A New Thermal Stable and Salt Tolerant Alkyl Polyether Benzyl Sulfonate Surfactant with Ultralow Interfacial Tensions for Enhanced Oil Recovery

A large variety of surfactants have been widely used in enhanced oil recovery, yet there is still a challenge for the application of surfactants in oil reservoirs with high salinity and high temperatures. Herein we report a new alkyl polyether benzyl sulfonate anionic surfactant named sodium iso-tridecanol polyoxyethylene ether benzyl sulfonate with ultralow interfacial tensions at high salinity and high temperatures synthesized through a strategy connecting the alkyl polyether with a benzyl group. Its structure was confirmed by 1H NMR. Effects of the temperature, salinity, divalent ion, and surfactant concentration on interfacial tensions and phase behaviors were investigated. The alkyl polyether benzyl sulfonate surfactant demonstrated a strong interfacial activity and excellent phase behavior with high solubilization parameters at salinities up to 18.0 wt % NaCl and temperatures up to 120 °C, which suggest that the new alkyl polyether benzyl sulfonate surfactant has good temperature resistance and salt tolerance and is promising for applications in enhanced oil recovery in high temperature and high salinity oil reservoirs.