Practice of ultra-high pressure hydraulic slotting pressure relief and permeability enhancement technology in deep high outburst and low permeability coal seam
No.2 coal seam of Fengfeng Group Jiulong Mine has a large buried depth and high gas content.In order to ensure the safe mining of the working face,the research on gas pressure relief and permeability enhancement technology was carried out.Compared with other fracturing methods,the ultra-high pressure hydraulic slotting pressure relief and permeability enhancement technology had low cost,high safety,and strong adaptability to geological conditions.It was an ideal permeability enhancement method for low permeability coal seams.This technology could destroy the'bottle plug effect'of boreholes,promote the generation,development and penetration of cracks,thereby improving the permeability and increasing the release of gas in coal seams.The field application of in No.15249N Face showed that the single-cut coal output of slotted borehole was 0.78 t,and the equivalent slotted radius was 1.89~2.31 m,which was 1.6 times higher than that of ordinary borehole gas extraction concentration and 3.79 times higher than that of gas extraction pure quantity,which had achieved good antireflection effect.
deep mininglow permeability coal seamhydraulic cuttingextraction concentration