Potential evaluation of deep coal seam coalbed methane resources in Qinshui Basin
Liu Suping 1, 2, Cai Demei 3, Huang Wenhui 3
1. Hunan Engineering Geological Mine Geological Survey and Monitoring Institute, Changsha 410014, China; 2. Hunan Provincial Medium-deep Geothermal Exploration and Development Engineering Technology Research Center, Changsha 410014, China; 3. Hunan Provincial Land Space Survey and Monitoring Institute, Changsha 410129, China; 3. China University of Geosciences ( Beijing ) Key Laboratory of Marine Reservoir Evolution and Hydrocarbon Enrichment, Ministry
of Education, Beijing 100083, China
The deep coal seam in Qinshui Basin has a huge amount of coalbed methane resources. With the increase of exploration and mining depth, the physical properties of coal reservoirs become worse, and the changes of different parameters are not synergistic. In this paper, the geological resources and recoverable resources of coalbed methane at different depths of ~ 600 m, 600 ~ 800 m, 800 ~ 1 000 m, 1 000 ~ 1 200 m, 1 200 ~ 1 500 m and 1 500 ~ 2 000 m in the weathered zone of Qinshui Basin are calculated by volume method. The calculation method of coal volume is proposed. The product of plane projection area and pseudo thickness of coal seam can represent the real volume of coal body. The calculation results show that the total amount of CBM geological resources above 2 000 m in No.3 coal seam and No.15 coal seam in Qinshui Basin is 31 107.95 × 108 m3, and the recoverable resources above 1 500 m are 9 265.28 × 108 m3. Among them, the geological resources with a buried depth of 800 ~ 2 000 m are 17 835.38 × 108 m3, and the recoverable resources with a buried depth of 800 ~ 1 500 m are 5 298.11 × 108 m3, accounting for 57.33 % and 57.24 % of the two coal seams, respectively.
