Analysis on production dynamic and main controlling factors of single coalbed methane (CBM) well in Liulin area

Liulin area is one of the hot places of CBM exploration and development in China, and preliminarily realized the commercial CBM development. Based on the CBM well production data of Liulin area, the gas dynamic of CBM wells was analyzed, and according to the output the gas wells statistics were made, the proportion of the middle production wells is high, accounting for 42.9%, the high gas production wells is 28.6%, and the low and very low gas production wells is 28.5%. Analysis of the CBM wells drainage curve, three types of CBM wells production modes were summed up, they are single peak, peak-stable and low-peak-peak-stable. From the influence of the structure, gas content, permeability, thickness of coal seam, coal seam depth, hydrogeological conditions and other geological factors on CBM wells production capacity, the influence of various geological factors on gas wells productivity was analyzed, and the relationship among various factors and the productivity of CBM wells was set up Studies suggested that the high yield of CBM wells in Liulin area is not controlled by a single factor, but depends on the advantageously match of a variety of main controlling factors and combined action.