All of the USGS values are available at our website U.S.Geological Survey Assessment of the Middle Devonian Marcellus Shale of the Appalachian Basin 2011.
The USGS publishes its geological reports supporting its oil and gas resource assessment on its Energy Resources Program web site as soon as they are completed, peer reviewed by scientists knowledgeable about the subject, and formatted for publication. ...
The USGS does not have any current plans to re-assess the Marcellus shale resource potential.  However, if new technology is developed and deployed, apparently resulting in substantial changes in technically recoverable resources, the USGS will look at...
Our standard practice in publishing the fact sheet of results is to use billions of cubic feet (BCF) and millions of barrels of oil (MMBO) or natural gas liquids, because we use a standard format for all assessment results.  Some basins have very little...
The USGS uses a statistically based process to calculate the likely range of its estimate.  The USGS publishes a range of values that encompasses 90% of likely outcomes from its modeling process.  That range extends from a 5% or greater likelihood of...
This question cannot be answered clearly, because the methodologies used by these and other entities to estimate resource volumes are not publically available to compare step-by-step.  The USGS does not include previously discovered and booked reserves...