阴离子双子表面活性剂驱油体系研究

Investigation on oil displacement system of anionic gemini surfactant

对一种新型双子表面活性剂GA12-4-12的耐盐性和驱油性能进行了研究。该表面活性剂在含NaCl为2.35×105 mg/L、CaCl2为1.5×104 mg/L的地层水溶液中表现出良好的表面活性,其临界胶束浓度为538.6mg/L。GA12-4-12溶液与稀油间的油水界面张力随着无机盐含量的增加而降低并趋于稳定,当NaCl含量为250g/L,能使界面张力降至2.2×10-3 mN/m。在高矿化度模拟地层水条件下,GA12-4-12及其与非离子表面活性剂复合体系SP的油水动态界面张力均能达到超低(10-3 mN/m)。进行模拟驱油实验表明,GA12-4-12与SP复合体系提高水驱采收率分别为6.25%、10.67%。

The salt resistance and oil displacement performance of a new kind of gemini surfactant GA12-4-12 was investigated.This surfactant exhibits good surface activity in the aqueous blending solution of sodium chloride 2.35×105 mg/L and calcium chloride 1.5×104 mg/L,and its critical micelle concentration is 538.6 mg/L.The oil-water interface tension between the GA12-4-12 solution and thin oil decreases with the increase of the concentration of inorganic salt first and then tends to stable.It decreases to 2.2×10-3 mN/m at the NaCl concentration of 250 g/L.Under the high-salinity simulation formation water,the oil-water dynamic interfacial tensions of GA12-4-12 and its composite system SP can reach the ultra-low value(10-3 mN/m).Oil displacing simulation experiments show that GA12-4-12 and its composite system SP can increase oil recovery displaced water by 6.25% and 10.67%,respectively.