Residual Oil Distribution of Heterogeneous Reservoir at Different Water Drive Velocity

The oil recovery rate is one of the factors affecting remaining oil distribution. Overseas sandstone oilfields were developed with high production rate in the early stage. However, when the oilfield development enters the high-water cut stage, further improving recovery rate has become one of the key issues for the researchers. Based on water displacing oil experiment in sand filling model of heterogeneous reservoirs, residual oil distribution characteristics and oil displacement efficiency of heterogeneous reservoir at different water drive velocity have been studied. Compared with low-speed water drive, high-speed water drive can reduce the micro-sweep efficiency, and ultimately reduce the oil displacement efficiency. There is little residual oil in the region affected by injected water, and the main types of residual oil are local continuous microscopic heterogeneous residual oil, so the key objective of improving oil displacement efficiency is to start micro-heterogeneous residual oil in the region affected injected water. The main directions of further enhancing oil recovery after high-speed water drive in heterogeneous sandstone reservoirs are to improve the microscopic and macroscopic sweep efficiency. The results indicate the direction for further improving the recovery rate of the sandstone reservoir after high-speed water drive.