Synthesis, Physico-Chemical Properties and Enhanced Oil Recovery Flooding Evaluation of Novel Zwitterionic Gemini Surfactants

摘要

In this work, a novel series of zwitterionic gemini surfactants with different hydrophobic tails were synthesized and characterized. The physico-chemical properties of these products (such as surface tension, oil/water interfacial tension, foaming ability, and the wetting ability of paraffin-coated sandstone) were fully studied. The CMC of the synthesized surfactants rang ed from 2.17 × 10~(-4) mol L~(-1) to 5.36 × 10~(-4) mol L~(-1) and corresponding surface tension (γ_(cmc)) ranged from 26.49 mN m~(-1) to 29.06 mN m~(-1), which showed excellent efficiency among the comparison surfactants. All the products can reduce the interfacial tension to a relatively low level of about 0.1-1.0 mN m~(-1). Additionally, results from applying different hydrocarbons suggested that the synergy will be clearer and oil/water interfacial tension will be lower if the oil components are similar to the surfactants. Contact angle and foaming measurements indicated that the surfactants exhibited good wetting and foaming abilities. The results of oil flooding experiments using an authentic sandstone microscopic model showed that C-12 and CA-12 could effectively improve the displacement efficiency by 21-29 %.