A new model of coalbed methane permeability is derived through theoretical research and is transformed to be compatible with conventional reservoir simulator. The variation of permeability is related not only to coal matrix characteristics,but also to the type of gas flowing through the medium and its flow state. In coalbed micropore system,Knudsen diffusion is a very important gas migration process. It can be seen through research that the apparent permeability of coal matrix is greater than Darcy permeability; this can well explain the high production of coalbed under the condition of low porosity and permeability.%通过理论研究的方法推导出了煤岩微孔隙系统气体渗透率新模型,并将渗透率模型变形为可与常规油藏模拟器相兼容的形式,渗透率的变化不仅与煤岩基质的特征有关,而且与通过介质的气体类型和流动状态有关.在煤岩微孔隙系统中,Knudsen扩散是1个非常重要的气体运移过程.通过研究可以看出,煤岩基质的表观渗透率大于达西渗透率,可较好地解释煤岩在低孔低渗的条件下高产的原因.
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