Wyoming CBM effect on groundwater studied

Aug. 11, 2009
The Wyoming State Geological Survey, in association with the US Bureau of Land Management’s Buffalo, Wyo., field office, has released a report about groundwater monitoring in the Wyoming portion of the Powder River basin.

Nick Snow
OGJ Washington Editor

WASHINGTON, DC, Aug. 11 -- The Wyoming State Geological Survey, in association with the US Bureau of Land Management’s Buffalo, Wyo., field office, has released a report about groundwater monitoring in the Wyoming portion of the Powder River basin.

Extraction of coalbed methane-produced groundwater from coal deposits in the basin has caused widespread public concern about declines in groundwater availability, according to the report, “Open-File Report 2009-10: 1993-2006 Coalbed Natural Gas (CBNG) Regional Groundwater Monitoring Report: Powder Basin, Wyoming”.

It said that between 1987 and 2006, BLM collected data from 111 monitoring wells in Wyoming’s portion of the basin using a deep network designed to evaluate potential leakage between the coalbed methane water-producing coal deposits and adjacent sandstone beds and to measure the drawdown in the producing zones.

During that period, coalbed methane (CBM) production in the Wyoming Powder River basin withdrew 4.1 billion bbl of groundwater at total pumping rates up to 77.3 million gpd, the report said. Based on BLM’s deep monitoring well data, water levels in some of the monitored CBM wells have declined up to 625 ft within the CBM production areas.

The Wyoming Geological Survey said that this report represents the initial analysis of data through 2006 and that additional data from 2007 and 2008 will be incorporated in a final version.

The report can be found at www.wsgs.uwyo.edu/docs/OFR-PRB.pdf.

Contact Nick Snow at [email protected].