Coalbed methane wellhead, Raton Basin, Las Animas County, December 2003. Photo credit: Chris Carroll for the CGS.

Coalbed Methane

Coalbed methane (CBM) is natural gas produced from subsurface coal deposits. Much of the technology uses standard well-drilling and production techniques. The primary difference is the total usage of water in the process. In most cases, water must be pumped out of the formation in order to allow the methane that is adsorbed onto the coal particles to escape and travel to the surface via extraction wells.

Typical natural gas wells reach a peak and then begin a volumetric decline in production relatively rapidly. Coalbed methane wells behave differently. They increase in production for a long time as more and more water is removed from the strata. Decline in production does not usually begin until late in the life of the well.

As of 2008, Colorado was responsible for more than one-fourth of all coalbed methane produced in the United States and the state has the largest reserves of CBM. Coalbed methane output accounted for about one-half of Colorado’s natural gas production at that time.