Sedimentology, facies architecture, and reservoir characterization of lacustrine rocks, Eocene Green River and Colton formations, Uinta Basin, Utah

Outcrop and petrographic studies of the Eocene Green River and Colton formations in the Uinta basin, Utah, document the facies architecture and internal heterogeneity characteristic of lacustrine reservoirs. A southwest-northeast transect of Eocene strata in the Uinta basin records three depositional environments: fluvial, deltaic, and wave-dominated. Heterogeneity exists between and within individual depositional systems.; Outcrops of fluvial and deltaic origin are dominated by complex facies architecture and large-scale heterogeneity. In contrast, outcrops exposing wave-dominated lacustrine rocks exhibit less complex facies architecture and are dominated by small-scale heterogeneity. Geological field data collected in this study were utilized in geostatistical and flow models in an attempt to document the effects of reservoir heterogeneity on hydrocarbon exploration and production efficiency in lacustrine basins.