Research on fracturing mechanism of low permeability coal seam and application of surface CBM drainage

Due to the low permeability of coal seam, surface CBM development process is slow. In this paper, the geological model of low permeability coal seam is studied, and the mechanism of using hydraulic fracturing technology to transform the reservoir and to enhance gas production in low permeability coal seam is discussed, and hydraulic fracturing was applied in surface CBM wells in Luling mine in North Anhui Province. The research shows that the technology of high strength hydraulic fracturing technology can produce relatively long cracks in low permeability coal seam and result in ideal gas production effect. The results of the research have certain action to promot surface CBM development of the broken soft and low permeability coal seams in China.