The calculation of Estimated Ultimate Recovery (EUR) from oil and gas production data of individual wells and the development of EUR distributions from all producing wells in an assessment unit are important steps in the quantitative assessment of continuous-type hydrocarbon resources. The U.S. Geological Survey has developed a method of calculating EURs for wells in continuous-type accumulations, including coal-bed gas accumulations. The EUR distribution of producing wells is used as a guide for the estimation of an EUR distribution for potential wells in areas of undiscovered resources. (C) 2003 Elsevier B.V. All rights reserved.