力—化耦合作用下泥页岩井眼动态破坏分析  

Progressive failure evolution analysis of mudstone wellbore under chemo-mechanical coupling

作　　者：朱宽亮[1] 吴晓红[1] 贾善坡[2] 吕方 肖志强 ZHU Kuan-liang;WU Xiao-hong;JIA Shan-po;LYU Fang;XIAO Zhi-qiang(Jidong Oilfield Company, Petro China, Tangshan 063004, China;Geotechnical Mechanics and Engineering Research Center, Yangtze University, Jingzhou, 434023, China;Hubei Oilfield Chemical Industry Technology Research Institute, Jingzhou 434000, China)

机构地区：[1]中国石油天然气股份有限公司冀东油田公司,河北唐山063004 [2]长江大学岩土力学与工程研究中心,湖北荆州434023 [3]湖北省油田化学产业技术研究院,湖北荆州434000

出　　处：《广西大学学报（自然科学版）》2019年第4期1052-1061,共10页Journal of Guangxi University（Natural Science Edition）

基　　金：国家科技重大专项(2016ZX05006-006)

摘　　要：为进一步研究中深层硬脆性泥页岩在水化条件下的井眼失稳问题,基于泥页岩矿物组成、微观结构及力学试验研究,考虑泥页岩吸水扩散、强度弱化、化学势变化以及流体流动对固体变形的影响,建立了泥页岩井壁稳定流—固—化耦合模型,提出了模拟泥页岩井眼动态破坏过程方法,并应用建立的模型计算实例井井眼动态破坏过程。结果表明:开挖后井眼围岩渗流场的变化不足以引起井眼继续破坏,水化效应对井眼扩大率的影响起决定作用,井眼扩大率随钻井液浸泡时间的增大而增大。提出的模型可有效模拟硬脆性泥页岩井眼动态破坏过程,计算出的井眼动态破坏过程与实际钻井基本一致。Due to significant hydration effect and existence of micro cracks in hard mudstone, the wellbore instability problem is prominent in the middle deep layer for Eastern oilfield in recent years.To further study the wellbore instability of hard brittle mudstone,based on the mineral composition, microstructure and mechanical tests of mudstone, the effects of water diffusion, strength weakening, chemical potential change and fluid flow on solid deformation are considered.A hydraulic-mechanical-chemical coupling model is established for wellbore failure analysis inhard mudstone.Then, a method for simulating progressive failure process of wellbore is proposed with ABAQUS software as the solver, and it is applied to calculate the progressive failure process of an actual well.The results show that hydration effect of mudstone plays a decisive role in the progressive failure of wellbore.The change of seepage field around borehole after excavation is not enough to cause progressive failure of wellbore.The wellbore failure increases with the increase of drilling fluid soaking time.The calculated progressive failure process of wellbore is basically consistent with the actual drilling.The proposed model can effectively simulate the progressive failure process of hard brittle mudstone.

关 键 词：硬脆性泥页岩 水化 钻井液浸泡 井壁稳定 动态破坏 

分 类 号：TU45[建筑科学—岩土工程] TE28[建筑科学—土工工程]