CBM surface extraction potential in Lishu mine of Jixi coalfield

Lishu mine is a high-gassy mine with large gas emission, thus the situation of gas control is increasingly severe. For evaluating CBM surface extration potential in Lishu mine, the paper uses numerical simulation software and carries out productivity prediction from 2 key evaluation parameters (gas content, permeability). The result shows that higher decreasing amplitude of gas content and higher gas saturation determine better desorption degree and development effect of the major mined seam. Taking well XX-01 as an example, the gas saturation is as high as 99%, the decreasing amplitude of gas content is as high as 10.8 m³/t. Coal structure (mainly native and cataclastic) determines better permeability of the major mined seam, reservoir is easy to transform and has better fracturing effect, thus resulting in good production-enhancing effect. Productivity prediction shows that the cumulative production of vertical single CBM well is up to 4.22 million m³ during 15 years, and safe and economic benefits are feasible. Therefore, Lishu mine has a good CBM surface extrction potential.