Permeability Enhancement Technology of Hydraulic Fracturing of Bedding Drilling Borehole in Outburst Coal Seam

In order to solve the problems of uneven effect and low efficiency of outburst elimination of bedding drilling borehole in coal mining face, taking the low permeability coal seam of Xieqiao Coal Mine in Huainan as the test object, the technology of hydraulic fracturing of bedding drilling was adopted to enhance to the permeability of coal seam, so as to improve the efficiency of gas control. This paper introduced the design scheme of anti-outburst measures in bedding drilling areas, and investigated the radius of hydraulic fracturing; the design of hydraulic fracturing drilling and gas extraction drilling, as well as the hydraulic fracturing process parameter test of water injection pressure, water injection volume and pressure holding time were carried out. The comparison of gas extraction effects between hydraulic fracturing and unfractured bedding drilling boreholes shows that, after hydraulic fracturing, the average gas concentration of drilling borehole is increased by 54%, and the average pure gas flow of single hole extraction is increased by 280%, and the time up to standard of extraction is shortened by one month; the inspection indexes of anti-outburst effect are all up to standard, and there is no excess gas concentration during stoping in the working face.