Surfactant flooding has been widely applied in high-temperature and high-salinity reservoirs. In this paper, the enhanced oil recovery potential of alkyl alcohol polyoxyethylene ether sulfonate (CEOS) was investigated in a combined study of surface activity, crude oil–water interfacial tension (IFT) reduction, emulsifying property, wettability improvement, and macroscopic oil displacement efficiency. The results illustrated that CEOS had high surface activity and IFT could be reduced to an ultralow level (10^–3 mN/m) at high-temperature and high-salinity conditions. When salinity ranged from 15 × 10⁴ to 22.5 × 10⁴ mg/L and reservoir permeability was ∼10 mD, linear CEOS solution could effectively displace crude oil for its favorable IFT reduction ability. Linear CEOS or CEOS with a benzene ring was optimized for their favorable IFT reduction ability or emulsifying ability when reservoir permeability was ∼50 mD or non-homogeneous. A 0.5 pore volume surfactant flooding and subsequent water flooding could remarkably enhance oil recovery to 16.19–19.38%. All of the results indicated that CEOS has great potential for improving oil recovery in high-temperature and high-salinity oil reservoirs.

中文翻译：

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高温高盐度油藏中烷基醇聚氧乙烯醚磺酸盐表面活性剂的采油潜力提高

表面活性剂驱油已广泛应用于高温高盐度油藏。本文通过表面活性，原油-水界面张力（IFT）降低，乳化性能，润湿性改善和宏观驱油效率的综合研究，研究了烷基醇聚氧乙烯醚磺酸盐（CEOS）的提高的采油潜力。 。结果表明，CEOS具有较高的表面活性，在高温和高盐度条件下，IFT可以降低至超低水平（10 ^–3 mN / m）。当盐度范围从15×10 ⁴到22.5×10 ^4时mg / L和储层渗透率约为10 mD，线性CEOS溶液具有良好的IFT降低能力，可有效替代原油。当储层渗透率约为50 mD或非均质时，对线性CEOS或带有苯环的CEOS进行了优化，以具有良好的IFT降低能力或乳化能力。0.5孔体积的表面活性剂驱油及后续注水可显着提高油采收率至16.19-19.38％。所有结果表明，CEOS在改善高温和高盐度油藏中的石油采收率方面具有巨大潜力。