表面活性剂在压裂液中对提高渗吸采收率的研究

Study on Improving Imbibition Oil Recovery by Adding Surfactants in Fracturing Fluid

针对致密砂岩油藏开展了3种表面活性剂(ZPS、SDBS、SB)在水溶液和低浓度瓜尔胶压裂液中对提高渗吸采收率的研究。只有非离子表面活性剂(SB)未起到润湿反转的作用。加有三种表面活性剂的溶液均使界面张力达到了岩心渗吸的最佳效果。分析实验得出:与注入水相比,在加有表面活性剂的溶液中对提高采收率都起到了一定的作用,在低浓度瓜尔胶压裂液中的渗吸采收率最高。改向和黏弹作用是低浓度瓜尔胶压裂液提高渗吸采收率的主要机理。

Improving imbibition oil recovery of tight sandstone reservoirs by adding surfactants（ZPS,SDBS,SB） in water and low concentration of guar gum fracturing fluid was studied. The results show that single nonionic surfactant（SB） does not play the role of wettability alteration. The interfacial tension of solution with three kinds of surfactants can achieve the best result of imbibition.Adding surfactants in the fracturing fluid can enhance oil recovery to a certain extent; Adding surfactants in low concentration of guar gum fracturing fluid can obtain the highest oil recovery. Changing the direction and viscoelastic effect of flow is the main mechanism of improving imbibition oil recovery by low concentration of guar gum fracturing fluid.