地面群孔瓦斯抽采技术应用研究

为保证新集一矿突出煤层13-1煤北中央采区的安全开采,先后开采131103、131105等11-2煤层工作面作为保护层。首先在上述两个工作面共布置了6个地面钻孔,建立了地面群孔瓦斯抽采系统,预抽采动区被保护层13-1煤瓦斯。接下来对地面钻孔抽采瓦斯参数进行了考察,主要包括基于示踪技术考察了131105工作面采动卸压地面钻孔走向及倾向瓦斯抽采半径,统计分析被保护层瓦斯抽采率,同时就地面群孔与井下底板巷穿层钻孔瓦斯抽采两种方法进行了抽采率、工程费用等方面的对比。研究结果表明：新集一矿的地层条件下地面钻孔抽采煤层卸压瓦斯沿煤层倾向和走向的抽采半径分别不小于160m和240m;采动区地面群孔瓦斯抽采率达35%以上;地面钻孔相对比井下底板巷,在抽采瓦斯方面具有技术上可靠、安全、经济等优点。

Application Study on Gas Extraction Technology by Surface Borehole

In order to ensure safe mining of 13-1 outburst coal seam of north central section in Xinji no.1 coal mine,131103 and 131105 working faces in 11-2 coal seam were mined out as protective seams.The first gas drainage system including six surface boreholes was built.It was used to extract gas in affected area by mining of protected seam 13-1.Parameters of gas drainage by surface boreholes were investigated,including gas drainage radius along strike and slope in stress relived areas of longwall 131105 by using tracer technology.Gas drainage rate of protected seam was analyzed,gas extraction rate,engineering cost and other aspects by surface boreholes were compared with that by boreholes drilled through the floor of coal seam.The results showed that radius of gas drainage in stress relieved areas by surface borehole under mining geological conditions in Xinji No.1 Coal Mine is not less than 160 m along slope and 240 m along the strike of coal seam;gas drainage rate by surface boreholes in the mining area is more than 35%;comparing with gas drainage by floor roadway,gas drainage by surface boreholes has advantages,such as reliable technology,safety,economic benefit,etc.