Theoretical Analysis and Practical Study on Reasonable Water Pressure of Hydro-fracturing

Abstract The hydro-fracturing technology is the depressurization antireflection elimination outburst technology for the low permeability outburst coal seam with high methane. At present, the mechanism of the depressurization antireflection elimination outburst is sufficiently mastered and the application effectiveness of field engineering also is well, but how to determine hydro-fracturing parameters is not systematically described, especially the reasonable water pressure. Based on the hydro-fracturing mechanism and process, the reasonable water pressure is theoretically analyzed, and then the pressure parameter of hydro-fracturing applicated in the low permeability outburst coal seam with high methane is obtained, finally the reasonable pressure formula of water injection is obtained. The application test results of field engineering shows that there is the difference between the theoretical analysis result and the pressure in field engineering test, namely, the theoretical analysis pressure is lower than the pressure in field engineering test.