Experimental Study of Sodium Carbonate and Dodecyltrimethylammonium Bromide Surfactant Effects for Enhanced Oil Recovery in Asmari Oil Reservoir

One of the efficient methods for enhanced oil recovery from a petroleum reservoir is the surfactant injection in the presence of alkaline material. Moreover, the contact angle of water and reservoir rock is reduced in the presence of surfactants. On the other hand, this material changes the interfacial tension. The alkaline materials in the present of surfactants also help the reduction of interfacial tension and the wettability alteration of reservoir rock. In this research, the effect of concentration (0.05, 0.1, 0.3, 0.5 wt %) and shelf-life of surfactant dodecyltrimethylammonium bromide in the presence of different concentrations of sodium carbonate (0.5, 1, 1.5, 2, 2.5 wt %) on the interfacial tension and wettability alteration of carbonated rocks of the Asmari petroleum reservoir were analyzed. The results of these experiments showed that surfactant dodecyltrimethylammonium bromide reduces the interfacial tension and alters the wettability of reservoir rock to the water-wet state. Furthermore, the interfacial tension and contact angle is reduced in the presence of sodium carbonate to a great extent which is one of the effective factors in the amount of oil recovery. By increasing the shelf life of the reservoir rock in contact with the solution containing surfactant and sodium carbonate for 7 days, the minimum contact angle was reduced from 59 to 46 degrees. At 0.3 wt.% micelle concentration of dodecyltrimethylammonium bromide and sodium carbonate with an optimum concentration of 0.5 wt.%, the most reduction in interfacial tension was obtained.