CO_(2)多层注入下盖层密闭性影响因素研究  

Influencing factors of caprock sealing performance for multi-layer CO_(2)injection

作　　者：马纪元 程国强 李霞颖 杨凌雪 李琦[1,2] 马晶 陈博文 杨川枫 张瑶 李凤洋 余涛 虎亭 许宗红 钟屹岩 MA Ji-yuan;CHENG Guo-qiang;LI Xia-ying;YANG Ling-xue;LI Qi;MA Jing;CHEN Bo-wen;YANG Chuan-feng;ZHANG Yao;LI Feng-yang;YU Tao;HU Ting;XU Zong-hong;ZHONG Yi-yan(State Key Laboratory of Geomechanics and Geotechnical Engineering,Institute of Rock and Soil Mechanics,Chinese Academy of Sciences,Wuhan,Hubei 430071,China;University of Chinese Academy of Sciences,Beijing 100049,China;Ningxia Hui Autonomous Region Institute of Hydroenvironmental Geology,Yinchuan,Ningxia 750011,China)

机构地区：[1]中国科学院武汉岩土力学研究所,岩土力学与工程国家重点实验室,湖北武汉430071 [2]中国科学院大学,北京100049 [3]宁夏回族自治区水文环境地质调查院,宁夏银川750011

出　　处：《岩土力学》2024年第11期3447-3460,共14页Rock and Soil Mechanics

基　　金：国家自然科学基金联合基金重点项目(No.U2244215);湖北省自然科学基金创新群体项目(No.2021CFA030);宁夏二氧化碳地质封存调查、试验与示范项目(No.TZZD/NZC220120C)。

摘　　要：中国大多数CO_(2)储层具有非均质性、低渗等特征,仅在单一储层内进行CO_(2)封存难以满足中国减排的需求。为了实现大规模CO_(2)地质封存,多层注入技术被提出以增加CO_(2)地质封存量。为探究CO_(2)多层注入条件下盖层密闭性的主要影响因素,通过渗流-应力耦合模拟分析,以孔压、位移和库仑破坏应力增量ΔCFS作为评价盖层密闭性状态的依据,并采用龙卷风分析法进行敏感性分析,筛选出对盖层密闭性影响较大的因素。研究结果表明:注入层数越多,盖层的位移、孔压和ΔCFS越小,盖层密闭性越好,但层数超过3层,层数带来的增效将不再显著;盖层密闭性的主控因素有盖层泊松比与杨氏模量、储层厚度与渗透系数和注入速率;最厚盖层的位置在整个地层的最上部时,盖层密封效果最好,产生垂直位移、孔压和ΔCFS最小。Due to the heterogeneity and low permeability of most CO_(2) reservoirs in China,CO_(2) storage within a single reservoir is difficult to meet the demand for emission reduction.To achieve large-scale CO_(2) geological storage,multi-formation injection technology has been proposed to increase the amount of CO_(2) geological storage.To explore the main influencing factors on the caprock sealing performance under the condition of multi-formation CO_(2) injection,the seepage-stress coupling simulation analysis was carried out.Pore pressure,displacement,and incremental Coulomb failure stress(DCFS)are used as the basis for evaluating the caprock sealing performance.The tornado analysis method was used for sensitivity analysis to select the factors that have a significant impact on the caprock sealing performance.The research results indicate that the more injection layers,the smaller the displacement,pore pressure,andDCFS of the caprock,and the better the caprock sealing performance.However,if the number of layers exceeds 3,the efficiency increase brought by the number of layers will no longer be significant;The main controlling factors for the sealing performance of the caprock include the Poisson’s ratio and Young’s modulus of the caprock,thickness and permeability coefficient of the reservoir,and injection rate;When the thickest caprock is located at the topmost part of the entire formation,the caprock sealing performance is the best,producing the smallest vertical displacement,pore pressure,andDCFS.

关 键 词：CO_(2)地质封存 盖层密闭性 多层注入 敏感性分析 库仑破坏应力 

分 类 号：TU42[建筑科学—岩土工程]