Use CO2 Soluble Surfactant to Decrease the Minimum Miscibility Pressure of CO2 Flooding in Oil Reservoir

Abstract

According to the mechanisms of carbon dioxide miscible flooding and previous researchers’ work on synthesis of CO2-soluble surfactant, Citric acid isoamyl ester was synthesized, and it’s oil solubility and the rate of viscosity reduction both in oil-water system and oil were evaluated. And then we found that this compound can solve in oil effectively; the optimum mass of Citric acid isoamyl ester introduced in oil-water system is 0.12g when the mass ratio of oil and water is 7:3 (crude oil 23.4g, formation water 10g) and the experimental temperature is 50°C , the rate of viscosity reduction is 47.2%; during the evaluation of the ability of Citric acid isoamyl ester to decrease oil viscosity, we found that the optimum dosage of this compound in 20g crude oil is 0.2g when the temperature is 40°C, and the rate of viscosity reduction is 7.37% at this point.