顺层钻孔抽采影响范围叠加效果模拟研究

为了更加合理地对瓦斯抽采系统进行布置，对煤层瓦斯抽采过程中有效抽采半径、瓦斯运移规律以及钻孔之间的相互影响进行研究，采用COMSOL数值模拟软件，对单钻孔与双钻孔的钻孔瓦斯抽采情况进行对比，从煤层瓦斯压力的分布、抽采达标时间与钻孔瓦斯流量等方面进行对比分析。研究得出:随着抽采钻孔间距的减小，在同样的抽采时间内，钻孔周围瓦斯压力也逐渐降低；当钻孔的间距变小时，钻孔瓦斯抽采达标的时间也就越短，而且瓦斯减小的幅度也越大；在刚开始进行瓦斯抽采时，瓦斯流量下降率较大，但是随着抽采时间的增加，慢慢趋于稳定。

Simulation study on overlapping effect of influence range of borehole drilling

In order to arrange the gas extraction system more reasonably，the effective extraction radius，the law of gas migration and the interaction between the boreholes are studied in the process of coal seam gas extraction，and the COMSOL numerical simulation software is used to compare the gas extraction conditions between single and double boreholes，the distribution of gas pressure in coal seam，the time of gas drainage and the gas flow rate in boreholes were compared and analyzed.The study shows that with the decrease of the spacing between the boreholes，the gas pressure around the borehole gradually decreases during the same extraction time；when the spacing of the borehole becomes smaller，the time for achieving the goal of gas drainage in the borehole is shorter，and the magnitude of gas reduction is also larger；at the beginning of gas extraction，the rate of gas flow decline is larger，but with the increase of extraction time，it slowly tends to be stable.The research is of great significance to the gas control in coal mine.