Assessment of the favourable areas of the coalbed gas resources in the Gulin-Xuyong mining district in southern Sichuan

The Permian Longtan Formation in southern Sichuan resides the important coal measures and coalbed gas resources. The Gulin-Xuyong coal mining district as a major coal production area in southern Sichuan is very rich in the coalbed gas resources. In this study, the target strata are evaluated and delineated in the light of regional geological and mineral resource survey, and the distribution of the coal measures, including C25, C23, C19, C17 and C11 as the target coal measures for the coal exploration in the Gulin-Xuyong coal mining district. The selected coal measures cited above are characterized by high contents of organic matter, high degrees of thermal evolution, medium to high ash contents, well developed endogenetic fractures and high contents of coalbed gas. According to coal thickness, regional structures and burial depth, the favourable areas for the enrichment of the coalbed gas resources may be delineated, including the Dacun and Shibao blocks, and relatively favourable areas consist of the Guanwen well area in the Guansha block, Shipin-Xiangding well area in the Gulin block, and Baitougou well area in the Heba block.