Study of Microcosmic Distribution Regularities of the Remaining Oil after ASP Flooding

Abstract

The ASP flooding is an effective method to enhance oil recovery. The main mechanism is to increase the viscosity of injection water by polymer, which reduces the mobility ratio of displacing fluid and displaced fluid so as to expand the sweep volume. The second mechanism is to improve the displacement efficiency by the combined interaction of surface active agent and alkali, which reduces the interfacial tension and improves the wettability of reservoir. The recovery of the ASP flooding usually can raise 10% more than the conventional polymer, but there are still a lot of underground crude oil residues after flooding. So we need take some other methods in order to further improve oil recovery factor. For the research of the ASP flooding microscopic remaining oil distribution, it is still blank all over the world. This paper studies on the microscopic remaining oil distribution after the ASP flooding by using both laser confocal technique and modern physics experiment simulation method. The result shows that the remaining oil is mainly Thin Film Type and Clusters Type, most of them are heavy oil which cannot be flooded easily. It can be a certain reference value for further study on the choices of enhanced oil recovery methods.