透气夹矸层对煤层瓦斯放散特性影响研究

Research on influences on gas emission characteristic of coal seam caused by penetration partings

利用自行研制开发的煤层瓦斯放散试验装置,以含透气夹矸层型煤试样为研究对象,以试样内瓦斯放散速度和累积放散量为研究参数,系统研究了透气夹矸层对煤层瓦斯放散特性的影响,并对瓦斯在含透气夹矸层煤层中的放散机理进行了分析探讨。结果表明:含透气夹矸试样与全煤试样瓦斯放散速度均随时间呈幂函数单调衰减,瓦斯累积放散量均随时间呈有上限的单调递增;瓦斯吸附平衡压力越大,瓦斯放散初速度越大,且相同时间段内瓦斯累积放散量越大;在相同吸附平衡压力下,含透气夹矸试样的瓦斯放散速度在初始10 min内明显大于全煤试样,在30~90 min之间两放散速度曲线出现交叉,而含透气夹矸试样的瓦斯累积放散量在前120 min均大于全煤试样。透气夹矸层的存在增大了煤层的渗透率,为煤层中瓦斯放散提供了运移通道,创造了瓦斯放散的有利条件,使煤层的瓦斯放散效率得到提高。

Based on a self-developed coal seam gas emission test device,taking briquette samples containing penetration partings as the research object,and taking gas emission speed and gas cumulative emission amount of coal sample as study parameters,the influences caused by penetration partings on coal seam were studied systematically,and the mechanism of gas emission of coal seam with penetration partings was discussed. The results show that the gas emission speed of all briquette specimens presents power-function decay over time,and the cumulative emission amount presents an upper limit monotone increase over time. Both gas emission initial speed and cumulative emission amount of coal samples increase with the increase of adsorption equilibrium pressure. Under the same adsorption equilibrium pressure,the gas emission speed of specimens containing penetration partings is faster than the ordinary specimens in the initial stage,but two emission speed curves appear intersection from 30 min to 90 min,while the cumulative emission amount of specimens containing penetration partings is more than that of the ordinary specimens in the former 120 min. Penetration partings can improve the permeability of coal seam,provide migrations path for gas emission of coal seam,and create favorable conditions for the gas emission,so the gas emission efficiency is improved.