Integrated study of gas condensate reservoir characterization through pressure transient analysis

Results show that gas compositions of a gas condensate reservoir have significant effects on the fluid flow behaviors. Different proportions of C5, C6 and C7+ are simulated with constant makeup of CO2, N2 and C1∼4, showing that small changes in composition of heavier components make distinct differences in the flow behaviors, as reflected on the liquids dropout curves. In addition, total compressibility factor varies with fluid compositions instead of remaining constant in a gas condensate reservoir. Through integrating PVT behaviors, the three-region model is able to accurately describe transient pressure behaviors of a production well in a gas condensate reservoir, which clearly characterizes three regions on the pressure derivative curves. A series of sensitivity studies are conducted to analyze the differences among the three regions.