U.S. Geological Survey Open-File Report 03-039
Figure 12

Figure 12.  Summary of technically recoverable oil and gas grouped by accumulation size class estimated to occur in the Brookian Clinoform Central Play in NPRA.  Histograms are based on the mean estimates of technically recoverable oil and non-associated gas in the play.  (A) Number of oil accumulations grouped by oil accumulation size class.  (B) Volume of oil in each accumulation size class.  (C) Number of non-associated gas accumulations grouped by gas accumulation size class.  (D) Volume of non-associated gas in each accumulation size class.  The left “tail” of each histogram is controlled by the assessment methodology, which is limited to accumulations larger than 50 million barrels of in-place oil or 250 billion cubic feet of technically recoverable natural gas.