Author: Craig D. Morgan

Publisher: Utah Geological Survey

Published: 2003

Total Pages: 105

ISBN-13: 155791690X

Hydrocarbon production in the Bluebell field is from three reservoirs in the Tertiary-aged Colton and Green River Formations: (1) overpressured Colton/Flagstaff, (2) lower Green River, and (3) upper Green River. Kerogen-rich shale and marlstone deposited in marginal and nearshore openlacustrine environments are the source of the waxy crude in the Colton/Flagstaff and lower Green River. Marlstone, or oil shale and possibly coal, are the sources for the asphaltic crude found in the upper Green River. Non-associated gas in the upper Green River could be from coaly deposits in the upper Green River, or migrated up from the lower Green River, or a combination of both. The lithology of all three reservoirs is similar; fractured sandstone, shale, limestone, and marlstone beds having generally low intergranular porosity and permeability. The strata were deposited in lacustrine and alluvial environments.