A New Class of Low Surface Energy Anionic Surfactant for Enhanced Oil Recovery

Abstract

A highly branched green low surface energy surfactant (LSES), stable in harsh conditions, was synthesized for enhanced oil recovery (EOR). Oil recovery factors were determined using a glass micromodel and indicated a 72% increase in oil recovery in both low and high brine solutions, a remarkable result for only a single chain surfactant flooding. The surface-interface analysis of brine and brine/surfactant solutions was carried out, while small-angle neutron scattering measurements were used to determine the changes in the surfactant structure in different brine solutions, and ζ potential experiments revealed the effect of monovalent and divalent cations in each solution. Adsorption analysis on crushed glasses was evaluated to see the maximum amount of surfactant adsorption in the system, and finally, oil recovery factors were discussed according to the interfacial tension and contact angle measurements. Based on our inclusive study we conclude that the cost-effective and environmentally friendly LSES presents a class of potentially important material for use in various EOR scenarios, such as low salinity, smart water, alkaline–surfactant–polymer, and nanoparticle–surfactant flooding.