Numerical Simulation Study on Remaining Oil Distribution for L Thick Reservoir

There is about 65% oil remaining in the formation after water flooding, which is proved by the core testing. Because the formation is of great heterogeneity, and the current evaluation techniques are limited, the macro distribution of remaining oil cannot be accurately and quantitatively determined. In order to quantitatively study the spatial distribution of remaining oil after water flooding, and to provide theoretical and methodological support for further development of oilfield, a numerical simulation study on L thick reservoir is carried out by using computational mathematics and numerical simulation. The results show that, the remaining oil is concentrated in the edge of the reservoir and places not affected by the water flooding, and the remaining oil saturation is up to 60%; the saturation of remaining oil is much lower around the injection wells and where the lithology is good, that is approaching to or up to the residual oil saturation. This study quantitatively describe the characteristics of remaining oil distribution of heterogeneous thick reservoirs-"overall dispersion, local enrichment", and put forward that further development of heterogeneous thick reservoirs needs to change the underground fluid flow directions by well pattern adjustment and profile control according to existing conditions of oilfields, or drill infill wells. This study points out the further development direction of oilfields. Compared with the other remaining oil distribution prediction techniques, numerical simulation technology is more rapid, economical and accurate.