保德矿区煤体渗透率对层理夹角的响应规律试验研究

Experimental Study on Response Law of Coal Body Permeability to Bedding Angle in Baode Mining Area

为分析保德矿区煤体渗透率对层理夹角的响应规律,制备了与层理呈不同角度的煤体试样,利用QTS-2煤岩渗透率测试仪,对不同围压、不同进气压力下的煤体渗透率进行了测试,分析了不同角度下气体渗流的容易区与困难区特征。结果表明:保德矿区煤体渗透率对层理角度的响应规律明显,随着气流方向与层理角度的增大,煤体渗透率呈线性减小的规律,0°角与90°角煤样的渗透率差1~2个数量级;随着围压的增大,煤体渗透率呈幂指数减小规律。煤样渗透率反映的是瓦斯气体沿流动方向的难易程度,在实际的瓦斯抽采工程中,当钻孔平行于层理布置时,煤体瓦斯流动的方向反而使垂直于层理,渗透率最小;当钻孔垂直于层理布置时,煤体瓦斯流动的方向反而平行于层理,渗透率最大。

In order to analyze the response law of the coal permeability to the angle of the bedding in Baode Mining Area,coal samples with different bedding angles were prepared.The QTS-2 coal rock permeation tester was used to test the permeability of coal under different confining pressures and inlet pressures.The results show that the coal body permeability in Baode Mining Area has obvious response to the bedding angle.With the increase of airflow direction and bedding angle,the permeability of coal body decreases linearly.The permeability of 0°angle differs from 90°angle coal sample by 1 to 2 orders of magnitude.With the increase of confining pressure,the permeability of coal body decreases exponentially.The permeability of coal sample reflects the difficulty of gas flow along the flow direction.In the actual gas drainage project,when the drilling is arranged parallel to the bedding,the direction of the coal gas flow is perpendicular to the bedding,and the permeability is minimal;when the drilling is arranged perpendicular to the bedding,the direction of coal gas flow is parallel to the bedding,and the permeability is maximal.