A Review on the Application of Ionic Liquids for Enhanced Oil Recovery

Abstract

Research is extensively ongoing on the application of ionic liquids (ILs) in technological application, particularly its application in the enhanced oil recovery (EOR). Research in this field, however, is often limited to researchers determining ionic liquids’ specific behavior in the aqueous solutions. A comprehensive study is necessary to provide a complete possible understanding of the ionic liquids’ surface interaction as the self-organization and micelle formation ability of ionic liquids in aqueous solution have significant effect on their applications and the environment. ILs that have surface activity are able to exhibit the critical micelle concentration (CMC) and reduce the interfacial tension (IFT) to the noticeable value even at high salinity and temperature conditions. The application of ILs as cosurfactant is also favorable to support the surfactant performance in minimizing the IFT values. This review indicates that further investigation is required to study the interphase behavior of ionic liquids in a more complex system where hydrocarbons, salts, surfactants, and other chemical additives are present. The alteration in behavior and system properties due to the interaction of ionic liquid with surfactant may determine its effectiveness in emulsion and foaming studies. These two studies are essential in the application of ionic liquids in oil and gas reservoirs, particularly water and chemical flooding to increase the recovery of oil.