Initial production characteristic and its controls in Fanzhuang coalbed methane field,Southern Qinshui Basin

Based on the temporal and spatial characteristics of production performance in the Fanzhuang block,this paper emphatically discussed the effect of burial depth,thickness,gas content,effective porosity and initial permeability,hydraulic fracturing on the initial production performance,and then quantitatively determined the key factors controlling the initial performance of high-rank CBM field through grey correction analysis.The results show that hydraulic fracturing is the most important factor which controls the initial production and determines the peak rate of the early pumping stage.However,its impact becomes less and less remark as time goes on.Additionally,gas content and initial permeability influence the gas and water rate and their trends during the total production.The larger gas content or initial permeability is,the better CBM wells perform and the slower the gas rate decreases after peak.