通过建立煤储层渗透率变化率与体积应变之间关系的数学模型,考察了煤储层的体积应变和渗透率变化率在煤层气开发过程中的变化.结果表明:煤层的体积应变在煤层气开发过程中分为2个阶段,初始阶段体积收缩,体积应变为负,随着有效应力的变化,体积应变逐渐变化为正并持续增加；而渗透率呈先减小后增大的不对称U型变化,最终增加到原来的1.5倍.%With the establishment of the mathematical model between the variation rate of permeability rate and volume strain of coal reservoir .The variation of the volume strain and permeability rate in the seam reservoir during the coal bed methane development process was investigated. The results showed that the volume strain of the seam reservoir during the coal bed methane development process could be divided into two stages.At the initial stage,the volume would be shrunk and the volume strain would be negative.With the effective stress varied, the volume strain would be steadily be positive and would be continuously increased.But the permeability rate would have an asymmetric U type variation with firstly reduction and then increasing and finally would be increased by 1.5 times.
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