Abstract

It is of importance to uncovering miscible behavior of hydrocarbon gas and crude oil in nanoslits for enhanced oil recovery. The comprehensive MD simulations are performed to investigate the miscible process of different hydrocarbon gas and crude oil in nanoslits under reservoir conditions. For the first time, absolute solubility of crude oil is calculated to estimate its miscibility with gas phase. The simulation results manifest that a longer chain length of hydrocarbon gas could help to increase its miscibility with crude oil due to the increasing interaction strength between them. Additionally, the miscibility of hydrocarbon gas and crude oil is reduced due to the increasing polarity of crude oil. Because the larger polarity could strengthen the interactions between crude oil and rock surface and then correspondingly reduce its solubility of crude oil in hydrocarbon gas. This investigation introduces a novel method to evaluate of miscibility of fluids in naoslits and contributes to more general applications of hydrocarbon flooding in reservoirs.