Study Of Coal Body Under The Action Of Seepage Mechanism Of Acoustic Wave

China is rich in coal bed gas resources, coal-bed methane is a kind of high quality clean new energy for nearly twenty years the world’s rise, on the other hand, coal seam gas is harmful source of major disasters in coal mine, in the energy crisis at present situation, to speed up the development and utilization of coal-bed gas, has the important practical significance to reduce environment pollution to improve the energy structure, China’s energy, production safety and make full use of. The method of sound field enhanced coalbed methane drainage rate based on indoor test, using, theoretical analysis, numerical simulation, field test study, carried out the sound field of coal microstructure before and after, acoustic waves in porous medium propagation law of coal body, sound field, sound field coalbed gas seepage characteristics of enhanced coalbed methane drainage rate of field test research, main achievements have:The acoustic field, pore structure change tendency of coal body for the performance of "the overall increase, discrete enhancement, feature type fluctuations" in paragraph two, show that the acoustic field changed primary pore structure of coal, coal body increases porosity, pore volume and specific surface area, increase of coal, the fracture rate the connectivity rate.Without sound field and sound field under two conditions with seepage law of methane in coal are basically the same, with the increasing effective stress, permeability of coal seam was decreasing negative exponential function. The acoustic field coal permeability greater than without sound field, and the permeability of coal gas increases linearly with the sound intensity, and increases with the time increasing, show that the sound field can improve the coal permeability.The acoustic field can reduce stress on the coal permeability damage, improve the permeability of coal body, the sound field after the coal permeability stress more sensitive, high frequency sound field under the action of stress sensitivity coefficient is higher than the low frequency sound field, so in the process of CBM extraction, the appropriate use of low frequency energy transducer.The results of numerical analysis and field test shows that, the coal permeability and stress correlated, temperature, pore pressure and the acoustic field, from the acoustic source closer, the effect more obvious, the farther away from the sound source, gas flow attenuation was a negative exponential function.The above research results enrich the theory innovation and efficient exploitation of coalbed methane, coal-bed gas, for efficient drainage has important scientific significance and practical value to reduce coal mine gas accident.