Abstract:
In order to improve the gas permeability of coal seams with low gas permeability, based on the characteristics of low temperature, high pressure and fast gas analysis of hydraulic fracturing, hydraulic fracturing and permeability improvement experiments were carried out in low permeability coal seams. The experiment shows that the fracture development area is formed around the fracturing area, and the extraction effect of the fracturing area is improved significantly. The average moisture content of the coal seam is increased by 1.8 times, the single hole extraction concentration is increased by 3.12 times, and the extraction rate is increased by 40% to 50%. Due to the double effect of increasing crack development and water flooding, the extraction radius is increased from the original 3 m to 20 m. Hydraulic fracturing anti-reflection technology is safer and more efficient.