ABSTRACT
Hydrogeological conditions are active factors of enrichment and development of coalbed methane (CBM), they are also the direct reflection and the main contributor of reservoir pressure. The runoff characteristics of groundwater, pressure state of coal reservoir, CBM saturation and water property in coal reservoir are analyzed. Based on the runoff characteristics of groundwater, CBM-controlling effect of hydrogeological conditions are divided into three patterns such as strong runoff-escape, slight flow and detention-seal. The methane-water relative permeability experiments show that the water-bounded saturation of coal blocks increases with coal ranks in China. Coal reservoirs are divided into 36 types according to pressure, water property, CBM saturation and well-testing permeability. And some common seen types of low rank, middle rank, and high rank coal reservoirs are farther analyzed.
