Experimental study of enhanced oil recovery by CO_(2) huff-n-puff in shales and tight sandstones with fractures

作     者：Chao-Fan Zhu Wei Guo You-Ping Wang Ya-Jun Li Hou-Jian Gong Long Xu Ming-Zhe Dong Chao-Fan Zhu;Wei Guo;You-Ping Wang;Ya-Jun Li;Hou-Jian Gong;Long Xu;Ming-Zhe Dong

作者机构：College of Construction EngineeringJilin UniversityChangchun 130026JilinChina School of Petroleum EngineeringChina University of Petroleum(East China)Qingdao 266580China Petroleum Exploration and Production Research InstituteSinopecBeijing 100083China Department of Chemical and Petroleum EngineeringUniversity of CalgaryCalgaryAB T2N 1N4Canada 

出 版 物：《Petroleum Science》 (石油科学（英文版）)

年 卷 期：2021年第18卷第3期

页      面：852-869页

核心收录：

学科分类：0709[理学-地质学] 0819[工学-矿业工程] 0808[工学-电气工程] 08[工学] 0820[工学-石油与天然气工程] 0707[理学-海洋科学] 0817[工学-化学工程与技术] 0818[工学-地质资源与地质工程] 0708[理学-地球物理学] 0807[工学-动力工程及工程热物理] 0815[工学-水利工程] 0816[工学-测绘科学与技术] 0827[工学-核科学与技术] 0813[工学-建筑学] 0703[理学-化学] 082002[工学-油气田开发工程] 0814[工学-土木工程] 0825[工学-航空宇航科学与技术] 0704[理学-天文学] 

基　　金：We gratefully acknowledge the National Key R&D Program of China(Grant No.2019YFA0705502,Grant No.2019YFA0705501) the fnancial support from the Shandong Provincial Natural Science Foundation(ZR2019QEE037,ZR2019MEE058) the Fundamental Research Funds for the Central Universities(17CX05005,18CX02104A). 

主　　题：Shale Tight sandstone CO_(2)huf-n-puf Fracture Injectivity of CO_(2) 

摘      要：The fractures and kerogen,which generally exist in the shale,are signifcant to the CO_(2) huf-n-puf in the shale reservoir.It is important to study the efects of fractures and kerogen on oil recovery during CO_(2) huf-n-puf operations in the fracture-matrix system.In this study,a modifed CO_(2) huf-n-puf experiment method is developed to estimate the recovery factors and the CO_(2) injectivity in the fractured organic-rich shales and tight sandstones.The efects of rock properties,injection pressure,and injection time on the recovery factors and CO_(2) usage efciency in shales and sandstones are discussed,respectively.The results show that although the CO_(2) injectivity in the shale is higher than that in the sandstone with the same porosity;besides,the recovery factors of two shale samples are much lower than that of two sandstone samples.This demonstrates that compared with the tight sandstone,more cycles are needed for the shale to reach a higher recovery factor.Furthermore,there are optimal injection pressures(close to the minimum miscible pressure)and CO_(2) injection volumes for CO_(2) huf-npuf in the shale.Since the optimal CO_(2) injection volume in the shale is higher than that in the sandstone,more injection time is needed to enhance the oil recovery in the shale.There is a reference sense for CO_(2) huf-n-puf in the fractured shale oil reservoir for enhanced oil recovery(EOR)purposes.