Wyoming State Geological Survey
Ronald C. Surdam
Director/State Geologist
Wyoming State Geological Survey
P.O. Box 1347
Laramie, WY 82073



Contact Information

Robert Waggener
Editor in Chief

307-766-2286, ext. 255

News Release March 31, 2010

WSGS releases updated Powder River Basin CBNG map

The Wyoming State Geological Survey (WSGS) has released an updated version of a map showing coalbed natural gas (CBNG) activity in northeastern Wyoming’s Powder River Basin.

“The map will be useful to the energy industry, landowners, regulatory agencies, conservation groups and others,” said WSGS geohydrologist Scott Quillinan. “Among the details featured are the location and status of all CBNG wells in the basin.”

A record 558 billion cubic feet of CBNG was produced from Powder River Basin coal beds in 2009.

“The Powder River Basin CBNG play is the largest natural gas producing area in Wyoming,” Quillinan said.

Since drilling started in 1987, nearly 3.7 trillion cubic feet (TCF) of CBNG has been produced from the basin. This is enough natural gas to meet the needs of approximately 4 million homes for 10 years.

“At the beginning of 2009, approximately 27,000 wells had been drilled in the basin, of which about 17,000 were producing and 10,000 were shut in,” Quillinan said. “During the year, the number of producing wells had decreased by nearly 3,500. Despite this drop, 2009 proved to be the largest production year to date.”

Another record was also achieved – the lowest water-to-gas ratio since drilling started in the basin. Approximately 1.02 barrels of water was produced for every 1,000 cubic feet of gas (the ratio is based on 42-gallon barrels).

Water in coal seams must be pumped to the surface to lower the formation pressure and release natural gas.

“The water-to-gas ratio for the Powder River Basin continues to decrease,” Quillinan said. “In 2000, the ratio was nearly 2.5 barrels per 1,000 cubic feet of gas. It had decreased to 1.7 by 2005, and next year it may dip below 1.0.”

He added, “We expect this trend to continue as the coal beds are depressurized.”

Despite record gas production last year, water production dropped approximately 17 percent – from 681 million barrels in 2008 to 566 million barrels.

WSGS coal geologist Nick Jones constructed a new diagram on the map showing subsurface distribution of key coals in the Powder River Basin. “This is important because it gives the user a better understanding for the coal stratigraphy in the basin,” Jones said.

The map, which is updated annually, also includes:

  • Locations of compressor stations
  • Natural gas pipelines and operators
  • Highway and railroad transportation networks
  • Federal coal leases and lease-by-application tracts
  • Areas where coal seams are exposed at the surface (outcrop areas)
  • The geology of the area, including faults and synclines
  • The area’s hydrology, including major drainages, lakes and reservoirs

WSGS Assistant Director Rodney De Bruin and geologic assistant Brett Worman helped develop Map Series 58 – Coalbed natural gas activity in the Powder River Basin, Wyoming.

The map, which measures 48 x 36 inches, is available as a rolled copy for $40 and on CD for $50, plus shipping fees and applicable taxes. The CD includes printable and viewable files, along with files that can be loaded into GIS software.

To order the map, go to the WSGS Online Store at http://sales.wsgs.wyo.gov/catalog/index.php, visit the WSGS on the University of Wyoming campus in Laramie, call the sales office at 307-766-2286, ext. 224 or e-mail wsgs.sales@wyo.gov.