Research for reducing the Minimum Miscible Pressure of crude oil and carbon dioxide by injecting citric acid isobutyl ester

Carbon dioxide miscible flooding has become one of the important technologies for improving oil recovery. The Minimum Miscible Pressure (MMP) is key parameter to realize flooding. As MMP in research area higher than formation fracture pressure, cannot be formed. To address this problem, it necessary find a way reduce MMP. Citric acid isobutyl ester chosen carbon and crude research. effect citric on reducing was measured by method long-slim-tube displacement experiment. experiment results show that 29.6 MPa can obviously reduced injecting slug ester. could decrease gradually with constantly adding injected ester, but becomes smaller smaller. optimum size chemical reagent 0.003 PV. Under condition size, 23.5 reduction 6.1 MPa.