The surface drilling and extraction technology of coalbed methane in coal mine area is the desorption and free coalbed methane in coal bed by using the surface drilling into the coal bed.

Key technologies: drilling process; Hydraulic fracturing; Coalbed methane drainage technology.

Process flow: drilling → cementing → logging → completion → fracturing → production discharge → gathering and transportation.

Technical index: According to the occurrence conditions of coal seam and topography, the surface drilling can choose vertical well, cluster well, horizontal well, horizontal plume well and so on to exploit coalbed methane. Drilling parameters, well spacing, well depth and other basic parameters are designed according to the specific conditions of the mining area. For example, Jincheng mining area uses 8 inches (215.9 mm) diameter casing, 7 inches and a half (190.5 mm) down, well spacing of 300 meters ×300 meters.

The technology has been applied in Jincheng, Hancheng, Fuxin, Yangquan, Huainan, Huaibei and other mining areas. Jincheng anthracite Group has formed vertical Wells - based surface drilling large-scale exploitation of coalbed methane. In 2010, surface Wells pumped 908 million cubic meters of CBM.

The surface CBM extraction technology in coal mine area solves the problems of low permeability of coal seam and high desorption difficulty, forms a complete set of technology from drilling, completion, fracturing extraction and gas collection and transportation, and realizes commercial operation, which can be popularized and applied in various CBM enrichment areas.