Exploration and Development History of Coalbed Methane on the Crow Reservation

This page was written by Erin Klauk as part of the DLESE Community Services Project: Integrating Research in Education. Funding was provided in part by the Montana Office of Public Instruction .

Map of US Coalbed Methane resources; click to enlarge. Details

Production of natural gas associated with coal beds accounts for about 7 percent of the total natural gas produced annually in the United States. Several important U.S. coal-bed gas-producing areas are in the Rocky Mountain region (i.e. Powder River Basin), where extensive shallow coal beds have produced or have the potential to produce coal-bed gas (Coal-Bed Gas Resources of the Rocky Mountain Region: National Assessment of Oil and Gas Fact Sheet (more info) ).

Although coalbed methane has a potential negative effect on the environment if not monitored and managed, if produced domestically, it reduces our need for import energy. Geologists are aware of the depositional environments that can produce coalbed methane, reducing the cost of extensive exploration. Also, methane is a relatively clean-burning source of energy, much cleaner than coal. Exploration costs for coal-bed methane are low, and the wells are cost effective to drill. Methane occurs in most coals, and the location of the Nation's coal resources is already well known (Coal-Bed Methane: Potential and Concerns (more info) ). These factors combine to make coalbed methane a locally-produced, affordable source of energy.

During coalification, large quantities of methane-rich gas are generated and stored within the coal on internal surfaces. Because coal has such a large internal surface area, it can store surprisingly large volumes of methane-rich gas; six or seven times as much gas as a conventional natural gas reservoir of equal rock volume can hold. In addition, much of the coal, and thus much of the methane, lies at shallow depths, making wells easy to drill and inexpensive to complete. With greater depth, increased pressure closes fractures in the coal, which reduces permeability and the ability of the gas to move through and out of the coal (Coal-Bed Methane: Potential and Concerns (more info) ).

A truck-mounted drill-rig in the Powder River Basin.
A truck-mounted drill-rig in the Powder River Basin. Details

To further investigate the exploration and development history of coalbed methane on the Crow Nation, follow the links below.

Investigate Resources Pertaining to Exploration and Development History of Coalbed Methane on the Crow Reservation

  • Coal-Bed Gas Resources of the Rocky Mountain Region: National Assessment of Oil and Gas Fact Sheet. This USGS fact sheet addresses coalbed methane resources in the Rocky Mountain region. Topics covered include a description of coalbed methane, how it is rediscovered, and the assessment of coalbed methane gas resources. (more info)
  • Coal-Bed Methane: Potential and Concerns. This USGS Fact Sheet serves as an introduction to coalbed methane. The two-page PDF document summarizes available coalbed methane resources, assessment methods, production methods, and environmental concerns. Also addressed is the need for further study of new methods used to recover this fuel. (more info)
  • Coalbed Methane Activities in the Energy Resources Program. This website provides information about the models the USGS is developing to accurately assess potential U.S. coalbed methane resources. These models evaluate controls on the occurrence and recoverability of coalbed methane, including geologic, geochemical, engineering, technological and economic factors, and resource development issues and environmental implications. Links to sites providing further research are included. (more info)
  • Coalbed Methane Development in the Powder River Basin of Montana: Economic and Social Impacts of Proposed Development. This 24-page Department of Environmental Quality PDF provides information about the effects of coalbed methane on the community of the area, the local and state economies, the local, county and state governments, the local education systems, social values, housing, public service systems, and the environment. (more info)
  • Coalbed Methane Publications in the Rocky Mountains. This USGS site is part of the Energy Resources Program and provides links to publications on coalbed methane in the Rocky Mountains. (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)
  • 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)

For ideas on how to use these webpages in a classroom, a Study Guide is provided.