Abstract:

In order to improve stable production period and recovery of Coalbed methane wells, the reasonable production intensity in initial production in Xinnan area is computed with differential geometry theory and Darcy′s law. Based on the measured data about the production wells in the condition of single drainage 3# coalbed in the southeast of Qinshui Basin, the relations between the initial and actual critical desorption pressure with the method of least squares is established, it is used to determine dropping height of dynamic liquid; an average pressure and influent volume in initial production are computed with differential geometry theory and Darcy′s law. They are used to determine the best effective radius; based on the relation between the best effective radius and drainage time, combined with dropping height, the production intensity in initial production is computed. The agreement of the final computation results with the practical data indicates this method can be used to prevent reservoir stimulation and reduce energy consumption, recovery can be improved.

Key words: coal bed methane, production intensity, coal bed methane wells, permeability