Technology Study On The Hydraulic Fracturing With Improving Permeability In Yan Ma Mine

This study of directional hydraulic fracturing pressure in the Yanma mine，using theoreticalanalysis, numerical analysis and field test a combination of methods, based on the existed researchresults. Through a systemic and in-depth study on low permeability, poor ventilation and high gas ofYanma mine, we obtain the following beneficial results:(1) According to that establish the mechanical model of the working seam and crossing seam,and illustrating the condition of next-level crevasse extension. We know that injection pressure mustgreater than original rock stress and tensile strength in weakened coal if want to expand thenext-level crevasse.(2) Based on the stress distribution condition of drilling, we studied on the crack mechanism oflow permeability coal, and the expanding and cracking mechanism when it gives a high injectionpressure.(3) We use RFPA2Dnumerical software to analysis fracture and increased range of thepermeability indifferent depth. According to the numerical calculation results, we get the fracturepressure and reasonable range of water pressure of hydraulic fracturing.(4) Base on the data tested in Yanma mine, we have designed the effective hydraulic fracturingplan for Yanma mine, Achieved effectual gas extraction results...