Effect of Oxygen on Minimum Miscibility Pressure in Carbon Dioxide Flooding

Laboratory studies of the effect of oxygen content in CO 2 on the minimum miscibility pressure (MMP) are conducted on the n -C 5 H 12 / n -C 16 H 34 model oil and Cottonwood Creek crude oil with three injection gases of different oxygen contents. The results indicate that the MMPs for these oils increase unfavorably with increasing O 2 concentration in the CO 2 stream. The experimental results are also supported by our modeling work using a multiple-mixing-cell model, which is found to capture the effects of compositions and temperature, and is found to be a robust and predictive method for determining the MMP. Our experiments and calculations indicate that the effect of O 2 contamination on the MMP is larger for heavier oil and the effect of N 2 impurity on the MMP is larger than that of O 2 impurity.