Evaluation on distribution mode and development effect of coalbed methane in Gujiao Mining Area of Xishan Coalfield

In order to reveal the distribution law and the main controlled factors of the coalbed methane in Gujiao Mining Area, comprehensive field geological survey, mining and excavation geology, coalbed methane well related information as well as coal core test data and other information, the paper had a discussion on the structure evolution, structure morphology, crack distribution, depth, coal structure, seam thickness, direct roof property and other factors affected to the coalbed methane distribution. The results showed that the structure condition and the depth would be the main factor to control the distribution law of the coalbed methane within the mining area. Thus the mining area was divided to four coalbed methane distribution modes of the gently-dipping monoclinal shallow overburden, gently-dipping monoclinal deep overburden, steep monoclinal and complicated fold. The gently-dipping monoclinal shallow overburden and gently-dipping monoclinal deep overburden would be the enrichment favorable zone of the coalbed methane. Under the mode of the gently-dipping monoclinal shallow overburden, the shallow depth and good permeability would be the favorable condition to the high production of the coalbed methane well. Under the mode of the gently-dipping monoclinal shallow overburden, the shallow depth and high gas content would be favorable to the high production of the coalbed methane well.