瓦斯抽采钻孔漏气规律现场试验研究

Field Experimental Study on Gas Leakage Law of Gas Extraction Drilling Holes

在煤矿井下进行瓦斯抽采时,外部空气会通过钻孔及周边煤岩裂隙流入到抽采管路中,造成抽采得到的瓦斯浓度大幅降低,严重制约后续的瓦斯利用,并埋下煤炭自燃、瓦斯爆炸等多种安全隐患。顺层瓦斯抽采时,封孔长度和抽采负压是影响钻孔漏气量的主要因素。以常村矿2103工作面为试验地点,以自主研发的瓦斯抽放钻孔负压测定装置为主要设备,测试分析了这2个因素对钻孔漏气量的影响,结果表明:(1)封孔长度为10~20 m较为合适;(2)增加负压会导致漏气量增加,不会增加瓦斯的抽采纯量。

When gas extraction is carried out underground in coal mines,external air may flow into the extraction pipeline through drilling holes and surrounding coal and rock fractures,causing a significant decrease in the concentration of gas extracted,severely restricting subsequent gas utilization,and burying various safety hazards such as coal spontaneous combustion and gas explosion.The length of sealing holes and the negative pressure of gas extraction are the main factors affecting the amount of gas leakage in drilling holes during gas extraction along the layer.Took the 2103 working face of Changcun mine as the experimental site,and used the self-developed gas drainage drilling holes negative pressure measurement device as the main equipment to test and analyze the impact of these two factors on the air leakage rate of drilling holes.The results show that:(1)a sealing length of 10-20 m is more suitable;(2)Increasing negative pressure will lead to an increase in gas leakage,and it will not increase the pure amount of gas extraction.