成果归属机构：

能源学院

作者：

Liu, Benjieming ; Lei, Xuantong ; Feng, Dong ; Ahmadi, Mohammadali ; Wei, Zixiang ; Chen, Zhangxin ; Jiang, Liangliang

单位：

Univ Calgary, Dept Chem & Petr Engn, 2500 Univ Dr NW, Calgary, AB T2N 1N4, Canada;China Univ Geosci Beijing, Sch Energy, Beijing 100083, Peoples R China;Eastern Inst Technol, Ningbo 315200, Peoples R China

关键词：

MOLECULAR-DYNAMICS; CONFINED FLUIDS; MISCIBILITY; PHASE

摘要：

Currently, CO2 flooding is the most promising carbon capture, utilization, and storage (CCUS) technology in the energy industry. Understanding the nanoconfinement effect on the CO2-oil miscible process is crucial for accurately determining the minimum miscibility pressure (MMP) of CO2/oil in shale reservoirs. In this study, we conducted molecular dynamics (MD) simulations to investigate the effects of pore size, surfactants, and pore type on the MMP of nanoconfined CO2/shale oil/surfactant systems. Validations against experimental data show a deviation of 2.98 % in the CO2 MMP. The MMPs under nanoconfinement are found to be significantly lower than those in bulk phase conditions (up to 22.94 %). The simulation results reveal that decreasing pore size can enhance the miscibility of CO2 and oil by increasing the CO2 adsorption ratio, improving CO2-surfactant interactions, and inhibiting the tendency of CO2 molecules to self-aggregate. The enhancement of CO2-oil miscibility caused by surfactants is ranked by CFP > SF > SDS according to the mixing degrees (Dmix) D mix ) and the spatial distribution of CO2 around surfactant molecules. In addition, pore type exhibits various abilities in influencing the MMP, owing to their different mineral surface properties and ability to influence CO2-surfactant interactions. Nanopores with stronger hydrophobicity and a denser CO2 distribution around surfactant molecules have lower MMPs. The results show that the order of MMP in terms of pore types is Quartz < Kaolinite < I/M clay. This study elaborates the micro-mechanisms of surfactant-assisted CO2-oil 2-oil miscibility under nanoconfinement, offering valuable insights for effectively designing CO2 2 miscible flooding in shale oil reservoir development.

基金：

National Natural Science Foundation of China [52204058]; Natural Sciences and Engineering Research Council (NSERC) /Energi Simulation Industrial Research Chair in Reservoir Simulation; Alberta Innovates (iCore) Chair in Reservoir Modeling; Energi Simulation/Frank and Sarsh Meyer Collaboration Centre

语种：

英文

DOI：

10.1016/j.seppur.2024.129826

来源：

SEPARATION AND PURIFICATION TECHNOLOGY,2025():.

出版日期：

2025-04-01

提交日期：

2024-10-22

引用参考：

Liu, Benjieming; Lei, Xuantong; Feng, Dong; Ahmadi, Mohammadali; Wei, Zixiang; Chen, Zhangxin; Jiang, Liangliang. Nanoconfinement effect on the miscible behaviors of CO₂/shale oil/ surfactant systems in nanopores: Implications for CO₂ sequestration and enhanced oil recovery[J]. SEPARATION AND PURIFICATION TECHNOLOGY,2025():.