水力压裂过程中页岩强度折减对套管变形的影响分析  

Influence of Shale Strength Reduction on Casing Deformation During Hydraulic Fracturing

作　　者：连威[1] 李军[1,2] 柳贡慧 席岩[3] 韩葛伟 LIAN Wei;LI Jun;LIU Gonghui;XI Yan;HAN Gewei(China University of Petroleum-Beijing,Beijing 102249,China;China University of Petroleum-Beijing at Karamay,Karamay,Xingjiang 834000,China;Beijing University of Technology,Beijing 100124,China;NO.1 Cementing Branch of Bohai Drilling Engineering Company Limited,Renqiu,Hebei 062552,China)

机构地区：[1]中国石油大学(北京),北京102249 [2]中国石油大学(北京)克拉玛依校区,新疆克拉玛依834000 [3]北京工业大学,北京100124 [4]渤海钻探第一固井公司,河北任丘062552

出　　处：《石油管材与仪器》2020年第4期46-50,共5页Petroleum Tubular Goods & Instruments

基　　金：国家自然科学基金—石油化工联合基金重点支持项目“页岩气水平井井筒完整性失效机理与控制方法”(项目编号:U1762211);国家自然科学基金面上项目“长水平段非均质页岩储层非均匀分簇射孔优化研究”(项目编号:51674272);企业创新发展联合基金-集成项目“海相深层油气富集机理与关键工程技术基础研究-构造应力集中区页岩气井套管载荷模型及结构完整性失效机理”(项目编号:U19B6003-05-04-02)联合资助。

摘　　要：针对四川盆地岩气开发过程中出现的套管变形问题,在定量分析了压裂液浸泡过程中页岩强度随时间变化规律的基础上,建立了页岩强度折减条件下的套管-水泥环-地层组合体三维数值计算模型,分析了页岩强度降低对套管变形的影响,并对影响套管变形量的因素进行了分析。计算结果表明:页岩强度发生折减时,会产生垂向位移,从而导致套管在垂向上产生变形。页岩强度降低幅度越大,套管变形量越大;随着岩性界面倾角的增加,套管变形量先线性增加后缓慢增加;增加套管钢级以及降低径厚比对于降低套管变形量有一定的效果。Aiming at the casing deformation in the process of shale gas development in the Sichuan Basin,based on quantitative analysis of the law of shale strength with time during fracturing fluid immersion,the casing-cement sheath-formation assembly considering the shale strength reduction was established,the influence of shale strength reduction on casing deformation were analyzed,and the factors affecting casing deformation was analyzed as well.The calculation results show that when the shale strength is reduced,vertical displacement will occur,which will cause the casing to deform vertically.The greater the decrease in shale strength,the greater the casing deformation.With the increase of the lithological interface inclination,the casing deformation increases linearly and then slowly.Increasing the steel grade of the casing and reducing the ratio of diameter to thickness have a certain effect on reducing the deformation.

关 键 词：页岩气 水力压裂 套管变形 岩性界面 强度折减 

分 类 号：TE925[石油与天然气工程—石油机械设备]