超低界面张力强化泡沫体系稠油驱研究

Heavy oil displacement by enhanced foam system with ultra-low interfacial tension

针对孤东六区稠油油藏条件,研究得到既能在不含碱的条件下与原油形成超低界面张力,又能形成稳定泡沫的超低界面张力强化泡沫体系。其配方为:3.0 g/L石油磺酸盐+5.0 g/L HEDP-Na4+0.6 g/LⅠ型两亲聚合物,气体为氮气。该体系具有较好的泡沫性能和乳化降黏性能,并且两亲聚合物能够改善泡沫的稳定性和体系对原油的乳化效果。超低界面张力强化泡沫体系对孤东六区稠油具有较好的驱替性能,原油采收率能够在水驱的基础上提高37.9%,总采收率达到65.7%,所注入体系能在较长时间里发挥调剖和驱油效果。

For the reservoir conditions of Gudong Oilfield,an enhanced foam system with ultra-low interfacial tension containing no alkali was developed to get ultra-low oil-water interfacial tension and the foam with good stability.The optimal formula was obtained and given as follows： 3.0 g/L petroleum sulfonate＋5.0 g/L HEDP-Na4＋0.6 g/L Ⅰ type amphiphilic polymer,and the gas is nitrogen.The evaluation results on the foam system performance show that the system has good foaming and emulsifying properties and good ability to reduce oil viscosity.Furthermore,the amphiphilic polymer can improve the foam stability and the emulsification ability on oil.The enhanced foam system with ultra-low interfacial tension can effectively displace the heavy oil in Gudong Oilfield.The oil recovery efficiency is raised by 37.9% after water flooding,and the total oil recovery efficiency reaches 65.7%.Meanwhile,the foam system can be effective for a long time in profile control and oil displacement.