Basin-wide Correlation of Petroleum Plays and Subplays in the Green River Petroleum System, Uinta Basin, Utah

Morgan, Craig and Kevin McClure
Utah Geological Survey, Salt Lake City, UT

The Utah Geological Survey is conducting basin-wide chronostratigraphic correlation of petroleum plays and subplays within the Green River petroleum system in the Uinta Basin, northeast Utah. The Eocene Green River Formation, a highly oil-productive formation, consists of open- and marginal-lacustrine rocks deposited in and around Lake Uinta. Plays and subplays are stratigraphic intervals within the U.S Geological Survey’s Green River assessment units that consist of one or more potential reservoir beds having similar depositional history, petrology, and diagenesis. The play and subplay intervals are bounded by key marker beds identified on geophysical well logs that can be correlated basin-wide. The marker beds represent time lines allowing the chronostratigraphic correlation of very different reservoir rocks deposited in or near different parts of Lake Uinta. For example, reservoir rocks in the greater Monument Butte field area were deposited in the southern part of Lake Uinta at the same time that lithologically different reservoir rocks were being deposited in the Altamont-Bluebell fields and Red Wash field in the northern part of the lake. Although reservoirs of similar age in different parts of the basin have very different characteristics, they were influenced by similar conditions such as rapid lake-level fluctuations, stable lake conditions with minor lake-level fluctuations, or tectonism. Once the plays and subplays have been delineated, we will identify and describe a type field and outcrop analog for each play and subplay.