Coal Bed Methane: Pros and Cons of This Energy Form

Natural gas is a valuable source of energy and can be produced through a couple of methods. The most recently developed method for the recovery of natural gas is through coal bed methane production. As the price of fossil fuels, continue to rise the means through which these products are produced will be come of greater importance. Methane is natural gas that is produced from non-oil bearing formations, while natural gas is produced from those formations that are oil bearing.

Methane is released from coal seams by first drilling a well bore down into the coal seam. This well bore is drilled to in the same manner as typical groundwater water wells. Then the water that is located within the coal. The water holds the methane under pressure in the formation. As the water is pumped out of the formation the methane can progress toward the well bore and then to the surface. Once the methane reaches the surface it is captured and pumped into a pipeline. Through the pipeline is transported to a gas processing plant.

Coal bed methane is not a very high quality form of natural gas. It most generally has a very high sulfur content and low energy content compared to other types of natural gas. There are several problems with coal bed methane because of its low quality. Most pipelines that are not designed for coal bed methane will purchase and transport coal bed methane. In order, to sell coal bed methane to consumers for heating and for other purposes, sometimes propane or natural gas from other sources must be added to make the energy content of the gas higher.

In order to relieve the pressure from the coal seam massive quantities of water must be removed from the formation. There are many issues caused by the large amounts of water produced and storage of the water. This water often consists of high concentration of sulfur and high pHs. This leads to problems if the water is simply discharged on to the surface or stored in unlined pits. It can be damaging to crops and animals if they are exposed to this water. In some areas the water is of high enough quality though, that it can be used to water livestock, wildlife and even irrigate crops. These uses are very beneficial to industry in those areas, these areas also benefit from having the natural gas industry in their area.

Coal bed methane is mostly produced in the Powder River Basin of northern Wyoming and southern Montana. The Big George and the Wyodak coal seams are those from which coal bed methane is produced from in the Powder River Basin. Coal bed methane is also produced in Arkansas and Louisiana.

As fossil fuels become more scarce and harder to produce the more important coal bed methane and other newer forms energy will become more important, even if those types of energy are not as high of quality or are harder to produce.

Sources:

www.waterquality.montana.edu/deas/methane/cbmpag.shtml
www.powderriverbasin.org
www.concernedaboutcbm.org