Effects of cosolvents on CO_(2) displacement of shale oil and carbon storage  

作　　者：ZHANG Yifan WANG Lu ZOU Rui ZOU Run MENG Zhan HUANG Liang LIU Yisheng LEI Hao 

机构地区：[1]College of Energy,Chengdu University of Technology,Chengdu 610059,China [2]State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation,Chengdu University of Technology,Chengdu 610059,China [3]School of Petroleum Engineering,Southwest Petroleum University,Chengdu 610500,China [4]Research Institute of Exploration and Development,Sinopec Jianghan Oilfield Company,Wuhan 430223,China

出　　处：《Petroleum Exploration and Development》2023年第6期1509-1518,共10页石油勘探与开发（英文版）

基　　金：Supported by National Natural Science Foundation of China(52304021,52204031);Natural Science Foundation of Sichuan Province(2022NSFSC0205);National Science and Technology Major Project of China(2017ZX05049006-010).

摘　　要：Molecular dynamics method was used to establish composite wall/inorganic nanopores of three pore sizes, three shale oil systems, five CO_(2)-cosolvent systems, and pure CO_(2) system. The process of CO_(2)-cosolvent displacement of crude oil in shale nanopores and carbon storage was simulated and the influencing factors of displacement and storage were analyzed. It is shown that the attraction of the quartz wall to shale oil increases with the degree of hydroxylation. The higher the degree of quartz hydroxylation, the more difficult it is to extract the polar components of shale oil. Nanopore size also has a great impact on shale oil displacement efficiency. The larger the pore size, the higher the shale oil displacement efficiency. The closer the cosolvent molecules are to the polarity of the shale oil, the higher the mutual solubility of CO_(2) and shale oil. The more the non-polar components of shale oil, the lower the mutual solubility of CO_(2) and shale oil with highly polar cosolvent. Ethyl acetate is more effective in stripping relatively high polar shale oil, while dimethyl ether is more effective in stripping relatively low polar shale oil. Kerogen is highly adsorptive, especially to CO_(2). The CO_(2) inside the kerogen is not easy to diffuse and leak, thus allowing for a stable carbon storage. The highest CO_(2) storage rate is observed when dimethyl ether is used as a cosolvent, and the best storage stability is observed when ethyl acetate is used as a cosolvent.

关 键 词：molecular dynamics shale oil NANOPORE carbon dioxide COSOLVENT displacement efficiency storage effect 

分 类 号：TE357.7[石油与天然气工程—油气田开发工程]