石油工程双语版课件05钻井技术及钻井问题

Chapter5

DrillingTechniquesandDrillingProblemsWelldeviates<3deg.per100ft(30m)Conewithamaximumangleof5degStraightholeIfthebithitsasubsurfacerocklayerwithadipgreaterthan45deg.,thebittendstobedeflecteddowndip.Ifrocklayerdiplessthan45deg.,thebittendstobedeflectedupdip.Awellwithanexcessiveangleinitthathasnotbeendrilledonpurposethatwayiscallacrookedhole.Modernrotaryrigscanbecontrolledsothatthewellisdrilledoutatapre-determinedangleduringdirectionalordeviationdrillingandendsupinapre-determinedlocationcalledtarget.

DirectionalDrillingorDeviationDrillingDirectionalDrillingDirectionallydrilledwellswillusuallybedrilledaccordingtooneofthreebasicholepatterns.DirectionalDrillingAftermakinganinitialdeflectionfromvertical,thewellmaybedrilledtothetarget,ordeflectedoncemoretoallowedthebottomoftheholetobedrilledvertically(“doubledogleg”).UsesofDirectionalDrillingSituationRequiringDirectionalDrillingDirectionalDrillingThedeviationbeginswhentheholeisdeflectedusingoneofseveraltechniques:(1)downholehydraulicmotorswitha“bentsub”(2)jetbits(3)whipstocksDownholehydraulicmotorswitha“bentsub”DeviceusedtokickoffawellJetbitJetbitWhipstockWhipstockAsteerable

downholeassemblyisacombinationofstabilizers,bentsubs,downholeturbinemotor,anddiamondbitthatcanmaintain,drop,orbuildangle.PlotofwellsurveydatashowingpathsofdirectionallydrilledwellsExtendedReachWelland

HorizontalDrainWellDepthofaWellProblemswhiledrillingFishingStuckpipeSloughingshaleLostcirculationFormationdamageCorrosivegasesAbnormalhighpressureDifferentialstickingofdrillpipebecauseofheavymudweightCrookedwellboreshowing