Western Cretaceous Coal Seam Project Measurement and Evaluation of Coal SorptionIsotherm Data. Topical Report, January 1988-December 1991

摘要

The proper measurement and interpretation of sorption isotherm data is of primaryimportance in understanding and predicting the gas production performance of a coalbed methane reservoir. These data are used to predict the release of gas from the reservoir as the pressure is reduced during production and the eventual gas recovery (reserves). A sorption isotherm is a laboratory measurement performed on a representative coal sample to determine the methane storage capacity as a function of pressure. The term 'isotherm' results as the experiment is performed at a constant temperature which should be equal to that of the reservoir. This paper presents the use of the data, procedures for performing the measurements, a methodology for interpreting the experimental data for estimates of gas storage capacity and diffusion coefficients of the coal matrix, and isotherms obtained from a variety of coal samples.