中文摘要：

为了更加准确的计算排采过程中煤储层渗透率的变化，考虑生产过程中外在产量数据对煤层内在渗透率的反映，在物质平衡方程、产量方程的基础上建立了利用生产数据反求煤层渗透率的方法。利用物质平衡方程对生产中储层的平均压力进行计算，纯产水阶段引入无量纲产水指数对产量方程进行转换。气水同产阶段则利用气水产量比进行转换，从而消除泄流半径、表皮系数等不确定因素对计算的影响。通过理论推导得到渗透率与地面累积产液量的关系可以用一元三次方程描述。对沁水盆地煤层气井进行计算，得到煤层渗透率呈先降低后上升的趋势。对计算结果进行分析得出，储层渗透率在排水阶段后逐渐增加，但渗透率增长率呈现降低的趋势，渗透率比与地面累积产液量呈较好的一元三次多项式关系，这与理论数学关系相吻合。

英文摘要：

In order to more accurately calculate the changes in the permeability of coalbed during production process, a calculation method for coalbed permeability based on production data is established by combining with material balance equations and production equations, and it gives the fact that the output data can be a good reflection of the inner permeability of coalbed. The average pressure of coalbed in production process can be calculated through material balance equation. Dimensionless water production index is introduced into the production equation in the stage only with water production. In the next stage with both gas and water, gas and water production ratio is introduced to eliminate the influence of flush-flow radius, skin factor as well as other uncertain factors on the calculation of CBM permeability. The relationship between permeability and surface cumulative liquid production can be described as a single-variable cubic equation by derivation. There is a trend that the permeability declines firstly and then increases after wells in Qinshui CBM field are calculated. The results show that reservoir permeability increase after drainage stage, but the growth rate decrease gradually. The regression result of the permeability ratio and surface cumulative fluid production agrees with the theoretical mathematic relationship.