Abstract：Fully understanding the characteristic of a coal bed is a key to develop coal bed methane. The previous researchers only pay attention to its stress sensitivity,and rarely consider the matrix shrinkage. A new method is presented,in which the production data is utilized,and it can invert properties of a coal bed,including reservoir pressure and permeability. In addition,a mathematical model of permeability has been built by combining pervious researches. The model can be regressed by permeability versus reservoir pressure. This method can describe the performance of permeability,and predict gas rate to guide production assignment.

Keyword：coal bed methane;stress sensitivity;matrix shrinkage;permeability performance;production data analysis;