某海上气田井筒完整性失效概率计算  

Wellbore Integrity Failure Probability Calculation of an Offshore Gas Field

作　　者：侯冠中 付建民 廖前华 孙连坡 张智[2] 赵苑瑾 HOU Guanzhong;FU Jianmin;LIAO Qianhua;SUN Lianpo;ZHANG Zhi;ZHAO Yuanjin(Tianjin Branch,CNOOC(China)Co.Ltd.,Tianjin 300459,China;State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation,Southwest Petroleum University,Chengdu,Sichuan 610500,China)

机构地区：[1]中海石油(中国)有限公司天津分公司,天津300459 [2]西南石油大学油气藏地质及开发工程国家重点实验室,四川成都610500

出　　处：《石油管材与仪器》2023年第5期68-73,共6页Petroleum Tubular Goods & Instruments

基　　金：国家自然科学基金“四川盆地深层超深层气井环空带压预防与管控基础研究”(编号U22A20164);国家自然科学基金“深层页岩气长位移水平井套管完整性研究”(编号52074234);四川省青年科技创新研究团队专项计划“油气井建井安全四川省青年科技创新研究团队”(编号2020JDTD0016);中国石油-西南石油大学创新联合体科技合作项目“深井/超深井/水平井安全高效建井关键基础理论与技术研究”(编号:2020CX040100)。

摘　　要：某海上气田属于“中等-高含二氧化碳、微含硫化氢”凝析气藏,长期生产时套管易发生腐蚀失效,破坏井筒完整性,诱发环空带压,不仅严重影响经济效益,还会危及到海洋的生态环境和工作人员的人身安全。因此,识别该气田潜在的安全隐患,建立完备的完整性评价方法具有重要意义。为此,系统调研了井筒完整性相关标准的发展现状,结合渤中该气田的特点,基于故障树分析法识别了井筒完整性失效的3个主要模式和34个因素,并通过故障树分析法与贝叶斯网络的映射关系,得到了气田井筒完整性失效的贝叶斯网络模型。最后以井X进行了实例计算,得到了其井筒完整性失效概率,并通过敏感因素分析,反向推理了该井井筒完整性失效的关键因素,并通过对受时间影响的参数进行调整,最终实现了气井筒完整性失效概率的动态预测。研究结果表明:X井服役第3年的井筒完整性失效概率为0.051,在第8年达到0.167,主要影响因素为腐蚀、环空带压,在生产中应当加强管控。An offshore gas field is a condensate gas reservoir with medium of high carbon dioxide content and slight hydrogen sulfide content.During long-term production,casing is prone to corrosion failure,damaging wellbore integrity and inducing annulus pressure,which not only seriously affects economic benefits,but also endangers marine ecological environment and personal safety of workers.Therefore,it is of great significance to identify the potential safety hazards of this gas field and establish a complete integrity evaluation method.Therefore,this paper systematically investigated the development status of wellbore integrity related standards,combined with the characteristics of the gas field,identified three main modes and 34 factors of wellbore integrity failure based on FTA(Failure Tree Analysis),and obtained the Bayesian network model of wellbore integrity failure of the gas field through the mapping relationship between FTA and Bayesian network.Finally,a case study of well X was conducted to obtain its wellbore integrity failure probability.Through the analysis of sensitive factors,the key factors of wellbore integrity failure of the well were inversely deduced,and the dynamic prediction of wellbore integrity failure probability was finally realized by adjusting the parameters affected by time.The research results show that the wellbore integrity failure probability of Well X in the third year of service is 0.051,and it reaches 0.167 in the eighth year.The main influencing factors are corrosion and annulus pressure,and management and control should be strengthened in production.

关 键 词：海上气田 井筒完整性 故障树 贝叶斯网络模型 失效概率 

分 类 号：TE58[石油与天然气工程—油气田开发工程]