Microscopic Oil Displacement Experiment of CO2 in Ultra-low Permeability Sandstone

摘要

CO2 flooding is considered to be a very important way to solve the problems of high starting pressure gradient,poor reservoir water absorption and low water flooding recovery in ultra-low permeability reservoirs.Moreover,the long-term storage underground of CO2 can be achieved,and the social benefits of CO2 emission reduction can also be realized.In order to study on the sweep region of CO2 miscible and immiscible flooding,ascertain the displacement efficiency of CO2 under different conditions.Through the micro-displacement experiment of CO2 in real sandstone,It is clear that the oil displacement efficiency of CO2 miscible flooding is the best,sweep region is the widest.Moreover,CO2 miscible/near miscible flooding can greatly improve micro-displacement efficiency.The analysis results of the experiment will provide guidance for the field test.