METHANE IN WYOMING
hasn't coalbed methane been produced before?
Although Wyoming coal fields contain large coal resources in numerous thick beds, the shallow depths and immature (low rank) coals were once considered too low in gas content to be economically produced using conventional coalbed methane production methods. These methods had worked well in higher rank, higher yield coals (those with higher gas contents, e.g., on the order of 350 cubic feet of gas per ton of coal) but met with no success in the Powder River Coal Field (Shirley, 2000). One of the main reasons for the acceleration in the number of wells and corresponding production in the Powder River Coal Field was the development of a new production technique in which wells are completed open hole (see section on production below). Renewed interest in coalbed methane has expanded to most of the other Wyoming coal fields. This interest is mainly due to spillover from success in the Powder River Coal Field and to increased exploration for more conventional (thermogenic) coalbed methane targets. (TOP of page)
is the current level of coalbed methane activity in Wyoming?
Future production in the Powder River Coal Field is expected to increase even more. Drilling on federal land, which had slowed because of a moratorium on permitting, will increase because an environmental impact statement has been completed which allows development to proceed. Recent completion of several new pipelines has added nearly a billion cubic feet per day of new capacity out of the basin.
There are a number of ongoing exploration projects in various other parts of the state, but development of new coalbed methane fields outside the Powder River Coal Field has not yet occurred.(TOP of page)
is coalbed methane produced?
gas and water produced at individual wells (Figure 8) are piped to a metering
facility (Figure 9), where the amount of production from each well is
recorded. The methane then flows to a compressor station (Figure 10),
where the gas is compressed for shipment in a pipeline. The water goes
to a central discharge point at a drainage or impoundment.
much coalbed methane is there?
long can a coalbed methane well produce?
much coalbed methane can be produced?
thick should a coal bed be for a viable coalbed methane target?
owns the coalbed methane?
Where one party owns both the surface and mineral estates, the land is said to be owned in fee simple. Homesteaders in Wyoming had the option of acquiring both estates, although many chose only to claim the surface estate (reserving the mineral estate to the federal government). To help finance construction of the transcontinental railroad, to give the builders of the railroad some financial incentives, and to assist in opening the developing nation to rail transportation, almost half of the mineral and surface estate was given to the railroads in select areas of Wyoming. In southern Wyoming, this area is called the Union Pacific land grant, and it includes a 20-mile-wide strip of land on both the north and south sides of the railroad route.
much of Wyoming, the owner of the mineral rights is often different than
the surface owner. It is common in Wyoming for the surface estate to be
owned by private individuals and the mineral estate to be owned by the
federal government (and leased to private individuals or companies). State
lands are usually underlain by state-owned minerals. The U.S. Supreme
Court ruled in 1999 that the owner of the oil and gas estate rather than
the owner of the coal estate owns the coalbed methane. The mineral owner
has rights to access and develop their minerals, and under the law, surface
owners are entitled to compensation for damages to their property due
to mineral extraction.
owns the coal?
has priority, coal mining or coalbed methane development?
does the surface landowner keep his rights if he does not own or lease the
6. Yearly production and number of producing
wells for coalbed methane in the
Figure 7. Schematic diagram showing open-hole completion technique for a typical coalbed methane well.Modified from diagram furnished by the Wyoming State Engineer's Office.
|Figure 8. A single coalbed methane well south of Gilette. As shown, the surface equipment for many producing wells is enclosed in a small fiberglass or aluminum shell; other wells contain no structures and are simply well heads enclosed by a fence. Photograph by Rodney H. De Bruin.|
9. Coalbed methane facility which houses equipment
that measures production from a number of coalbed methane wells.
Photograph by Rodney H. De Bruin.
|Figure 10. Compressor station where coalbed methane is compressed before transport through a pipeline. Photograph by Rodney H. De Bruin.|
|Figure 11. Production history of a coalbed methane well. Modified from U.S. Geological Survey, Energy Resource Surveys Program, 1999, Coalbed methane an untapped energy resource and an environmental concern: U.S. Geological Survey web site on coalbed methane.|
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