The Characterization of Natural Surfactant and Polymer and Their Use in Enhanced Recovery of Oil

Studies have been done to examine the applicability of natural surfactant and polymer for enhanced oil recovery. A detailed investigation has been made on interfacial and rheological properties of natural guar gum polymer and surfactant obtained from extracted soapnut shell. Based on the physicochemical properties of the surfactant and polymer solutions, optimum compositions were designed for flooding experiments. Three sets of experiments were performed to study enhanced oil recovery by injecting the same pore volume of polymer, surfactant–polymer, and alkaline–surfactant–polymer slug after brine flooding. Significantly higher additional recovery (~24% original oil in place) was obtained by alkaline–surfactant–polymer flooding compared to the other two methods over waterflooding (~50% original oil in place).