Volume 57

Performance of Electric Field-Enhanced Oil Recovery in Shale Kerogen Pores During CO₂ Injection: A Molecular insight Jieying La, Wentong Zhang, Hai Huang, Zhilin Cheng, Zejiang Jia, Can Shi

Abstract

Enhancing shale oil recovery during CO₂ injection is crucial for advancing carbon neutrality. However, the strong affinity between the surface of organic pores and hydrocarbons limits the effective oil displacement efficiency. Therefore, it is imperative to find effective methods to improve shale oil recovery. In response to this challenge, this study employs electric field technology to investigate its impact on shale oil recovery during CO₂ injection. In this study, molecular dynamics (MD) simulations were used to study the effect of an electric field on CO₂-enhanced oil recovery in shale nanopores. A composite system consisting of organic nanopores, multicomponent oil, and CO₂ was adopted. Simulations were conducted after applying different electric field intensities (0 V, 5 V, 10 V, and 20 V) to the crude oil. The results show that the electric field increases the difference in interaction energy between CO₂ – oil and oil – pore walls, enhancing the ability of CO₂ molecules to displace hydrocarbons from the pore surface. The displacement efficiency improved after different electric field intensities were applied. Specifically, the electric field intensities of 5 V, 10 V, and 20 V increased the displacement efficiency by 3.20%, 2.85%, and 1.61% respectively compared to the case of 0 V. These findings indicate that the electric field is an effective strategy to overcome oil retention at the pore scale, and its directional application is a key parameter for optimizing CO₂ – enhanced oil recovery in shale formations. This method not only improves the extraction efficiency of hydrocarbons but also supports the achievement of carbon neutrality goals by enhancing the CO₂ sequestration potential.

Keywords Electric field, Shale oil, Carbon dioxide, Enhanced oil recovery, molecular dynamics simulation