冀东油田东营组硬脆性泥页岩井壁稳定性分析  

The Analyses on Wellbore Stability in Hard Brittle Shale in Dongying Formation of Jidong Oilfield

作　　者：陈金霞[1] 周岩[1] 朱宽亮[1] 丁乙[2] 梁利喜[2] CHEN Jin-xia;ZHOU Yan;ZHU Kuan-liang;DING Yi;LIANG Li-xi(Institute of Drilling and Production Technology,Jidong Oilfield,CNPC,Tangshan 063004,China;State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation,Southwest Petroleum University,Chengdu 610500,China)

机构地区：[1]中国石油冀东油田钻采工艺研究院,唐山063004 [2]西南石油大学油气藏地质及开发工程国家重点实验室,成都610500

出　　处：《科学技术与工程》2018年第20期109-115,共7页Science Technology and Engineering

基　　金：国家自然科学基金面上项目(41772151);国家自然科学基金重点支持项目(U1262209)资助

摘　　要：硬脆性泥页岩地层的钻井过程中,井壁垮塌现象频发,严重影响了油气田的高效开发。为减少该类地层井壁失稳问题,通过室内试验对硬脆性泥页岩理化特性进行分析,并定量分析钻井液作用对泥页岩的影响程度。基于室内试验结果,利用线弹性理论和单一弱面准则,建立了考虑弱面结构、温场作用、水化特性的井壁稳定模型。利用该模型对井壁稳定性影响因素进行分析,结果显示:弱面结构的存在使得坍塌压力明显升高。弱面产状变化,造成坍塌压力分布复杂,不再存在单调变化的井斜方位;随温差增大,造成地层坍塌压力上升,但上升幅度相对较小;钻井液作用会显著缩减安全钻井方位范围,提高井壁垮塌风险。现场实例分析结果表明:利用提出的井壁稳定模型可以准确地预测坍塌压力分布,从而指导现场钻井作业。For the drilling operation in hard brittle shale formation,wellbore collapse occurs frequently,highly restricting the development of oil and gas.In order to reduce wellbore instability,experiment was used to analyze the physical and chemical properties of hard brittle shale,conducted quantitative investigation on the influence of drilling fluid on shale.Based on the experiment results,elastic theory and single weak plane criterion had been used to establish wellbore stability model,which considers influences of weak plane,formation temperature and hydration.Investigation on influence factors of wellbore stability was conducted.The results showed that the existence of weak plane causes increment of collapse pressure.In particular,the distribution of collapse pressure is variable with changing occurrence of weak plane.The monotone change pattern disappears due to weak plane.With increasing temperature difference,collapse pressure rises.However,its increment is relatively smaller.Drilling fluid impact will shrink safe well trajectory,boosting risk of wellbore collapsing.Finally,the application indicates that this model is able to precisely predict collapse pressure,offering reference for drilling in oilfield.

关 键 词：硬脆性泥页岩 井壁稳定 温场作用 水化 坍塌压力 

分 类 号：TE355.5[石油与天然气工程—油气田开发工程]