超声机械效应致裂煤岩增渗规律研究

超声机械效应致裂煤岩过程中裂纹的萌生、扩展过程及增渗规律仅凭借物理实验无法得到，煤岩破裂能量变化、煤岩应力-应变关系及储层渗透特性变化缺乏深入的研究。结合CT观测及渗透率的气测实验对煤岩破裂声发射、有效声压及声波对煤岩体裂纹扩展规律进行了深入探讨；开展了超声机械效应致裂煤岩的数值试验研究。结果表明:煤岩破裂过程应力变化率和煤岩声发射现象具有一致性；有效声压的增大有利于裂纹扩展和贯穿，使煤岩体内部原本互不相通的裂纹裂隙形成了相互贯通的网络，从而提高了煤岩的渗透率。

Research on permeability enhancement laws of coal fracturing by ultrasound mechanical effect

The ultrasound mechanical effect is one of the major effects of coal fracturing. The initiation and propagation processes of crack and the laws of permeability enhancement for coal fracturing by ultrasound mechanical effect can't be obtained only by physical experiment, and people have not made deep research on the energy change of coal fracturing, the stress-strain relation of coal and the change in permeability characteristics of coal reservoir. Combined CT observation with gas measuring test on permeability, the crack propagation laws of coal under the effect of acoustic emission, effective sound pressure and sound waves in coal fracturing were discussed in detail, then the numerical experiments on coal fracturing by ultrasound mechanical effect were conducted. The results showed that the changing rate of stress is consistent with acoustic emission phenomenon of coal in coal fracturing process. The increase of effective sound pressure is beneficial to the extend and breakthrough of the cracks, which make the cracks and fissures being mutually unintelligible inside the coal originally form the interpenetration network, thus increase the permeability of coal.