Effects of Modified Natural Mixed Carboxylates in ASP‐Flooding Systems

Abstract A series of surfactants, whose major components are natural mixed carboxylates from the heels of vegetable oil and fats such as soybean oil, vegetable oil, animal oil, and tea oil etc., was developed. An orthogonal‐test‐design method was used to screen the alkaline/ surfactant/polymer (ASP) flooding systems by measuring the transient interfacial tensions at the oil/aqueous interface, and the optimal formations were obtained. The results show that the oil recovery can be increased by 26.8% of the original oil in place (OOIP) using the core‐flood experiment. The wastewater resulting from the production of SDC (natural mixed carboxylates) also has high surface activity, especially the wastewater of SDC‐V, which was treated as SDC solution, and can increase the oil recovery ratio by 19.0% (OOIP).