沁南盆地樊庄煤层气田早期生产特征及主控因素

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

在对樊庄区块煤层气井早期产能空间和时间分布特征分析的基础上,重点探讨埋深、煤厚、含气量、孔隙度和渗透率、压裂效果对气井早期产能的影响关系,同时采用灰色关联分析方法,定量确定影响高煤阶煤层气井(田)生产的主控因素。研究表明:压裂效果对煤层气井早期产能的影响最大,并决定气井早期高产的峰值大小,但随着排采时间的推移,其对气井产能的影响程度逐渐降低;而煤层含气量和初始渗透率影响气井整体产能及其变化趋势;含气量越高或初始渗透率越大,气井产能越好,早期高产后其下降速度也越平缓。

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.