Carbon dioxide injection in coal beds: from molecular simulations to reservoir simulations
Résumé
Injecting carbon dioxide in coal bed methane reservoirs facilitates the recovery of the methane, a process known as enhanced coal bed methane recovery (ECBM). Such a technique enables also to store carbon dioxide, thus partially compensating the emissions of carbon dioxide associated with the consumption of the produced methane. But the injected carbon dioxide gets adsorbed at the surface of the coal pores, which makes the coal swell. Such a swelling leads to a closure of the cleat system (small natural fractures) of the reservoir and therefore to a loss of injectivity. In this work we propose a multiscale approach in order to compute the variations of injectivity of the reservoir over time during the process of injection.