非均质油藏三元复合驱室内物理模拟试验研究

Laboratory physical simulation experiment of ASP flooding in heterogeneous reservoir

针对三元复合驱在采油现场应用中存在的作用机理较复杂的问题,建立了二维非均质物理模拟模型,以五点井网的1/4单元作为物理模拟对象,研究了三元复合驱提高采收率的渗流规律,并对比分析了水驱、聚合物驱及三元复合驱的驱油效率与含水率的变化特征。结果表明:注入三元体系后,在三元复合体系的协同作用下,在油藏内形成了从主流线向两侧扩展的油墙,同时中、低渗透率层的剩余油得到明显的动用,形成高含油饱和度带逐渐向生产井运移,大幅度提高了中、低渗透率层的波及体积。对于非均质油层,三元复合驱可以降低低效、无效的水循环,较好地控制流度比,扩大波及范围,提高驱油效率及原油采收率。

Aiming at the problem of complex mechanism of ASP flooding applied in oil extraction field,the two-dimensional heterogeneous physical simulation model is established,and the permeability rules of ASP flooding enhancing oil recovery are studied,the oil displacement efficiency and moisture content change rule of water flooding,polymer flooding and ASP flooding are compared and analyzed.The results show that in the process of ASP flooding,the main linear pressure difference of plane model increases gradually,which makes the fluid flow to both sides and improves the plane sweep range.At the same time,the change of saturation shows that the formation of oil wall in reservoir has the same law with the increase of pressure.For the low permeability layer,the resistance of the high permeability layer increases,and the flow direction of the liquid to the low permeability layer turns,that improves the sweep efficiency of the low permeability layer.Therefore,for heterogeneous reservoirs,ASP flooding can not only reduce the inefficient and ineffective water cycle,but also better control the mobility ratio,expand the scope of spread,and improve the efficiency of oil displacement,so as to improve the oil recovery to a greater extent.