A New IOR Method for Mature Waterflooding Reservoirs: “Sweep Control Technology”

Abstract For improving the recovery of water flooding heterogeneous oil fields, the classical conformance control method is to enlarge the swept volume as far as possible, usually by fine layering, profile control and water shutoff, and fracturing and acidizing, etc. However, with watercut rising, the remaining oil distributes in deep reservoirs, making the classical methods less effective. “Sweep Control Technology (SCT)”, a new IOR method, is put forward. The whole production-injection flowing field is taken as the studying target. The waterflooding effect impacting factors were classified into three levels: large-scale macroscopic heterogeneity, middle-scale mesoscopic heterogeneity and pore-scale microscopic heterogeneity. Based on the impact of the three levels of heterogeneity on sweep efficiency, we developed new corresponding SCT materials. For large-scale heterogeneity, we put the materials in accurate place to effectively inhibit water flow prevailing channels. For the middle and small scale heterogeneity, the water flow is diverted to achieve effective sweep control by means of effective material migration. So that we can realize complete adjustment and control of the whole flowing field to achieve efficient remaining oil displacement, and to improve the recovery of water flooding phase. The research and experiments in laboratory and field have proved the advancement of the method.