不同布置方式下穿层钻孔瓦斯抽采数值模拟研究

为了对比分析相同条件下穿层钻孔“矩形”布置和“三角形”布置方式的瓦斯抽采效果，建立了2种布置方式下的三维物理模型，并根据推导出的钻孔瓦斯流场控制方程，利用COMSOL数值模拟软件中的PDE模块对建立的物理模型进行了求解。研究抽采30 d时2种布置方式下的瓦斯压力分布状态，结果表明:穿层钻孔由于呈发射状，钻孔之间的瓦斯压力由下至上逐渐增加；相同位置处，“三角形”布置方式在倾斜方向上的瓦斯压力分布与“矩形”布置方式相同，在走向方向上瓦斯压力分布更加均匀；“三角形”布置方式与“矩形”布置方式相比，钻孔之间的最大瓦斯压力会降低，且高瓦斯压力区域范围会有所减小，条件允许时，可以考虑采用“三角形”布置方式来提高穿层钻孔瓦斯抽采效果。

Numerical simulation research on gas drainage used by layer-through holes with different layouts

In order to compare and analyze the gas drainage effects of the "rectangular" and "triangular" arrangements of through-layer boreholes under the same conditions，established three-dimensional physical models under two layout modes，and according to the derived control equation of borehole gas flow field，the PDE module in the COMSOL numerical simulation software was used to solve the established physical model.Study the gas pressure distribution state under the two layouts when the drainage was 30 days.The results showed that the gas pressure between the boreholes gradually increased from bottom to top due to the emission shape of the through-layer boreholes；at the same position，the gas pressure distribution in the inclined direction of the "triangular" arrangement was the same as the "rectangular" arrangement.The gas pressure distribution was more uniform in the strike direction；the "triangular" arrangement was compared with the "rectangular" arrangement，the maximum gas pressure between boreholes would be reduced and the area of high gas pressure would be reduced，when conditions was permitted，you could consider adopting the "triangular" arrangement to improve the gas drainage effect of the through-bed drilling.