Experimental study on low permeability coal seams with CO₂ fracturinganti-reflection technology of Hongfa coal mine

In order to study the effect of CO₂ fracturing anti-reflection technology on Guizhou low permeability coal seams，this paper took Guizhou Hongfa coal mine 1903 tailentry as study object，the CO₂ cracker fracturing experiment was studied.The results show：after fracturing anti-reflection，the average permeability coefficient is 3.05 times of that of original coal seams，the permeability of coal seam has been improved remarkably；the average concentration of coal seam gas extraction is 4.19 times and the average pumping capacity is 3.99 times of the area of no fracturing；in the borehole gas drainage rate，the single hole gas extraction effect in CO₂ fracture enhanced permeability area has been increased by 2.58～3.92 times than the area borehole gas extraction without fracturing.The amount of drilling work in the fracturing enhanced permeability zone is 4 times lower than that without fracturing.The extraction time of the mining face is shortened by 55 days，the gas emission rate of the working face is reduced by 40%，and the gas extraction efficiency of the coal seam has been improved remarkably.The CO₂ fracturing and permeability enhancement technology provides a reference for solving the problem of gas extraction in low permeable seams in GuiZhou mining area.