Synthesis of a new sulfobetaine surfactant with double long alkyl chains and its performances in surfactant-polymer flooding

A new zwitterionic surfactant with double long alkyl chains, 3-((3-((1,3-bis (decyloxyl) propane-2-yl) oxy) -2-hydroxypropyl) dimethylamonio) -2-hydroxypropane-1-sulfonate (diC10GE-HSB), was synthesized, and its performances in Surfactant-Polymer (SP) flooding were studied. As a hydrophobic surfactant diC10GE-HSB solely cannot reduce Daqing crude oil/connate water IFT to ultralow, but ultralow IFT can be achieved by using binary mixtures of diC10GE-HSB with various conventional hydrophilic surfactants such as α–olefin sulfonates, dodecyl polyoxyethylene (10) ether, and cetyl dimethyl hydroxypropyl sulfobetaine, over a wide total concentration range (0.625 ∼ 10 mM) at reservoir temperature. This new sulfobetaine surfactant is therefore a good candidate for SP flooding free of alkali.