Synergetic System of Zwitterionic/Anionic Surfactants with Ultralow Interfacial Tension and High Salt Resistance for Enhancing Heavy Oil Recovery

Abstract

Conventional water flooding strategy has limited the further development of heavy oil recovery due to the lower displacement efficiency. In this work, a potential zwitterionic/anionic surfactant system to enhance heavy oil recovery in the high salinity was proposed through low budget and feasible mixing. We evaluated the capabilities of the mixed surfactant systems consisting of zwitterionic cocoamidopropyl sulfonate betaine (CSB) and anionic sodium dodecyl benzene sulfonate (SDBS) in terms of surface tension, interfacial tension (IFT), emulsion size distribution, emulsion stability, apparent viscosity, emulsion viscoelasticity, viscosity reduction, and recovery efficiency. The IFT could substantially reduce to an ultralow level (<10 −2 mN/m) at a higher salinity. The smaller droplets (0.1−3 μm) were formed to stabilize the heavy oil emulsions. The viscoelasticity test confirmed that the intensity of the interface film was enhanced because SDBS/CSB molecules could coabsorb at the heavy oil−water interface in a most closely packed arrangement. Furthermore, the water flooding experiments with different surfactant systems were also implemented to affirm the great potential of the synergetic surfactant systems for heavy oil recovery.

Review and Perspective on the Mechanisms and Application of In Situ Emulsification for Enhanced Oil Recovery

“…83 Chen et al 84 combined the advantages of dilution and surfactant addition, using a toluene in water emulsion stabilized by AES− DOA mixed surfactants to emulsify extra-heavy oil. Ma et al 85 proposed a salt-tolerant zwitterionic/anionic surfactant system with enhanced heavy oil recovery, which will produce synergistic effects and form smaller droplets (0.1−3 μm) to stabilize heavy oil emulsions. Yu et al, 28 using a fine emulsion system, found tha it exhibits well-plugging and sweep-volumeenlargement behaviors.…”