DEEP COALBED METHANE IN ALBERTA, CANADA: A FUEL RESOURCE WITH THE POTENTIAL OF ZERO GREENHOUSE GAS EMISSIONS

摘要

A huge incentive to develop Alberta's deep coalbed methane (CBM) resources is found in evolving enhanced gas recovery (EGR) technologies using CO_2 injection, somewhat similar to enhanced oil recovery (EOR). However, unlike CO_2-EOR where CO_2-breakthm eventually occurs, the injected CO_2 is sequestered in the reservoir by sorption to the coal surface. The mechanism is that the CO_2 displaces the sorbed CH_4 from the coal surface, two molecules of CO_2 being trapped for every molecule of CH_4 released. Already this CO_2-EGR process, although in an embryonic stage, has shown increased yields of produced CH_4 over conventional CBM recovery.