A Pseudo-Steady-State Productivity Prediction Method for Fractured Carbonate Gas Wells Considering Stress-Sensitivity Effects

To accurately evaluate the impact of the non-Darcy and stress-sensitivity effects on the productivity of fractured carbonate gas wells, a new dual-media binomial productivity model for radial compound reservoirs was established. The model is divided into an inner zone and an outer zone, in which the inner zone is designed to simulate the production process of gas wells after fracturing treatment. The new model is used to calculate the productivity of a well in a fractured carbonate gas reservoir in the Sichuan Basin. The calculation results showed that the model can predict the absolute open flow of gas wells in fractured carbonate reservoirs more reasonably and has achieved better field application results than the one-point method. According to the parameter sensitivity analysis, stress sensitivity factors mainly influence the late production stage of gas wells, and the formation coefficient plays an important role in influencing the absolute open flow, which demonstrates that formations with higher permeability and thickness are more favorable to the development of gas wells. The productivity prediction model of fractured carbonate gas reservoirs, which comprehensively considers non-Darcy and stress-sensitive effects, can provide a theoretical basis for the efficient development and reasonable production allocation of gas reservoirs.