Abstract：Aiming at the low permeability and high gas coal seam, in order to strengthen the effect of coal seam gas extraction, the influence of water injection pressure on the fracturing effect of coal seam hydraulic fracturing was simulated and analyzed, and the simulation results were verified by field test. Through simulation, the increase of water pressure promotes the fracturing effect of coal rock, and 19.5 MPa water pressure can make the coal seam produce good crack propagation effect. The field test shows that after fracturing, the initial gas emission is 4.49 times that of the natural drainage hole, the attenuation coefficient of gas flow decreases from 0.035 8 d?1 to 0.008 34 d?1, the attenuation of gas flow decreases by 76.71 %, and the maximum increase of coal seam permeability coefficient is about 44 times that of the original, indicating that the hydraulic fracturing and permeability increasing technology has a good effect on promoting drainage of coal seam.
