地史中煤层甲烷扩散散失作用的数值模拟

以扩散传质微分方程为基础，建立游离甲烷在盖层中扩散散失的数学模型，并对不同地质条件进行模拟计算。结果表明扩散作用是游离态煤层甲烷散失的重要途径之一，扩散散失速度与储、盖层特征、煤层有机质热成熟历史等有关；烃浓度封闭对阻滞煤层甲烷的扩散散失起了重要的作用。

NUMERICAL SIMULATION ON COALBED METHANE DIFFUSION IN GEOHISTORY

Based on the differential equation of material transportation by diffusion,the mathematical model of free CBM escaped from coal reservoir by diffusion is built and the processes in different geological conditions is simulated.The results indicate that the diffusion is one of important ways of CBM escaped from coal reservoir and its speed depends on the matural history of coal organism and the characters of reservoir and cap.The closure of hydrocarbon consistency acted an important role to slow down the diffusion escape of CBM.