A Modeling Experiment of Enhancing Coalbed Methane Recovery by Carbon Dioxide Injection

Abstract

In accordance with the problem of lower productivity and longer recovering period in coalbed methane exploitation of China,a modeling experiment of carbon dioxide displacing coalbed methane was accomplished.On the basis of experimental results,the production characteristics of CH_4 in displacing process was calculated using the extended-Langmuir equation.The compare research between displacing process and pure CH_4 desorption process was carried out.The results indicate that the desorption rate of CH_4 at unit pressure drop in the process of carbon dioxide displacement is obviously bigger than that in the process of pure CH_4 desorption.The coalbed methane desorption rate at unit pressure drop of Jincheng coal was increased by 150%,and that of Lu'an coal was increased by 270%.Hence,the recovery of coalbed methane can be efficiently enhanced by carbon dioxide injection.