A Comparative Study on Enhancing Oil Recovery of CO2 Miscible Displacement with Several Displacement Ways in an Extra-low Permeability Reservoir

摘要

Efficiency of oil recovery with water flooding process is poor in low permeability oil reservoirs.By contrast, gas flooding is a efficient technology to improve oil recovery of such reservoirs. Considering good results of previous miscible displacements, experiments of physical model are performed by using the long core flow test, and variations of recovery factors and pressure are obtained under the different flooding processes in miscible pressure condition In this paper, It includes pure gas flooding、 pure water flooding、 gas flooding after water flooding、 water flooding after gas flooding and WAG. The research will provide the principle for selection of reasonable development manner of low permeability reservoirs and basic data for further numerical simulation.