesubstantiallymoreeffective wT+ Sleeve bll Pa’ Radial ~/Bearing Cone~ Assembly BitB A El Be#lCollar,“ ‘ ‘”wI+Holder B Figure7TwoConeRBDRB(A OperatingPosition;BTransport)thanthealternatives In19691973, prototypesofdrilling toolsweredeveloped andmanufactured– coreheads,corebar rels,retractableblade reamer,retractable threeconebit,and retrievableDHM–for drilling217mm(8% in)boreholesinhard formationsAseriesof testsandmodifications ofthedesignsof varioustoolswas carriedoutin19741978intheborehole“SputnikSD3”This boreholewasspeciallyconstructed50m boreholeoftheKolaSD3forexperimental work Thetestsprovedthepotentialtodrill withoutpullingpipeincrystallinerocks However,thissystemwasnotusedinthe KolaSD3boreholeThemainreasonwas thatthe168mm(66in)drillstringwasnot turnedouttoberunintothe214mm(84in) openholeforthemorethanthe5km (16,400ft)lengthdrilledwith147mm(57/sin) drillpipeCommercialmasteringofthis technologywastransferredtotheKrivoyRog 7fromthemain — 1 Bit Body Section ~Middle )_ Lower‘; Section: ,, Figure8ThreeConeBodylessRB (Type3DR) DevelopmentofRetractableDrillBifsinRussia SD8wellinUkraine,whichwasdrilledwith168mmaluminumpipesFieldtestswere completedin1987in217mm(8Y2in)pilotboreholeatdepthsupto3500m(11,480ft) The295mm(116in)motherboreholewasdeepenedtoadepthof5432m(1993) withcombinedtechnology:coringwithoutpullingpipe,drillingandreamingwith standardmethodsRBswereplannedtobeusedafter2445mm(96in)casingwas runatadepthofabout7000m(23,000ft),buttheprojectwasterminatedbecauseofa lackoffunds InaccordancewithanorderfromtheUSSRAcademyofSciences,investigations ondrillingwithoutpullingpipeusingDHMsandRBsforscientificdrillingintheocean beganin1984Asaresult,thereweretestsin1991inunderwatermountainsofthe Josefin,AmperandGorringebankintheAtlanticoceanfromthedrillship“Bavenit” whichprovedtheprospectsofthistrendfordeepwaterriserlessdrillingItshouldbe notedthatsince1978thethreeconeRBdesignhasnotbeensubstantiallychanged Testscarriedoutinavarietyofgeologicalconditionsshowedbitserviceabilityand allowedverifyingreasonabledrillingpracticesForlateruseinthedeepwaterdrilling program,itwasplannedtoimprovetheRBinaccordancewiththemodern achievementsinconebitcuttingstructureandbearingdesignThisprogramwas cancelledin1992aswellduetoalackoffundsforcompletingconstructionofthe scientificdrillship Theideatorevivedrillingwithcasingtechnologyhasresurfacedfromtimetotime Inthe1970s,anattemptwasmadetodevelopitforthefirst 95i8in casingsetupin WestSiberiaFourconeRBshavebeensuccessfullytestedforthispurpose,butthe completedesignhasnotbeenworkedoutproperlyandthistestdidnotleadtoany furthercommercialapplications(Actually,therewerenosignificanteconomicreasons fordrillingwithcasinginthisregionatthattime) BasedonbroadexperienceinRBresearch,developmentandfieldapplication, relatedtechnologiesforunderreamingweresuccessfullydevelopedWelldesignswith minimalclearancesbetweencasing/linersbecamecommonpracticeintheregionsof theNorthCaucuses,MiddleAsia,Azerbaijan,KazakhstanandothersComplicated geologicalconditionsrequiredthatfivetosixcasingstringsberunwithatotalwell depthofabout6000m(19,690ft)Underreamerapplicationsimprovedthequalityof wellconstructionandproducedlargesavingsbecauseoflowerdrillingmudandcasing volumes,highratesofpenetrationandrelativelylowrequirementsfordrillrigcapacity Morethan100,000m(328,00ft)ofintervalswereunderreamedin1970s80s Reliableunderreamersforgravelpackingandotherspecialapplicationshavebeen developedaswell 23RecentDevelopmentsinRussia Technologyfieldtestedin1991forscientificdrillinginoceansbecamealogical foundationfordeepwaterstratigraphicdrillingThelatterconceptwasofferedbyIKU PetroleumResearchinNorwayinviewofthefactthatdeepwaterexplorationforoil 8 DevelopmentofRetractableDrillBitsinRussia hadbecomeafieldofstrategicresearchToevaluatepotentialproductivityofoiland gasprovinces,soilsamplesandrockcoresneedtoberecoveredandinvestigated duringstratigraphicboreholedrillingTheseholesaredrilledusingriserlesstechniques withrelativelysmalldrillshipsnormallyusedforgeotechnicalpurposesHowever,the conditionsofthesedrillingoperationsarebeyondthecapabilitiesofthesetypesof vesselswhenthewaterdepthsatthelocationexceed500600m(16401970ft)A solutiontothiswastheuseoflargediameterinternalflushaluminumdrillstringand techniquestodrillwithoutpullingpipeForthisparticularapplication,theComplete CoringSystem(CCS)wasdevelopedandtestedbytheAquaticCompanyin collaborationwithFugroEngineersBV,theNetherlandsRBsareanessentialpartof CCSthatallowspuddingboreholes,drillingandreaming,especiallyinhardrocks TheCCSalongwith164mm(65in)aluminumpipeswassuccessfullyemployed in19931997todrillfromtwosimilarlysizedgeotechnicalvessels“Bucentaur”and “Bavenit”withdisplacementsofonlyabout5000tonnesDrillingoperationswere performedinareasoftheAtlanticOcean(VoringBasin,RockallBank,offshoreWest Africa),GulfofMexico(MississippiCanyon,GreenCanyon,VioscaKnoll,Garden Banksarea),GibraltarStraitandoffshoreJapan TheexperiencegainedforoffshoreapplicationofRBsleadtothedevelopmentof aspecialtriconeRBTRB300fortheOceanDrillingProgram(ODP)ofTexasA&M University,USATheaimofthisbitwastospudanddrillaboreholetopsectionin conjunctionwithaspecificallydesigneddrillinBHAThisactuallyconsistedofdrilling withcasingtechnologyfordrillingthroughunstableandfracturedcrystallinerocks UnfortunatelythisbitwasonlybenchtestedandODPneveruseditoffshorebecauseof shortcomingsintheBHAdesignandotherunrelatedreasons 9 DevelopmentofRetractableDrillBitsinRussia 1o 3DesignofRBs 31GeneralRequirementsandClassification Aretractablebit(RB)consistsofaconeassemblyandaretractingmechanism (seeFigure7onpage7)TheRBisrundowntothebottomoftheholeandpulledup tothesurfacethroughthedrillstringAsurfacecontrolledretractingmechanismis usedtoconfiguretheconeassemblytoeitheroperatingortransportpositionsatthe bottomoftheholeDrillingfluidswithsolidadditivesorcuttingsaccumulatedatthe bottomcomplicatetheoperationofthemechanismRBdesignmustofnecessitybeas simpleandreliableinoperationaspossible ReliabilityrequirementsforRBsencompassthefollowing: QAnunobstructedtripofthebitassemblyinsidethedrillstring 0Failurefreemovementofthebittotheoperatingposition,andfailsafeoperation ofthemechanismwhenthebitcannotbesetduetopotentialproblems ElStrengthofallassemblieswhenoperatedundernormaldrillingpractices ClFailsafetransferofthebitintothetransportpositionforpullingout ReliabilityrequirementsmaywelldeterminetheselectionofanRBtypeandthedesign ofitscomponents TheexistingdesignsofRBscanbegroupedintotwogroupsaccordingtothetype ofoperationThefirstgroupincludesbitsfordrillingwithouttrippingthedrillstringBits inthesecondgrouparerundownonpipeExpandabledrillbitsthatarerundownon pipe(mostlyofreamerdesign)areusedfordrillingbelowthecementedcasingshoea holelargerthantheIDofthecasingstring Accordingtothetypeofdrive(drillingmethod),RBscanbesubdividedintobits usedwithdownholemudmotors(turbines,etc)andbitsrotatedbythedrillstringThe twobittypeshaveimportantdistinctionsInthefirsttype,specialcomponentsmustbe usedtotransferdrillingloadsfromthedownholemudmotortotheconeassemblyIn thesecondcase,adrillstringshoecanperformthefunctionofaretractingmechanism Basedonthetypeofrockdestruction,RBsaresubdividedintocutting,crushing/ shearing,andscrapingbitsThecorrespondingbitsareblade,rollercone,and diamondtypes Basedontheshapeoftheresultingbottomhole,RBscanbesinglestage,two stage,ormultistage,withonelevelorseverallevelsofcuttersRetractablereamers withpilotbitsoftendrillatwostagehole 11 DevelopmentofRetractableDrillBitsinRussia MostdesignsofRBsincludeseparatelyturningbitlegsInonebitdesign,turning legsarebuiltintoanintegralsoliddrillinghead(“BD”type)Designswithseparateor solidbitlegsdifferentlyaffectoperatingconditionsthandobitlegsintegraltothe assembly,andusedifferentmechanicalmotionsoftheretractingmechanismRoller conedrillbitswithseparatebitlegsaredividedintwogroups: 1 Bitswithtwoandthreelevelsoffestoontype,orgarlandseries,ofseparate coneassemblies–D2PV,DRB,and3DRtypes(seeFigures7and8) 2 Bitswithtwolevelsofpairedconesections–4DVtype(seeFigure31) Basedonthemethodofapplyingforceforsettingthebitintotheoperating position,twotypesofdesignsaresingledout:1)designswithhydraulicforceapplied, and2)designswithmechanicalforceapplied(taggingthebottomhole,thrusting againstashoe,etc)Bitdesignsdifferaccordingtomethodsforcreatingtheapplied forceForcescanbecreatedbythrustingonashoe,pullingacable,fluidpressureon apiston,springforce,weightofmovablepartsofthebit,impactforceofacatching device,andothermeans 32RBComponents ConeAssembly Asetofconesconsistsoftwoorthreeseparateassembliesorsectionswhichin combinationwiththeretractingmechanismcomprisetwoorthreeconeRBs(see Figures7and8)Aconeassemblyconsistsofalegandaconemountedonaleg mountedrollerandplainjournalbearingBasedonthelevelofthesectionsinthe transportposition,atwoconebithasanupper(bitbody)andlowersection,whereasa threeconebithasonemore(middle)section Thecommoncomponentofthesectionsofaconebitisthelegattachment assemblyTheassemblyisataperedshankwitha4048°apexangleInatwocone bitthesectionsareassembledalongasplitplane,whereasinathreeconebitalong dihedralangleplanes Eachlegofaconeassemblyhasanidenticaltaperedpart(halfconeoronethird ofcone),aswellasabearingassemblyThereareseveraldesignschematicsof bearingassemblies Threerowballbearingswithoneortwolockpinsoracombinationofplainjournal 3earing/threerowballbearing/plainjournalbearingareusedinbitsforhighRPM DHMs AnothercombinationschemeisusedinbitsforlowRPMmotors:thrust bearing/plainjournalbearing/ball/roller(orjournalbearing) 12 DevelopmentofRetractableDrillBitsinRussia Aneyewithahingedsocketforattachmentofmovablepartsoftheretracting mechanismislocatedinthemiddleofthelegsofthelower(middle)sectionThe hingedsocketoftheuppersectionlegislocatedintheshankabovetheconnection coneAchaseforacomponentofthebitbody(carrier)islocatedbelowtheconical sectionbaseThecarrierisusedfortransferringloadmomentswhiledrillingThebit leghasalsostrapsforinteractionwiththemechanismholder ConeUnit ConesizeisdeterminedbyRBdiameterinthetransportpositionThecorrelation betweenbitdiameterintransportandintheoperatingpositionforvarioussizebitsfor turbodrillingis066withadieunitforbitlatchingand066061withseatapplicationto latchthebit Conesizedependsonthedesignoftheretracting mechanismLargerconescanbebestpositionedina twoconebitGarlandtypepositionedconesarealways smallerthanconesinaregularthreeconebitSize correlationsrangefrom0809 Thislimitationrequiredspecialdesignimprovements inbitcuttingstructuretoimproveperformanceFollowing isanexampleforatwoconebit Atypicaltwoconebit,ascomparedtoathreecone bit,haslongerteethandathinnerfluidpathbetweenthe teethrowsThisisduetothefactthatthefluidchannels inatwoconebitoverlapwithateethrowofonlyone coneInthecaseofathreeconebit,thefluidchannel overlapswithteethrowsoftwoadjacentcones Therefore,cuttingsremovalinatwoconebitisless effectivethaninathreeconebitThenewconedesign intheDRB248Sbithasbettercorrelationbebween lengthofatoothandlengthofthefluidchannel(Figure 9) Attnesametime,theareaofthebottomholethatis notoverlappingwiththecuttersremainsthesameor becomesevensmallerTeethrowsoftheconeare dividedintohalfrowsof180°each,whichareshifted alongtheaxisAsmallerconecontactareawiththe cresssub Collet ,,,! ,, ,, — , ,,, ,:;,,,, ,< :~”: l,, ),J,’i, ,i~ \ ,,r,i”,,,, ’ ,,A~,,, ,“——_ — Ultzlll gmovc —forcollet & slidevah’c dial bearing , _ [email protected] choke I r barrel sleeve movable ‘IMIIS stroke &_ belcollar bottomresultsinhigherspecificloadsontherock,deeperFigure9Retracting penetrationofteethintotherock,andacertainincreaseofMechanism durabilityofthebitjournalbearingwhiletheaxialloadon I thebitisunchanged 13 DevelopmentofRetractableDrillBitsinRussia BitLegAttachmentAssembly Aconebearingistheonlyelementinastandarddrillbitwithmechanically movableelementsRBs,inadditiontobearings,haveanumberofjointswithmovable partsThesearetheconeshapedbitlegattachmentassembly,jointplanes,hinged sockets;elementstransmittingtorque,andalockingelementtopreventbitlegsfrom skewingwithrespecttojointplanesasaresultofperipheralforceswhiledrilling Wearofcontactingsurfacesresultsinreducedintegrityofthebitlegattachment assemblyMethodsofincreasingdurabilityofasetofconesincludemakinglowinitial clearance(ornoclearanceatall)betweenjoiningpartstoachievehighwearresistance ofactivesurfaces BitHydraulics JoiningelementsofbitlegsdonotpermitefficienthydraulicsofRBs,whichare importantforgoodperformanceThisproblemwasresolvedbyintroducingacentral nozzlerigidlyconnectedtotheconelegbodyTheupperendofthejetnozzleissealed withaslidingbushinginstalledinsidetheretractingmechanismInaddition,thecentral nozzlefunctionsasalockingelement,preventingthebitlegsfromshiftingorskewingin the jointplane(planes) whiledrilling,asaresultofperipheralforces 33RetractingMechanism GeneralDesigns Aretractingmechanismconsistsofinternalfixedpartsandexternalmovableparts (seeFigure9)UnlikeRBsforrotarydrilling,RBsforretrievableDHMscannotdirectly transmitappliedforcesfromthedrillstringtothebitlegsTherefore,theinternal systemoffixedpartsintheretractingmechanismisdesignedtocarryaxialandtorque loadswhiledrilling,andconsistsofstrong,rigidtubularpartsThesystemofmovable externalpartsmainlyoperateswhentheconebitistransferredfromthetransport positiontotheoperatingconfigurationDuringdrilling,theexternalsystemisaffected byinertiaforces(duetovibration),andisexposedtotorsionalmomentsTensilestress fromdifferentialpressureonthepistonisnegligible Thesystemofinternalfixedpartsconsistsof(movingupward):aconicalbellcollar andabarreltheupperendofwhichhasathreadforconnectionwithaturbineshaft Theexternalsystemconsistsof(movingupward):aholder(s),asleevewithradial bearings,andacollet Thereisalsoahingedsystemtoconnectsectionsofconeassembliestoelements oftheretractingmechanismAretractingmechanismofatwoconeRBhasone 14 DevelopmentofRetractableDrillBitsinRussia externalholderforarticulatedfixtureofthelowersectionofaconebitAretracting mechanismofathreeconebithastwoofthistypeofholder SequenceofMovement Themostimportanttypicalfeatureofaretractingmechanismisthespecific sequenceofmovementsofitsmovablepartsInagarlandtypetwoconebit,theupper sectionofthebithastobesetupintheoperatingpositionfirstbeforethelowersection canbeengaged InathreeconeRB,themovableholderstartsmovingwiththelowersectionofthe bit,whilethemovablemiddleholderwiththemiddlesectionofthebitisstillfixed Simultaneouswiththemovingholder,thebitbodysectionisswungintotheoperating positionWhenthelowersectionofthebitreachesthelevelofthemiddlesection,the middleholderisreleasedThetwomovableholders,alongwiththeattachedsections thatareincontactwithoneanotheratdihedralangleplanes,simultaneouslyapproach thebitlegbodyuntilaconicalsectionofaconeassemblyentersintothebellcollarof thefixedsystemThespeciallatchpreventsundesirablemovementofthemiddle holderduringbittransferfromtransportconfigurationtooperatingandback HydraulicMechanismforSettinginOperatingPosition ExternalandinternalresistanceforcesinterferewiththeprocessofsettinganRB intotheoperatingpositionTheseareovercomebyforcescreatedinthebitretracting mechanismthatexceedthecombinedvalueofpossibleresistanceforcesduringnormal drillingoperations Themethodutilizinghydraulicforcefromcirculateddrillingfluidisconsideredthe mostefficientwayofsettinganRBintotheoperatingpositionAsufficientforcecanbe createdalongwiththepossibilitytosetthebitintheoperatingpositioninanominalsize holeanydistancefromthebottom TheslidingcontrolvalveenablesreliableoperationofthemechanismThevalve closesacirculationchannelintheretractingmechanisminthetransportpositionand reopensittoallowcirculationoffluidatthefinaltravelofthemechanismmovable systemAtthesamemoment,thebitissetintotheoperatingpositionUpwardtravel ofthemovablesystem(piston)iscriticalforreversemotionofthepistonwhenthebitis transferredtothetransportposition Becauseofinstallationofaslidingvalveattheheadendunderthepiston operatingarea,pressureinthemechanismcorrespondstoresistanceforceswhenthe bitismovedintotheoperatingposition AxialclearanceisanimportantaspectoftheslidingvalveItcharacterizes hydraulicresistanceofthemechanismoutcomesealSmallaxialclearancesresultina 15 Tr, , ——, ,_ r,—,—— ,—e— — —— — —= DevelopmentofRetractableDrillBitsinRussia sufficientlevelofactiveforce,whichincreasesreliabilityoftheretractingmechanism operationAtthesametime,smallaxialclearancespromoteerosionofthesliding valve,especiallywithheavymudsLargeaxialclearancesresultinloweroperating reliabilityoftheretractingmechanismThetaperedshankoftheconeassemblymay notfullyenterthebellcollar,whichmaycausebreakageofthemechanismholders whilereamingtheboreholebeforeanRBstartsdrillingManufacturingtechnologydoes notallowhighlypreciseaxialclearanceintheslidevalve Amechanismcombiningaslidevalveandachokewasdevelopedtoincrease reliabilityofslidingvalveoperationAhydraulicresistancedevice(choke)wasinstalled inthecentralfluidcourseofabarrelbelowtheslidingvalveItassistsincreatingan activeforcewhichissufficient,evenwithaninaccuratelymanufacturedslidingvalve,to settheconeassemblyintotheoperatingpositioncompletelyThisisparticularly importantwhiledrillinghardcrystallinerocks Thehydraulicmechanismwithaslidingvalveallowsthedrillertoreceiveaclear signalindicatingthatthebithasbeensetintheoperatingpositionTheslidingvalve allowsconestoretaintheiroperatingpositionswhenthebitisliftedoffbottom ItisofutmostimportancethattheRBbesetinthe DHMisstartedOtherwise,relativelyfragilepartsof retractingmechanismmaybeaffectedbytheadditional betweentherotatinghalfopenedbitandboreholewallsoperatingpositionbeforethe themovablesystemofthe stresses,becauseofcontact In thisrespect,developmentofa devicewouldallowstartingtheturbine position InternalFixedElementsblockingdevicefortheRBisof interest The onlyafterthebithasbeensetintheoperating Strongandrigidinternalelementsare formedoftubularmaterialTheyaredesignedmadeofstructuralalloysteel tosupportdrillingworkloadsandare Thebellcollaristhemaincomponentsupportingaxialandmomentloadswhile drillingItsjunctionwiththetaperedshankoftheconeassemblyisexposedto intensivewearSurFacehardeningofthebellcollarincreaseswearresistanceofthe JunctionassemblyThebellcollarsurfacematerialmustalsobeharderthanthe materialofaconeassemblyshankthatisreplacedaftereachtripThebellcollarcan bereplacedaswell Thebellcollaristhreadedtothebarrel,withacentralfluidcourseinterruptedat theprotrusionoftheslidingvalve 16 DevelopmentofRetractableDrillBitsinRussia ExternalMovableElements Theexternalsystemofmovableelementsincludes(movingupward):aholder(s), asleeve,andacolletTheholderisdesignatedforjointhingeconnectionwiththe lower(middle)sectionoftheconebitItisthemostloadedelementofthemovable systemTheholderisexposedtoabendingmomentwhentheRBissettothe operatingpositionThisoccurswhenswingingintotheoperatingpositionwhenthe conepushesthelowerpartofthestringfromtheboreholewallstowardthecenter Thesleeveiscylindricalandcenterstheexternalsystemwhileitismovingalong thefixedinternalbarrelAradialbearingispositionedontheoutsideofthesleeve,and whiledrillingisincontactwiththeBHAbottomlinerTheinnersurfaceofthesleeve hasagroovewhichisapartoftheslidingvalveAnannularswiveltypejointconnects theholdertothesleeve,toreleasetorsionloadontheholderproducedbyrotatingthe RBasaresultoffrictiontorqueintheradialbearingofthesleeveTheupperpartof thesleeveisrigidlyconnectedtoacollet ThelowerendofthecolletworksasanannularpistonwhentheRBis hydraulicallytransferredintotheoperatingpositionTheupperpartofthecollet consistsofelasticpetalshapedelementsthatwillnotextendbeyondtransportdiameter limitsoftheretractingmechanismWhentheexternalmovablesystemmovesup,and theconeassemblyassumesitsoperatingposition,thepetalshapedelementsofthe colletmoveovertothecylindersurfaceofthebarrelwithadiameterlargerthanthe transportlimit HingedJointtoConnectConeAssembly Thehingedjointconnectingthelower(middle)sectionoftheconeassemblytothe holderisaffectedbyinertia(vibration)forcescreatedbytheweightoftheexternal movablesystemandisthemostheavilyloadedjointSmallinitialclearanceandhigh wearresistanceofcontactsutiacesarenecessarytoreducewearofthehingedjoint Thehingedjointconnectingthebitbodysectionoftheconeassemblyisnotloaded whiledrilling,andcanexperienceloadsonlyifthebellcollariscompletelywornout LockingelementsareimportantpartsofthehingedjointTheymustprovide reliablefixationofthehingedjoint,andensurefastandeasyreplacementofthecone bitsectionsatthedrillingsite Atypicalhingedjointdesignincludesapinwithaspringloadedlock,andalock washerwithaholethatisinsertedinholderbossslotsThespringloadedlockgoes throughtheholeandlocksthewasher 17 DevelopmentofRetractableDrillBitsinRussia 34RBOperation RunninganRBDowntheHole AnRB,asapartofaretrievabledrillingtool,isrundownbygravityCirculationof drillmudincreasesspeedofthefallingtoolBitdiameterinthetransportpositionmust allowthebittopassthroughthesmallestdiameteroftheBHA,whichissituatedbelow theretrievableassemblyseatingshoulderFora248mmbit(9Ydin),themaximum diameterforthetransportconfigurationis154mm(61in)Fora217220mm(8%in) bit,thediameterinthetransportpositionis134mm(53in) WhenanRBistransportedtoabottom,specialattentionshouldbegiventothebit enteringaseatandthesmallestpartoftheBHAAsmoothconfigurationofthelegsof thelowerandupperbitsectionsallowsthemtoentertheseatandtheproceeding advancementoftheRBinsidetheBHA RBTransferinOperatingandTransportPositions Whenabitisrundownwithcirculationofdrillingfluid,aftertheretrievabletoolhas landedintheseat,themechanismmustsmoothlysetitselfintheoperatingpositionand theDHMbestartedItisofcrucialimportancethattheradialbearingsarenotworn, whichallowsrestoringfluidcirculationinthewell(ataraterequiredtostartthemotor) onlyafterthemechanismhasfullyopenedandtheconeassemblysetintheoperating positionThebitretractingmechanismisdesignedsothatthereshouldnotbeany stagnantzonesinsidetheinternalareasofthemechanismforfluidcirculationThisis necessarytoavoidabuildupofsediment,whichmightcomplicatethemechanism movementfromtheoperatingtothetransportpositionConfigurationandelementsof theholderandthebitsectionlegsensureasystematicprocessofsettingthebitinthe operatingposition 35ReviewofRussianPatents Thefollowingpatents(InventorCertificate(lC))relatedtodrillingwithoutpulling pipewereregisteredintheUSSR 1)ICNo112631datedJanuary10,1956 a)GSBarshai,AZRomanov,N1Buyanovsky,andYAGelfgat,“Hydraulically OperatedMechanismforSettingupaRetractableBit” b)Aslidingvalvethatclosesfluidcoursesofabitinthetransportandinthe intermediatepositions,andopensthembackatthelastintervaloftherodstroke, whentheelementsofanRBtaketheiroperatingpositions 2)ICNo247162datedMay10,1967 18 DevelopmentofRetractableDrillBitsinRussia a)AZRomanov,GSBarshai,andD1Indrupsky,“ConeBit” b)Retractabletwoconemilledtoothorinserttoothbitwitheachtoothrow consistingoftwohalfrowsoffsetfromeachotheralongtheconegeneratrixorof differentwidths 3)ICNo695260datedApril2,1967 a)GSBarshai,“RetractableThreeConeBit” b)Athreeconebit,consistingofthreeseparatelegswithcones,connected throughajointhingetotheelementsoftheretractingmechanism c)Centralbarrelwithashoeandtworingholdersinstalledonthebarrel 4)ICNo461218datedApril23,1973 a)GSBarshaiandSMKhodzhayev,“RetractableFourConeBit” b)Aretractablefourconebitincludingahollowhousingwithataperedseat c)Aconeassemblywithtwofixedandtwomovablelegswithcones d)Thelegsareconnectedthroughajointhingetoaplungermechanismthat expandsbittooperatingposition e)Fixedlegshaveconicaltailswithgroovesformovablelegs 5)ICNo395557datedDecember30,1971 a)PNApostolsky,GSBarshai,IYBlokhin,YAGelfgat,GFGorshkov,D1 Incirupsky,BAKorolev,andUGSharaf,“WellDrillingDevice” b)AspecialdevicefordrillingwellsusingdiamondbitsandretrievableDHMs c)Rotationofthedrillstringallowsreamingaborehole 6)ICNo481689dated1972 a)GSBarshai,MYGelfgat,AMZarkhin,GSGevorkov,andYAGelfgat, “RetractableDiamondReamingBit” b)Anexpandablediamondbladeunderreamerincombinationwitharigidpilotbit c)Theunitfeaturesasystemfortransferringbladesintheoperatingandtransport positions,aswellasforsecuringbladesinabitbody d)Lowerendfacesofthebladesareusedtodrilloutaboreholeannularshoulder 19 DevelopmentofRetractableDrillBitsinRussia 7)ICNo415346datedMarch3,1972 a)GSBarshai,RSAlikin,BAKorolev,andPNApostolsky,“DevicetoTransmit AxialLoadtoaDrillBit” b)AhydraulicloadingdeviceallowscreatingadditionalaxialloadonanRBusing differentialpressureinaDHMandthebit c)Thedeviceconsistsofarodandatravelingpistonabuttingagainstashelfofthe abovepistonarea 8)[CNo501139datedDecember14,1973 a)RSAlikinandGSBarshai“HoleOpener” b)Atwoconereamer,consistingofabarrelandtheattachedmovableholder connectedthroughjointhingestolegswithcones c)Thesystemincludesslideregulatorvalvesandamechanismforsecuringthe legsinthetransportposition,whichisinstalledinsidethebarrelandmadeasa rodwithataperedtipinteractingwiththecorrespondinginnersurfacesoflegs 9)ICNo583278datedAugust30,1974 a)RSAlikin,GSBarshai,andMYGelfgat,“RetractableBladeReamer” b)Aretractablebladereamerconnectedtoapilotbit c)Theupperendofeachbladehasacollarbeadandthereamerbodyitselfhas guidesingroovesthatfitthecollarbeads d)Theseelementsenablethebladestochangepositionfromtransportto operationTungstenCarbide,orCompositeDiamond,orPDCinsertedfacesof bitbladesperformreamingofaborehole 10)ICNo672937datedOctober28,1974 a)PNApostolsky,D1Indrupsky,andAZRomanov“RetractableConeBit” b)Aretractabletwoconebit,includedacentralbarrelandaholderwithhingedlegs withcones c)Ahydraulicpistonmechanismforsettingabitintheoperatingposition d)Ahydraulicjetnozzleconnectedthroughajointhingetoabarrelandinteracting withaconelegfixedtotheholder 20 , DevelopmentofRetractableDrillBitsinRussia e)Thenozzleallowsbettercleaningofthebottomholeandpreventsdivergenceof thelegsinajointplaneunderperipheralforces 11)ICNo585266datedJuly26,1974 a)GSBarshaiandSMKhodzhayev,“DeviceforAttachmentofaDHMtoaDrill String” b)Acolletlinerwithpetaltypeelementsisusedtoinstallamotorhousinginsidea drillstring c)Thepetaltypeelementsarelocatedintherodgrooves d)Duetoaxialdisplacementoftheelementstheirlateralsidescaninteractwith keysinthehousing 12)ICNo601390datedJanuary12,1976 a)RSAlikin,T1Alikina,GSBarshai,andMYGelfgat,“Deviceforcreatingan axialloadwhilepullingoutaretrievabletool” b)Overshotwithmechanicallatchisusedtogripandpullouttheretrievabletoolby wireline c)Thehydraulicsystemattachedtotheovershotprovidesadditionalpullingloadto startretrievabletoolmovementfromtheBHA d)Actualpullingforceavailableisexceededthewirelineloadlimit 13)ICNo581238datedFebruary23,1976 a)RSAlikin,GSBarshai,IVVasilichenko,andMYGelfgat,“Grippingdevice forretrievabletool” b)Whilepullingoutaretrievabletoolbyreversecirculation,mudispumpinginto annularspacebelowclosedblowoutpreventer c)Togripheadoftoolanovershotwithhydraulicandrubbershockabsorberis installedintotheupperpartofperforatedpupjoint 14)ICNo569698datedFebruary25,1976 ~a)RSAlikin,T1Alikina,andMYGelfgat:“CoringDeviceforDrillingwith RetrievableTool” b)RetrievabledownholemotordrivencorebarrelinstalledintheBHAshoewith possibilityofaxialmovement 21 — ,— 3, ! ,:, r ,,> v—— DevelopmentofRetractableDrillBitsinRussia c)Thedeviceequippedwithtorquereactionandthrustsystemprovidingproper parametersforcontinuouscoringwithDHMapplication 15)ICNo669778datedMarch1,1976 a) b) c) d)RSAlikin,PNApostolsky,GSBarshai,YAGelfgat,BAKorolev,andYO Firger:“Deflectorforretractablebit” Inthepresentdevice,adeflectingforcecreatesbytheexpandingpadonthe BHAshoe Controlofthepadextensionisexecutedbythespecialsleevewithoutpullingout drillpipe RBcanbeusedinconjunctionwiththedeflectorinanyofitpositions 16)ICNo655843datedMarch22,1977 a) b) c)GSBarshai,YAGelfgat,D1Indrupsky,BAKorolev,GMFinkelstein,and YOFirger,“SwallowTailTypeReleasableJoint” Areleasablejointconnectingreplaceableconeaxlewithareamerleg Thedevicehasaspringloadedlockpinwithataperedtip,locatedinsidethe axle,andaplatewithtaperedshelvesandaconicalpinhole 17)ICNo781312datedMarch7,1978 a) b) c) d) e)GSBarshai,MYGelfgat,YAGelfgat,andD1Indrupsky,“BladeReamer” Abladereamer,consistingofareamerbody,rodpistonwithbladesconnected throughajointhinge Thebladesinteractwiththeexternalconicalsurfaceofthereamerbodyandthe rod Thedeviceincludesasystemofselfregulationofclearancesbetweenthe contactingwearsurfacesofthebladesandthebody Thesystemallowsachievinglongeroperatinglifeofthereamer 18)ICNo786411datedMarch26,1979 a) b)GSBarshaiandD1Indrupsky,“RetractableConeBit” AtwoconeRBincludingacentralbarrel,anexternalholder,bitlegswithcones 22 DevelopmentofRetractableDrillBitsinRussia c)Oneofthelegsisconnectedthroughahingedjointtothebarrel,andtheother onetotheholder d)Ahydraulicpistontypemechanismforsettinglegsintheoperating astoplock,articulatelyconnectedtoabarrel e)Astoplockcaninteractwiththestringwhenthebitsetsdown 19)ICNo899820datedJune29,1979position,and a) b) c) d)RSAlikinandMYGelfgat,“DevicetoDeterminearetrievabletoolpositionin thedrillstring” Asubwithacolletinsideisinstalledatacertainplaceinthedrillstringto determinethemomentwhenretrievabletoolispassingthisplacewhilerunning downtobesetupintheBHA Whileretrievabletoolcontactsacollet,thepressureincreasesinthemudline andcanbefixedtocontrolthemudflowandaccordinglyretrievabletoolspeed Whilepullingouttheretrievabletool,thecolletispushedintheinitialpositionfor thenextrundownoperation 20)ICNo955765datedFebruary9,1981 a) b) c) d)YAGelfgat,MYGelfgat,andD1Indrupsky,“RetractableThreeconeBit” Aretractablethreeconebitincludingacentralbarrelwithashoe,tworing holderswitharticulatelyattachedlegswithcones,andasleeve,whichin combinationwiththebarrelworksasaslidevalveforsetthgthebitinthe operatingposition Thebitfeaturesaswiveltypeconnectionofoneoftheholderstoasleeve,using ringshapedquadrants,lockedbyabushingfrominsideandretainedbythe centralbarrel Thecentralbarrelhasachokecreatingadditionalhydraulicforcetohelp compactlypositionbitlegsinthebellcollaroftheshoe 21)ICNo1304470datedAugust31,1984 a)YAGelfgat,MYGeifgat,RSAlikin,TAAndreeva,andN1Andrianov:“A methodofcoredrilling” b)Themethodincludesusingofcoredrillingwithretrievabletoolinpilothole 23 r! , ,, 7C A ,,,,,, — DevelopmentofRetractableDrillBitsinRussia c)Toincreaselengthofthepilotholedrillingwithretrievabletool,extensionpipes wereinstalledbetweenthecorebarrelanddrillstringshoe 22)ICNo1808972datedMay22,1991 a)MlVorozhbitov,OYBergshtein,andD1Indrupsky,“WellDrillingDevice” b)Anexpandableoneconereamerincludesapilotbit,asub,ahousingwitha hollowinclinedpinwithfitonitbearingandareamercone c)Thereamerconeretractingmechanismconsistsofanattachedtothesub rotatinglinerwithalongitudinalleadintheupperpartandhardfacedlongitudinal ribswitharighthandhelixontheexternalsurface d)Thereamerincludesamovablerotatingsupportoffsetfromanupperendboss onthethickersectionandalowerendbosswitharadialslotholdingtheliner lead 24 ,, , , , 4RBManufacturingTechnology 41ManufacturingRBBitLegsandCones ConeassembliesforRetractableBits(RBs)requiremanufacturingtechnologythat isdifferentfromtechnologyusedinmanufacturingconventionaldrillbitsThisis becausearetractableconeassemblyincludesreleasablejointelements,hinges,eyes, andsmoothattachmentcones,allofwhichrequirehighprecisionmanufacturing Requirementsformaterials,billets,andthermaltreatmentofRBconeassembliesmust complywiththosesetforthinthespecificationsforsimilartypeelementsfor conventionalbitsofthesamesizeBitlegsandconesaremadefromcasehardened alloyVADsteelRollersandballsaremadebybearingmanufacturingplantsfrom specialsteelaccordingtothetechnicalspecificationsforballbearingsandrollers suppliedtobitplantsBitconesandshirttailshavesinteredmetalhardalloyteeth Standard drillbit manufacturingtechnol ogywasusedforthe conesThebitbearings arealso similarto bearingsforastandard drillbit However, designfeaturesofRBs relatedtothejointplane (ordihedralangleplane) ofaspecifiedlength,did notallowpropergrinding oftheupperbearing racewayIntroductionof grindingmachinesfrom the Nova Company (Italy)withsmallgrinders eliminatedtheproblem Severalbitdesigns(Figure10)usedweldedoncoverpadsthatallowedmakingthe bearingopenandaddressedthisdrawback, Thefollowingbearingpatternisusedinatwoconebitdesign(DRB248C)to improveitsoperatingreliability:triserialballbearingswithplainendjournalbearingand twoballplugs Followingisthesequenceofoperationsformanufacturingbitlegsofatwocone assembly(fromforgings)attheKuibushevburmashplantThisplantisnowthe VolgoburmashCompanyinthecityofSamara 25 , , IFigure10Cone/BitAssemblyDRB248S I 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19DevelopmentofRetractableDrillBitsinRussia Machineprocessingofthejoiningplainsurfaceandanupperendedgeofthe shortleg,andtheshoulderoftheupperlegshirttail Weldingofapinbosstothelowersectionoftheupperlegjoiningsurface Aligningtheupperlegwiththejointplanefromthepinbossandtheshirttail endtopreventlateraloffsetofanaxleandaconicalpartofaleg AssemblingthetwolegstogetherThelegsabutagainsteachother’sedges andfittightlyagainstthejointplaneThesidesofthelegaretackwelded Turningthelegcone,backsideoftheupperleginthetransportposition,and itsshirttailoncenter Millinglegeyes Drillingandboring Legsbreakingupahingeholeintheshortlegbasedonthelegcone Drillingholesforjournalballplugs Drivingandcenterpoppinglockpins Preprocessingofjournals Finishturningofraceways(tobecarburizing)tofitballs,rollers(plain bearing)withanallowanceforgrinding Carburizingthelowerpartoflegs(bearingandshirttail) Finishturningofthejournalaftercasehardening–removingshouldersand chamfers Hardening Grindingofthejournal Boringahingeholeintheupperlegshirttail Machiningofthebackoftheshortleginthetransportposition Weldingcoverpadsontheupperleg Thistechnologicalprocesshasaninherentdrawbackifoneofthelegsisspoiled duringseparatemachiningofthe“union,”theotheronehastoberejectedalsoThis drawbackwaseliminatedinthetechnologythatwasusedformanufacturing500two 26 DevelopmentofRetractableDrillBitsinRussia coneDRB248CassembliesattheDKGplantinHungaryForexample,the manufacturingprocessfortheshortlegincludedthefollowingoperations: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16Machiningthejointplanesurfaceandtheendface BoringaccessholesonthejointplanesurfaceTheholesaretheprincipal elementsforfurthermachiningoftheleg Millingofthehingeeye Drillingholesforlockpins Drivingandcenterpoppinglockpins Preprocessingthejournal Finishmachineturningofracewaysforballandrollerbearings(with allowanceforgrinding)tobecarburizing Carburizingoftheleglowersection(bearingandshirttail) Finishmachineturningofthejournalaftercarburizing–removingshoulders andchamfers Machinemillingoftheshirttail Hardening(quenching) Grindingthejournal Drillingahingeholeintheeye Machineprocessingofahingeeyebackside Machinemillingoftheupperpartofthebitbody Machineprocessingoftheseatingconeconnectedtothematingleg Alargenumberoflesscriticalsurfaces(shirttailsofthelegsinthetransport position,sidesurfaces,watercourses,etc)arenotmachined(theyremainasinthe deliveredforging)Thissignificantlyreduceslaborrequirementsandcostofthe product Whensectionsofthebitareassembledtogether,plugsareputinaccessholes usingthermalresistantglue Becauseofspecializationwithintheindustry,coneassembliesaremadeatbit plants,butretractingmechanismsfortheconeassembliesaremadeatengineering 27 — , ,, , — _ J,,———— DevelopmentofRetractableDrillBitsinRussia plantsAcrucialtaskistoensurefullinterchangeabilityoftheseelementsoftheRB, especiallyconsideringthattheyareassembledontherigsite Forthispurposeasystemofcontroldeviceswasdeveloped,simulatingthejoint‘ elementsoftheretractingmechanismThesecontrol devicesaremadeforconditionsincludingtheworst casecombinationofdimensionsofthematingsurfaces Themaindevice(Figure11)isataperedcupwith holesforleghingesThefollowingparametersofthe coneassemblyarecontrolledusingthisdevice,along withaclocktypeindicatoronapedestal,heightgauge, gaugerings,asnapgauge,andfeelers 1Tightnessofthefitoflegjointsurfacesand sidesoflargecoverpads 2Relativepositionofhinges,symmetryofside planesofashortleghingeaboutaseated cone 3Rotationofconesandabsenceoftooth engagement 4 5 6 7 8 P&!!zl Interferencefitofa cone Bitsizeandweight Differenceincone elevationwiththecone axis Radialplayofthecone assemblyaboutthe coneaxis Radialplayofcones aboutthejournalaxis 9Coneskew I Figure12SecondaryControlDevice I 28 DevelopmentofRetractableDrillBitsinRussia Thesecondarydevice(Figure12)isusedtocheckthatthesectionsofthecone assemblyfallwithintheclearancelimitsforthetransportconfigurationThedevice includesinternalelementsonwhichsectionsonthehingesaremounted,andan internalslidinglinerTheinsidediameterofthelineristhesameasthediameterofthe coneassemblyinthetransportpositionThedeviceisalsousedtocontrolfree turnaroundofsectionsonhingesfromthetransporttotheoperatingposition 42ManufacturingTechnologyforThreeConeAssemblies Smallpilotlotsofthreeconeassembliesweremanufacturedatbitplantsin Drogobych,WestUkraine(248mm)andKuibyshevBurmash(217220mm)Pilot prototypesofvariousthreeconeRBassembliesweremadeattheVNIIBTexperimental plantinasuburbofMoscow Theprincipaltechnologicalrequirementaffectingqualityofthefinalproductis precisionofthedihedralangleplanes Becausethenumberofunitswassmall,theseweremanufacturedatthepilotand experimentalproductiondivisionsoftheplantusinguniversalequipmentandalimited numberofspecialdevices Thetechnologyusedformanufacturingsmalllots(about300bits)ofthreecone assemblieshadsomedrawbacksFirstwasthelackoffinishmachiningofthedihedral angleandtheattachmentlegconeDeformationsduringchemicalandthermal treatmentresultedinlargeclearancesalongthedihedralangleplanesofthelegsThis clearancebecameevenlarger,becauseofdifferingelevationsofconesandtheirplay, andreduceddrillingefficiencyandsubstantiallyreducedoperatinglifeoftheretracting mechanism Inaddition,thetechnologyinvolvedanumberofadditionaloperationsthatwere hardtoarrangeforfullscaleproductionAmongthemwere:1)alignmentofthebitlegs andweldingthemtogetherina“union”forjointmachiningoftheconnectioncone;2) breakinguptheunionintoseparatelegsforfurthermachining;and3)selectinglegsfor onebitaccordingtothebitassemblyserialnumberafterchemicalandthermal treatmentThereisalsoanotherdisadvantageofthetechnologicalprocessadoptedIf oneofthebitlegswasdamagedwhilemachiningtheseparated“union,”theothertwo alsohadtoberejected Thesedrawbackswereeliminatedbyatechnologicalprocessthatincludesfinish machiningofthedihedralangleandthelegconesMoreover,alloperationsfor premachiningofthedihedralangle,journal,andhingesremainedunchangedNew operationsincludefinishmachiningofadihedralanglebasedonahingeholeanda journalraceway,andturningtheconeinalathewithlegsfixedinthesamepositions Forexample,Figure13showsthesequenceofoperationsfortheshortleg(with positionsindicated): 29 , — ,,~, ,,/,, ,,,,r,,,, ,,,) ,,,, >, ,,~, ,,,fs , :< =— 1 2 3 4 56 7 7A 8 8A 8B 9 10 11DevelopmentofRetractableDrillBitsinRussia Machininawithallowancefor I 23 dihedralangleplanes Machinemillingtheinitial productionthrustsurfaceof thejournal Millingtheupperendfaceof thelegcone Millingacavity(pocket)for thebitlegjournal Preparingandcenteringthe axle Premachiningthejournal; finishmachiningthejournal elements(raceways)that aretobegroundafter carburizing Carburizingthelowerpartof theleg(thelegjournal) Finishmachiningthejournal (cuttingoffshoulders,end faces,chamfers,etc) Hardening(quenching) Grindingthejournalraceways Drillingaholeforaplug Millinganeyeforahinge Drillingahingehole 910 1314 8 Ii!? 12 15 Figure13MachiningSequenceforShortLeg 1213Machinemillingthebacksideofthetransportpositionandtheeye 14Finishmachiningthedihedralangle 14AAssemblingthelegstogetherintoa“union” 15Machiningtheconeandshirttail 30 Aspecial accuracyof assembledbitDevelopmentofRetractableDrillBitsinRussia deviceisusedtocontrol thedimensionsofthe whilemanufacturingpilot lotsofthreeconeassemblies(Figure14) Withextendedholders,thesectionsofthe coneassemblyareinstalledonthe elementsofthedeviceusinghingeaxles, andtheirtailsareputinsideaconecup, similartotheoperatingpositionoftheRB Thefollowingparameterswerecontrolled: bitsizeandshirttailclearance,difference inconeelevationwiththebitbodyaxis, tightnessofthefitalongthedihedralangle danes,radialplayoftheconeassembly abouttheconeaxis,andaxialandradial coneskewInaddition,usingextended holdersofthedevice,thefitofthethree coneassemblyinthetransportconfig urationischecked 43 ManufacturingRetracting MechanismsforRBsand Reamers Asmallnumberofretracting mechanismsofvariousdesignsandsizes were manufacturedatthePavlov’s EngineeringPlant(PermRegion) E# 1/ ‘1 ,,,, , , , , !’ —— ,, , —— ,, —, — — r_ Figure14ControlDevicefor ThreeConeAssemblies _l Conventionalequipmentwasusedformanufacturing Regardlessofthesizeofmanufacturedelementsoftheretractingmechanism,a standardmachiningtechniquewasusedsincetheelementswereidentical Thesleeveisathinwallcylindricalelementwithlengthequaltoabout57outside diametersTheinternalsurfaceofthesleevehasapocketthatispartofaslidevalve ofthemechanismThepocketmustbemachinedwithhighprecisionTherefore,it wasrecommendedthatamastertemplatebeusedUnfortunately,this recommendationwasnotfollowed,andtheslidevalvehadlowprecision,which negativelyaffectedperformanceoftheRBAnadditionalchokehadtobeinstalledto offsetlowaccuracyofslidevalvemanufacturing Theexternalsurfacehaspocketsforaradialbearing,madebyvulcanizationofa polymer(specialcompositionrubber)inamoldThisdictatestheuseofthefollowing procedureforsleevemanufacturing: 31 1 2 3 4 5 6 7DevelopmentofRetractableDrillBitsinRussia FinishmachineturningontheOD,andmakeagroovefortherubbercoating ToleranceforlengthandIDmustbeaccountedfor Thermaltreatment Surfacepreparationforrubbercoating(sandblasting,cleaning,and decreasing) Rubbercoatinginamold Machineturning(presurfacingandfinishsurfacingoftheinternalsurfaceand theslidevalve) Internalsurfacegrinding Makingtheendthreadandturningthelowersectionofthesleeveforahinge connectionwiththeholder Theholderisthemostlaborintensivecomponentofthemechanismduetolow productionefficiencyAdiskbilletmustbeusedbecausethelowertaperedsectionhas bosseswithhingeholesforconnectingbitsections Theoperationforupsettinglowerendsofthinwalledtubularbilletsformsmetal ~iecesusedfortheholderbossesUnderconditionsoffullscaleproduction,this operationiseconomicallyfeasible Laborrequiredtomanufacturetheholdercanbereducedbyusingdieforgingthat allowsformingallspruesthatarecurrentlymadebymillingwithspecialmills Thebellcollar(cone)isthemainandreplaceableinternalelementofthe mechanism,transmitthgaxialandmomentloadswhiledrillingOperationssuchas turning,milling,threadcutting,anddrillingareusedinbellcollarmanufacturingThe mostimportantproblemofthetechnologyistoincreasewearresistanceoftheconical bellcollarThisproblemisresolvedbycasehardeningthecollarsurface,quenching, andgrinding Inaddition,methodsweredevelopedtomakethebellcollarsurfaceharderby depositingahardalloyintospeciallymilledgroovesandthengrinding 44ManufacturingDefectsandTheirImpact AnRBdesignmustallowoperationinhighlycontaminatedandabrasivedrilling fluidsThisrequirementdictatesthenecessitytoincreasetheinitialclearancebetween thejointedelementsFurthermore,backlashinmovablejointsmustbeincreased,to correctskewingandmisalignmentofaxes,becauseofmanufacturingdefectsThis backlashandplayincreasesduetooperationalwear 32 DevelopmentofRetractableDrillBitsinRussia Whenthemovablesystemoftheretractingmechanismisinmotion,friction resistanceoccursasaresultofinaccuracyinthefabricationofcertainelements ExperienceinmanufacturingandtestingRBsindicatesthatmisalignmentofaxesof matingcylindricalsurfaces,aswellasskewnessandasymmetryofhingeassemblies, arethemostcrucialfactorsDuringassembly,inaccuraciesoffabricationofcertain elementsareadditiveSincefrictionfactordependsonsurfaceconditions,averyhigh surfacefinishingclassisrecommended Duringwelldrillingoperations,anRBisalternatelyexposedtodrillingfluidandair Therefore,oxidationisapotentialproblemChromiumcoatingsslowthecorrosion processThisisparticularlyimportantforsurfacesonwhichrubberelementsofthe mechanismmove Thesystemdevelopedandimplementedforfinalinspectionofthecone assembliesandretractingmechanismsallowthemtobeinterchangeableand minimizesadditionalfittingoperationsinworkshopspriortosendingabittotherigsite Table1showstypicalmanufacturingfaultsandtheireffectonoperationofanRB Table1TypicalRBProblemsandEffectsonOperation — — 1 — 2 — 3 — 4 — POSSIBLEMANUFACTURINGDEFECTSTHATCAUSED NOTES PRODUCTFAILURE/FAILURE OPERATIONCOMPLICATION TransportingBitstuckinthe Bitlegs donotfitinthetransportposition; RBinsidedrillBHAseatbitlegsdonothavechamfers stringClearancebetweencolletandconical (runningbitshoulderofretractingmechanismbarrel downhole) wasnotobserved SettingRB RBhasnotbeenLowqualityweldingofcoverpadsonbit intooperating](orhasbeenIleg I positionIpartially)setupinIAxialclearanceinslidevalveofretractingI theoperating mechanismwasnotobserved positionODofradialbearingofsleevewaslow DrillingIntensivewearofLargeclearancesbetweenmovablejoints bearingsandFailuretocorrectlythermallyand cutters;bellcollarchemicallytreatelements wea~hingeThepartsdonothaverequiredradiiand failure;cracksonfillets Iholderhousing TransferringIThebitcannotbe!Threadconnectionbetweencolletand!Sediment RBintocompletely sleevenottightenedproperlybuildingup transportmovedinto belowpiston positiontransportposition ofcolletis mainreason 33 _T 7— , DevelopmentofRetractableDrillBitsinRussia 45DesignsofCommercialRBs BitsUsedwithDHMs Table2presentsstandarddesignsandsizesofretractabledrillbitsTable3 showsarangeofconeassembliesforRBsandtheirtechnicalparameters Table2StandardDesignsandSizesofRBs BIT SIZE — #9 #1o #12RB TYPEID MARKOFIDMARKINGOFDRILL ExPANDING SOFIMEDIUMTOHARD MECHANISM ROCK ROCK Two DRBI9°DRB29S conebitDRB2220DRB29SZ Three3DR2203DR217S conebit III 3DR220S Reamer WIpilot Two conebit Three conebit + I DRB31oIDRB3 DRB248 3DR1248 M3DR2248 10“M 3DR220SZ DRB3I0“s DRB3IO“ST DRB248S(020) DRB248SZ(030) DRB248ST(040) 3DR248S 3DR248SZ 3DR248ST Four4DV4DV295020 conebit295010 ‘w’ =l=T= RVAI 217 I134 217020 DRB3248154 1O“T 248154 DRB 295203 34 DRILLBITID MARK DRB29”S DRB29”SZ 3DR217S 3DR217K 3DR2170K 3DR220S DRB3I0“s DRB3IO“ST DRB3IO”T DRB248S DRB248SZ DRB248ST DRB248T 3DR248S 3DR248SZ 3DR248ST 3DR248T 4DB295 DevelopmentofRetractableDrillBitsinRussia Table3ConeAssembliesofRBs BITODIN OPERATE MODE (MM) 220 220 217 217 217 220 248 248 248 248 248 248 248 248 248 248 248 295 NaBITLEG JOURNAL ANGLE 51 51 51 57 57 57 475 475 475 50 50 475 475 51 51 51 51 60 S: BB–tBEARINGPATTERN BBBBBB JBBBBBBB JBBBBBBB RBBBB JBBBBBB JBBBBBBBJB RBBBRB RBBBRB RBBBRB JBBBBBBJB JBBBBBBJB JBBBBBBJB JBBBBBBJB BBBBBBJB BBBBBJB RBBBRB RBBBRB BBBBBBJB II bearing;RB–rol , ,, “, , , , , , r — v,mme ,— = —, ,’ CONECUTHNG STRUCTURE Milledteeth ChiselTCI Milledteeth Hemispherical TCI Hemispherical TCI Milledteeth Milledteeth Milledteeth Milledteeth Milledteeth ChiselTCI Milledteeth Milledteeth Milledteeth Chisel TC teeth Milledteeth Milledteeth Milledteeth “bearing;JB–j TYPEOF FLUSHING Central(extended jetnozzle Central(extended jetnozzle) Centraljetcourse Central(extended jetnozzle) Centraljetcourse Centraljetcourse Sideandcentral Same Central nmalbearing SELF CLEAN TEETH Used Used Used Used Used Used ThedesignfeaturesofRBsconeassembliesmadeas1)MilledToothBitsand2) BitswithTungstenCarbideInserts(TCI)arepresentedinbrief Milledteethontheouterconesurfaceperformthefunctionofrockdestruction Drillbitsformediumrockhaveextendedteethwitha4043°sharpenedangleandlarge spacingBitsforharderrockhaveshortandcloselyspacedteeth Anumberofconeassemblydesigns(DRB3IOS,DRB29SZ,DRB248SZ,DRB 248ST)feature155mmconeoffsetaccordingtothecorrespondingrockhardness 35 : DevelopmentofRetractableDrillBitsinRussia Tungstencarbidealloysareusedforhardfacingteeth,includingthegagesurface Toenabledurablebitoperationinabrasiverock,TCIareinstalledatthebitlegshirttail (3DR248ST,DRB248ST) Certainbitdesigns(DRB248S,DRB248SZ,andDRB248ST)havebearingswith twoballplugs ConeshavepressedintheshellchiselshapedorsphericalTCIfordrillingmedium andhardrockrespectivelyThesetypesofbitsdonothaveconeoffset SZtypebitshaveconesfittedwithvariousdiametersofchiselshapedinsertsina checkerboardlayoutineachrow Rearflanksofshirttailsof3DR217K,3DR2170Kbitsfittedwithgagecompact insertsTable4presentstypicaldesignsoftheretractingmechanismsofretractable drillbitsandtechnicalparameters Table4RBRetractingMechanisms BASICUNITSMECHANISMOF Two MECHANISMOFTHREEMECHANISMOF PARAMETERCONE RB CONE RB FOURCONE RB DRB2220DRB2483DR2203DR12484DV29501O ODmm134154 1355154203 Length mm1486 1880 22502518 945 Movable mm 238245 395440125 system travel MaximumMPa pressureof(psi)(1’:5)(::5) (:::)(:::) (;::) transferto operation position Connection31023121 310231213121 thread(3%IF) (3%IF) GOST 528658 (API) Weightkg110180 200270 190 , 36 DevelopmentofRetractableDrillBitsinRussia RBsforRotaryDrillinqDesiqnedbvMINHGP Basedonthepromisingfuturefortheapplicationof medium(no8and9)andsmall(no6)bits,MINHGP (EngineersofGubkinInstituteofOil,Chemical,andGas IndustryinMoscow)specialistshaveconcentratedon developingRBsforrotarydrillinginthesesizesAnRB (Figure15)consistsofthefollowingmainelements: cylinder,housing,rodpiston,replaceable cone assemblies,andovershotReplaceableconeassemblies areessentiallylegswithmilledtoothrollingcutters Aspecialshoeissetonthelowerendofadrillstring Thebitistransportedtothebottomthroughthedrillstring bygravityorbymudcirculation Whenthebitcontactsthethrustshoeshoulder,mud iscirculatedunderthepistonandforcestherodupThe biglegmoveswiththerodalongshapedsurfacesand groovesfromthebitaxistotheboreholewallThesmall leg(withtheshorttraveldistance)alsomovesasidefrom thebitaxis Whenthepistonrodreachestheuppermostposition, legswithconesarepulledintoataperedshoe Simultaneously,drillmudflushcoursesareopenedinside thebit Torquefromthedrillstringistransmittedtothedrillbit throughaconnectionbetweentheconicalwallsofthebit legsandataperedboreinthestringshoe AB Figure15RBforRotary Drilling(AOperating;B Trans~ort) Toretrievethebittothesurface,anovershotisrundownonwirelinethroughthe drillstringTheovershotarrivesatthebitandcontactstheprotractedrodTherod thenmovesbacktoitslowerpositionConsequently,theovershotdogsengagethe cylinder,andthebitcanbepulleduptothesuiface Someofthesebitsweremadeastestprototypes,andsomeweremanufacturedin pilotlots TheDVR36VbitrepresentstheprincipaldesignThesebitsdrilledover6000m (19,700ft)withanaveragefootageperbitofabout60%ofregulartriconebit performanceinsimilardrillingconditionsSpecialistsdevelopedcuttersformedium, hard,andveryhardrocks 37 DevelopmentofRetractableDrillBitsinRussia Amoreadvancedbitdesign(DVR6I51;Figure 16)withthesocalledlowerjointhingeshasreplaced theDVR36Vinthe151mmsizeThebitincludes shorterandsimplerlegs[naddition,tierodscarry lessloadthanintheDVR36VbitThebitalsohasa moreadvancedflushingsystem Duringfieldtestingintheinterval600800m, DVR6I51pilotprototypesshowedbetterperformance thantheDVR36V 38 ( “/ A Figure16RBDVR6I51 (AOperating;BTransportPosition) , 5DrillingWithRBs 51DrillString Retractablebits(RBs)wereoriginallydesignedfor drillingwithsimultaneousrunningofcasingRBswere connecteddirectlytothecasingshoeDrillingexperience indicatedthepossibilityofutilizingthismethodforpile drivingorsettingsurfacecasingthatconsistedofseveral jointsofpipe However,drillinglongintervalsusingcasingwasnota successduetoalackofstrengthincasingthread connectionswithoutthrustfaces,whichdidnotallowthem tocarrydrillingloads t !a195 1 — 0 0 u? + 0 c c m — I ‘IiEiE3 [naddition,designimperfectionsin thefirstRBscausedfrequent failuresofthemechanismofbit transfertothetransportposition, whichrequiredpullingoutthecasing stringCasingthreadconnections witha60°profileand1:16taper requiredalargeamountoftimefor trippingoperations Therefore,designersdevelop edspecialinternalflushdrillpipe withtooljointsusing1:12tapered threadsSteelandaluminumdrill pipeswith195mm(77in)tool jointsweredevelopedandusedfor drilling220mm(87in)holesThe pipeIDwas146mm(5%in),and D195 2 D;46 1 2 thetooljointIDwas1445mm(569in)Figure17showssteel pipeswithbuttweldedslimtooljointsFigure18presentsthe designofanaluminumdrillpipeAcompaniontopicalreport, “DevelopmentofAluminumDrillPipeinRussia,”provides detailedcharacteristicsofthesepipes Thebottomholeassembly(BHA)includesthecasing shoe,retrievabletoolhousingwithlandingseat,torqueand weightonbit(WOB)reactionmechanismhousing,andseveral heavywalldrillpipes(197mmODdrillcollars)Areamerora stabilizermaybeinstalledontheBHAshoe,andinsidethe 39 DevelopmentofRetractableDrillBitsinRussia shoearadialbearingforcenteringthedrillbit ThecompleteBHAincludesaretrievableassemblyset insidetheBHA(Figure19)TheretrievableBHAforfullface drillingincludestheRB,aDHM(aturbodrillwithalanding unit),andatorqueandWOBreactionmechanismwitha fishingneckontop 52DrillingOperations DrillingorrockdestructionwithRBsissimilarto conventionalturbinedrilling,andisaffectedbyacombination ofbasictechnicalparameters:WOB,mudcirculationrate, andturbineRPMTurbineRPMdependsonWOB,mud circulatingrate,rockphysicalproperties,andbittype Originally,directdrivehydraulicturbineswith500600RPM operatingspeedswereusedindrillingBecauseofthehigh speeds,durabilityofbitbearingswasverylow ThelaterintroductionoflowRPMDHMsenabledtheir applicationwithRBsForexample,theTRV142turbinewith gearreducerandDVO142screwDHMat120200RPM weredevelopedtoworkwith220mmRBs MaximumWOBiscomposedoftheweightofthe retrievableBHA,thehydraulicloadequaltothepressure dropintheretrievableBHAmultipliedbytheturbine crosssectionalarea,andadditionalhydraulicloads = createdbyatorqueandWOBreactionmechanism ActualWOBfora220mm(87in)bitwasbelow12tonnes(26,460lb)at7080MPa (10001160psi)pressuredropinaretractabletool RBswiththeBHAdescribedabovewereusedexclusivelytodrillverticalwells Thedesignersdidnothavetheobjectiveofdevelopingretractabletoolsfordrilling directionalorhorizontalwellsinthefieldsoftheSaratovneftegasProductionCompany orfordrillingscientificwellsbothoffshoreandonshore Nevertheless,designersdevelopedspecialtoolstocontrolthewelltrajectoryThe mostsimplearetoolswithcontrolledstabilizingcoverpadsorwithasymmetricalfixed coverpadsinstalledintheBHAshoe 40 DevelopmentofRetractableDrillBitsinRussia 53TrippingOperations TheprincipaldifferencesbetweendrillingtechniquesusingRBsandconventional bitsarerelatedtoretractabletooltrippingoperationsTheretrievableBHAis transportedtothebottomanduptothesurfacethroughthedrillpipe Figure20Dropping RBDownHoleUnlikeacorebarrel,aturbinewithabitalmost completelyfillstheinternaldiameterofthedrillpipeand moveslikeapistonwithasmallfluidbypassaroundthe toolThisallowsmudcirculationinsidethedrillstringand intheannulus Thetoolcanberundownonawirelineordropped insidethedrillstringInthelattercase,mudiscirculated insidethedrillstringtoreducetimetoruntheassemblyto bottomWhenthebitapproachesthelandingseat,the mudpumprateisreducedtobringtheimpactenergytoa safelevelandavoidanypossibledamageofelementsthat comeintocontactwiththeretrievableBHAseatActual runningspeedsareintherangeof1823m/see(350450 ft/min) Aspecialovershotisusedfordroppingaretractable tooldownthedrillstring(Figure20)Todropthe retrievabletool(1)downthedrillstring(2),pins(4)are mountedinthedogsoftheovershot(3)Whenrunning thetoolinthedrillpipe,thepinsinteractwithaflange, movingapartdogsandreleasingtheheadofthe retrievabletool Theretrievableassemblycanberetrievedusinga wireline,byreversecirculatingthemud,oracombined method(pullingonwirelinewhilesimultaneouslypumpingmuddowntheannulus Figure21showsweliheadequipmentfortoolretrievalwithwirelineApupjoint withopeningstoallowcommunicationbetweenthepipeandannulus,isinstalledonthe upperpipetopreventdrillmudoverflowWhilethekellyismadeup,openingsinthe pupjointareclosed Figure22showswellheadequipmentforretrievingthetoolbyreversecirculation TheprocedureisdescribedasfollowsWhenpullingoutaretrievabletool(1)by reversecirculation,mudisroutedfromthemudpumpstotheannulus,whichisblocked abovebytheBOP(2)Anovershot(4)isusedtogriptheretrievabletoolwitha hydraulicshockabsorber(5)mountedintheupperpartofthedrillstringinaperforated pupjoint(3)Whengrippingtheretrievabletoolbyanovershot,theshockabsorber 41 DevelopmentofRetractableDrillBitsinRussia stem(6)ismovedupward, displacingfluidfromthecylindrical chamberthroughhydraulic resistance develo~inabrakinq! force Attheend”o;theste~* stroke,thetoolisstoppedbya rubberbuffer(7)Simultaneous withthebeginningofbraking,the mudpumpsareswitchedoff Severalfactorsshouldbe takenintoaccountwhenselecting themethodofretrieval,suchas hydrodynamicconditionsof horizonsinanyuncasedintervals, includingtheirabilitytowithstand pressuredropwithoutcausing problemswithfluidinfluxorlost circulation Whileretrievingthetoolby wireline,pressureintheannulus dropsbelowstaticmudpressure Themaximumpressuredropis observednearthedrillstringshoe Thelevelofpressuredropdepends onmudtheologicalproperties, hydraulicresistanceintheannulus andinsidethedrillpipe,andthe foolspeedItshouldbementioned thattheODofthespecialdrillstring orcasingusedwithRBsislarger thanthatofadrillpipestringfor conventionaldrillingTherefore,the describedmethodofdrillingfeatures additionalpressuredropsdueto Perforated Overshot /’ i —I IJ ‘PupJoint Wireline Casing ,DrillPipe /“”” Retrievable /TCIOI t I L Retrievabie Tool I Figure21PullingOutRetrievableTool I hydraulicresistanceintheannulus,bothwhiledrillingandtripping Whenthetoolisretrievedusingreversecirculationofdrillmud,pressureinthe annulusrisesabovehydrostaticpressure Themaximumpressureincreaseinthe uncasedintervalisobservedbelowtheshoeofthepreviouslysetcasing Thecombinationmethodoftoolretrievalallowsmaintaining levelintheannulusand,atthesametime,fastertoolretrieval 42adesiredpressure Oneofthespecific featuresofthis , DevelopmentofRetractableDrillBitsinRussia drillingmethodisthe necessityofsynchronizingwirelinepulling forcewithpumpingmudintotheannulus 54CoringOperations Coreisrecoveredwhiledrillinga pilotholewithacorebarrelandadrilling headthathasasmallerdiameterthanthe BHAshoeAsthewellisdrilleddeeper, intermediateextensionpipesareinstalled betweenthecorebarrelandtheturbine shaftPilotholedepthcanbeuptotens ofmetersandisdictatedbyeconomic feasibilitybecauseoftheneedtomake andbreakextensionpipesTheturbine usedfordrillingthemainholerotatesthe corebarrelSincecoreheaddiameteris smallerthanthediameterofanRB,a certainamountofmudisdischargedinto theannulusthroughajetnozzleAfter coring,thepilotholeisreamedtothe designeddiameterusinganRB 55FishingOperations Alongwiththesedrillingtools,RB designershavedevelopedanumberof ‘%1EEEE!! ,, ,, ,, :, , — ,!,,, ——,— rf _ _ __— T b a Figure22PullingRetrievableToolby ReverseCirculation(seetextforlegend’ auxi~aryretrievabletoolsforfishingjobs,bottomholecleaning,andsettingcement bridgeplugsAsmentionedpreviously,durabilityofRBbearingsat500700RPMfora directdriveturbodrillwaslow,whichcausedfrequentbearingfailuresand, consequently,coneslostonthebottom Fishingoperationsinvolvingamagneticmillthatwasrunonadrillstringrequired significanttriptimeToreducetriptime,aretrievablemagneticmillwasdeveloped Themillwassuccessfullyusedforretrievinglostconesandothersteelpartsthatfit throughtheIDofthedrillstringshoe Aretractablebasketthatengagespartsleftonthebottomhasbeendevelopedto retrievelargerfishHowever,retrievingthebasketrequirespullingthedrillstringIn somecases,aretrievablefacemillcancrushalargefish,aretrievablemagnetcanfish thefragments,andthenaretrievablesludgetrapcleanssmallmetalfragmentsfromthe bottom 43 DevelopmentofRetractableDrillBitsinRussia Thetechnologypracticesdescribedabovehavebeenworkedoutduringyearsof testsandcommercialdrillingSomeresultsfromeachstageoftestingarepresentedin thenextsection 44 6RBTestsandFieldApplications 61FirstTestIntervalsDrilledwith12inRB(19481956) Retractabletoolswereoriginallydevelopedfor295mm(116\s in)wellsAtthattime,thiswasthemosttypicalwellsizeformany oilandgasregionsinRussia219mm(8~ein)casingpipewas usedinplaceofadrillstringSpecialthinwalltooljoints(250mm (98in)ODand200mm(79in)ID)with1:12taperedthreads connectedthecasingpipestogether Asteppedbitwasusedwhichconsistedofastandard197 mm(73Ain)triconebitandatwoconeretractablereamerinstalled aboveit(Figure23)/nFigure23,fpiston;2–crosssub;3– spring;4–housing;5mandrel;6–cutte~7–seal;8–pilotbit Awedge,activatedandmoveddownwardbyhydraulicforce pushingapiston,expandedreamerlegsonhingestotheoperating positionThroughawedgeshapedcentralwatercourse,drilling fluidwasdirectedtoreamerconesandapilotthreeconebit , El Figure24 TurbodrillSeal AssemblyWhenitwastimetoretrievethebit,themud pumpswereshutdownandthewedgewas movedtoitsoriginalpositionbyanaxialspring Afterthat,thelegswithconeswerepulled insidethestringshoe A192mm(756in)retrievableturbodrill withanaxialflowturbinewasengagedwiththe stringusingsplinesonaturbodriilnippleThe uppersectionincludedasystemofrubber compartmentsforsealingtheturbineinthe pipes(Figure24)Whendrillingfluidwas circulated,theupper“(thinwall)compartment expandedtothepipewallduetooverpressure causedbythedifferentvelocityheadsinsidethecompartmentAfter that,thelowerthinwallcompartment,designatedtopartiallyremove torquereactionusingfrictionforces,expandedbecauseofpressure dropattheturbine Theresultsofearlytestingin1948(sixrunsintheinterval90 130m)promptedfundamentalmodernizationofretractabletool componentsandassemblies Aramanchorwasdevelopedtofix theturbineintheshoe 45 1 DevelopmentofRetractableDrillBitsinRussia SeeFig25C —TurbodriH SeeFig25B I SeeFig25A Figure25 Modernizedretractabletoolswithpilotreamers(Figure25)weretestedin1950 (26runsintheinterval60450m)andin1952(46 runs intheinterval210740m) Duringthe1952tests,totalpenetrationperbitwas3035%thatofconventional bitsinoffsetwells(averagepenetrationratewasthesame)Tentripsweremadedue tounreliableoperationoftheramanchorandbitretractingmechanismIndeeper intervals,pullinguptheretractabletoolcausedswabbingeffects Theresulting 46 DevelopmentofRetractableDrillBitsinRussia differenceinfluidlevelsinsidethestringandannulusledtohigherloadsonthe wireiineTherefore,thetoolwaspulledupslowlywithperiodicstopsAttheendof testing,whiletheretractabletoolwaspulled,aperforatedpipewasinstalledinthe uppersectionofthestringInternalspaceofthepipecommunicatedwiththeannulus throughcrosscutholes,whicheliminatedtheproblemofdifferentlevelsoffluidinthe pipesandinthewellThisallowedessentiallyreducingretrievaltimeIna730m (2395ft)well,triptimewas32minutesTestinginvolvedthefirsttrialofthemethodof retractabletoolrundownbygravity Anumberoftestsintheyears19481952indicatedthepossibilityofturbinedrilling usingretractableconebits Furthermodernizationofstepshapedbitswashaltedandreplacedby developmentofnewdesignsofsinglestepretractableconebitsBecauseofextensive wearofthereamerlegjointassembly,engineersdecidedtoinvestigatethepossibility ofdevelopinganRBwithamonolithicdrillheadAsaresultof thiswork,anewdesignofthesinglestepRBwithatwocone monolithdrillheadappeared In<954,aretractabletoolassemblywithnewbitswas testedinwellno128oftheSaratovneftProductionCompany Theretractabletoolincludedanaxialturbodrillwithanopen rubbersealingcupandaramanchorforseatinginthestring shoe,andabitBD3I2(Figure26)Thedrillheadinthisbit consistedoftwolegs(1),(2)withconesweldedontoacast holder(3)Theretractingmechanismincludedanhydraulic drivewithaslidevalve,developedin19511952,thatprovided reliabletransferofthebittotheoperatingposition Fluidwaspassedthroughtheannulusbetweenahousing (5)andacylinder(6),comingthroughtheloweropeningsof thecylinderintoaspacebelowthepistonAsmorefluid entered,apiston(4)withsleeve(7)movedupAtthesame time,arod(8)hangingontheinternalfaceofacylinder extension(9)remainedfixedItsupwardmovementwas blockedbyhydraulicresistanceforces,whicharosewhenfluid flowedthroughslotopeningsbetweenthecentralizer(1O)and arodshoulder Afterthedrillheadwassetinahorizontalposition,the upperfaceofthesleevebuttedagainsttherodshoulderand movedupwiththepistonrodThedrillheadmoved translationallyanditswedgeshapedcamsenteredslotsof joint(11) 47 , , , , ’ — —= _, ,, ,7 ,rr ,: = ,> —, m DevelopmentofRetractableDrillBitsinRussia Therewasanannularrecessontheexternalsurfaceof sleeveAttheendofthemechanismtravelrange,fluidflowed thebitwatercoursesthathad beenmadeintheformofaxial openingsinthejointanddrilling headAlldesignsofRussian madeRBsincludethemain elementsofthishydraulic retractingmechanismwithaslide valveandanupwardmoving piston Testdrillingatwellno128 wasconductedthrougha338mm 133in)conductorpipeAfter42 runs(15ofthemonwaterand27 onmud)699m(2293ft)were drilledintheinterval3331032m WOBwas1618tonnes(35,300 39,700lb) —thelowerpartofthe throughthisrecessto Tooljoint / Ca$hg’pipe 219MM l=i 1 2 3 Thefollowingaverage Figure27CasingwithSpecialToolJoints(l–shrunk indicatorsof RBperformance pipe;2–tooljoint3threadwithshoulderconnection) wererecorded:penetrationper run–166m(545ft);penetrationrate–115m/hr(377ft/hr)Performancewasmuch improvedascomparedtodrillingwithsteppedbitsAscomparedtoperformanceof conventionalbitsinthesameintervalsinoffsetwells,penetrationperbitwas67’Yo, whilepenetrationratewas122Y0 Thetestdrillingrevealedthatstrengthof219mmcasingdidnotmeetthe requirementsofturbinedrillingSixfailureswithpipebreakagewererecognizedinthe iowersectionofthestringalongtheplaneofloweststrength,thatis,theareaofthe threadconnectionsWeakplanesofpipebelowthelastthreadrequiredthatlateral bendingforcesthatcausedfatiguefailurebereducedThiswasachievedby strengtheningpipeconnectionswithtooljointsusingshrinkringsfitonthepipebody with03O5mminterferenceTheringswereweldedtothetooljointsusingelectrical weldingPipethreadsinthistypeofdesignareaffectedmainlybyaxialloadsThe ring,builtuponthepipe,carriesdangerousbendingforcesLater,thisstabilizingrim wasshrinkfitonthetooljoint(Figure27)Thefirstlotoftooljointswithstabilizingrims wasmadein1955Afterwards,tooljointsofthisdesignwerewidelyused fabricationofsteelpipesandaluminumpipeswithsteeltooljoints Thetestingalsoshowedessentiallyworseperformanceofallcomponents retractabletoolswhenwatercirculationwasreplacedwithmudcirculation 48[nthe ofthe The DevelopmentofRetractableDrillBitsinRussia necessitytoapplysignificantlyhigherforcestotransferthebittothetransportposition becameobvious Figure28showsaretrievabletoolassemblyusedtodrillwellno128 3 4 5 6 Figure28RBAssembly (I=pipe;2=seal;3=turbodrill;4=shoe;5=landingdevice;6=RB) Duringtestdrillingofwellno128,aperforatedpupjoint(Figure29)wasusedto balancefluidlevelsduringtrippingoftheretrievabletoolTheperforatedpupjointand amodernizedramanchorinthelastruns(9501130m)alloweddevelopingamethodof runningdowntheturbodrillbygravityThisresultedinsignificantlyfasterretrievable tooltrippingIna1030m(3379fi)deepwell,triptimewas30minutes(runningdown 13minutes;pullingout17minutes) Thenextseriesoftestsin1955atwellno164wasatrialoperationofan improveddesignretractabletoolatdepthsbelow1000mRBswithamonolithicdesign drillingheadmade40runsintheinterval11001544mTrippingoperationsweremuch fasterthistimeTriptimeatadepthof1500m(4921ft)was55minutes,including25 minutesforrunningdown(bygravity)and30minutesforpullingout 62TestBoreholesDrilledwith10inRB(19571964) in1959,aretractableassemblyfordrillingwithano10bitusing182mm(72in) pipeswasfirstattemptedinwellno39oftheSaratovneftProductionCompanyTest drillingwasinitiatedat650mDrillingfluidusedhadadensityof12125g/cm3and viscosityof2037sec(accordingtoSPV5Russianstandardfunnelviscometer) Variousretrievabletoolassembliesmade27runsintheinterval6501010m VerypositiveresultswereachieveddrillingwithtwopistonbitsAfterfiveruns therewasnowearobservedonthesurfacesofelementsinthelegattachment 49 ,, ,, : ,“, , —— — ,— — — —— — — DevelopmentofRetractableDrillBitsinRussia assembliesHowever,neitherofthedesignstestedprovided reliabletransferofthebittothetransportpositionInsufficient reliabilityofRBsduringtheirtransferfromtheoperatingtothe transportpositionusingahydraulicormechanicaldevice requiredadditionalanalysis Whiledevelopingnewdesigns(BDI610andD2PBIIO) engineersconcentratedtheireffortsoneliminatingthepotential forsludgeandcuttingsaccumulationinthebitretracting mechanism Thiscouldsufficientlyreducefailuresinbit transfertothetransportposition Newbitsweretestedinwellno39intheGuselskyfield thathadbeensuspendedat1045m(3428ft)afterbittesting in1959Drillingforthenewtestswasconductedat1018 tonnes(22,00039,600lb)WOB,3040liters/see(113151 BPM)pumprate,and100125kg/cm2(14191774psi) pressureDrillingfluiddensitywas12127g/cm3(10106 pp9)andviscositywas2540sec Successfultestresultsshowedthereliabilityofbittransfer tothetransportpositionandbroughtforwardtheideaofdrilling apilotholeof20002200m(65627218m)depths Testdrillingwasconductedatwellno18intheGuselsky field(Saratovregion)withaTDof2080mTherigincluded Uralrnash5equ~pmentwithadieseldrive,whichallowed EFigure29Perforated controllingpumpratewhiledrillingAU245wirelineunit PupJoint(l–rod;2– witha16mm(063in)cablewasusedforpullingthe seals; 3perfedpup retractabletoolAnelectricmotor(160kW)drovethiswinch Aspecialsensorwasinstalledontheadditionalcrown joint; 4crossoversub) sheavetoenablecontrolofhoistinglinetension TestdrillingwasstartedonSeptember22,1961belowconductorcasingfrom354 m,andfinishedafterreachingTDat2080mRBsdrilled1375m,including1315m withD2PVIM10(163conebits)and60mwithBD16M10(12drillingheads)Forty eightconventionaltriconebitswereusedtodrill350minvariousintervalsRBsmade 183runs,includingmorethanonerunofeightbits Downto694m(27bitruns)thewellwasdrilledwithwatercirculationThe remainingintervalwasdrilledonmudwith122128g/cm3(102107ppg)density,18 40secviscosity,and021 ?40 sandThemudtreatmentsystemincludedaconveyor typeshaleshakerandamudditch Drillingdownto1900mwasconductedwithasinglesection97stageturbodrillat apumprateof36liters/see(136BPM)Theremainingintervalwasdrilledwithatwo 50 DevelopmentofRetractableDrillBitsinRussia section150stageturbodrillat2930liters/see(113BPM)WOBwas1016 tonnes (22,00035,000lb) AveragepenetrationperRBwas79m(259It)atapenetrationrateof47m/hr (154ft/hr)Comparedtoperformanceofconventionaltriconebits(no12)inoffset wells,penetrationperbitwas56Y0,andpenetrationratewas70’YoComparedto performanceofconventionaltriconebits(no10)insimilarhorizonsofwellno18, penetrationperbitwas75%andpenetrationratewas102% Timereportsofalloperationsbetweentwobitrunsat1800mincludedthe following(turbodrill–singlesection) ClPullingout:breakingkelly25rein;makingupovershot05rein;runningin withovershot8rein;bittransfertooperatingposition1rein;pullingout retractabletool17minTotal:29min 0Changingbit:installingovershotlockring,visualinspectionofbitandturbine 1rein;changingbit11rein;bittest1minTotal:13min 0Runningin:droppingretractabletoolinsidepipe05rein;makingupkelly25 rein;circulationwithtwopumps12rein;circulationwithonepump4min Total:19min Thus,timebetweenthetwobitrunswas1hourThisrangeoftrippingspeed allowedmaking89bitrunsperdayatthedepthof18002000m Drillingofthesecondtestwell(wellno19inthePristannayafield)with2100m TDbeganinNovemberof1962intheSaratovregionAtwosectionturbodrillwitha ,, ,, , ,, , ~, , ,“, ,— : ,,,, +, ,, ,,, ,,> ,+%, ,=7, <9X, ~ / , < — retrievablerotor(TVR3M8), andtwopistonbits(D2PV3 10),modifiedaftertest drillingofwellno18,were usedfordrillingthenew well Retractabletoolsmade 186runsin42daysinthe interval4662112mand drilled1308m(4291ft) ~ecauseofashortageof RBs,theinterval17071984 mwasdrilledwithmWell18 ~ Well19 conventionaltriconebits(71 f“Lu u runs)overtheThenumberofrunsper dziy period JanuaryNovember1963 Figure30RBRuns perDay 51 DevelopmentofRetractableDrillBitsinRussia Figure30(numberofrunsperday)andTable5(tripsofthedrillstringduetotool failureandbreakage)illustrateimprovementofoperationalreliabilityoftheretractable toolachievedwhiledrillingwellno19Thedatashowa23timesreductioninthe numberofextratripsduetosatisfactoryRBperformanceThenumberofbitruns,with 69bitsperdayreplaced,nearlydoubled Table5NumberofExtraTripsper100BitRunsDuetoFailureofRBs TYPEOFFAILUREWELLNo18WELLNo19 Lostcones368322 Failureofbitretractingmechanism062 Turbinefailure307054 Turbinemalfunction054 Total1005438 Toaidintheanalysisofresultsobtainedwhiledrillingwithoutpullingpipe,wellno 20(offsetfromwellno19)wasdrilledinthesummerof1962usingtriconebits(no10) Wellno20wasdrilledwiththesameriganddrillingcrewthatdrilledwellno19Table 6presentsperformancecomparisondataforpenetrationperrunandpenetrationrate for retractableandconventionaltriconebits Table6ComparisonofRB(Well19)andConventionalTricone(Well20) PENETRATIONPERBIT(M)PENETRATIONRATE(M/HR) STRATIGRAPHICHORIZON WELLWELL %WELLWELL 70 No19 No20No19 No20 PodolskianKashirskian228 28815191131 146 Myachikovskian3159525i98183 108 Melekesskian3028510515175 86 CheremshanskianPrikamskian19427729798 99 SerpukhovianOkskian10167 6064 74 87 Tulskian1117655585 65 Cherepovetskian5011455 4062 645 Zavolzhskian818244598 74 DankovianLebedyanskian62 82755 5139 131 ZadonianYeletskian51144443 56 77 YevlanianLivenskian44 9646 4849 98 Voronezhskian281162437 40 925 Alatyrskian,Semilukskian31111283638 95 Mulinsldan,Starooskolian27 485653227 119 Vorobyevskian28 33853720 185 Averaae 17I122I575I63I56I113 Themainobjectivesforeffortsin1964wereRBtestsinwellsupto3000mTD, andfurtherdevelopmentofthismethodofdrilling Drillingwasplannedatexploratorytestwellno3(3100mTD)atthe DvoyenskayafieldoftheSaratovneftegazProductionCompanyThedrillingrig 52 DevelopmentofRetractableDrillBitsinRussia includeda53m(174ft)derrick,Uralmash5Dunit,andawirelinewinchwithstandard drawworksBU75Brwithadditionaldrumflangestoprovidetherequiredwirecapacity AB2300enginewasusedasadriveforthewinch DrillingwithRBsbeganinAprilandstoppedinOctoberof1964atadepthof2814 m(9232ft)afterencounteringacrystallinebasementaboveTDWhiletestdrilling, 1403m(4603ft)weredrilledin91dayswith423bitrunsintheinterval13662814m Twopistonbits(D2PV3IO)madethemajorityofruns(334)Theremainderofthe runs(89)weremadewithtestbitsofnewdesignsthatdrilled317m(1040ft)Two sectionturbineswithretrievablerotors(TVR38)wereusedinthetestdrilling Drillingparameterswere:pumprate3035liters/see(113132BPM)atpump dischargepressure110120kg/cm2(15611703psi);WOB1016tonnes(22,000 35,200lb);mudweight123128g/cm3;mudviscosity2526see;fluidlossupto3 cc/30min“ Averagepenetrationperrunwas33m(108ft)withapenetrationrateof36m/hr (118ft/hr)Table7presentsacomparisonofresultsfordrillingwithretractableand conventionaltriconebits Table7ComparisonofRB(Well3)andConventionalTriconeBit(well1) STRATIGRAPHICHORIZON Melekesskian CheremshanskianPrikamskian Namyurskian SerpukhovianOkskian Tulskian Bobrikovskian Turneiskian DankovianLebedyanskian ZadonskianYeletskian YevlanianLivenskian Voronezhskian AlatyrskianSemilukskian KynovskianPashiiskian MulinskianOskolskian Vorobyevskian Chernoyarskian Morsovskian Archeiskian Average inDvoyenskayaField PENET WELL No3 r 100 46 49 45 70 53 36 37 50 27 27 23 20 13 34 26 16 33 ATIONPERBIT(M) WELL ‘%0 No1 93 73 100 100 64 42 79 75 92 75 81 69 41 62 54 40 36 24 66 53 111 137 46 49 71 161 67 48 405 67 33 40 56 31 24 85 72 67 50 PENETRATION RATE WELL No3 59 43 36 38 33 57 39 34 33 33 28 24 29 29 17 33 22 16 32 WELL No1 57 42 47 52 39 25 42 33 31 31 26 29 23 26 25 19 16 17 31 M/HR) %0 104 102 75 74 85 228 69 103 107 107 107 84 125 111 68 174 138 94 103 — , ’fs “ DevelopmentofRetractableDrillBitsinRussia OneofthereasonsforlowpenetrationwithRBswashighturbinespeed Measurementswithaturbinetachometerwhiledrillingwellno3intheDvoyenskaya fieldindicated750900RPMoperationalspeedoftheTVR38turbodrillThishighRPM especiallyaffecteddrillinginlowerintervals,whichwerecomposedofconsolidatedand frequentlyabrasiverocks Twentyseventestrunswithathreesectionturbodrillintheinterval27382814m provedtheefficiencyofdrillingatlowerspeedsUtilizationofathreesectionturbodrill withmorestages(thenumberofstageswasincreasedfrom142to228)allowed reducingRPMby1520%andincreasingWOBfrom14to18tonneswhiledrillingtough clayInaddition,duringthetestruns,penetrationwithretractableandtriconebitswas muchcloser,andpenetrationrateofRBswassignificantlyimproved LowaveragepenetrationperRBwasalsoduetoutilizationofasingletypeofbit forthewholewellintervalThiswasprovedbythelargevariationofpenetrationperrun (ascomparedtotriconebitpenetration)invariousstratigraphichorizonsAccordingto Table8,penetrationwasover100%inthreehorizons,801OO!XOinone,6080%infive, 4060%insix,andbelow40%inthreehorizonsApparently,developmentofRBswith variouscuttingstructuresshouldgreatlyimprovetheirperformance Table8ComparisonofConventionalandRBsinKvasnikovskaiaField I CONVENTIONALDRILLINGDRILLINGWITHOUTPULLINGPIPE* 1 WELLYEARWELLDRILLING COSTWELL YEARWELL DRILLING COST NoDEPTH(M)RATE(RUBIM)NoDEPTH(M) RATE (RuB/M) (M/RIG(M/RIG MONTH) MONTH) I 319632822321 8421119652717 522 984 —i19663005 380 1541 i19653000400 15022819662678 315 1830 101965 ?849487 99631 19663019 387 1578 19 I 6 I1963 I 2860I295 1600!15 — 1I 1 I1 1 1 1966I 2790I“ 1922350 i319673009 371 147:8 1 I, 1 29I1972I 1, 2972 I 486 1610I2219673010 443 I1380 I 19672972 695 1212 t 50 I1972I3050407 I1770]23, 1, , 1972I 3000 I 492 1720I1919683039 405 2117 I I [ 3007310 2314 “, a 4619733071549 I196624 19682901 282 2312 421974 4019713022 308 2141 5319743020204412544 19713031 384 1810 41* 19753010 560 1880 IIf 1I 1 ! I, 1 Average** 29543981600I “Average3951 397 1692 *WellNo41intheintervalof25133010mwasdrilledbystandardmethods l*WithoutwellsNo12andNo53asunsuccessful(sidetracks) 63OilFieldTestingandCommercialDrilling(19651971) DuringtheprocessofcommercialtestingattheExperimentalTurbodrilling DepartmentofPO“Saratovneftegas”(ProductionAmalgamation)from1965to1971,26 54 DevelopmentofRetractableDrillBitsinRussia exploratoryanddevelopmentboreholes25003000mdeepweredrilledThetotal footagedrilledbyRBwasnearly41,000mintheinterval10003000mMostfootage wasdrilledintheKvasnikovskajaoilfieldwithverycomplicatedgeologicalconditions– gasandwatershows,unstableformations,cavingtendencies Table8summarizesperformanceontheboreholesdrilledintheKvasnikovskaja fieldbyRBandbyconventionalmethodswith10in(248mm)bits Developmentofthefamilyofretractabletoolswith9in(220mm)bitswasbased ondesignsfor10in(248mm)RBThesubstantialdecreaseindiameterresultedin insufficientstrengthanddurabilityofthetoolsTheproblemofincreasingtotalfootage per9inbithasnotbeensolvedforanextensiveperiodoftimeDrillingexploratory boreholesin19681969withDRB220bitsdidnotproducepositiveresults Tangibleprogresswasachievedwhentestingthreeconerockbitsof3DR220 typeandanewdesignofatwoconebit(DRB2220)Whentestedindrilling,thesebits showedappreciableincreaseoffootageperrun Theexploratoryboreholeno32anddevelopmentboreholeno41inthe KvasnikovskajafieldwerethetestenvironmentIntheno32boreholetheretractable conerockbitsmade120runsintheinterval14252407manddrilled399mA substantialincreaseinlifeandfootagewasobtainedwith9inRB Inthe11472227mintervalofboreholeno41,retractableconerockbitsmade 102runs;1054mweredrilledin218hrThatincludedthreeconebits3DR220,which drilled659min52runs,andtwoconebitsDRB2220thatdrilled392min50runs Theaveragetimedrillingwith3DR220bitswas2hr/20rein,andwithDRB2220bits1 hr/55min ComparativedataonbitperformancearegiveninTables9,10,andd1 Table9AveragePenetrationperRBRun ,, , ,, ,, ~— ,,, !!,>,, ,W ,,,, > +,,< ,,,, ,,—7:? ,,J)=<> ,,6 ,,$ —— STRATIGRAPHICHORIZON91NBIT(220MM) 10IN BIT (248MM) WELLWELLWELLWELL WELLWELL WELL No18,No2,No25,No32,No41,No23,No40, 19671968196919731975 1967 1970 PodolskoKashirsky81596472202 148 109 VereiskoMelekessky79736911515281 155 CheremshanoPrikamsko312528101 11577 80 Protvinsky SerpukhovskoOksky34252569 12845105 TulskoBobrikovsky232728523574 85 Turney202120 756263 70 DankoLebedjansky232422 8254 67 ZadonoEletsky222222 6536 85 Total:343132791036796 55 DevelopmentofRetractableDrillBitsinRussia Table10ComparisonofRBstoBestConventionalBits TOTAL STRATIGRAPHICM HORIZON I PodolskoKashirskyt242 VereiskoMelekess_ky167 Cheremshano126 PrikamskoProtvinsky SerpukhovskoOksky213 TulskoBobrikovsky49 FOOTAGE IM% 210100 343100 273100 168100 170100 148100 204100 CONVENTIONALBITSRETRACTABLEBITSINWELL41 WELLS46,53 ALLTYPESOF RBs3DR220 BITSONLY [AVERAGE) ROP FOOTAGEI ROP FOOTAGE ROP MIH 77 88 53 53 43 43 59 I %M 100202 100152 100115 100125 10035 10062 100108 m% MtH%0M 9621131528208 44479898170 42250944195 74445853131 2062046545 m% M/H 0/0 9901151554 49762704 715551038 78045849 26418419 521 I5oI1163II 643I54I915 Table11BitPerformanceinPodolskoKashirkyHorizon TiEir No 46 41 BITTYPE OFBITS M %0M/H % Regular 5K214SZG4 2901000101 1000 2K214T423079395 940 Retractable 3DR220SZ8 223770117 1158 , ItshouldbenotedthatthemanufacturingqualityoftheRBsandassociated mechanismswaslowanditwasnecessa~tocheckpartsandadjustfitbeforedelivery totherigsiteTheprimaryproblem–badconjugationofbitlegswiththebellcollarin themechanism–resultedindecreasedlifeofthebellcollarFatiguecracksappeared inmechanismholdersduetotheactionoftorquefromfrictionintheradialbearingof themechanism FollowingareconclusionsrelatedtodrillingatPOSaratovneftegas 1 2 3WhenhighdurabilityrockbitsareusedinstandarddrillingatlowRPM, drillingwithRBswithincreasedRPMmaintainsitspromisingfuture Incomparisonwithhighperformance,lowRPMrotarydrilling,RBswith DHMsareverycompetitiveundercertaingeologicalandtechnicalconditions Withfootageperbitrunincreasinginstandarddrilling,theefficiencyofdrilling withoutpullingpipewilldependontherateofpenetrationincreasewithRBs andtheactualdecreaseinfootageperbit 56 DevelopmentofRetractableDrillBitsinRussia 4TherearespecificapplicationsforRBtechnologythatcanbehighlyefficient irrespectiveofRBdrillingperformance: l Drillinguniqueultradeepwells l Drillingextendedreachdirectionalboreholeswithcomplicatedprofiles withhighanglesofinclination,includinghorizontalboreholes l Drillingwithcasingandleavingitintheboreholeasasurfaceor intermediatecasingstring l Underbalanceddrilling 64FieldTestsofDrillingwithCasing Thefirstprototype4DV295bitwasmanufacturedandtestedinWestSiberia (Figures31and32)in197475Thiswasthefourconerockbit,withconesarrangedin thetransportpositionbypairsattwolevelsTwocones(fordrillingthecentralareaof thehole)arerigidlyinterconnectedwitheachotherandtheseatingmechanism,and twoperipherallegswithconesarehingedinthemovablebodyThebitwastestedwith ahighRPMturbodrillwhendrillingforsuifacecasinginsoftformations400mwas drilledin7hrwithanaverageROPof57m/hr(187ft/hr)TherangeofROPwas30to 80m/hr(98to262ft/hr)throughdifferentintervalsTheaverageROPwitha conventionalbitis78m/hr(256ft/hr) ,, ,, , , ,, , , v m — — — Movable Cutter Sections AB Figure 31 FourConeRB4DV 295(A– transport; B– operating) = 57 DevelopmentofRetractableDrillBitsinRussia 65ScientificDrillingExperience Thefirstofthetrendsdescribedabovefordrillingwithoutpullingpipewas developedwithintheprogram“InvestigationsofEarth’sCrustandUltradeepDrilling” FieldtestswereconductedintheSputnikSD3(asatelliteoftheKolaultradeep borehole)andKrivoyRogSD8boreholes Thefirstdesignsofbitsforhardformationswerebasedonthe3DR220bitThis isathreeconebit(Figure33)withagarlandarrangementoflegsinthetransport positionTheupperleghasahingedconnectionwiththebitbodyandtwootherswith externalmoveableholdersIntheworkingposition,allthelegsarelockedinthebell collar(partofthebitbody)Workingloads(torqueandWOB)aretransmittedtothe legsbythisunitThemainmodificationswereconnectedmainlywithconecutting structure;bitdiameterwasdecreasedto217mm(85in)(thecodeofthefirstbitwas 3DR2170K) I Figure33RetractingMechanism3DR220 I Thefirstthreerunsweremadeatshallowdepths(upto300m)inharddiabases; thenexttestrunsweremadeby3DR217Kbits(Figure34)intheintervalof580700m composedofthediabasesandgabbrodiabasesinterbeddingwithtuffsHere,thebits werealsousedtoreamtheboreholepilotcoreTheresultsaretabulatedinTable12 AllrunsweremadewiththethreesectionalturbodrillTRVI98Twitharetrievablerotor androtaryspeedof500rpm 58 , DevelopmentofRetractableDrillBitsinRussia Table12RBTestsinSputnikSD3(197475) I, I 1 2 3 4 5 L6 7 8 9 10 113DR2170K,1 2 9 3DR217K,3429 3517 3441 3470 3631 3675 3688 343124922582 26482744 27442866 57985854 58786000 60006126 66656693 66936730 67306814 68726972 70917181 90 96 122 G 22 31 09 100 86 100 95 28 28 84 10190 210 575 G 085 070 033 035 150 () DRILI EM/l(NH:)Q 470 26 440 26 21026 37426 215265/46026 125465/76026 100128026 067270/42022 215/39022 200300/45022 INGPARAI P(BAR) ,, ‘,, ,, , , ,— ==?7 ,~T#,,,,,LmL,,,,,,,,,,,,, ,,r 120 120 120 140 125130 130 130 80 80 130 ,95100 S WOB m 79 79 && 89 56 5 56 56 56 56 1 When penetrationrate(andtoalesser degreebitlife)resultsweresatisfactory, theretractingmechanismdesignneededtobeimprovedThemainconclusionwasthe necessityofreducingbitrotaryspeedtoincreaseitsreliabilityandlifeForthispurpose aretrievablePDM(typeDVO142)wasdevelopedand usedinfurthertests Testsofthefirstcommercialbatchofbitswere carriedoutin1976intheinterval9531316mDuring thetests,30runsweremadewiththeRB,140mdrilled, and47mreamed,withatotaltimeofoperationsof76hr DrillingwasconductedwithaTVRI98TturbodrillOne runwasmadewithaDVO142motor9m(30ft)were reamedin60hrTestswerecarriedoutinthefollowing rocks:fineandmediumgraineddiabasesof240400 kg/mm2(341568ksi)hardness(seenoteinnext paragraph)intheinterval9531000m;siltstonesand phyllitesofupto150kg/mm2(213ksi)hardnesswas penetratedintheinterval10001143m;andgabro diabasesofupto350kg/mm2(497ksi)hardnessinthe interval11431316m Note:“Hardness”asusedintheRussianoilindustry refersto“hardnessbypunchindentation,”amethod commonlyusedintheUSSRforrockcharacterization TherelevantstandardisGOST1228866The load/deformationcharacteristicsarerecordedbasedona standardsizepunchthatispressedintoasmallblockof rockHardnessisdefinedastheloadatrockdestruction dividedbytheareaofthepunchThisparameterisnot 59 “7 I1 1 Is! i I II Figure34RBCone Assembly3DR217K DevelopmentofRetractableDrillBitsinRussia the sameascompressionstrength Performanceofthe3DR217Kbitinthreeformationswasacknowledgedas satisfactoryMaximumfootageperbitwhendrillingwas192m(63ft);maximum penetrationratefordrillingwas76m/hr(25ft/hr)andforreamingwas12m/hr(39 ft/hr)Averagefootageperbitwhendrillingandreamingwas78m(26ft)The averagebitoperationaltimewas24hr(notincludingtimelostduetoaccidents) Greatconcernwasraisedbymanyunexpectedfailuresofretractingmechanisms withholdersbreakingandleavinglegswithconesonthebottomoftheholeIn previoustestsin1975therewerenofailures,includingSputnikSD3andthePO Saratovneftegas,whereinwellno41Kvasnikovskaya52runsweremadewiththese bitswithoutfailureAftercarefulanalysisthreereasonsforthesefailureswere highlighted:1)incorrectassemblingofthebitwiththeturbodrill;2)drillingwasbegun withthebitnotyetcompletelytransferredintotheoperatingposition;and3)when drillingveryhardformations,bitlegsdisengagedfromlandingsurfacesbecauseofhigh vibrationandinzonesofholeenlargementduetocuttingsgettingbetweenbitlegs Thedesignwasmodifiedtoincreasethehydraulicforcesthatfixlegsinthe mechanism;turbodrillstartupwasalsopostponeduntilaftercompletetransferenceof thebitintotheoperatingposition Afterpreliminarytestsin1976,commercialtestsof3DR217bitswerecarriedout intheinterval7001100min19771978Altogether35runsweremadewithbitsof types“K,,,SZand!,OKII DetailedinformationisgiveninTable13Comparedwith fourconedrillheadsofthetype2VK214/60TKZinsimilarintervalsofthemainKola SD3borehole,thefootageper RB was 70!40 withthesameaveragepenetrationrate 60 E BITDOWNHOLE NoMOTOR* DevelopmentofRetractableDrillBitsinRussia Table13RBTestsinSputnikSD3(197778) DRILLINGPENETRATION ~—I ROP DRILLINGPARAMETERS~ lNTERVAL(M)(MIH) (M)DRILL REAMDRILLREAMDRL/RMQPWOB (L/s) (BAR)(TON) 1549DVO142720072232328308126403 23480DVO142728073426243314428508 3551DVOI42753075522278183300122/260285068 43816DVO142772577603527012728 5060 5,3816DVO1427760779333167197284050 6,3316TVRI98T867386881517092050160/340289510526 77320TVR198T8961902160150/40028 87313TVRI98T9024908157167/34028 97220TVRI98T9078912143150 /28728 10723TVRI98T912191725121233050220/42028130710 11728TVRI98T918292234110225025180/4002812010 12,2575DVOI4297889868805331502425505539 132599DVOI42986898730510010067090245567 142545DVO1429923993310150067265568 152609DVO1421,00781,015173775094264855811 162624DVO1421,01491,02257668311126 5055810 172620DVO1421,02281,0301733502082660751314 182598DVO1421,03011,037977408189266070614 192548DVO1421,03791,03870818133083120265060214 202543DVO1421,03901,046474467158265013 212387DVO1421,04641,05074342510126 5055313 222623DVOI421,05221,0616945501712675801314 232722DVO1421,07081,07140611604263318326 50601213 3DR217 SZBit 2416DVOI427400745252 I 433 I121I2850I78 252CVO1427640772888I85600458I140/197I2850I78 26,10IVI rR198T8589867384183 /4602810527 77111lTVRl!Xl~ 868886930505010028 100 r 871587452505092025270/36028 10045 1 L 2811tiR1981 2911TVR198T8758879032067 1480281055 305TVR198T879088243418117050290/360281055 318 TVRI98T8836888145225 /200 328DVOI4299721,001846925050264555411 334DVO1421,00181,006244100804026384080814 3DR217OKBit 3469DVOI427223728057 I367 I1542845I48 3570DVO142 I7342740058 I1450 I1292850I78 Total 6421367 DVO142=RetrievablePDM thatTVRI98T=Turbodrillwithretrievablerotor(3powersections) Theaverageperformanceof3DR217KbitsisgiveninTable14Despitethefact penetrationratewaslower,theuseofPDMsincreasedbitlifesubstantiallyAfter 61 ,—m e—~—rr T,s— w DevelopmentofRetraceableDrillBifsinRussia anothermodificationoftheretractingmechanism,theproblemsrecurredThe connectingunitbetweenthemovableholderandhousingbymeansofaspringring turnedouttobeunreliableBecauseofconsiderablevibrationonthehardbottom,the holderoftenbecamedisconnectedfromthehousingThissometimesresultedin pullingoutthedrillpipeBytheendoftests,thisdefectwaseliminatedbyanewly proposedswiveltypeconnectionusingspecialbushings Table14Resultswith3DR217KRBinSputnikSD3 RETRIEVABLEDOWNHOLEDRILLING NUMBEROFPENETRATION ~BITLIFE BITSUSEDPERBIT~M) (M/tiR)~ TurbodrillTVR198T866924 652527519 720783 PDMDVO1429871072 1376014553 I In1986,the3DR217Kbitwithimprovedmechanism3DR220(Figure35)was usedinpilotdrillingintheKrivoyRogultradeepboreholeTwobitswereusedinthe interval18531857mwhichconsistedofveryhardferruginousquartziteof520kg/mm2 (738ksi)hardness(seenoteonpage59)ComparativeresultsareshowninTable15 Atgreaterdepths,alsoinveryhardplagiogranites(420650kg/mm2(596922ksi) hardness)sixmorebitswererun(Table16)DrillingwasconductedwithlowRPM retrievableDHMs:gearreducerturbodrillsTRV142(fourbits)andPDMsoftypeDVO 142(twobits) Swivel Choke IFigure35AdvancedRetractingMechanism3DR220] 62 , DevelopmentofRetractableDrillBitsinRussia Table15BitPerformanceinHardQuartzite(KrivoyRogSD8) BITTYPE AND IDTURBINEDRILLINGNo~VG TYPElNTERvALOFPENE (M)BITS TRATION USED(M) Diamondcore3TSSh184142215 bit ISM214,3/6019518457 T2 FourconeTCIA7GTSh184574180 curebitKS18529 TKZ(pilot coring) RetractablebitTRVI42185292190 3DR217K(1gear)18567 (reaming) 3TSSh195–7YinODconventional3sec AVG BIT LIFE (HR) 105 69 52 25 RF :M/HR) 020 026 046 076 DRILLINGPARAMETERS Q\P\ WOB]RPM :Us) (BAR)(TON) 308068640 308068300 25703590 2580810300 CORE RECOVERY % 100 76 75 cmturbod A7GTSh7%inODregularturbodrillw/2powersectionsandonesectionofhydraulicbreaks TRV142–56AinODretrievablegearreducerturbodrill Table16ResultswithRB3DR217KinKrivoyRogSD8 DOWNHOLEDRILLINGPENETRATIONBITLIFE ROP DRILLINGPARAMETERS MOTORlNTERVAL(M)(M)(HR)(kI/H)Q (L/s)(BIR)::N: 1 TRVI422,54572,549442300140257024 2TRV1422,54942,55454613334525955 3TRV1422,55452,54944212533625905 4TRV1422,56073,56696232519025903 DVO1422,60892,610920250 08030802 DVO1422,61092,61292027507330802 4 , , ‘,, ,, , ,, ,“, ,, , ,,, ,,, , ,, ~~ ,,7 , ,~ , ——— , PerformanceobservedwasworsethanintheboreholeSputnikSD3duetotwo factors:1) morecomplicatedgeologicalconditions(veryhardformationsandinclination anglesat thebottomfrom6to15°)and2)bitcuttingstructureswerenotcompletely wornThebitwasoftenpulledoutoftheholetocheckthemechanismconditionand observethewearInaddition,thesewerethefirsttestswiththegearreducerturbodrill, andthelackofexperiencesometimesresultedinbitsbeingpulledprematurely The3DR217Kbitwiththe3DR220retractingmechanismwastheprincipaltool fordrillingandreamingholesinoffshorescientificdrillingtechnologyseatrialsonthe drillship“Bavenit”in1991Thisbitdrilled1474m(57%ofthetotalfootageinthe expedition)including935m(307ft)drilledand539m(177ft)reamedaftercoring 63 DevelopmentofRetractableDrillBitsinRussia LowRPMDHMssimilartothoseusedintheKrivoyRogboreholewereappliedDuring testing,threeretractingmechanismsandfivebits(Table17)wereused,ofwhichonly fourbitswerewornTheaveragefootageperbitwas364m(119ft)during106hours Table17Resultswith3DR317KinOffshoreScientificDrilling(1991) BIT No BOREHOLE/NUMBERPENETRATION(M)TIME (HR) ROP (M/HR) 3DR2203DR RUNNoOFRUNSDRILLREAMDRILLREAM DRILLREAM MECHANISM217K CONES 1 482B/1;2B/4;3106109410150258 727 2B/7 1562B/1O;4B;4150 65675100 322 650 4G;4D 122894E/1;4E/5;74232501076492322 508 6B;5/11; 5/15;5/1;518 Subtotal14 67842402161742314 571 292A1 170292052 033’ Subtotal1170325 052 322776C/1;7/1;42401150103530232 383 7/4;716030’ Subtotal4240115010653,0232 383 TOTAL19935053903482i042269 517 063’ *Additional timeforreamingboreholetonominalsize Therewaspracticallynocuttingstructurewear(exceptforsomebrokeninserts); thebitswerechangedbecauseofconeplayandlossofdiameterOfthethree3DR 220mechanismsused,onlyonemechanism(no3)remainedinworkingcondition Mechanismsno1(worked29hr)and2(worked325hr)requiredchangingthelarge holderTherewereatotalof19runsmadeoftheRBEventhoughthebitswere manufacturedin1977,theirdesignturnedouttoberelativelyefficientfortestingthe technologicalconceptsofbarerockspuddinganddrillingdeepwaterboreholesinhard formationsAcomparativeevaluationofRBtestconditionsinavarietyofareasis shownintheFigure36 ThefirstoffshoredrillingexperiencewithRBsinitiatedacommercialapplicationof thistechnologyinoffshorestratigraphicdrilling 64 DevelopmentofRetractableDrillBitsinRussia 12 11 10 9 38 — v, I 57– S I ,:6 0 m L5 2‘ 4~ — , 3 —v # ~ h I I — II , +——”!””~—; ,, ‘,’ , ~, ~’” , —— ,, ,, , ~ —m ,, ,, ,, ,,!,,,,, _ — — — 1 1 I IADC Code 425243435482 51526133 616284 1234”56 78 9 1011ii HardnessIndex Areas/RockProperties 0AtlanticOceanBedintheDS“Bavenit”expedition ~Kvasnikovskayaoilfieldintheinterval10003000m oKolaSG3holeintheinterval7701280m @KrivoyRogSG8holeintheintervals18501860mand25002600m Figure36PhysicalandMechanicalPropertiesofRocksversusDrillBitTypes 66OffshoreStratigraphicDrilling ThreeconeRBsoftypes3DR217K and SZwereusedinthestratigraphicdrilling projectofIKU PetroleumResearch (Norway)in1993Thiswasthefirstfieldtestofthe CompleteCoringSystem(CCS)indeepwaterenvironmentsTheNorwegiandrillship 65 DevelopmentofRetractableDrillBitsinRussia “Bucentaut’wasusedforthisprojectWaterdepthwasabout1500m(4921ft),and welldepthintherangeof150200mTotalfootageofboreholereamingintheintervals composedofconsolidatedsandstonewas363m(119ft)inthreerunswithanaverage generationrateof27m/hr(89ft/hr)Whilespuddingthetestborehole,3DRdrilled 102m(33ft)inclaywithanaveragepenetrationrateof136m/hr(45ft/hr)(Table18) Table18Resultswith3DR317KinOffshoreStratigraphicDrilling(1993) PENETRATION(M)TIME(HR)PENETRATIONRATE BOREHOLE/RUNNORUNS(MIHR) DRILLINGREAMINGIll DRILLINGREAMINGDRILLINGREAMING DrillingintheNorwegianSeafromDS“Bucentaur” 1B1131128417306 1B1461215135159 2/4/5120058345 3/4/2107067104 Testdrilling1102075136 Subtotal51093631421825768195 DrillingintheStraitofGibraltarfromDS“Bavenit” 3B14510543 3C1404010 3H12520812 6A17013552 6B16037516 Subtotal52401223196 Total 1 In1995,whiledrillingtestboreholesintheStraitofGibraltar,fiverunstospud boreholesonthehardseabedcrustweremadewitha3DR217SZbitat300m(984ft) waterdepthTotalpenetrationoftheserunsinhardcarbonaceousrockwas24m(79 ft)withanaveragepenetrationrateof266m/hr(87ft/hr)Nofailuresofretractable mechanismsorbitswereobservedInaddition,theretractablereamertypeRVA217 withPDCcutterswassuccessfullytestedduringthisprojectaswell RBswithDHMswereconsideredasthebestmethodtospudboreholeswithouta seabedframetoguidetheBHAifsoftsedimentswerenotoverlyinghardrocks 67BenchTestsforODP TheexperiencesdescribedaboveledtothedevelopmentofatriconeRBthatwas abletoimprovetheabilitytospudinanddrillwithcasinginhardunconsolidatedbasalt rocksattheoceanfloorDuringtheOceanDrillingProgram(ODP)fieldtrials,this problemwasencounteredwhilespuddinganddrillingintheseconditionsevenwitha guidebasepresent 66 DevelopmentofRetractableDrillBitsinRussia TriconeRBs weredevelopedunderacontract betweentheAquaticCompanyand TexasA&MResearchFoundation(ODP)TwoRBsweremanufacturedattheVNIIBT plantinLubertsi(Moscowregion)TestingoftheRBwas conductedatVNIIBTbench drilling riginPovorovka(Moscowregion)inJulyandAugust1994Theshoeandtest subweresuppliedbyODP TheRBwas designed forODP’SlargediameterBHAThetriconeRBwasone componentofthesystemdevelopedforspuddingintobarerock,whichisolatesthe upperunstableportionoftheformationTriconeRBsalloweddeploymentof10%in drillcollarstosupportafracturedbasaltzone ThedesignoftheRBprovidedforitsusewithavailableBHAhardware:a mechanicalbackoffsub,seafloortemplate,and103AindrillcollarsThemain exceptionwasthemethodofconnectingthebittothebackoffassemblyThebitwas connectedviaacrossoveradapterand63Aindrillcollars10%indrillcollarswere alsoprovidedwiththespecial shoe ThisRBrequiredonlyone wayoperationAssemblingthe BHAwiththebitandlatchingthe bitintotheoperating(working) positionwascompletedonthe drillfloorpriortoloweringthebit andBHAtoaseafloorThe conventionalODPprocedures couldbeusedforrunning, spuddinginanddrillingwithan RB(Figure37) After10%indrillcollars latchedintheseafloortemplate, theRBwasremovedfromthe 10%indrillcollarsusingadrill string TransferoftheRBfrom theoperatingtothetransport positionwasmadebythecollet contactingtheshoe ThedesignoftheRBhad beenmodifiedtomeetODP designrequirementsAbrief descriptionofthetriconeRB designandsometechnical all ,, , , ,,, ,, ,’” ?,,,, — ? J,>” ! , ,J , ,’, —’ —— 1I ‘!1 I I IIEES1’ IEI\, llE+x $,I u Figure37TRB300OperationalSchematic (left–drillin;rightbackoffandretrieval) 67 , DevelopmentofRetractableDrillBitsinRussia characteristicsaregivenbelow TechnicalCharacteristicsofTriconeRBs: 1Bitoutsidediameter 2 BitODinthetransportposition 3 Bitlength 4Bitlengthinthetransportposition 5Strokeofmovablepartsofbit 6 Shoelengthwithdiamondbit 7 ShoeODbody 8 Spiralblades 9 ShoeID 10Weightofbit 11Connectingthreadto6%indrillcollars OperatingCharacteristicsofTriconeRBs: 1Weightonbit(maximumforbit) 2 Rotationalspeed 3Flowrateofwater 4Pressuredropacrossthebit300Mmm(1113/16in) 185mm(73in) 3250mm(128in) 3800mm(150in) 550mm(216in) 28655mm(113in) 273mm(10%in) 2953mm(1 15/8 in) 1873mm (7’3/8 in) 540kg(1214lb) box5%inFHfor5%inFHModifyPin upto20tonnes(44,100lb) 80120RPM 400500gal/rein 1220bar(170285psi) ThetriconeRBconsistsofanexpandingmechanismandthreereplaceableroller conecuttersectionsWhiledrilling,thebitisplacedinsidetheshoe RetractingMechanism:TheretractingmechanismoftheRBinstallsthecutter sectionsintotheoperatingandtransportpositionsIntheoperatingposition,the sectionsarejoinedtogether;inthetransportposition,thecuttersectionsarestacked oneabovetheother(likeagarland)Eachcuttersectionisattachedtoaspecificpart oftheretractingmechanism 68 , DevelopmentofRetractableDrillBitsinRussia Barrel:ThebarrelisthemainelementoftheretractingmechanismAllother componentsaremountedonthebarrelThebarrelhasacentralbore,oneorhvoports iorjetnozzlesintheuppersection, two portsinthemiddleandtwosetsofthreadsfor connectingtoa63AindrillcollarandforaconesubInthecentralbore,twosteel nozzlesareinstalledinseries ConeSub:TheconesubisconnectedtothelowerendofthebarrelItperforms severalfunctions:thearmAismountedintothesub;weightonbitandtorqueare transmittedbythesub;andthesubjoinsthethreearmstogether TwocatchesareplacedinsidetheconesubOnerestrainsthepivot;theother maintainstheshortholderintheworkingpositionwhiletheholderismovingtothe transportposition MovingParts:Themovingsystemoftheretractingmechanismisplacedoutside thebarrelandconsistsofseveralthreadedparts:holder,holderbushing,colletwith colletsub(oneunit)andshortholderTheholderkeepsthelowerarmC;theshort holderkeepsthemiddlearmB Theretractingmechanismhasadditionalparts:pivots,seals,rings,bushings, washersetc Twodifferenttypesofconecuttingstructuresweredesignedfordrillingin fracturedbasaltandforgraniteblocks CuttingStructureforBasalt:Mediumextension,70°conicallyshaped,closely spacedinnerrowinsertsandhemisphericalgagerowinserts DrillingAction:Primarilycrushingandchipping(somescraping) CuttingStructureforGraniteBlocks:hemisphericalshapedinserts Bearing:Nonsealedrollerball/rollertypeJournalangle39°,offsetangleOO HardfacingforArms:fivetungstencarbideinsertspositionedaroundtheplug Conicallyshapedinsertsallowsatisfactoryratesofpenetrationwithverylowweighton bit TheRBsweremanufacturedattheVNIIBTplant(20kmfromMoscow)Thisplant specializesintheproductionofdifferentdrillingtools,includingdrillbits Tworetractingmechanismsweremanufactured,alongwithtwosetsofcutter sectionsandtwosetsofadditionalconesTwofabricatedsetsofconeshadcutting structureswithconicalinsertsandtwoothersetshadhemisphericalinsertsThe conicalinserts(diameter1414mmxlength197mm(056x078in))weresuppliedby ODP 69 DevelopmentofRetractableDrillBitsinRussia Afterassembly,factorytestsofthebitswereconductedThebitsweretransferred totheoperatingandtransportpositionsTheODofthebitintheworkingpositionwas checkedwithaspecialgagewithID300mm(118in),andinthetransportposition withtheshoebushing TheinitialtestsofthetriconeRBwereconductedattheVNIIBTbenchdrillingrig onJuly29August9,1994Thetestsitewaslocatedabout50kmfromMoscowThe benchdrillingrigisastandardrigwithspecialfacilitiesfortestingdrillbitsanddownhole motors Thetechnicalcharacteristicsoftherig: derrickheighttocrownblock53m(174ft) l pump(s)output5100 !/S (781587GPM) l weightonbitupto30tonnes(66,150lb) l rotarytorqueupto150kNm(110,630ftlb) Controlledandrecordedparameters: l l l l l Allweightonbit torque pumppressure pumpoutput rotaryspeedofarotarytableormotorshaft testswereconductedinaccordancewithODP’Sprogramandrequirements Theprogramincludedthreetestphases: 1Thefirstphaseprovidedforassemblingthebit,shoe,testingsubandPDM togethertoensurecompatibilityandinterchangeabilitybetweenallthe manufacturedhardwareThistestensuredthatailcomponentsofthesystem weredesignedandfabricatedcorrectlyThemethodoftransferringthebitto theoperatingandtransportpositionswasdeveloped 2 Thesecondphaseincludeddrillingaminimumof20m(66ft)ingranite blocks,retrievingthebitfrominsidethe10%inshoe,andcheckingthebit gageTwograygraniteblockswereusedfortestingThepropertiesofthe drilledgranite:density=267268g/cm3;porosity=12!X0 Rockhardnesswasevaluatedbythestrengthincompressionp=P/S,whereP= breakingstrength(kg);S=areaofpunch=314mm’Apunchwith2mmfoot diameterandupto3000kgloadingwasusedForthisgranite,p=330kg/mm2(468 ksi)(seenoteonpage59) 70 , DevelopmentofRetractableDrillBitsinRussia Duringthetests,18holesweredrilledintwoblocksThebitwasretrievedwithout problemfrominsidethe10%inshoefivetimesafterdrillingthefirstfiveholesandafter drillingthelastholeWhiledrilling,WOBwasmaintainedwithintherange4555 tonnes(9,92012,130lb)TheROPvariedfrom138m/hr(45ft/hr)(newbit)to0262 m/hr(086ft/hr)BringingWOBupto12tonnes(26,460lb)resultedinanincreasein ROPupto226m/hr(74 ft/hr)althoughthecutting structurewaswornoutA totalof2018m(6621ft) weredrilledintwogranite blocks;cumulativedrilling timewas3668hrThe TRB300intheoperating position, includingan assemblywithshoe,is showninFigure38 Thus,themaintasksof theprogramwereaccomplished,Figure38TriconeRBTRB300 providingfordrilling20mwithan averageROPnotlessthan05m/hr 3Thethirdphaseoftestingaddresseddisassemblingandcheckingdull conditionofcutters,bearingsandhardfacingonthebit Afterdrilling,thesystemandbitweredisassembledTheretractingmechanism hadpracticallynowearandcouldbeusedagainThecuttersectionshadworncutting structuresandshellofconesbetweentungstencarbideinsertsontheInnerHeelRows OnetungstencarbideinsertwasbrokenAbout23mmwearwasfoundinsomeareas onthebackfaceofthe armsThebearings hadpracticallynowear Figure39showsthe TRB300coneassem blyafterdrilling TheconeCwas removedfromthearm andthebearingwas examinedThediamet ersofthejournaland theconeballandroller racewayshadwearof about01015mm I Figure 39 RBTRB300ConeAssemblies I Afterinspection,theretractingmechanismwasreassembled 71 ,, ,, ~— ~r,m,~~ >,>hr,,!,: ,,?,,/ & —~,tzm, ,? ,,, ” TT— DevelopmentofRetractableDrillBitsinRussia 68DemonstrationofRBatMaurerEngineeringInc AtriconeRBofthetype3DR220wastestedatMaurerEngineering’sDrilling ResearchCenter(DRC)inHoustoninJanuary1999Thetestwasconductedaspart oftheproject’stechnologytransfertasksTheprimarypurposeofthetestswasto demonstratethepotentialoftheRetractableBittotheUSAdrillingindustry AhorizontaldrillingteststandattheDRCwasusedforthetestsFigure40shows thestandwithRB3DR220installedDemonstrationtestsincludedthefollowing operations: 1 Transferringthebittotheworkingpositionhydraulicallyandmechanically 2Drillingamarbleblock 3Mechanicallytransferringthebittothetransportposition I Figure40RBinTestStandforDemonstrationinHouston I 72 DevelopmentofRetractableDrillBitsinRussia [naddition,specialtestswereconductedtodetermineRBperformance characteristicsCarthageMarbleandTexasPinkGraniteblocksweredrilledwitha rangeofdrillingparameters Figure41summarizesrateofpenetrationversusweight onbitforthesetests 40 35 30 10 I I I I t CarthageMarble;150RPM;600020,000lbWOB;120GPM ————— ———— — P u ———— “ ,———— ________ — <———____ Sco3 ?Om9om llcmo 13XU Ixoo 17CC0 19(XO a!lwdghl(uls) 25‘l ! PinkGranite;150RPM~3~fi&B~ 1I— 20 asm c = 3000 500070009000f100013000 15000 17000 19000 Bit Weight(Lbs) Figure 41 RBDrillingTestsinHouston 73 y> ,, ,, ,em, — —— < ,,, DevelopmentofRetractableDrillBitsinRussia 74 7Underreamers 71Introduction Russianexperienceapplyingretractablebits(RB)allowedthesuccessful developmentoftoolsforunderreamingboreholestodiameterslargerthantheprevious casingstringThistechnologyhasgainedwideacceptanceintheUSSRExpandable reamers(ie,underreamers)havebeendevelopedandwidelyusedsince1975,to reammorethan100,000m(328,000ft)indeepdrillingareasthroughouttheUSSR 72FieldofApplication Anexpandableunderreamerisadrillingtoolwithworkingmembersthatcanbe positionedinthetransport(closed)positionwhenthetoolisruninandpulledout,orin theoperating(opened)positionwhenthetoolcuttersreamtheboreholeAspecial mechanismtransfersworkingmembersfromthetransportpositiontotheoperating positionThereamerODinthetransportpositioncorrespondstothetoolhousingOD Intheoperatingposition,theworkingmembers(armswithcutters)comeoutfromthe housingandexpandtothedesigndiameteroftheborehole Becauseofthesefeatures,thetoolcanreamanyintervalofapredrilledholetoa diameterlargerthanthediameterofthecasingrunandcementedabove Underreamers,unlikedrillbits,areauxiliarydrillingtoolsHowever,theirapplication allowsresolvinganumberofproblemsencounteredindrilling Expandableunderreamersmaybeusedinthefollowingoperations: l Boreholereaminginaproductivehorizonintervalforasandscreen l Boreholereaminginproblemintervals,suchaslostcirculation,rock bulging,caving,tosetisolationtools,cementbridgeplugs,etc Runningdownamarinedrillingtemplatewithsimultaneousdrillingofthe borehole Intheminingindustry,reamingaholeforhighpowerblastingcharges withtheupperintervaloftheholenarrowerthanthelowerinterval Expandableunderreamersweremostwidelyusedin complicatedgeologicalconditionsThesewellsrequire intermediatecasingstrings,sometimesfourorfiveormoredrillingdeepwellswith runningdownseveral Expandableunderreamersallowchangingawelldesignandusingcosteffective wellconstructiontechnologyTheinitialdiametercanbeshrunktocorrespondtothe designeaboreholeorproductionstringsizebyreducingradialclearancesbetweenthe adjoiningstringsAnexpandableunderreamerprovidestherequiredradialclearance 75 DevelopmentofRetractableDrillBitsinRussia betweenthecasingstringandwallsoftheborehole,whichenablestroublefreerunning andcementingofacasingstring Changingaboreholedesignbyreducingitsoriginaldiameterallowssavingmetal andothermaterialsThisalsoenablesutilizingalowercapacitydrillingrigThus,with dueconsiderationtoreamingcosts,expandableunderreamerseventuallymakewell constructionmorecosteffective 73DesignsofExpandableUnderreamers De:ignsofexpandableunderreamersdifferinboththetypeof workingelements (coneorblade)and thedesignofthemechanismthattransferstheworkingelements fromthetransporttotheoperatingpositionandback Variousdesignsofarmswithconecuttersandtransfermechanismsledto developmentofseveralclassificationsforexpandableunderreamersEachofthese classificationsisusuallybasedonmosttypical(fromthedesigner’spointofview) designfeaturesAmongthesearetypesofconecutters,methodsoftransfertothe operatingandtransportpositions,methodsofapplyingforcetotheunderreamer’s movingparts,etc Belowisthe industrystandard Theclassification mechanism,as positivecutter elements Accordingclassificationofexpandableunderreamersthatcorrespondstothe OST3916784oftheformerMinistryofOilIndustryoftheUSSR isbasedonthedesignfeaturesoftheunderreamerretracting relatedtothepilotguideTheclassificationcoversunderreamerswith orbladeopeningbydirectpumppressureappliedtothemoving tothestandard,expandableunderreamersaresubdividedintothree types: RRA,RRB,andRRV TypeRRAincludesconeandbladetypeunderreamersthatcanbeusedin combinationwithapilotbit,whichenablesboreholedrillingandsimultaneousreaming Figure42presentsaschematicdesignofRRAunderreamers 76 DevelopmentofRetractableDrillBitsinRussia Dr ; TransportOperating“ i % \ / D&, * Transport, L I / D< Operating RockConeTypeBladeType I Fimre42TypeRRARetrievableUnderreamerI TypeRRBincludesconeandbladeunderreamerswithoutapilotguideThistype ofunderreamerisusedforreaminganyintervalofadrilledborehole(Figure43) ( “5!23 “4 Dw &_lT~ansport 1) J Operating dTransportOperating RockConeTypeBladeType IFigure 43TypeRRBRetrievableUnderreamerI 77 ,’ ,,, , , ,, , ,“, , DevelopmentofRetractableDrillBitsinRussia TypeRRVincludesconeandbladeunderreamerswithapilotguidethatarealso usedforreamingapreviouslydrilledhole(Figure44) Transport~ Operating Transport mu Operating RockConeTypeBladeType Figure44 TypeRRVRetrievableUnderreamer Severalgroupsofdesignengineershavebeendevelopingexpandable underreamersRRBunderreamersweremostwidelyusedintheUSSRoilindustry Whiledevelopingthistypeofunderreamers,VNIIBTspecialistsusedtheirexpertisein RBdesign RRBunderreamersareprimarilyusedforreamingacontinuousboreholeinterval beforeacasingstringisrunFigure45showsoneofthemosttypicalmultistring designsofadeepwellthatwasimplementedwithRRBconeunderreamers Expandableunderreamershavebeenfoundtoallowmoreoptionsfor implementingwellcasingprograms 78 DevelopmentofRetractableDrillBitsinRussia CASINGPROGRAM KOHCTPYKIJHHCKBA)KHHH Mdqameaxc 620,720 MM Casing 2440+28346” Aosfolo490559MM Bit193’’22” Ko_p426 MM Casing 16772” flomnn393,7 MMT Bit151/2” KOJIOHW3 324,340MM Casing16,772,133/8” Aonom 295,3 MM Bit11626” pticu[npll?elhPI% 295/345 UnderreamerPP6295/345 Konomra273w Casinglo 3/4” gono~o 244,5MM Bit518W PacmapmenbPPE2431285 UnderreamerPP15243/285 Kononna 219MM Casing8518” Aonom 190,5w Bit71/2” Pacunipnl’en%Pm190/230 Underminer PP6190/230 XBOCTOBHIC168 MM Liner65/8” Aonom139,7MM,, s ,77< —,3 ,,,, , y ,, – 1 I I I BitS 314* L1 1 I I i I 1 I Figure45TypicalCasingProgram forReamingOperation I 79 DevelopmentofRetractableDrillBitsinRussia Since1972,specialistswithinVNIIBThavedevelopedarangeofRRBtype expandableunderreamersTable19presentsbasicsizesDesignsofvariouslysized underreamersarethesameinprinciple Table19DimensionsofRRBUnderreamers UNDERREAMERCUTTERTYPEDIAMETER (MM) TYPE TRANSPORT POSITIONOPERATINGPOSITION RRB161RRBI61/200S;ST160200I RRB190RRB190/230MS;S;ST188230 RRB215RRB2151255M;S;SZ212255 RRB243RRB243/285M;MS242285 RRB295RRB295/345M;MS292345 Thenumberintheunderreamertypedescriptorindicatesthediameterofthe reamedholeAdoublenumberintheconetype(eg,161/200)indicatesthediameter ofthereamedholeandtheunderreamerdiameterintheoperatingpositionLettersin theconetypereflectthecorrespondingformationhardness: M=softformation MS=softformationwithintercalationofmediumhardrock s=mediumformation ST=mediumformationwithhardstringers Sz=mediumformationwithabrasivestringers Selectionofanunderreamerdiameterintheoperatingpositionisdictatedbythe necessitytoprovidetherequiredradialclearancebetweentheboreholewallsandthe casingstringItalsodependsonthewidthofthedrilledshoulderthatguarantees troublefreeoperationofaconeunderreamerwithoutapilotbitTheseparametersare summarizedinTable20 Table20RRBUnderreamerApplicationRecommendations ~ UNDERREAMERODOFODOF ODOFCASINGRADIALCLEARANCEWIDTHOF TYPEHOLE(MM)REAMED THATCANBEBETWEENBOREHOLEDRILLED HOLE(MM) RUN(MM)ANDCASING(MM) SHOULDER(MM) RRB161161;165200 1403020;175 RRB1901905230 168;17831;26 20 RRB2152159255 19430 20 RRB243243;2445285 21933 21;20 RRB295295334527336 25 1 80 DevelopmentofRetractableDrillBitsinRussia Figure46showsanRRB215underreamerinthe positionsAlsoshownissectionAAoftheconesection descriptionofRRBunderreamerdesignandprinciplesof underreamerasanexampletransportandoperating attachmentBelowisa operationusedwiththis — D=255 — 1 Operating \J_ 7 6 AA 1 ,, ‘,, ,, , ,, , ,“ VL~,,,, T—? ,,4, ,”, D=2Y2J Transport Figure46TypeRRB215Underreamer Theunderreamerhasasystemofmovingelements(1)outsidethehousing(2) connectedthroughasub(3)tothedrillstringCones(4,“5;and6)onaxles(7)are locatedinslotsoftheholder(8)Inthetransportposition,thesystemofmovableparts (1)withconeassemblies(4,5,and6)isinthelowerposition,retainedbyaspring loadedrod(9)thatpreventsupwardtravelWhentheunderreamerisruninahole,the centralmudcourseintherod(9)isopened,whichallowsfluidcirculationwhilethe underreamertravelsinsidethecasingstringinthetransportposition Whentheunderreamerreachestheopenhole,itistransferredtotheoperating positionbypumpingdrillmudAvalve(1O)isdroppedintheholeforthispurpose Whenthevalveenterstheseat,differentialpressurepushesarodsemirotarypiston andmovestherodtotheupperposition,releasingthearmassemblies 81 DevelopmentofRetractableDrillBitsinRussia Simultaneously,pressuredropaffectsthesemirotarypistonandmovesthesystem upwardWhenthestringisrotatedandsmoothlyrundown,rollingcutterscutinthe boreholewallsandassumetheiroperatingpositionsPressurerequiredfortherolling cutterstocutintotheboreholewallis56MPa(725870psi)Operatingpressuredrop acrosstheexpandingmechanismis1020MPa(145290psi)Drillingfluidisdirected throughholesinthearmstotheconecutters AnimportantfeatureoftheRRBarmisaleverofthefirstorderTaperedsurfaces ofallthreearmsaremachinedtogether,whichallowsachievingfirmattachmentofthe armstothemechanismintheoperatingpositionAxialloadistransmittedthrougha taperedsurfaceinthelowerpartofthebarrel(2),andtorqueistransmittedthroughside surfacesoftheslotsintheholder(8)Theinternalsurfaceofeacharmisshapedtoa dihedralangle Aslidevalve(11)controlstransferoftheunderreamertotheoperatingposition, openinganadditionalwatercoursefordrillmudintheoperatingpositionPressure dropsof35MPa(435725psi)inthedischargelineindicatethattheunderreamerhas transferredtotheoperatingposition Rotaryspeedwhilereamingis70110RPM Thereameristransferredfromoperatingtotransportmodesbyfrictionbetween theoutermovingcomponentsandtheboreholewallswhenthedrillingtoolismoving up,orduetointeractionofconesectionswiththecasingshoeabovethereamed interval Sinceanunderreamerhasasystemofexternalmovingparts,theforce requiredfortransfertothetransportpositioniscreatedbypickingupthedrillstring Asmentionedabove,RRBunderreamersdonothaveapilotguideThisallows usingconesofmaximumdiameterwithstrongbearings,whichisparticularlyimportant whilereaminglongintervals Conesectionshaveaconventionalbearingscheme:ball/roller/roller Theretainingballbearingofanunderreameroperatesinadifferentmannerthan inadrillbitTheresultantforceappliedtotheconeisdirectedtotheunderreameraxis andtendstodisplaceaconewithawornbearingtowardthecenter Table21showsoperatingparametersrecommendedforunderreamers 82 DevelopmentofRetractableDrillBitsinRussia Table21OperatingParametersforRRBUnderreamers UNDERREAMER AXIALLOAD PRESSUREDROP(MPA) (KN) DRILLIN REAMING RRBI6150 561020 RRB19060561020 RRB21580561020 RRB24390 561020 RRB295120 561020RPM 70110 70110 70110 70110 70110 UnderreamersweremanufacturedattheVNIIBTexperimentalplantinthecityof KotovointheVolgogradregionConesectionsweremanufacturedattheVNIIBT experimentalplantintheMoscowregionandDrogobychBitPlantinthewesternpartof theUkraine 74RRBUnderreamerApplications IntheFormerSovietUnion,RRBtypeexpandableunderreamerswereusedin deepwellsinoilfieldsintheNorthCaucasus,Azerbaijan,WestKazakhstan, Turkmenistan,andotherregionsExpandableunderreamerswereusedforreaming oneorseveralintervalsoftheborehole,dependingongeologicalconditions,well depths,andcasingprograms Overtheperiod19751991,thetotalreamedfootageindeepwellintervals between16505750mwasmorethan100,000m,asmentionedpreviouslyAfterthe collapseoftheSovietUnionandrapiddecreaseindeepdrillingactivity,especiallyin theNorthCaucasus,underreamershavebeenutilizedonlyoccasionally RRBO~erationsbvGrozneftDrillinaandProductionCompany DrillingcrewsfromGrozneftintheChechenRepublicconductedmorereaming thananyothergroupintheUSSRFigure45presentedatypicalwelldesignintheoil andgasfieldswhereunderreamerswerewidelyusedTheintervaldrilledwith2953 mm(116in)bitswasreamedbyRRB295/345to345mm(136in)for273mm(103A in)casingTheintervaldrilledwith2445mm(96in)bitswasreamedbyRRB 243/285to285mm(112in)for219mm(85\&in)casingTheintervaldrilledwith 1905mm(7%in)bits was reamedbyRRB190/230to230mm(9in)fora168mm (6%in)casingstring A2445mm (9~8h) stringwasrun~insomewellsinsteadof273mm(lO%in) casingTheintervalbelowwasdrilledwith2159mm(8%in)bitsandcasedwitha 1937mm (75/8h) stringPriortocasingbeingrun,theboreholewasreamedbyan RRB215/255underreamerto255mm(1Oin)Theperformanceofthese underreamersisdescribedbelow 83 , ,, ,> ‘, , , : , — ,,,, , T , ,7— _,_ DevelopmentofRetractableDrillBitsinRussia AnRRB295/345reamedmostintervalsUnderreamerswithRRB295/345MS conesectionsreamedintervalsinthedepositsofLowerChokrakandUpperandLower Maikop,whicharecomposedofsoftandmediumhardclay AnRRB295/345reamedboreholeintervalsat16504760m(541315,616ft)in variousfieldsTable22showstypicaloperatingparametersofthesereamersbasedon informationfromseveralwells:wellno139 –Pravoberezhnaya,no238– Oktyabrskaya,andno67–Braguny AccordingtothedatainTable22,muddensitywasover2000kg/m3(167ppg) andaxialload(weight)ontheunderreamerbelow10tonnes(22,000lb),sinceweight increasescausefrequentstallingofdrillingtoolsaswellaslongitudinaloscillations Largedifferencesinunderreamerpenetrationratesareexplainedbyconditionsinthe reamedhole,whichoriginallyhadalargenumberofcavities Intervalsat25005500m(LowerMaikop)drilledwith2445mm (g5/8h) bitswere reamedbyRRB243/285underreamersfora219mm(87&in)casingstringTable23 showsperformanceresultsofexpandableunderreamersRRB243/285MSfromseveral wells ThescopeofutilizationofRRB215andRRBI90expandableunderreamerswas limited 84 i , Table22 DATE NoNoOF YREAM 1979 OFCWTER FROM URS SECTION 2628 152,953 Auqust 2830 153,433 Auaust 0203 254,102 Sept & 0810 112,540 ~March 1 2628 22 3,046 March 2930 12 3,633 March 0709 233,951 Amil ! 2124I21I2,690 ~erformanceofRRI *D INTERVALM REAM TO TOTALTIME (HR) 3,43348090 mDataforUnderreamer 3,3248342675 3,898574 2725 4,2053072625295/345UnderreamersinOctyabrskayano238 WASH ROP REAMINGPARAMETERS REASON TIME(M/HR) WOR RPM FLOW PRESSURE DENSITY FoRPOOH (HR) (TON) RT (BAR)(KG/DM’) (L/s) 55533 610230100208Timelimit 1125470810 102301202,09Timelimit 70296810 10230120209Completed II1 I III nersRRB295/345inwellno67Braqunvfield 62534359235100210 Timelimit 7752616 9235120210Timelimit , I I 1 7519,016192135120210IDidnot work 16,0275 6 9235120210Completed I I II III RRB295/345inwellno139Pravoberezhnvafield 1625312 36 7235100120202Pressure increasing 175211 38 72321102,02Problemw/ surfeuui~ 300117 68 72 2980100203205Completed ,a 1 ,, ’,, ,,, Table23PerformanceofRRB243/285UnderreamersinVariousWells &0’)I DATEWELLNoREAMEDINTERVAL(M)TIME ROP DRILLINGPARAMETERS 1980 FROMTOTOTAL(HR)(MM) WORFLOW RPMPRESSURE DENSITYCOMMENTS (ToNNE)(L/S)(BAR) (tWDM3) 250911 7Yastre3,1863,290104 164963430 9090100 20 ROP reduced 2909binay3,2903,954664 175379Timelimit 02103,9544,360406 105387Comdeted 1311 86Braguni2,2942,532238 734432 909021822 ROPreduced 2,5323,651111934329Comdeted 091189Braguni2,3602,542182975187 2430 11090208 ROP reduced 2,5423,3468048975892445120 Cleaninghole 3,3463,702356 3759523060 Cleaninghole 3,7023,7747211756123080 Comdeted 280587Braguni3,6893,90521614,25152430 9010019820 ROPreduced 0106‘3,7913,905114 12095 4Cleaninghole 30083,9054,00495140718 01094,0044,0656170878 04093,6894,0653762751344Completed 1405139Pravo4,2104,412202 19,75102425 72110 210212 ROP reduced berejnay4,4125,045633 23,25272327 ROPreduced 24064,3504,537187 17,51078SecondUR’ing 4,5374,59558 1155043Second UR’inq 0610150Pravo3,9734,387414 160259325 92100 216Repairequipmt 1510berejnay4,3874,49377 10573 827 ROPreduced 18104,4164,713297 261146 2111‘4,4504,49646 8583Comdeted 27082593,5023,892390 13304321041302,10211 ROPreduced v 0209Octabrska38924401,,509 2124 4Z8Completed *UsedcuttersectionFormationclay \ DevelopmentofRetractableDrillBitsinRussia RRBO~erationsbyPrikas~iiburneftDrillinaCom~anv ThePrikaspiiburneftdrillingcompanydrilledinWesternKazakhstanThisoiland gasprovincewassecondonlytotheNorthCaucasusforRRBunderreamer penetration RRBI90,RRB215/255,andRRB295/345expandableunderreamerswereused indrillingdeepwellsintheTengizoilfieldandadjacentfieldsRRBtypeexpandable underreamerswerefirstusedinthisfieldinwellno44Tengizskaya In1983,anRRB295underreamerwasruninwellno44The295mm(11%in) boreholehadtobeunderreamed,aswasdictatedbyspecificwellconditionswhile drillinginsalinedepositsMuddensitywas13801400kg/m3(415117ppg)duetothe presenceofalostcirculationhorizonabovesalt,whichwasnotcased Becauseoflowmuddensity,thesaltmigrated,makingtheboreholediameterin thatintervalsmaller,whichmadeitimpossibletorun2445mm(9%in)casing NumerousandlongboreholeconditioningoperationsfailedtorectifythesituationA decisionwasmadetouseanexpandableunderreamerRRB295intheintervalwith saltFollowingaredatafromwellno44:welldepth–4084m;settingdepthof324 mmcasingshoe–2192m;reamedintervalinsalinesediment–31124084m Accordingtostratigraphicclassification,thereamedintervalwasintheKungurian stage,composedofhalitewithstringersofanhydrite AftertwoRRB295/345Sunderreamersreamedtheinterval3fl~24084m,itwas isolatedwitha2445mmcasingstringUnderreamerspenetrated621m(2037ft)and 351m(1151ft)in61and41hours,respectivelyLater,toavoidtheproblems described,twodifferentcasingswereplacedabovetheformationtoisolatesalt sediment BelowisatypicalwelldesignintheTengizfieldwhiledrilling300400mina productiveformation: 426mmconductor(168in) 340mmintermediatestring(133/8 h) l 245mmintermediatestring (%!/8 in) l I%&mmher(75/8h) l 168x127mmproductionstring(65Ax5in) AtypicalwelldesignintheTengizfieldwhiledrillingabout600minaproductive formation: l 426mmconductor(168in) l 340mmintermediatestring(133/8in) 87 — —, ,, ,,,,, ,,, ,”+,, <+,, ,,,,T’,,,,> 7*>,,,,——<—=—— T DevelopmentofRetractableDrillBitsinRussia l 273mmintermediatestring(10%in) l 219mmintermediatestring(87’sin) l 168mmliner(65/8in) l 114x127mmproductionstring(4%x5in) Thefollowinginformationfromwellno20intheTengizfieldillustratesRRB 295/345underreamerperformance:welldepth4156m;340mmcasingshoesetting depth 3026m;reamedinterval–30264124mAccordingtostratigraphic classification,thereamedintervalwasintheKungurianstage,composedofrocksalt, occasionalgypsumintheupperpartanddolomiteinthelowerpartTherockis mediumdrillabilityDrillmuddensitywas20302050kg/m3(169171ppg)Average boreholediameterbeforereamingwas292mm(2953bit) Table24presentsdatadescribingRRB295/345expandableunderreamer performanceinwellno20inTengizAftertheboreholewasreamedandacaliperlog run,a273mm(lO%in)casingstringwasrundownandcementedwithoutproblem Figure47showsportionsofacaliperlogfromtheintervalreamedbyRRB295/345 expandableunderreamers Nominalsizeofreamedboreholewas345mm(136in) Table25indicatesthelargeamountoftime(1month)spentreaming,whichwasdueto organizationalproblemsandtheattemptstoimproveperformanceoftheexpandable underreamers Table24PerformanceofRRB295/345inTengizno20 PERIODIN REAMEDREAMED ~REAMREAMINGPARAMETERS 1998INTERVAL(M) SECTIONTIMERATE WEIGHTON RPMPUMPPRESSURE (M) (HR)(MIHR) UNDERREAMER RATE(BAR) (TONNE) (l/SEC) Feb1417 3,0263,0935748251224 80 2090100 Feb18213,0933,393 3004556635 802090100 Feb2225 3,3933,62022752343568020 90100 Feb26293,6203,7571373425 40568020110120 Mar35 3,7573,95019359533568020110120 Mar710 3,9504,08513554525568020110120 Mar1214* 4,0854,11631475653568020110120 Mar1416* 4,1164,12484219256 8020110120 Total1089 30336 l Duetoalackofnewcuttersections,cuttersruninupperintervalswerereused 88 DevelopmentofRetractableDrillBitsinRussia I Figure47PartialCaliperLogfromWellno20atTengiz I RRB215expandableunderreamersreamedintervalsofboreholesinproductive formationsdrilledby2159mm(85in)bitsbelowacasingshoeof2445mm(9%in) casingfora194mm(7?Ain)stringInaccordancewithregulations,a300m(984ft) intervalwasthemaximumlengththatcouldbedrilledintheproductiveformation withoutrunningdownacasingstringThissizeunderreamerwasrunin24wells Initially,thewholeintervalfromcasingshoetobottomwasreamedAccordingto regulationsondrillinginproductivezones,anunderreamerhadtoberuntobottomto allowmudcirculationandwellcleanupTherefore,toreducetotalreamingtime,a decisionwasmadetoreamtheboreholeintwosectionsonlyabottomholezoneand belowthecasingshoeofthe2445mmstringTheexperienceprovedthatthemethod 89 ,,— , ,, , ,, “ DevelopmentofRetractableDrillBitsinRussia ofdiscretereaming,whenperformingashortextensionofthecasingstring,canensure troublefreerunningandcementingofa194mmliner Table25showsperformanceresultsofRRB215/255Sexpandableunderreamers inseveralwellsintheTengizfield Table25PerformanceofRRB215/255SinTengizWells WELLNoINTERVALOFREAMINGREAMEDSECTIONREAMINGTIMEREAMINGRATE (M)(M)(HR)(MIHR) 11”1 4,3004,34949102547 3,9113,960499552 1154,2884,34052182528 3,9423,99048197524 MoredetailedinformationispresentedbelowaboutRRB215/255Sexpandable underreamerperformanceinwellno113atTengizDrillbitsize–216mm;welldepth –4306m;casingshoesetdepthof2445mmstring–3894m;reamedinterval–3894 3966mand42424306mThereamedintervalwasinLowerCarboniferouscomposed ofargillaceouslimestonewithcalcareoussandstonestringersMuddensitywas2060 2100kg/m3(172175ppg) Table26showsperformanceresultsofRRB215/255Sunderreamers Table26PerformanceofRRB215/255SinTengizno113 INTERvALoi=REAMEDREAMINGREAMINGREAMINGPARAMETERS REAMING(M)SECTIONTIME(HR)RATE WEIGHTONRPMPUMPRATEPRESSURE (M)(MIHR) UR (TONNE)(l/SEC) (BAR) 4,2424306646251024670806 60 3,8943,96672170424670806 60 4,2504,2752560425467080 660 Total161292555 Duringthefirstrun,problemswereencounteredtransferringtheunderreamerto thetransportpositionThetransferwassuccessfulonlyafterthedrillstringwaspicked upwithanoverpullof35tonnes(77,000lb)Thereasonforthefailurewasdetermined tobedefectsinunderreamerassembly UnlikereamingsoftformationstypicaloftheNorthCaucasus(withpenetration ratesupto4050m/hr(130165ft/hr)),penetrationratesforreaminginmediumand 4ardformationsaremuchlowerInaddition,thesetypesofrocksrapidlywearretaining bearings,resultinginreduceddurabilityofunderreamers Toimprovetheefficiencyofreamingoperations,aspecialworkprogramwas initiatedfordevelopingexpandableunderreamerswithimprovedconebearingdesign, 90 , DevelopmentofRetractableDrillBitsinRussia underreamersforsimultaneousdrillingandreaming,aswellasunderreamerswithPDC cutters RRBOperationsbvAzneftDrillinuandProductionCompanv TheDrillingandProductionCompanyAzneftwasinvolvedinonshoredrillingin AzerbaijanAsmallnumberofexpandableunderreamerswereusedtochangewell designsandeliminateproblemswhiledrilling RRB2295expandableunderreamerswereruninwellno64inYuzhnaya Kyursangyabeforerunninga273mm(lO%in)casingstringThreesetsofRRB 295/345Scutterswereusedtoreamtheinterval34124250m,whichhadbeendrilled witha295mmbitbelowthecasingshoeofa340mmstringin97hoursAverage reamingratewas86m/hr(28ft/hr)Muddensitywas2060kg/m3(172ppg) Noproblemswereencounteredrunningdownandcementingthe273mmstring AnRRB243expandableunderreamerwasruninwellno75intheKarabaglyfield andusedtoreamedtheinterval29004200mfor219mmcasingMuddensitywas 1980kg/m3(165ppg)Noproblemswereencounteredwhilerunningdownand cementingthecasingstring RRBI90expandableunderreamersreamedseveralwellsthathadbeendrilled with1905mmbits,fora178mm(7in)linerOneRRBI90/230Sunderreamer reamedtheinterval35504296minwellno7inGyurzundagAveragereamingrate was15m/hr(49ft/hr)Runningdownandcementing178mmlinerwassuccessful Anexpandableunderreamerwithonesetofcuttersreamedtheinterval4063 4553minwellno241atMuradkhanlyatanaveragereamingspeedof42m/hr(14 ft/hr)Runningdownandcementinga178mmlinerwassuccessful SummarvofRRBO~erations ThegeneralexperienceoperatingRRBtypeexpandableunderreamersindeep wellsforreducingradialclearancesbetweentwoneighboringcasingstrings,provedthe efficiencyofthismethodofwellconstruction[nthe1980s,thecostimpactinvarious regionswas820rubles/meterreamed OvertheperiodofRRBunderreamerapplication,therehasbeenonlyonespecific underreamerbreakdown:anRRB215didnottransferintothetransportpositionWhile thedrillstringwasbeingpulled,twojournalswithconeswerebrokenandthe underreamerwaspulledout Thehighestefficiencyisachievedbyintegratingexpandableunderreamersinthe wellforreamingintervalsforseveralcasingstringsHowever,experiencehasshown thatthebestperformanceisachievedwhilereamingintervalswithsoftformations 91 ~ , ,“ ,, ~ ,, t —— ,,~, ~,,+ ,,>,A,, G :~,y,*,,, ~m:, , ,,—;—>;,;< ,,,,:~,=~ ,

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