When a reservoir is subjected to long-term water and polymer flooding, the formed preferential flow paths are widely distributed in the formation, and the displacing fluid effect is reduced, thus leaving a large amount of remaining oil unexploited. To enhance the oil recovery efficiency after polymer flooding, it is important to provide effective methods to block the preferential flow paths. The statistical data analysis results of 20 wells after polymer flooding in the Daqing oilfield show that the remaining oil and the preferential flow paths are mainly distributed vertically in the sedimentation units named PI2 and PI3, and the physical plugging and traditional adjusting techniques are not effective. Considering the above, an adaptive compound flooding method is put forward, which is based on the idea of “plugging, adjusting, and flooding. Laboratory experiment results show that the enhanced oil recovery (EOR) of the new polymer flooding method is 13.6%, which is 4.9% higher than that of alkaline/surfactant/polymer (ASP) flooding. The polymer consumption of the new method is more than 10% lower than that of conventional polymer flooding.

油藏长期遭受水驱和聚合物驱时，形成的优先流道在地层中广泛分布，驱替流体作用减弱，大量剩余油未开发。为了提高聚合物驱后的采油效率，提供有效的方法来阻断优先流路是很重要的。大庆油田聚合物驱20口井的统计数据分析结果表明，剩余油和优先流道主要在PI2和PI3沉积单元垂直分布，物理封堵和传统调整技术效果不佳。综上所述，提出了一种基于“堵、调、淹”思想的适应性复合驱方法。室内试验结果表明，聚合物驱新方法的提高采收率（EOR）为13.6%，比碱性/表面活性剂/聚合物（ASP）驱高4.9个百分点。新方法的聚合物消耗量比常规聚合物驱低10%以上。