Coalbed Methane Resources And Exploration Potential Of Qinshui Basin

Qinshui Basin is currently the highest level of China’s coalbed methane exploration and development. Coal-bearing strata are mainly Upper Carboniferous Taiyuan Formation and the Lower Permian Shanxi Formation. Coal seam is thick and the distribution is stability. Coal-bearing has a high degree of thermal evolution of gas and production is big. Coal reservoir cleat develops well; tectonic line intersection site crack is in a high development. Coalbed methane production conditions are good; Effective thickness of the overlying is large and hydrodynamic conditions are good, CBM preservation conditions are favorable;Through this study the following key results was achieved: 1 Based on Qinshui CBM exploration and development and resource characteristics, the coalbed methane resources exploration evaluation system is built,that is based on AHP, and Gray Clustering Method. Evaluation system contains resources conditions, mining conditions, economic conditions index system of three categories, including the geological resource, resource abundance, depth, mining coefficient, permeability, reservoir pressure gradient, Ratio of critical pressure and reservoir pressure seven quantitative indicators and structural complexity, Seam stability, market demand, topography and infrastructure five qualitative indicators,12 indicators.2 First, AHP evaluation is used to determine the weight of the share in the comprehensive evaluation, then according to the rate parameters or conditions, to gray cluster, the evaluation unit is evaluated the potential of coalbed methane exploration, dividing to excellent (priority to carry out exploration work) good (encouraging exploration) may (can carry out exploration work) poor (suspended to carry out exploration work) four levels. Draw up of the exploration potential evaluation map of CBM in Qinshui area.3 Based on the resource evaluation and exploration potential evaluation, analyze the potential of coalbed methane resources exploration, predict and filter favorable target areas of the coalbed methane exploration and exploitation, proposed area of geological exploration of coalbed methane exploration direction and planning proposals. Potential zone of coalbed methane resources in Qinshui gas exploration is: Excellent level block mainly gas-bearing zone is in the southern Qinshui, especially the Changzi-Duanshi-Mabi for the best, here is the most successful region of the current development of China’s coalbed methane exploration. Qinshui gas zone in the north and east of Shouyang-Xiyang-Heshun exploration potential is also excellent-good level. The exploration potential zones of may-level and poor levels are mainly in the deep basin area.