摘要
受环境载荷和自身缺陷的影响,页岩气井套管在服役过程中可能发生变形失效,对页岩气井的正常生产造成严重影响。为控制页岩气井套管变形失效风险,采用事故树和事件序列图方法识别页岩气井套管变形失效原因和后果,建立页岩气井套管变形失效场景模型,将事故树和事件序列模型转化为贝叶斯网络,采用条件概率表考虑事件之间的推理关系,建立页岩气井套管变形失效的贝叶斯网络模型。进行失效诊断分析和概率学习,识别页岩气井套管变形失效最可能的致因因素,引入先兆事故,评估各失效场景的动态发生概率。以川东地区A页岩气井为例开展模型应用研究,获取导致套管变形失效最可能的致因组合,得到套管变形失效及其失效后果的动态发生概率,与工程现场气井套管的安全状况比较吻合,分析结果可为页岩气井套管变形失效风险防控和决策提供理论支撑。
Due to the effect of the environmental loads and the defects of its own, the casing in shale gas wells may suffer deformation failure in the process of service, which will bring serious impact on the normal production of shale gas wells. In order to control the risk induced by the deformation failure of the casing in shale gas wells, its causes and consequences were identified by means of event tree and event sequence diagram. Then, the scenario model for the deformation failure of the casing in shale gas wells was established, and event tree and event sequence models were transformed into the Bayes network. The inference relations between events were presented by using conditional probability table, and the Bayes network model for the deformation failure of the casing in shale gas wells was established. Failure diagnosis and analysis and probability learning were carried out, and the most possible cause for the deformation failure of the casing was identified. Threatened accident was introduced and the dynamic occurrence probability of each failure scenario was assessed. Finally, model application study was carried out with shale gas well A in the eastern Sichuan Basin as the example. And the most possible cause combination for the deformation failure of the casing was figured out, and the dynamic occurrence probability of casing deformation failure and its consequence was calculated. It is indicated that they are in better accordance with the safety situation of the casing in gas wells in the field of engineering. The research results can provide the theoretical support for the risk control and decision making on the deformation failure of casing in shale gas wells.
作者
张认认
闫怡飞
王鹏
闫行
闫相祯
ZHANG Renren;YAN Yifei;WANG Peng;YAN Xing;YAN Xiangzhen(School of Mechanical and Electrical Engineering,China University of Petroleum (East China),Qingdao 266580,Shandong,China;Oil and Gas CAE Technology Research Center,China University of Petroleum (East China),Qingdao 266580,Shandong,China;State Key Laboratory of Performance and Structural Safety for Petroleum Pipe and Equipment Materials,Xi’an 710077,Shaanxi,China)
出处
《石油钻采工艺》
CAS
CSCD
北大核心
2018年第6期736-742,共7页
Oil Drilling & Production Technology
基金
国家自然科学基金"基于多目标约束优化方法的页岩气储层微裂缝分析及压裂缝网扩展机理研究"(编号: 51374228 )
国家科技重大专项"普光气田高钢级厚壁套管变形规律研究"(编号: 2016ZX05017-003 )。
关键词
页岩气井
套管
变形失效
贝叶斯网络
诱因
风险评估
shale gas well
casing
deformation failure
Bayes network
cause
risk assessment
