高温低渗油藏表面活性剂驱影响因素研究

Study on the Influence Factors of Surfactant Flooding in High-Temperature Low-Permeability Reservoir

孙琳 田园媛 蒲万芬 辛军 吴雅丽

SUN Lin TIAN Yuan-Yuan PU Wan-Fen XIN Jun WU Ya–Li

为改善高温低渗油藏开发效果，开展了表面活性剂驱影响因素研究。通过在114℃条件下，对亲水、亲油低渗岩心进行表面活性剂驱油实验，考察了界面张力、乳化作用、润湿反转以及注入时机对注入压力、驱油效率等的影响。研究结果表明，表面活性剂体系与原油间的界面张力越低，提高驱油效率和降低注入压力的幅度越大。表面活性剂的乳化速率越高，原油采收率越高；乳化降黏能力越强，降压效果越好；同时，适当降低乳状液稳定性也对驱油有利。表面活性剂的润湿反转作用使其能在较高界面张力下有效驱油，并在亲油岩心中获得较亲水岩心更好的增油降压效果。此外，在中等含水阶段进行表面活性剂驱，能够利用最低的投入获得最高的原油采收率。

In order to improve the development effect of high-temperature low-permeability reservoir，the influence factors of surfactant flooding were researched. At the temperature of 114℃，the influence of interfacial tension（IFT），emulsification，wettability reversal and injection time on the injection pressure，displacement efficiency were proded by carrying out the surfactant flooding experiments in water-wet and oil-wet cores. The results showed that the lower the IFT between surfactant and crude oil，the clearer the increment of displacement efficiency and decrement of injection pressure. The faster the emulsion rate of surfactant，the higher the oil recovery; and the stronger the ability to reduce viscosity by emulsification，the better the pressure reduction effect. Meanwhile，it was beneficial to decrease properly the emulsion stability as for displacement. The wettability reversal of surfactant made the displacement become more effective even when the IFT was higher. Moreover，it made the effect of increasing oil production and decreasing injection pressure in oil-wet core better than that in water-wet core. Furthermore，the surfactant flooding at medium water cut stage could obtain maximal oil recovery via minimal input.