Abstract:
Based on the gas-bearing property of main coal seams of Panzhuang Block in southern Qinshui Basin, the geological control factors such as coal rank, C oal maceral, geologic structures, and hydrogeological conditions, which have influence on the gas-bearing property, were discussed in the paper. The results showed th at the gas-bearing property of main coal seams had two typical characteristics: on the one hand, the gas-bearing property of No.15 coal seam of Taiyuan Formation wa s better than that of No. 3 coal seam of Shanxi Formation, which was closely related with the characteristics that the hydraulic migration-escape process relatively weak ly destroyed the CBM preservation conditions of Taiyuan Formation; on the other hand, with the burial depth increasing, the gas-bearing saturation increased first and t hen decreased, and the turning depth was around 500 meters. It was also found that with the coal rank heightening in this block, gas content, porosity and adsorption al | increase first and then decrease, which is considered to be the specific embodiment of the 4th coalification jump's control effect on CBM geological conditions. Meanw hile, the gas content displays typical characteristics of subsyncline-controlled CBM.