Investigation of Hybrid Ionic Liquid Surfactants for Chemical Enhanced Oil Recovery

Enhanced oil recovery (EOR) is being vastly applied and studied in the oil industry and various technologies have emerged over the last decades in order to optimize oil recovery after primary and secondary recovery methods have been applied.
Surfactant flooding is a chemical EOR method of injecting one or more liquid chemicals and surfactants into the reservoir for tertiary recovery in which the phase behavior of the reservoir can be manipulated by the injection of surfactants and co-surfactants, creating advantageous conditions in order to mobilize trapped oil. An excellent surfactant system can create micro-emulsions at the interface between water and crude oil, thus reducing the interfacial tension (IFT) which consequently will mobilize the residual oil and result in improved oil recovery.
Ionic liquids (ILs) are salts that are in liquid state below 100°C, composed wholly of anions and cations. Over the past decade, ILs has become one of the fastest growing „green‟ media for chemists and engineers due to their superbly versatile physicochemical properties. Studies have shown that long alkyl chain ionic liquids have the potential to decrease the interfacial tension (IFT) of n-alkanes. The application of Hybrid ILs as a chemical EOR agent has a great potential in lowering the IFT against crude oil whilst being able to withstand harsh conditions in reservoirs such as high temperature and highly saline environment, thus giving good recovery factor of the stock tank oil originally in place (STOOIP).