高压水射流割缝对煤层瓦斯抽放影响分析

Influence analysis of high-pressure water jet slotting on coal seam gas drainage

为了探究高压水射流人工割缝对煤层瓦斯抽放的影响,选定32211工作面巷道进行工业试验,首先根据该工作面工况条件确定了瓦斯抽放方案,对瓦斯抽放钻空进行人工割缝前、后瓦斯抽放量进行比较,结果表明,在经过高压水射流切割煤层之后,瓦斯抽放量和瓦斯浓度都比割缝前提高了数倍。但随着时间的延长,因为人工裂隙的闭合以及煤层中应力的变化,瓦斯抽放量会随着时间衰减,但在一定时间后,瓦斯抽放量重新趋于稳定。通过瓦斯抽放数据可知,应尽量延长瓦斯抽放时间,提高瓦斯抽放效率。

In order to explore the effect of artifical slotting by high-pressure water jet on coal seam gas drainage,the 32211 working face roadway was selected for industrial test. First,the gas drainage scheme was determined according to the working condition of the working face,and the gas drainage amount was compared before and after the artificial seams of the gas drainage drill. The results showed after the coal seam cutting by high-pressure water jet,the amount of gas drainage and gas concentration are increased several times before the slotted seam. However,with the extension of time,because of the closure of artificial cracks and the changes in the stress of the coal seam,the amount of gas drainage will decrease with time,but after a certain time,the amount of gas drainage will be stabilized again. Through gas drainage data,it is necessary that gas drainage time should be extended as much as possible to improve gas drainage efficiency.