CO_(2)地质封存中随机裂隙网络走向对盖层密封性影响  

Effect of Random Fracture Network Orientations on Sealing Performance of Caprock in CO_(2) Geological Sequestration

作　　者：盛丹娜 王惠民 盛金昌[1] 郑惠峰 黄泰仁 吴洪涛 黄石峰 Sheng Danna;Wang Huimin;Sheng Jinchang;Zheng Huifeng;Huang Tairen;Wu Hongtao;Huang Shifeng(College of Water Conservancy and Hydropower Engineering,Hohai University,Nanjing 210098,China;Huadong Engineering Corporation Limited,PowerChina Huadong Engineering Corporation,Hangzhou 311122,China)

机构地区：[1]河海大学水利水电学院,江苏南京210098 [2]中国电建集团华东勘测设计研究院有限公司,浙江杭州311122

出　　处：《地球科学》2025年第1期349-360,共12页Earth Science

基　　金：国家自然科学基金项目(No.42202286,62103198);江苏省博士后科研资助项目(No.2021K350C);河海大学自由探索专项-新引进教师项目(No.B210201037);河海大学大型仪器设备共享基金(No.B220370201)。

摘　　要：在CO_(2)地质封存过程中,为探究盖层中裂隙网络走向对CO_(2)-咸水两相运移的影响规律,进而评价盖层密封性,本文数值模拟选用了6种不同走向的裂隙网络(其角度分别为0°~180°、30°~150°、45°~135°、60°~120°、90°~90°和90°~180°),实现显式裂隙网络下CO_(2)驱替咸水的两相流研究.研究发现裂隙网络走向会直接改变液相饱和度的赋存情况,从而影响CO_(2)-咸水驱替难度;当CO_(2)在盖层中达到相同渗透深度时,驱替时间随裂隙倾角(0°~60°)降低了12.59倍,但倾角增大到60°后不再有明显影响;随着裂隙网络渗透范围的扩大,CO_(2)在盖层中的渗透量增加.其中,正交裂隙(90°~180°)的渗透量最大.因此,考虑裂隙网络走向对于盖层密封性的评价具有重要意义.In the process of CO_(2) geological storage,in order to explore the influence of fracture network orientations on the two-phase transport of CO_(2)-salt water in the caprock and evaluate the sealing performance of the caprock,six fracture networks with different orientations(with angles of 0°-180°,30°-150°,45°-135°,60°-120°,90°-90°and 90°-180°,respectively)were selected for numerical simulation,so as to realize the two-phase flow study of CO_(2) displacement of salt water under explicit fracture network.It is found that the fracture network orientations directly change the occurrence of water saturation,thereby affecting the difficulty of CO_(2)-salt water displacement.When CO_(2) reaches the same penetration depth in the caprock,the displacement time decreased by 12.59 times with the fracture angle(0°-60°),but there is no obvious effect after the inclination angle increased to 60°.With the expansion of the permeability range of the fracture network,the permeability of CO_(2) in the caprock increases.Among them,orthogonal fractures(90°-180°)have the largest permeability.Therefore,considering the fracture network direction is of great significance for the caprock sealing evaluation.

关 键 词：CO_(2)地质封存 盖层密封性 裂隙走向 离散裂隙基质模型 数值模拟 

分 类 号：TU45[建筑科学—岩土工程]