Research on Hydraulic Fracturing Technology of Long Borehole in Coal Mine

In order to achieve effective large-scale fracturing for long borehole in coal mine, in combination with the construction situation of the feather long boreh ole in Zhongmacun Mine, HTB500 type hydraulic fracturing pump package was adopted for repeated hydraulic fracturing test, and the earth electric field lithology detect ors was used to detected the effective scope of hydraulic fracturing. The test results showed that gas drainage scalar increased from zero before fracturing to 739. 8 m 3/ d, gas drainage volume fraction increased from zero before fracturing to 44. 1% ~ 99. 9%, the coefficient of permeability for coal seam increased from3. 2 ~ 4.0 m2/ ( MPa2.d) to 25.6 4.8 m2/ ( MPa2.d) . The effective scope of hydraulic fracturing centered on fracturing borehole and formed in asymmetrical distribution, the length a long the directional drilling was 370 m, the width was 30 ~ 60 m.