Investigation of the confinement effect on fluid-phase behavior in shale oil reservoirs during CO2 injection process

• DOI: 10.1007/s13202-023-01730-2
• Publication Date: 2023-12-14T08:02:28Z
• Authors: Xiangji Dou; Yisong Zhang; Jing Guo; Kun Qian
• Keywords: Nanopore

Abstract Due to the confinement effect of nanopores, fluid-phase behavior shale oil reservoirs is much different from that conventional reservoirs. The accurate description phase change characteristics fluid in nanopores basis design development plan, production system, and EOR methods In this study, molecular dynamics simulation was employed analyze single-component system hydrocarbon–CO 2 mixture organic nanopores. results show on pressure influenced by distribution electron cloud. hydrocarbons with even cloud would be increased, while CO decreased due instantaneous dipole moment. addition, as length carbon chains increases, becomes stronger. When temperature weaker. when occurrence condition changes bulk nanopore 5 nm, bubble point decreases 39.21–68.85%, critical decrease 75.98% 7.13%, respectively. On whole, P–T envelope shrunken under effect. easier miscible Moreover, full mixing keeping single liquid –hydrocarbons can reduce adsorption pore walls. Therefore, injection could a feasible method enhance recovery matrix