水力冲孔增透技术在大淑村矿防治煤与瓦斯突出中的应用

Application of hydraulic piercing technology in coal gas control outburst of Dashucun Mine

开采保护层、预抽煤层瓦斯均可以有效的消除突出危险,达到消突的目的。在没有保护层可开采时,一般选择预抽煤层瓦斯消突技术。大淑村矿所开采的2号煤层属于低透气性煤层,在进行预抽煤层瓦斯时,钻孔施工难度大,瓦斯抽采率较低,预抽钻孔之间易出现"空白带",给突出治理留下了一定的隐患。为了消除预抽后留下的突出隐患,提高预抽效率,该矿采用水力冲孔增透技术,利用高压水射流的冲击破煤,增加煤层透气性,提前释放煤体中的瓦斯,使煤层中蕴藏的瓦斯能量得到有效卸压,进而使煤层消除突出危险性。试验表明,在10~15 MPa水流的冲击下,单孔冲煤量在1.2~4 t/m,冲孔后,单孔瓦斯抽采量平均提高4.68倍,孔径94 mm的抽放钻孔抽放时间达到15 d时,其影响半径为8 m。

Mining protective layer,pre-extraction coal seam gas enables to eliminate outburst risk,pre-drainage gas outburst technology was adopted without protective layer mining,No.2 coal seam with low air permeability,difficult drilling construction,low drainage rate,became the safe hazard.In order to eliminate the outburst an danger and improve the drainage rate,hydraulic piercing technology was adopted to increase gas permeability,releasing the gas in the coal body and clearing the outburst danger.The test showed that single hole coal injection 1.2~4 t/m,the average amount of gas extraction in a single hole increased by 4.68 times after punching,bore diameter 94 mm extraction time of the extraction hole reached 15 d,radius of influence 8 m,pre-drainage radius increased two times pre-drainage time 75 d.