Abstract

Hydrocarbons are produced from the Eocene-aged Lower Green River Formation in the Monument Butte area of central Uinta Basin, Duchesne and Uintah Counties, Utah. Secondary recovery (water flooding) has greatly increased the production rate and estimated ultimate oil recovery for the area. The productive beds are sandstone in the Garden Gulch, Douglas Creek, and Castle Peak members of the Green River Formation which can be correlated from one to several square miles. The sandstone beds occur within transgressive-regressive depositional cycles that can be correlated over a much larger area. Typically, three to five sandstone beds are flooded in an individual unit. Many of these beds are interpreted as fluvial-deltaic distributary mouth bars and channels.

Development drilling in the Monument Butte area has greatly increased the understanding of the complex reservoirs of the Lower Green River Formation in the central Uinta Basin. As a result the water-flood technology continues to improve and its use is expanding to other parts of the Monument Butte area. The improved reservoir characterization and economic success of the Monument Butte area should encourage new exploration throughout the central Uinta Basin.