Feasibility Study on Circulating Gas Injection of Low Permeability Condensate Gas Field in Wenchang Area

To solve the problems of serious retrograde condensation phenomenon, intensified water intrusion of edge water and rapid production decline, feasibility study on enhancing condensate gas reservoir recovery has been systematically carried out by circulating gas injection. Through the PVT and core displacement experiment methods, we make clear that the recovery can be enhenced by injecting dry gas with different CO₂ contents. By means of components numerical simulation method, the displacement characteristics under different development modes were clarified and the key injection-production parameters such as injection mode and gas injection rate were deeply optimized . The research shows that the development effect of the target area can be greatly improved by circulating gas injection. Injecting dry gas rich in CO₂ can effectively inhibit retrocondensation and edge water invasion, and improve the recovery of condensate oil and gas. It is estimated that the recovery degree of condensate gas and condensate oil can reach 57.65% and 36.88% in 10 years of circulating gas injection. Compared with depletion development, it increases 14.63% and 10.17% respectively, and effectively prolongs the economic life of gas reservoir. The results provide technical support for the efficient development of this block and have important guiding significance for the development of similar condensate gas reservoirs.