http://www.usgs.gov/newsroom/article.asp?ID=2893
[font face=Times, Serif][font size=5]USGS Releases New Assessment of Gas Resources in the Marcellus Shale, Appalachian Basin[/font]
Released: 8/23/2011 11:30:00 AM
…
[font size=3]The Marcellus Shale contains about 84 trillion cubic feet of undiscovered, technically recoverable natural gas and 3.4 billion barrels of undiscovered, technically recoverable natural gas liquids according to a new assessment by the U. S. Geological Survey (USGS).
These gas estimates are significantly more than the last USGS assessment of the Marcellus Shale in the Appalachian Basin in 2002, which estimated a mean of about 2 trillion cubic feet of gas (TCF) and 0.01 billion barrels of natural gas liquids.
The increase in undiscovered, technically recoverable resource is due to new geologic information and engineering data, as technological developments in producing unconventional resources have been significant in the last decade. This Marcellus Shale estimate is of unconventional (or continuous-type) gas resources.
Since the 1930's, almost every well drilled through the Marcellus found noticeable quantities of natural gas. However, in late 2004, the Marcellus was recognized as a potential reservoir rock, instead of just a regional source rock, meaning that the gas could be produced from it instead of just being a source for the gas. Technological improvements resulted in commercially viable gas production and the rapid development of a major, new continuous natural gas and natural gas liquids play in the Appalachian Basin, the oldest producing petroleum province in the United States.
This USGS assessment is an estimate of continuous gas and natural gas liquid accumulations in the Middle Devonian Marcellus Shale of the Appalachian Basin. The estimate of undiscovered natural gas ranges from 43.0 to 144.1 TCF (95 percent to 5 percent probability, respectively), and the estimate of natural gas liquids ranges from 1.6 to 6.2 billion barrels (95 percent to 5 percent probability, respectively). There are no conventional petroleum resources assessed in the Marcellus Shale of the Appalachian Basin.
These new estimates are for technically recoverable oil and gas resources, which are those quantities of oil and gas producible using currently available technology and industry practices, regardless of economic or accessibility considerations. As such, these estimates include resources beneath both onshore and offshore areas (such as Lake Erie) and beneath areas where accessibility may be limited by policy and regulations imposed by land managers and regulatory agencies.
…[/font][/font]
The DoE just updated their document, to be in line with the USGS estimate.
http://stateimpact.npr.org/pennsylvania/2011/08/24/department-of-energy-defers-to-u-s-g-s-on-shale-gas-estimates/[font face=Times, Serif][font size=5]Department of Energy Defers to U.S.G.S. on Shale Gas Estimates[/font]
August 24, 2011 | 1:27 PM
By Susan Phillips
[font size=3]In a report released Tuesday, the United States Geological Survey increased its own calculations on the amount of natural gas within the Marcellus Shale. From their previous report published in 2002, the U.S.G.S amended its measurements of untapped shale gas 40 times higher.
But the 84 trillion cubic feet of natural gas the U.S.G.S says lies within the Marcellus Shale is far less than estimates made in July by the Energy Information Administration. The EIA reported the Marcellus Shale holds more than 400 trillion cubic feet of natural gas.
So, why the huge gap? A spokesman for the EIA says they haven’t yet figured that out. But, Jonathan Cogan tells StateImpactPA that the U.S.G.S is the gold standard when it comes to the final say on how much gas lies beneath Pennsylvania’s forests and farms.[/font][/font]
= new reply since forum marked as read
