二元复合驱中表面活性剂的提采机理分析

Mechanism of Enhanced Oil Reovery by Surfactant in Polymer-surfactant Dual Composite Flooding

为了探究二元复合体系中表面活性剂的作用,将甜菜碱型(S1)、阴离子型(S2)、脂肽生物型(S3)、非离子-阴离子型表面活性剂(S4)4种表面活性剂分别与部分水解聚丙烯酰胺(HPAM)组成二元复合体系,通过测定体系的黏度、油水界面张力、乳化性与岩心驱油实验,分析表面活性剂提高采收率的作用机理。结果表明,在二元复合驱中,表面活性剂对体系黏度有影响,但影响很小,最终决定体系黏度的是聚合物。4种类型的表面活性剂均具有双亲结构,可以降低油水界面张力至10^(-3)mN/m,促进油水乳化。二元复合驱的采收率较单一聚合物驱采收率高。S4/HPAM二元体系可将油水界面张力降至2.4×10^(-3)mN/m,形成的油水乳状液黏度最高,稳定性最强,提高采收率效果最好。

In order to explore the role of surfactant in dual composite system,four surfactants,such as betaine type(S1),anionic type(S2),lipopeptide biotype(S3)and nonionic-anion surfactant(S4)were combined with partially hydrolyzed polyacrylamide(HPAM)to form a dual composite system,respectively.By measuring the viscosity,oil-water interfacial tension,emulsification and core flooding experiment of the system,the mechanism of enhancing oil recovery by surfactant was analyzed.The results showed that in dual composite flooding,surfactant had a very small influence on the viscosity of system,and the polymer ultimately determined the viscosity of system.All four types of surfactants had amphiphilic structure,which could reduce the interfacial tension between oil and water to 10^(-3) mN/m and promote oil-water emulsification.The recovery ratio of dual composite flooding was higher than that of single polymer flooding.S4/HPAM dual system could reduce the interfacial tension between oil and water to 2.4×10^(-3) mN/m.The formed oil-water emulsion had the highest viscosity,the strongest stability and the best effect of enhancing oil recovery.