深部低透气性煤层水力冲孔措施防突机理分析

Analysis on Outburst Prevention Mechanism of Borehole Hydraulic Flushing Measures for Deep and Low Permeability Seam

针对淮南矿区谢桥、潘三等矿开展的水力冲孔消突试验,利用数值模拟软件ANSYS对水力冲孔措施前后所形成的孔洞进行了模拟解算;定量分析了冲孔前后孔洞周围煤体应力、应变和位移的变化情况,并结合现场实际对水力冲孔措施的防突机理进行了分析,结果表明:在深部无保护层可采的低透气性突出煤层中采用水力冲孔措施后,冲孔后的瓦斯浓度不仅比冲孔前提高了50%左右,而且抽放浓度和抽放瓦斯纯流量也增加了3倍左右,大幅提高了煤层的瓦斯抽放效率,降低了煤体的弹性潜能和瓦斯潜能等突出潜能,减少了煤层的突出危险性。

According to the borehole hydraulic flushing trials conducted in Xieqiao Mine and Pansan Mine in Huainan Mining Area, the numerical simulation software ANSYS was applied to the simulation resolution of the cavity formed before and after the borehole hydraulic flushing measures conducted. The variation conditions of the coal stress, strain and displacement around the cavity before and after the flushing conducted were quantitatively analyzed. In the site reality, the analysis was conducted on the outburst prevention mechanism of the borehole hydraulic flushing measures. The results showed that after the borehole hydraulic flushing measures conducted in the minea- ble low permeability outburst seam in a deep mine with no protective layer, the gas content after the borehole flushing conducted was improved about 50% higher than before the borehole flushing conducted, the gas drainage concentration and the drained gas pure flow were also improved about 3 times, the gas drainage rate of the seam was highly improved, the coal elastic potential, the gas potential and outburst potential were reduced and the outburst danger of the seam was reduced.