下保护层开采保护效果与瓦斯运移规律

Flow law and protection scope of below protective seam mining under medium distance

为研究中远距离下保护层回采后的保护效果和瓦斯运移规律,运用达西定律和Brinkman方程建立了回采工作面、采空区与被保护层的二维模型,结合郭庄矿与寺河2#井的实际地质条件,运用COMSOL多物理场数值模拟软件对其进行了数值模拟研究;对郭庄矿和寺河2#井的试验工作面进行了现场试验.数值模拟结果表明:保护层开采过后对被保护层具有卸压作用;同时得到了保护层、采空区与被保护层的瓦斯运移规律.现场结果表明:中远距离下保护层开采过后,瓦斯压力降低了0.5 MPa;瓦斯含量降低了5.25 m3/t;透气性系数增加到了原来的600多倍.

In order to study the gas flow law and protection effectiveness after underneath medium-long distance protecting seam being extracted, two dimensional model of working face, goaf and the protecting seam was constructed by using Darcys law and Brinkman equation. Numerical simulation was conducted using COMSOL numerical simulation software of Multi-physics field with the actual geological condition of Guozhuang coal mine and Sihe two coal mine. Field test was carried out at working face in Guozhuang coal mine and Sihe #2 well coal mine. The results of numerical simulation show that the protecting seam pressure was released after underneath protective seam extracted and obtained the gas flow law of working face, goaf and the protective seam. The field test results show that the gas pressure was reduced by 0.5MPa, the gas content was reduced by 5.25m3/t, and the permeability coefficient increased to 600 times of the original.