A New Method for Predicting Coalbed Methane Recovery Based on Permeability and Well Spacing
The prediction methods of coalbed methane recovery mainly include:the analogy method,the desorption method,the estimation method of gas content reduced,the isothermal adsorption curve method and reservoir numerical simulation method.Among them,the first four methods con-sider fewer factors with lower reliability,while the fifth method comprehensively considers multiple factors and has reliable prediction results,but its process is complicated and takes a long time.With comprehensive consideration of other factors,the chart method takes permeability and well spacing as the key factors affecting CBM recovery,using numerical simulation technique to establish a sim-plified model to explore the relationship between permeability,well spacing and coalbed methane re-covery and to establish the chart.At the same time,gas saturation and isothermal adsorption curve characteristic coefficients are used to correct the recovery efficiency.This method can quickly deter-mine CBM recovery,and it has been applied in Linxing East Block with good effects.