聚合物驱窜流实验研究

聚合物驱油是提高采收率的重要方法,但由于地层经过长期的注水开发,储层物性发生变化,形成优势流场,导致聚合物驱油过程中聚合物沿优势流场窜流指进,降低了聚合物驱油效率,应用与地层孔隙相似的微观填砂模型,模拟地层非均质性进行聚合物驱窜流微观实验研究,通过微观动态图像处理系统对聚合物的窜流规律、聚合物驱后残余油的形式进行分析.结果表明聚合物驱提高了采收率,但仍沿高渗透条带指进窜流,指进速度与地层系数密切相关,后续水驱中由于聚合物阻力效应,扩大波及系数,提高了采收率,但低渗透地层的采收率仍然较低,提高低渗透地层的采收率是聚合物驱后开发重点.

Experiment study on crossflow of polymer flooding

Polymer flooding is the main method of enhanced recovery,but after long time of water flooding,reservoir heterogeneity becomes more serious and dominant flow region has been formed,leading to polymer crossflow and fingering along dominant flow region during polymer flooding.A micro-model with pore structure similar to reservoir heterogeneity is applied to study polymer crossflow.Polymer crossflow and residual oil after polymer flooding are analyzed through micro dynamic image processing system.The result shows that polymer flooding had improved recovery factor,but the polymer still fingers along high permeability path,the fingering velocity is closely related to formation coefficient.In follow-up water flooding,polymer resistance effect expands sweep efficiency and enhances recovery,but the recovery factor of low permeability reservoir is still low.Enhancing oil recovery of low permeability reservoir is the key to oilfield development after polymer flooding.