Synthesis and Properties Evaluation of Nonionic-Anionic Surfactants Suitable for Enhanced Oil Recovery Using Sea Water

Abstract In view of imperfections of conventional anionic and nonionic surfactants used for enhanced oil recovery, especially the characteristics of high salinity and high Calcium/Magnesium for sea water flooding, a new novel displacement agent suitable for sea water flooding was synthesized through alkoxylation, epoxidation, sulfonation reaction with fatty alcohol as core. The structure of the product was characterized by IR. The properties of the product, including salt tolerance, temperature resistance etc. were evaluated. At 70 °C, when the concentration of this surfactant is 0.3 %, the interfacial tension between simulated water solution and Bohai1A-4 well crude reaches 10 −3 mN/m order, the salt tolerance reaches 50 000 mg/L, the resistance to calcium and magnesium reaches 2000 mg/L. The laboratory physical simulation test shows that the binary complex system (polymer + surfactant) can enhance the recovery ratio by 17.9 %, while better synergistic effect of the system is obtained.