Critical parameters for EOR techniques are reviewed

This article addresses critical parameters, displacement studies, core-flooding techniques, and scale-up considerations for the surfactant-polymer, alkaline, and in situ combustion EOR processes. Significant quantities of residual oil usually remain in reservoirs after conventional secondary waterflooding. This oil is held to the reservoir rock by capillary forces. In some reservoirs, surfactant-polymer flooding has the greatest potential of all EOR methods for recovery of this incremental oil. Recoveries of 100% of residual oil are achievable in linear laboratory corefloods. Lowering of interfacial tensions between oil and water and mobility enhancement are primary mechanisms of oil recovery.