Main Geological Controls on Distribution and Occurence and Enrichment Patterns of Coalbed Methane in China

The distribution and enrichment of coalbed methane ( CBM) are controlled by multiple geological factors in china, which including geological tectonic, co al burial depth, hydrogeological condition, sedimentary environment, coal physical properties and magmatic intrusion.The results show that, tectonic subsidence, hydra ulic sealing and hydraulic jam-up processes, reverse fault, and syncline axis are beneficial for CBM preservation; tectonic uplift, hydraulic migration-escape process, no rmal fault, anticline axis, and collapse column are unfavorable factors for preserving CBM. With increasing coal burial depth, content increases but subsequently decrea ses starting at critical burial depth.The CBM can be more easily preserved within coals, which developing thicker and tighter roof and floor. The CBM content is positivel y related to coal thickness. According to the effect degree of the geological factors, the law of CBM distribution and enrichment can be summarized as comprehensively controlled by multiple factors and influenced by multiple factors, primarily controlled by one or two factors.