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文章采用数值模拟方法，从煤层甲烷的流动机理入手，利用朗格缪尔等温吸附方程描述甲烷从煤表面解吸过程，利用Fick定律描述甲烷从煤基质和微孔隙中的扩散，综合考虑了煤层甲烷的解吸附、扩散、渗流三个过程，并考虑了水力压裂产生高渗透裂缝对渗流场的影响，在煤层理想化等七个假设条件下，建立了煤层甲烷的非平衡拟稳态吸附扩散模型，利用该模型编制了煤层气井产能预测软件，并进行了模拟计算，给出了计算实例。结果表明：煤层在没有经过水力压裂处理时，煤层的气、水产量是很小的；经过水力压裂处理后，由于煤层的排水降压效果，煤层气井气、水产量有明显的增加，具有经济开采的产量规模。

PRODUCTIVITY PREDICTION OF COAL-BED GAS WELLS 1)

With numeral simulation, according to the flow mechanism of coal-bed methane, using Langmuir isothermal adsorption equation to describe the adsorption process of methane from coal surface, using Fick law to describe the diffusion of methane from coal matrix and tiny pores, and integrative considering the 3 processes of adsorption, diffusion and percolation, and the influence of fractures with high permeability produced by hydraulic fracturing on the percolation field, the non-balance pseudo-stable state adsorption and diffusion model of coal-bed methane is established under the 7 assumed conditions such as coal-bed idealization, etc. With the model, the software of production prediction for coal-bed gas wells is developed, and the simulating calculation is conducted, and the calculated real case is provided. The results show the gas and water output of the coal-bed is very small before hydraulic fracturing, but the output increases apparently to the scale of commercial exploitation after hydraulic fracturing because of water-discharging and pressure-dropping affect of the coal-bed.