Molecular interactions of surfactants with other chemicals in chemical flooding processes: A comprehensive review on molecular dynamics simulation studies

Due to the growing demand for fossil fuels and the transition of many oil fields into a high water-cut stage, enhanced oil recovery (EOR) techniques have become more prevalent to meet this rising demand. Among these techniques, chemical flooding stands out as an effective method, supported by numerous experimental and simulation studies. However, the complexity of a chemical slug composition under harsh reservoir conditions makes the physicochemical phenomena involved in a chemical flooding process highly intricate. To comprehensively understand the microscopic mechanisms governing the phase behavior of complex fluid systems underground, molecular dynamics (MD) simulations have been increasingly employed in recent years to investigate the molecular interactions between various chemicals involved in chemical flooding processes. In this work, we have comprehensively reviewed the recent MD studies focusing on the molecular interactions between surfactants and other chemicals in the chemical flooding processes. Based on the molecular interactions within different chemicals, various nanoscale mechanisms have been proposed to shed light on the physicochemical flow in porous media. Additionally, the MD techniques used in these studies have been summarized, and challenges in the application of MD simulations in the field of chemical flooding have been identified for improving the quality of future MD studies.