应力作用下的煤层瓦斯运移规律

Migration Law of Coal Bed Methane Under Role of Stress

为了研究地应力对煤层瓦斯运移规律的影响,采用巷道瓦斯浓度观测方法,对平顶山天安五矿己15-23190工作面回风巷的瓦斯浓度变化进行分析。结果发现:受地应力影响,沿采场方向分为卸压区、应力集中区、原始应力区和采场后面的应力恢复区,不同的应力区对应了不同的裂隙发育状况,这种差异导致了煤层瓦斯运移能力的区带性分布,在煤层的应力集中区,由于高应力的挤压剪切作用,产生大量新的节理和裂隙,同时有更多的裂隙被封闭,该区段瓦斯的运移能力反而会降低。

In order to study the earth stress influenced to the coal bed methane migration law, the observation method of the mine roadway gas density was applied to analyze the gas density variation of F 15-23190 coal mining face in No. 5 Mine of Pingdingshan Tian＇an. The results showed that with the influence of the earth stress, the mining block shall be divided to a pressure released zone, stress concentrated zone, original stress zone and stress recovered zone beyond the mining block along the mining block direction. The different stress zone would be corresponding to the different fracturing growth condition and the differential would cause the distribution of the gas migration ca- pacity zone in the seam. In the stress concentrated zone of the seam, due to the high stress compressing and shearing role, there would be many new joints and fractures Occurred and more fractures would be sealed. Therefore the gas migration capacity would be reduced.