CO₂ mobility control using CO₂ philic surfactant for enhanced oil recovery

CO₂ enhanced oil recovery by using newly synthesized CO₂ philic surfactant as CO₂ mobility control agent is reported. Nonyl phenol ethoxylate sulphonate (NPES) was prepared by the esterification of alcohol with maleic anhydride followed by its sulphonation. Effect of interfacial tension (IFT) between CO₂ and brine using NPES was investigated to verify the CO₂ philicity of the surfactant. The detailed account of effects of pressure and temperature on IFT between CO₂/brine in the presence and absence of surfactant on specified pressure and temperature conditions is studied and discussed. NPES effectively lowered the IFT between CO₂/brine (30 mN/m) to less than 5.23 mN/m. Foam quantity was improved by using betaine as foam booster. The static foam endurance properties in the presence and absence of oil were also examined prior to the actual performance test of surfactants using a reservoir core plug sample. It was noted that the foam stability was 900 s in the presence of oil at 90 °C in CO₂ environment. The effect of foam by using synthesized NPES on mobility of CO₂ is also presented. The CO₂ mobility reduction factor was found to be 3.1. It is concluded that NPES has great potential for CO₂-EOR applications.