Analysis of the visible fracture system of coalseam in Chengzhuang Coalmine of Jincheng City, Shanxi Province
In No. 3 coalseam of Chengzhuang Coalmine of Jincheng City, there exists the visible fracture system consisting of joints, gas-expanding fractures and cleats. The gas-expanding fractures develop mainly in the bright coal sub-layer and cleats, in the vitrain and bright coal. The joints fall into two types, one developing in the coalseam and the other cutting through the whole coalseam and entering into the top and bottom rock layer. The development direction of joints is basically similar to that of gas-expanding fractures:NNE and NNW. The formation of the visible fracture system is classified as the stage of the development of cleat fissures in the coalification period, the stage of the full development of cleats and the formation of gas-expanding fractures in the second coalification period and the stage of the formation of joints by structural function. There is the spatial unhomogeneity in three dimensions for the visible fracture system of the coal seam in Chengzhuang Coalmine: the regular distribution of the visible fractures as groups in the plane and the coal sub-layer with high permeability rate in profile. The research findings of the visible fracture system of coal seam can be applied to the drilling of the coalbed methane and to heightening the let-off efficiency of coalseam gas.
作 者： WANG Shengwei HOU Guangjiu ZHANG Ming SUN Qinping 作者单位： Faculty of Resources, China University of Geosciences, Wuhan 430074,China 刊 名： 科学通报（英文版） SCI 英文刊名： CHINESE SCIENCE BULLETIN 年，卷(期)： 2005 50(z1) 分类号： P61 关键词： the visible fracture system of coal seam development character origin coalbed permeability gas let-off of coalseam