COALBED METHANE RESERVOIRS AND THEIR CO2 SEQUESTRATION POTENTIAL

Coalbed methane (CBM) is an important part of the world’s natural gas resource. The energy industry classifies coalbeds as unconventional gasreservoirs and continuously looks for methods toeconomically develop gas production from them. Coalbeds can store several times as much gas asa conventional natural gas reservoir of equal rock volume due to the large internal surface area of coal. In general, CO2 will commonly be moreadsorptive onto coal than methane. ThereforeCO2 injection into coalbed methane reservoirs can potentially displace methane from coal matrix and consequently enhance methaneproduction. Major part of injected CO2 is also permanently stored in the subsurface. In this paper, coalbed methane reservoirs with theirreservoir engineering characteristics and their CO2 sequestration potential are discussed.