超高界面活性阴阳离子表面活性剂复合驱油体系研究

Study on Highly Efficient Mixtures of Anionic/Cationic Surfactants for Enhanced Oil Recovery

为提高高采出、高含水老油田采收率,研发了超高界面活性阴阳离子表面活性剂复合驱油体系S1。结果表明,针对胜利河口原油,在温度75~120℃,矿化度6000~50000 mg/L,二价离子100~2000 mg/L,表面活性剂浓度0.05%~0.50%条件下,体系油水界面张力达到2×10-3 mN/m,增溶参数达到20。此外,该体系还可将岩石润湿性由油湿调变为中性润湿,是一种可有效调控油、水和岩石三相界面作用力,实现剥离原油和降低油水界面张力的超高界面活性原位微乳液表面活性剂体系。

To improve oil recovery of mature oilfields with high recovery degree and high water cut,an efficient formulation consisting of blend of anionic/cationic surfactants(S1)was developed.The experimental results showed that when the temperature was 75-120℃,total dissolved solids(TDS)were 6000-50000 mg/L,divalent ions were 100-2000 mg/L,surfactant concentration was 0.05%-0.50%,ultra-low interfacial tension of 2×10-3 mN/m and solubilization parameters of 20 could be obtained with Shengli Hekou crude oil.In addition,surface wettability of the rock was altered from oil wet to neutral wet.The in-situ microemulsion with S1 showed remarkable capacity for altering the three-phase interface forces of oil,water and rock,which help to remove the crude oil from formation and decrease the interfacial tension between oil and water.