Advancements in Molecular Simulations of Chemical Enhanced Oil Recovery Processes: A Review

Enhanced Oil Recovery (EOR) processes are crucial to maximize oil extraction from reservoirs beyond primary and secondary recovery methods. The demand for energy and the need to recover large volumes of unrecovered oil have driven advancements in EOR techniques. In EOR processes, understanding molecular scale interactions among oil, brine, and injected materials is very important to minimize the uncertainty and maximize oil production. Conventionally, resource intensive laboratory experiments are conducted to study the effectiveness of the EOR process for a reservoir. Many times, macroscopic parameters such as contact angles, interfacial tension (IFT), viscosity, and rheological properties are experimentally measured to justify the performance of EOR processes. These parameters are a direct or indirect manifestation of underlying complex crude oil/brine/rock (COBR) interactions at the molecular scale. Therefore, a prior understanding of COBR interactions at the molecular level certainly predicts these parameters and design better EOR formulations. For this purpose, molecular dynamics (MD) simulations are a valuable tool to understand EOR mechanisms as they are able to provide information on inter- and intramolecular interactions. Insights from MD simulations contribute to better understanding of the microscopic mechanisms of EOR processes and help optimize EOR formulations. The present Review encompasses a range of chemical EOR topics, including polymers, surfactants, low-salinity waterflooding (LSW), CO2 EOR, and nanoparticles (NP) EOR processes. This Review highlights the versatility and applicability of MD simulations in improved understanding of EOR processes and in developing innovative EOR solutions. It also presents a systematic approach to existing literature on MD simulation for EOR processes.