The prolific Mancos Shale formation in western Colorado’s Piceance Basin is now said to hold 66 trillion cubic feet of natural gas, according to a newly released study by the US Geological Survey.
In 2003, a USGS assessment of the basin estimated the Mancos held 1.6 trillion c/f of gas. The expanded estimate is the result of “a decade of new drilling that provided additional geologic data” into the extent of technically recoverable, undiscovered oil and gas.
A forty-fold increase in the estimate of recoverable natural gas by the USGS is significant and aligns with an increase in recoverable gas in all US resource basins announced last year by the Potential Gas Committee, an independent project lead by the Colorado School of Mines.
Released in 2015, the Potential Gas Committee’s biennial report estimated that due to increased tight-gas development in basins such as the Marcellus, Woodford, Haynesville, Barnett and Piceance, the total for technically recoverable natural gas in the US stood at 2,515 trillion c/f, an increase of 113 trillion c/f from 2012.
Stretching from Utah to Glenwood Springs and from Gunnison to Grand Junction, the Piceance basin has seen some 2,000 natural gas wells drilled and completed in the Mancos Shale formation since 2003. The additional development greatly expanded the survey’s understanding the Mancos Shale, a formation that is more than 4,000 ft. thick as it occurs in the Piceance and is considered source rock for shale gas and oil.
USGS called the Piceance the second largest assessment of potential gas resource the agency has ever studied.