ASP三元复合体系在非超低界面张力下的乳化性能及其对提高采收率的影响

Emulsifying Property of ASP System with Non-ultra-low Interfacial Tension and Its Effect on Enhanced Oil Recovery

为明确碱-表面活性剂-聚合物(ASP)三元复合体系在非超低界面张力下的乳化作用及其对提高采收率的影响,以综合乳化性能指数Ie为指标,评价了5种表面活性剂的乳化性能,筛选出了一种界面张力非超低但乳化性能优良的体系,并通过平面径向流模型驱油实验研究了该体系的驱油效果。研究结果表明:所考察表面活性剂的综合乳化性能Ie由强到弱依次为OP-10、HABS(重烷基苯磺酸盐)、BS-12(十二烷基二甲基胺乙内酯)、AES(脂肪醇聚氧乙烯醚硫酸钠)和OP-4;碱质量分数为0.3%时,ASP三元复合体系综合乳化性能最优。优选的乳化性能优良的非超低界面张力ASP三元复合体系配方为:Na OH质量分数0.3%、表面活性剂(60%OP-10+40%HABS)的质量分数0.3%、聚合物(部分水解聚丙烯酰胺,相对分子量2000×104)质量浓度1500 mg/L,该体系的黏度为42.9 m Pa·s(45℃、转速6 r/min),与模拟油间的界面张力为0.0415 m N/m,综合乳化性能Ie为0.688,在驱油过程中能够扩大波及体积且可提高波及范围内的驱油效率,提高采收率效果不亚于常规超低界面张力体系。

To investigate the emulsifying property of ASP system without ultra-low interfacial tension（ITT） and its effect on EOR, the emulsifying property of 5 different surfactants were calculated by using an emulsifying property index h, and an ASP system formula with good performance in emulsifying and non-ultra-low interfacial tension was screened out; the radial fluid flow flooding experiments were also conducted to investigate the oil displacement effect of the ASP system. The results showed that the L of the surfactants from strong to weak were OP-10, HABS （sodium alkylbenzene sulfonate）, BS-12 （lauryl betaine）, AES（sodium alcohol ether sulphate） and OP-4 in the same conditions, and when the alkali mass fraction was 0.3%, the ASP system had the best emulsifying property. The optimum formula of the ASP system with non-ultra-low interfacial tension was as follows, NaOH mass fraction was 0.3%, the surfactant （60%OP-10＋40%HABS） mass fraction was 0.3%, and the polymer （relative molecular weight 2000 x 104） mass concentration was 1500 mg/L. The viscosity of the system was 42.9 mPa s （45~C, 6 r/rain）, and the interracial tension between the ASP system and oil was 0.0415 mN/m, and the L was 0.688. The optimized ASP system could not only expand the swept volume, but asso improve the oil displacement efficiency during flooding process, and its effect on enhanced oil recovery was no less than that of the traditional ASP system with ultra-low-IFT.