二元复合驱流度控制作用效果及其合理流度比研究

针对大港油田港西三区油藏,研究聚合物-表面活性剂二元复合体系流度控制作用对驱替效果的影响,考察二元复合驱合理流度(黏度)比的影响因素。结果表明:随油藏原油黏度、储层平均渗透率和渗透率变异系数增大,流度控制作用对二元复合驱采收率的贡献率增加;与聚合物溶液相比较,表面活性剂溶液流度控制作用效果较差,它在储层内仍沿原水流通道流动,仅靠降低通道内剩余油含油饱和度提高采收率,增油效果较差;流度控制作用对二元复合驱采收率的贡献率超过65%,大港油田港西三区合理黏度比为0.81~1.45。

Study on mobility control of polymer/surfactant oil-displacing agent and reasonable mobility ratio

The oil reservoir in Gangxi III block of Dagang Oilfield was studied, in which the influence of the mobility control effect of polymer/surfactant (PS) on the flooding effect and the influencing factors of reasonable mobility(viscosity) ratio were investigated. The results show that with the increase of oil viscosity, average permeability and permeability variation coefficient, the contribution rate of mobility control to the oil recovery efficiency of compound flooding increases. Compared with polymer solution, the mobility control effect of surfactant solution is poor relatively. In this process, it still flowed along the primary channel of water flooding, and the oil recovery efficiency was only increased by reducing the remaining oil saturation of the channel, which resulted in the undesirable flooding effect. The mobility control contributes more than 65% to the oil recovery efficiency of PS flooding and the reasonable viscosity ratio of chemical oil-displacing agent to crude oil is between 0.81and 1.45for Gangxi III block of Dagang Oilfield.