摘要
在页岩气压裂作业过程中,套管容易出现变形、破裂、错断等破坏性形式。为此,运用ABAQUS有限元分析软件建立套管的二维平面应变模型,模拟计算压裂后套管Mises应力及变形分布,找到套管损坏的主要影响因素。然后利用ABAQUS中关键字*Field实现地层岩石的性能随压裂进行不断降低,从而对四川某井套管失效问题进行了三维模型的实例分析。通过对有限元结果分析和对比压裂后MIT多臂测井曲线,认为套管失效是压裂过程中地层岩石性能降低、改造区域不对称、施工压力大以及地应力场重新分布共同作用的综合结果。最后提出压裂过程中套管失效的应对措施。该项研究结果可为页岩气压裂引起套管失效的防治提供理论依据。
The casing is prone to failure like deformation, fracture and dislocation during the shale gas fracturing operation. To study the principal influence factors of casing failure, a two-dimensional plane strain model of casing is built using ABAQUS to simulate Mises stress deformation distribution of easing after fracturing. Then the keyword ＊ Field in ABAQUS is used to let rock property decrease with the continuing operation of fracturing, and based on which a three-dimensional model is applied for analysis of casing failure of a well in Sichuan. According to the results of the finite element analysis and comparison of MIT multi-arms logs after fracturing, that casing failure is coefficient results of rock property decrease during fracturing, asymmetry treatment zone, high fracturing pressure and ground stress field redistribution. Finally, measures to address the casing failure issue during fracturing are proposed. The study results could provide a theoretical basis for preventing casing failure in shale gas fracturing.
出处
《石油机械》
北大核心
2014年第8期84-88,93,共6页
China Petroleum Machinery
基金
国家教育部博士点基金项目"基于XFEM和细观力学的超深井钻工具疲劳破坏机理研究"(20135121110005)
