考虑裂纹的CNG地下储气井剩余强度数值模拟  

Numerical simulation of residual strength of CNG underground gas storage well considering cracks

作　　者：计喆 何莎 陈华燕[1] 曾祥国[1] JI Zhe;HE Sha;CHEN Huayan;ZENG Xiangguo(College of Architecture and Environment,Sichuan University;CNPC Chuanqing Drilling Engineering Company Limited Safety Environment Quality Surveillance&Inspection Institute)

机构地区：[1]四川大学建筑与环境学院 [2]中国石油集团川庆钻探工程有限公司安全环保质量监督检测研究院

出　　处：《油气储运》2020年第3期284-289,306,共7页Oil & Gas Storage and Transportation

基　　金：国家自然科学基金委员会与中国工程物理研究院联合基金资助项目“金属材料断裂的多尺度研究”,U1530140。

摘　　要：由于天然气中存在的硫化氢等气体具有腐蚀性,因此储气井在建设和服役过程中,井管内表面容易在腐蚀和应力的双重作用下产生裂纹,最终导致井管破裂失效。建立储气井井管-水泥环-地层数值模型,采用传统基于工作应力的方法和基于断裂力学应力强度因子的方法分析了含裂纹储气井的剩余强度,得出不同条件下许可裂纹的尺寸。结果表明:基于断裂力学应力强度因子的分析方法可以更准确地判定危险点位置,能够有效排除CNG储气井安全事故隐患。Since the gases such as hydrogen sulfide contained in natural gas are corrosive,cracks are likely to occur on the inner surface of the well pipe under the double effects of corrosion and stress during the construction and service of gas storage wells,and eventually lead to fracture failure of the well pipe.The numerical model of gas storage well pipe–cement sheath–stratum was established.The residual strength of gas storage wells with cracks was analyzed by the traditional methods based on the working stress and the stress intensity factor of fracture mechanics,and the allowable crack sizes under different conditions were obtained.The results show that,the location of dangerous points can be more accurately determined,and the hidden hazards that may cause safety accidents of CNG gas storage wells can be effectively eliminated by the analysis method,which is based on the fracture mechanics stress intensity factor.

关 键 词：CNG储气井 裂纹 应力强度因子 有限元 剩余强度 

分 类 号：TE832[石油与天然气工程—油气储运工程]