渤海盆地渤中区域浅层钻井井壁稳定周期及抗失稳对策研究.pdf
2025年1月石油工业技术监督Jan.2025
第41卷第1期TechnologySupervisioninPetroleumIndustryVol.41No.1
渤海盆地渤中区域浅层钻井井壁稳定周期及
抗失稳对策研究
王桂萍,李文博
中海石油(中国)有限公司天津分公司(天津300459)
摘要渤中X油田前期探井作业过程中,井壁失稳情况较为严重,后续待钻浅层大位移井钻井安全面临巨大风险。为减少后
续钻井复杂情况的发生,并及时对现场作业提供技术支持,采用岩石力学实验及数值模拟分析等方法,针对浅层含水敏性黏土
矿物泥页岩和弱固结砂岩等易失稳层位开展井壁稳定周期及抗失稳对策研究。研究表明,井壁稳定周期主要影响因素为井眼
方位、钻井液离子浓度及密度,采用合适密度及离子浓度的钻井液在垂直井、最小主应力方向、水平最大主应力方向分别可以维
持65、40、93h井壁稳定,并提出针对性抗井壁失稳对策。研究结果为维持渤中X油田大位移井钻井过程井壁稳定及降低钻井
复杂情况提供了技术指导,起到了良好的应用效果。
关键词井壁稳定周期;井壁失稳;坍塌压力;力化耦合
DOI:10.20029/j.issn.1004-1346.2025.01.009
StudyonWallStabilityPeriodandAnti-InstabilityCountermeasuresofShallow
DrillingWellinBozhongAreaofBohaiBasin
WANGGuiping,LIWenbo
TianjinBranchofCNOOC(China)Co.,Ltd.(Tianjin300459,China)
AbstractIntheprocessofearlyexplorationwelloperationinBozhongXOilfield,thewellborewallinstabilitywasrelativelyserious,
andthedrillingsafetyofsubsequentshallowextendedreachwellswasfacinghugerisks.Inordertoreducethecomplicationsoccur-
renceofsubsequentdrillingandprovidetechnicalsupportforon-siteoperationsintime,rockmechanicsexperimentandnumerical
simulationanalysiswereusedtostudythewellborestabilityperiodandanti-instabilitycountermeasuresfortheshallowwater-sensi-
tiveclaymineralshaleandweaklyconsolidatedsandstoneandotherunstableformations.Theresultsshowthatthemaininfluencing
factorsofwellborestabilityperiodarewellboreorientation,ionconcentrationanddensityofdrillingfluid.Thedrillingfluidwithap-
propriatedensityandionconcentrationcanmaintainwellborestabilityfor65h,40hand93hrespectivelyintheverticalwell,the
minimumprincipalstressdirectionandthemaximumhorizontalprincipalstressdirection.Accordingly,thetargetedcountermeasures