The microscale analysis of reverse displacement based on digital core

Abstract The recovery of the reservoir is always the center of development because of its renewable characteristic. There are many methods designed to enhance the development of residual hydrocarbon, such as water flooding, polymer flooding, and the adjustment of well pattern. But the microscale mechanisms of fluid flow in porous media is still ambiguous, especially for reverse flooding. So in-situ displacement experiment based on CT scanning was designed in this paper to analyze the trapped oil after various flooding. In pore scale level, the total number of residual oil and average volume were counted. For further observing distribution changes, we classified the shape of residual oil based on shape factor and Euler number, and calculated the corresponding proportion. These results show that the adjustment of flow streamline can effectively improve oil recovery after water forward flooding and polymer displacement.