Abstract:
By means of numerical analysis and field engineering test, the hydraulic punching and hydraulic fracturing coupling permeability improving technique is studied, which affects the “three soft” coal seam displacement, stress distribution and permeability. Research results show that the hydraulic punching and hydraulic fracturing coupling permeability improving technique is able to reduce the stress in coal more than 20% and increase the permeability of coal more than 35%. The average pumping gas concentration of 23041 roadway (north) in Gaocheng Mine that uncovers coal seam is 4.3 times higher and the average daily pumping gas is 6.7 times higher than that of the same gas geological conditions. The research finding can be popularized and applied to the regional prevention measures of the through beds boreholes in Zhengzhou Mining Area.