THE FORMATION MECHANISM OF COALBED METHANE RESERVOIR IN THE SOUTH QINSHUI BASIN

Based on the data obtained from the exploration for oil and gas, coal, and coalbed methane, the characteristics of coalbed methane reservoir in the South Qinshui Basin is systematically discussed in this paper. The description on the static characteristics (including coalbed geometry, content and composition of coalbed gas, physical property of the reservoir, adsorption, reservoir pressure, and sealing condition) and the dynamic process(including the generation, migration and accumulation of coalbed methane) of the coalbed methane reservoir show that the coalbed methane generated from the Upper Paleozoic coal seams during the Indosinian and Yanshanian Orogenics is adjusted reformed to the current South Qinshui coalbed methane reservoir in the Himalayan Orogeny. The coalbed methane accumulation is controlled by the roof and floor of coal seams, boundary fault. The groundwater stagnant zone is the optimal area for coalbed methane accumulation. The current coalbed methane wells locate almost in the zone.