CO_(2) gas stripped off membranous residual oil from pore surfaces: Effects of temperature, pressure and wettability  

作　　者：Tao Yu Haixiang Hu Qi Li Yongsheng Tan Liang Xu Xiaomin Cao 

机构地区：[1]State Key Laboratory of Geomechanics and Geotechnical Engineering,Institute of Rock and Soil Mechanics,Chinese Academy of Sciences,Wuhan,430071,China [2]University of Chinese Academy of Sciences,Beijing,100049,China

出　　处：《Journal of Rock Mechanics and Geotechnical Engineering》2023年第12期3209-3220,共12页岩石力学与岩土工程学报（英文版）

基　　金：supported by the Creative Groups of Natural Science Foundation of Hubei Province,China(Grant No.2021CFA030);the National Natural Science Foundation of China(Grant Nos.41872210 and 41274111).

摘　　要：The threshold values of CO_(2) gas stripped off membranous residual oil from the pore walls are not clear under different temperatures, pressures and wettability conditions. The extent to which temperature, pressure and wettability influence CO_(2) flooding for enhancing the recovery of residual oil in membranous formations also remains uncertain. Therefore, further quantitative characterization is entailed. In this study, the molecular dynamics method was employed to explore CO_(2) flooding under different temperatures, pressures and wettability conditions, aiming to enhance the production of membranous residual oil. The results reveal that the interaction energy between CO_(2), decane molecules and pore walls exhibits a decrease with increasing temperature and an increase with increasing pressure, respectively, in distinct wettability scenarios. When the temperature was at or below 363 K and the pressure was not lower than 40 MPa, CO_(2) gas could detach the membranous residual oil from the pore walls in the water-wet systems. When the temperature was equal to 363 K and the pressure remained under 40 MPa, or the temperature surpassed 363 K, CO_(2) gas failed to detach the membranous residual oil from the pore walls in the water-wet systems. For the mixed-wet and oil-wet systems, CO_(2) molecules could not detach the membranous residual oil from the pore walls. The hierarchy of influence regarding temperature, pressure and wettability on the competitive adsorption capacity of CO_(2) and decane molecules on the pore walls emerged as follows: wettability > temperature > pressure. The findings of this study offer valuable insights into the application of CO_(2) gas flooding for the exploitation of membranous residual oil on pore walls.

关 键 词：Molecular dynamics simulation CO_(2)flooding WETTABILITY Interaction energy Residual oil CO_(2)utilization CO_(2)capture utilization and storage(CCUS) 

分 类 号：TU45[建筑科学—岩土工程]