USGS estimates Colorado’s Mancos shale to hold 66 tcf of gas

The Mancos shale of the Piceance basin in Colorado holds mean undiscovered, technically recoverable resources of 66 tcf of shale natural gas, 74 million bbl of shale oil, and 45 million bbl of NGLs, according to an updated assessment by the US Geological Survey.

The previous USGS assessment of Mancos was completed in 2003 as part of a comprehensive assessment of the greater Uinta-Piceance province. That estimate amounted to 1.6 tcf of shale gas.

Tight gas in the younger, shallower parts of the Mancos is produced primarily from vertical and directional wells in which the reservoirs have been hydraulically fractured. Shale oil and gas in the older and deeper intervals are produced mostly from horizontal wells that have been fraced.