Application of controllable electric pulse wave permeability-enhancing technology in the low-permeability coal seams

Controllable electric pulse wave permeability-enhancing technology is one of the ideal measures for anti-reflection transformation of low-permeability coal seams. The optimization of construction schemes needs to be solved urgently. Aiming at this problem, in the low-permeability coal seam of Baode coal mine, controllable electric pulse wave permeability-enhancing technology was adopted to optimize the permeability-enhancing construction scheme of the boreholes. Test results show that the controllable electric pulse wave permeability-enhancing effect is the best under the condition of the average permeability-enhancing section of 131 m, the impact density of 0.5 times/m and the average daily extraction volume in an anti-reflection borehole group is 4.7 times higher than that of the permeability-enhancing hole group. The daily average drainage volume of the permeability-enhancing borehole group is 5 m observation hole, 15 m observation hole, 30 m observation hole and antireflection hole in order from high to low, the influence radius is greater than 30 m. Comprehensive analysis based on comparative verification tests shows that the controllable electric pulse wave can significantly increase the gas drainage of the coal seams, and the impact density and the range of the permeability-enhancing operation in the boreholes are the important influencing factors to improve the permeability-enhancing effect. In harder coal seams the best permeability-enhancing effect is under condition of an average permeability-enhancing range of 100 m and an impact density of 0.5 times/m. The research results provide a reference for the design of operation scheme of the controllable electric pulse wave permeability-enhancing technology in China's low-permeability coal seams.