Research and Application of Binary Quantitative Evaluation Method for Gas Reservoir Recovery

Recovery is a crucial index for evaluating the development effectiveness of gas reservoirs, and improving recovery is an eternal goal in gas reservoir development. However, numerous factors affect gas reservoir recovery, making it challenging to identify key factors and quantify their influence effect. By introducing dynamic reserves, the recovery of gas reservoirs is divided into two parts: reserve utilization degree and dynamic reserve recovery, establishing a binary quantitative evaluation method for gas reservoir recovery. By analyzing reserve utilization degree and dynamic reserve recovery from the reservoir to the block and then to individual wells, key factors affecting recovery can be effectively identified, and the impact of each factor can be quantified. The study of the Shuangjiaba Carboniferous gas reservoir shows that the reserve utilization degree is 77.3%, and the dynamic reserve recovery is 83.4%. The comprehensive recovery of geological reserves is 64.5%, with an influence degree as high as 35.5%. Low permeability affects the reserve utilization degree by 22.7% and dynamic reserve recovery by 4.4%. Water invasion influences recovery by 5.4%, and abandonment conditions affect it by 3.0%. Through the analysis of reserve utilization degree and dynamic reserve recovery, the binary quantitative evaluation method provides a new approach for analyzing and quantitatively evaluating the key factors of various gas reservoir recoveries, laying a solid foundation for formulating technical countermeasures to improve recovery.