近距离煤层群瓦斯立体抽采技术研究

Study on Gas Cubic Drainage Technology in Contiguous Seams

针对桐梓煤矿近距离煤层群开采,首先选择瓦斯含量较小、突出危险性低的煤层作为保护层进行开采,利用其开采扰动作用提高下部卸压煤层的透气性。采用顺层钻孔、低位走向穿层钻孔、采空区埋管和底板上向穿层钻孔等措施对煤层群进行立体化综合抽采,试验表明:保护层工作面瓦斯预抽采率在55%以上,消除了煤与瓦斯突出危险性,工作面开采后上隅角瓦斯体积分数控制在1%以下;6号、7号和9号被保护煤层经卸压后透气性系数分别增加了392、320和289倍,瓦斯抽采率超过60%,实现了煤与瓦斯安全高效共采。

According to the mining in contiguous seams of Tongzi Mine, a seam with low gas content and low outburst danger was selected as a protective seam for coal mining. The mining disturbance role was applied to improve the permeability of the below pressure released seam. The borehole drilled along seam, low level strike borehole drilled through seam, pipeline buried in goaf, floor upward borehole drilled through seam and other measures were applied to comprehensive cubic gas drainage of the seam group. The experiment showed that the gas drainage rate of the coal mining face in protective seam was over 55% , coal and gas outburst danger was eliminated and the upper corner gas volume fraction was controlled below 1% after mining operation of the coal mining face completed. After the pressure released by the protective seam, the permeability coefficient of No. 6, No. 7 and No. 9 seam was individually increased by 392,320 and 289 times, the gas drainage rate was over 60% and the safe and efficient coal and gas jointly mining realized.