大庆石油地质与开发2025，Vol.44Issue(3)：93-102,10.DOI:10.19597/J.ISSN.1000-3754.202402040
塔里木盆地东河储气库盖层密封性定量评价
Quantitative evaluation on caprock sealing performance of Donghe gas storage of Tarim Basin
摘要
Abstract
In view of the problem of insufficient understanding of caprock sealing capacity before reconstruction of underground gas storage(hereinafter referred to as gas storage)in Donghe oilfield,with the help of laboratory rock experiment and 4D geomechanical simulation technique,3-factors-combination evaluation method mainly based on"capillary+mechanical sealing"and assisted by geological analysis is developed to quantify sealing capacity of cap-rock from different aspects.The results show that capillary sealing capacity of caprock mainly depends on break-through pressure of caprock and buoyancy exerted on hydrocarbon column.Based on experiment and interpretation models,the predicted minimum breakthrough pressure of caprock is 6 MPa.After storage area fully filled with gas,buoyancy exerted on gas column(with a height of 120 m)is 1.4 MPa.On the basis of original pressure reaching 62 MPa,pore pressure is required to be increased by 4.6 MPa for gas to breakthrough caprock.Hydraulic sealing ca-pacity is closely related to in-situ stress variation.Pore pressure reduction causes decrease of horizontal principal stress.However,since the minimum horizontal principal stress is much higher than reservoir pore pressure,the caprock will not undergo tensile failure.After pore pressure decreases,shear risk of caprock increases,with aver-age shear safety index of caprock rising from initial state of 0.37 to 0.44,but still less than the critical value of 1.00,indicating low risk of mechanical instability.This evaluation method not only demonstrates effective caprock sealing performance to gas since the development of reservoir,but also clarifies the caprock stability in different in-jection-production cycles of gas storage.关键词
密封性评价/盖层/突破压力/地质力学模拟/剪切破坏/储气库/塔里木盆地/东河油田Key words
evaluation on sealing performance/caprock/breakthrough pressure/geomechanical simulation/shear failure/gas storage/Tarim Basin/Donghe oilfield分类
天文与地球科学引用本文复制引用
张超,姚杰,李伟娜,伍藏原,曹烨,吴以臣,王刚..塔里木盆地东河储气库盖层密封性定量评价[J].大庆石油地质与开发,2025,44(3):93-102,10.基金项目
中国石油天然气股份有限公司塔里木油田公司科学研究与技术开发项目"油藏型储气库封闭性前期评价技术研究"(T202126). （T202126）
