This report presents an improved methodology for estimating volumes of continuous (unconventional) oil and gas resources within the United States and around the world. The methodology is based on previously developed U.S. Geological Survey methodologies that rely on well-scale production data. Improvements were made primarily to how the uncertainty about estimated ultimate recoveries is incorporated in the estimates. This is particularly important when assessing areas with sparse or no production data, because the new methodology allows better use of analog data from areas with significant discovery histories.

Revised November 9, 2012

First posted December 3, 2010