Study On The Influence Of Formation Oil Between CO₂ And Minimum Miscibility Pressure

In this paper,the history and development situation at home and aboard of CO₂ flooding process for improving oil recovery are introduced,the mechanisms of CO₂ injection EOR are presented,also introduce the application prospect of CO₂ injection EOR in China and how the recovery influenced by miscibility pressure.The slim tube test may be the most accurate method and can achieve duplicating results to determine the minimum miscibility pressure.In CO₂ miscible displacement experiments on a long and thin tubed model,the effects of the nature of reservoir oil,the reservoir temperature,and the composition of the injection gas upon CO₂ minimum miscibility pressures are investigated.The results show that:On one hand,oil with high viscosity,high density,low GOR,high temperature,less air and more natural gas mixed result in a high MMP.On the other hand,slim tube with long length,small diameter,low flooding rate and low permeability cause a low MMP.