Assessment of Undiscovered Oil and Gas Resources of the Uinta-Piceance Province of

Colorado and Utah

By

M.A. Kirschbaum, R.C. Johnson, S.B. Roberts, M. Henry, T.M. Finn, E.A. Johnson, R.F. Dubiel, L. Anna, R.R. Charpentier, T.S. Collett, T. Cook, R.R. Crovelli, R.D. Hettinger, T.R. Klett, P.G. Lillis, P.H. Nelson, V.F. Nuccio, C.A. Rice, L.N. Roberts, C.J. Schenk, and J.W. Schmoker

U.S. Geological Survey, Denver, CO

The U.S. Geological Survey (USGS) recently completed an assessment of the undiscovered oil and gas potential of the Uinta-Piceance Province of northwestern Colorado and northeastern Utah. The assessment of the Uinta-Piceance Province is geology based and uses the Total Petroleum System concept. The geologic elements of Total Petroleum Systems include hydrocarbon source rocks (source rock maturation, hydrocarbon generation and migration), reservoir rocks (sequence stratigraphy, petrophysical properties), and hydrocarbon traps (trap formation and timing). Using this geologic framework, the USGS defined five Total Petroleum Systems and 20 Assessment Units within these Total Petroleum Systems, and quantitatively estimated the undiscovered oil and gas resources within each Assessment Unit. The USGS assessed undiscovered conventional oil and gas and continuous (unconventional) oil and gas, including coal-bed gas. The USGS estimated a mean of 21 trillion cubic feet of gas (TCFG), a mean of 60 million barrels of oil (MMBO), and a mean of 43 million barrels of natural gas liquids (MMBNGL) in five Total Petroleum Systems. Nearly all of the undiscovered gas resource is continuous (unconventional). Of the 21 TCFG, 13 TCFG is estimated to be in the Mesaverde Total Petroleum System and 7 TCFG is estimated to be in the Mancos/Mowry Total Petroleum System. The Phosphoria and Green River Total Petroleum Systems contain the balance of the undiscovered continuous gas resource. The Ferron/Wasatch Plateau Total Petroleum System and Mesaverde Total Petroleum System are estimated to contain a mean of 2.3 TCF of coal-bed gas.

AAPG Search and Discovery Article #90004©2002 AAPG Rocky Mountain Section, Laramie, Wyoming