Implementation of a high-performance surfactant for enhanced oil recovery from carbonate reservoirs

Over half of the original oil in a location is retained in a reservoir after the implementation of primary and secondary production schemes. The implementation of chemical stimulation such as surfactant flooding as tertiary-stage recovery methods as part of an enhanced oil recovery (EOR) scheme is inevitable. An important element of oil recovery mechanisms based on surfactant flooding is the lowering of the interfacial tension between the aqueous and oil phases. The implementation of surfactant extracted from Zyziphus spina christi leaves for enhanced oil recovery (EOR) in carbonate reservoirs has not yet been addressed in the literature. This research investigates the implementation of natural surfactant in aqueous solutions for EOR applications and reservoir stimulation. Core displacement experiments were implemented to assess the effectiveness of the introduced surfactant as an enhanced oil recovery agent in carbonate reservoirs. These tests were performed on carbonate cores saturated with brine and oil that were injected with the extracted surfactant in six different concentrations. The results show that with the increase of the introduced surfactant concentration, the ultimate recovery increases; this trend is attributed to the lowering of the interfacial tension between the oil and aqueous phases and to the increase in the viscosity of the aqueous phase. Results from this research can aid in the appropriate design of the chemical stimulation process like the use of surfactant flooding in carbonate reservoirs. (C) 2013 Elsevier B.V. All rights reserved.