Methane, CH4, is a naturally occurring gas; it is the major component (95 percent) of natural gas. It can be produced in a variety of ways. For example, methane is produced during the natural coalification process, when organic matter such as trees or vegetation is quickly buried and then heated. Methane can also be produced by farming and ranching activities or as a byproduct of industrial processes. Methane is a greenhouse gas that remains in the atmosphere for up to 15 years, and it is also a relatively inexpensive, clean burning fuel.
Coalbed methane is natural gas that is produced as organic material and turned into coal. It is then stored on the many surfaces of the coal. The methane is usually held in place by water pressure.
Coalbed methane is associated with coal deposits, and is found in coal seams. In the past, the gas was the cause of numerous explosions in underground mines. More recently, the gas has been vented to the surface from underground mines. It is only during the last twenty-five years that it was realized that coalbed methane could be used as a resource. Various basins in the Rocky Mountains, such as the Powder River Basin, partly on the Crow Reservation, hold much of this country's coalbed methane resources.
When water is removed from a coal seam, it lowers the reservoir pressure. Methane that was held in place by water pressure tends to follow the water as it is pumped to the surface, where it is captured and transported through pipelines to storage facilities or shipped. This relatively inexpensive and straightforward procedure has made coalbed methane a useful, easily accessible form of energy.
To further investigate methane gas, follow the links below.
Resources containing information on methane gas.
- Methane. This EPA website provides basic information about methane. Topics covered include methane's role as a greenhouse gas, atmospheric concentrations of methane over time, processes that remove methane from the atmosphere, and links to atmospheric measurement data. (more info)
- Methane Sources and Emissions. This site, published by the EPA, discusses the sources of methane emissions, including landfills, coal mining, the oceans and livestock, among others. (more info)
To further investigate coalbed methane, follow the links below.
Resources containing information on coalbed methane.
- Coalbed Methane Development in the West: Primer. This 352-page PDF document, compiled by the Colorado University School of Law, is a comprehensive introduction to all aspects of coalbed methane. This primer seeks to contribute to public policy making for CBM development by providing an accessible reference tool. The document is composed of four sections: 1) defining CBM, where it is found, and how it is developed; 2) the problems, conflicts and challenges associated with CBM development, including environmental concerns; 3) regulation of CBM development; and 4) suggestions to minimize environmental and other impacts of CBM extraction. (more info)
- Coalbed Methane Development: Boon or Bane for Rural Residents?. This 8-page PDF fact sheet provides information about coalbed methane including what it is, where it is found, how it is developed, problems associated with development, why it is being developed, and what laws and regulation govern development. (more info)
- Colstrip Coalfield, Powder River Basin, Montana: Geology, Coal Quality, and Coal Resources. This 41-page PDF provides information about the Colstrip Coalfield in the Powder River Basin, Montana. Topics covered include geology, coal quality, and coal resources. Maps, tables and figures illustrate the text. (more info)
- Existing and Potential Coal Bed Methane Development and Resources. This 27-page PDF document is a chapter from a book on coalbed methane (CBM). This chapter discusses CBM reserves, water resources and coal geology in the major basins of the United States, including the Gulf Coast Basin, the Illinois Basin, the Powder River Basin, and the San Juan Basin, among others. Maps of the basins and coal reserves are also included. (more info)
- Frequently Asked Questions: Coal Bed Methane (CBM)
. This resource from Montana State University includes information about coalbed methane, such as what it is, where it is found, and how the resource is developed. (more info)
- Introduction to Coal Bed Methane. This 14-page PDF document is a chapter from a book on coalbed methane (CBM). This chapter discusses the origins of coal and coalbed methane. Other topics include controls on CBM production, such as the cleats in coal and gas migration pathways, as well as basins that produce CBM and extraction methods. Helpful diagrams, tables and maps are also included. (more info)
- Minerals Appendix. This 45-page PDF is part of the final statewide oil and gas environmental impact statement and proposed amendment of the Powder River and Billings Resource Management Plans. This section is a minerals appendix for the Crow Reservation. Included is a discussion of coalbed methane in the emphasis areas, conventional oil and gas production trends, the Reasonably Foreseeable Development Scenario, and a description of the cumulative effects projects evaluated for this study. (more info)
- Powder River Basin Coal-Bed Methane Project. The purpose of this web site is to offer a comprehensive yet
concise resource on coal-bed methane documentation. This searchable database contains reference listings for publications, books, and articles that relate to coal-bed methane development and related natural resources. Included in the database are flags that help determine if a specific publication is relevant, and a description of where to find a copy. (more info)
- Technically Recoverable Resources in Continuous-Type Deposits. This USGS site provides links to a map and tables of recoverable methane in the lower 48 States. Included are areas where methane is already being extracted, and potential additions to reserves of coal-bed gas. (more info)
- USGS Resource Assessment of Selected Tertiary Coal Zones in Wyoming, Montana, and North Dakota. This concise 6-page PDF document summarizes the full USGS reports on coal resources within the Northern Rocky Mountains and Great Plains Regions (the full length reports are available on CD-ROM from the USGS). The assessment includes maps of the resource basins as well as geologic, stratigraphic, palynologic, and geochemical studies and resource calculations for the major coal producing basins in the Rocky Mountains and North Dakota. (more info)