The currently used U.S. Geological Survey methodology for assessing continuous (unconventional) petroleum resources of the United States was developed in the 1990s. This methodology poorly incorporates uncertainty about the estimated ultimate recoveries (EURs). This is especially problematic for hypothetical assessment units where this may be the largest source of uncertainty that needs to be reflected in the estimates. An improved methodology estimates the uncertainty of mean EUR directly. It uses analog data that have been compiled from production histories of many developed U.S. continuous assessment units. The analog databases provide a way of estimating the variability of not just EURs but other production parameters useful in assessing continuous resources.

First posted December 28, 2010