井下注氮结合地面钻孔抽放置换采空区瓦斯技术研究

Study on Goaf Gas Control Technology of Underground Nitrogen Injection Combined with Drainage by Ground Drilling Hole

为了削弱采空区"呼吸"现象对相邻8204回采工作面的影响,对塔山煤矿8206采空区采用注氮(井下)与钻孔抽放(地面)相结合的方法。实践结果表明:通过调整采空区注氮压力和注氮量,采空区"呼吸"现象消失,采空区气体(CH_(4)、O_(2)和CO)逐渐趋于平稳;钻孔瓦斯抽放浓度最终降低至2.0%,并且采空区中的瓦斯浓度从16%降低至小于1.5%,有效消除了采空区内瓦斯和煤自燃的风险;研究成果对于采空区瓦斯的治理及综合利用具有重要意义。

In order to effectively curb the "breathing" phenomenon in the goaf during the excavation and recovery of the 8204 fully mechanized caving face in Tashan coal mine. The 8206 mined-out area was treated with underground nitrogen injection combined with ground drilling to replace gas in the goaf. The practice results showed that by adjusting the nitrogen injection pressure and nitrogen injection amount in the goaf, the "breathing" phenomenon in the goaf disappeared, and the gas in the goaf(CH_(4), O_(2) and CO) gradually became stable. The gas concentration in the ground gas drainage hole was finally reduced to about 2.0%, the gas concentration in the goaf was reduced from 16% to less than1.5%, and a low gas content mixed gas was formed in the final goaf. Effectively eliminated hidden dangers of gas and coal spontaneous combustion in goaf. The research results are of great significance for the treatment and comprehensive utilization of gas in the goaf.