利用覆岩移动特性实现煤与瓦斯安全高效共采

Realizing safe and high-efficient exploitation of coal and gas by making use of characteristics of movement and development of strata

为了实现高瓦斯煤层群条件下煤与瓦斯的安全高效共采,运用数值模拟和现场试验相结合的方法,对远距离下保护层开采的采动效应进行了分析与研究。结果表明:下保护层开采使覆岩产生不同程度的卸压,煤体产生膨胀变形,生成大量的次生裂隙,从而导致煤体的透气性增加,为远程卸压瓦斯的抽放创造了有利条件;同时,覆岩的水平应力分布也发生了改变,由原始的水平压应力变为拉应力,从而导致了水平位移的产生,在该位置形成丰富的竖向裂隙,为瓦斯的运移提供了通道。在高瓦斯煤层群条件下,可以通过合理的开采顺序和有效的瓦斯抽放方法,实现煤与瓦斯两种资源的安全高效共采。

In order to realize safe and high-efficient exploitation of coal and gas under the condition of high-gas coal strata, the effects caused by the exploitation of the long-distance under-protecting coal stratum are analyzed and studied deeply in this article by the methods of numerical simulation and colliery on-the-spot test. The results indicate the pressure of the protected stratum is relieved with various degrees because of the exploitation of the long-distance under-protecting coal stratum, the protected coal seam expanded and great numbers of crannies was produced. As a result, the permeability of the protected coal seam increased and the long-distance pressure-relief gas could be extracted out easier than before. At the same time the initial horizontal stress field of the protected stratum was destroyed too. The initial horizontal stress changed from compressive stress into tensile stress in some area, so the horizontal displacement happened and great numbers of vertical crannies which provided channels for gas to flow were produced. So under the condition of high-gas coal strata the safe and high-efficient exploitation of coal and gas can be realized if we adopt reasonable exploitation order and efficient gas extraction method.