对超低界面张力泡沫体系驱两个关键问题的讨论

Discussion on two key questions of ultraI-low interfacial tension foam system displacement

针对大庆油田进行的超低界面张力泡沫体系驱先导性矿场试验注气量不足的情况, 讨论了试验是否形成泡沫及究竟提高多少采收率的重要问题。通过对试验发泡条件及试验与三元复合驱、天然气驱的动态反应差别, 即超低界面张力泡沫体系驱注入压力、吸液指数、产液指数、地层压力的变化幅度都大大高于三元复合驱; 注采压差大幅度增加; 其注气压力大大高于天然气驱时的注气压力及气窜现象得到抑制等问题的讨论, 得出超低界面张力泡沫体系驱矿场试验在油层中形成了有效的泡沫的认识, 该试验已提高采收率 22 04%, 超过了三元复合驱提高采收率的幅度, 根据试验动态预测最终可比水驱提高采收率 25%左右。

Aiming at the lack of gas injection amount in the pilot test of ultra-low interfacial tension foam system displacement in Daqing Oil Field,this paper discusses if foams form in the test and how much recovery ratio is increased. The experiment of the difference between the form formation condition and the dynamic reaction of ASP flooding and gas drive,i.e., the change amplitude of the injection pressure,fluid absorption index,fluid production index and formation pressure of ultra-low interfacial tension foam system displacement are much higher than that of ASP flooding. The injection-production pressure difference increases a lot.Its gas injection pressure in much higher than that of gas drive, and the gas channeling is prevented.It concludes that ultra-low interfacial tension foam system displacement pilot test has foams formed in the reservoir. This test obtains the incremental recovery of 22.04%,exceeding ASP flooding.Dynamic test predicts that it can increase the recovery 25% more than water flooding.