New USGS assessment digs deep into Marcellus Shale prospects

A new assessment by the U.S. Geological Survey (USGS) sheds more light on the opportunities that exist in the Marcellus Shale for gas industries, and the discovery could ultimately add to the nation’s propane supply.

In “Assessment of Undiscovered Oil and Gas Resources of the Devonian Marcellus Shale of the Appalachian Basin Province, 2011,” the USGS details how the Marcellus Shale contains 84 trillion cubic feet of undiscovered, technically recoverable natural gas and 3.4 billion barrels of natural gas liquids (NGLs).

The numbers are a drastic difference from USGS’ last assessment of the Marcellus Shale in the Appalachian Basin, in 2002, when 2 trillion cubic feet of natural gas and 0.01 billion barrels of NGLs were estimated. This is a result of new geologic information and engineering data, as technological developments in producing unconventional resources have been significant in the last decade, USGS noted.

The USGS assessment estimates continuous gas and NGL accumulations in the Middle Devonian Marcellus Shale of the Appalachian Basin, the oldest producing petroleum province in the United States. The assessment covered areas in Kentucky, Maryland, New York, Ohio, Pennsylvania, Tennessee, Virginia and West Virginia.

USGS estimates 43.0 to 144.1 trillion cubic feet of undiscovered natural gas (with respective probabilities of 95 percent to 5 percent) and 1.6 to 6.2 billion barrels of NGLs (with respective probabilities of 95 percent to 5 percent). The new estimates are for technically recoverable oil and gas resources and don’t account for economic or accessibility limitations, such as policy and land regulations, USGS said.