Hydrocarbon Potential of the Upper Green River Petroleum System in the Uinta Basin, Utah: A Basin Modeling Approach

The Late Cretaceous Uinta Basin is a foreland basin located in northeastern Utah within the northern most portion of the Colorado Plateau. The basin's uplift and subsidence history and thermal evolution have impacted the maturity of source beds in the Parachute Creek Member. Sixty wells and three 2-D models generated from well logs are used in a basin modeling study of the Uinta Basin’s thermal structure, tectonic history, and petroleum system. These factors impact the maturation of source rocks within the Parachute Creek Member of the Green River Formation. All models were calibrated to measured data, including vitrinite reflectance and transformation ratios from Rock-Eval pyrolysis. The models predict that the heat flow ranges from 65 mW/m2 to 45 mW/m2 from south to north in the study area. Additionally, model calibration provides a means for estimating the amount of uplift and erosion in the Uinta Basin. For the three 2-D models, uplift and erosion predicted for the Uinta Basin ranges from 6700 ft to 7200 ft (2042 m to 2195 m). Based on the eroded thicknesses and heat flow values determined from calibration to measured thermal maturity indicators, the maturity of the rich oil shales of the Parachute Creek Member is inferred. Model predictions have suggested that source intervals of the Parachute Creek Member follow a general trend of increasing maturity from south to north in the study area. Local variations in predicted maturity that deviate from this trend most likely occur due to the effects of decreasing heat flow outpacing the effects of greater burial depths from south to north.