Abstract This study presents facies descriptions and interpretations of the Eocene Sunnyside delta interval of the Green River Formation in Nine Mile Canyon, Utah, to document and constrain reservoir architecture and heterogeneity in lacustrine strata. Detailed measurement of vertical outcrop sections, paleocurrent directions, lithologic descriptions, and facies mapping of photopanoramas and digital Light Detection and Ranging (LIDAR) data were completed to define and interpret stratigraphic architecture at centimeter to meter scales. Results favor a depositional setting that fluctuated among delta plain (overbank, distributary channel, and mouth bar), marginal lacustrine, shoal water, and offshore lacustrine deposits. These strata were deposited at a distributary-dominated shoal-water deltaic margin and form four pro-grading parasequences that coarsen upward over the approximately 150 m (492 ft) thick study package. Measured channel dimensions and calculated sinuosities indicate a meandering fluvial system, and channel deposits include isolated lenticular, amalgamated lenticular, and amalgamated undulatory sandstones. Along with distributary mouth bar deposits, these channelized sandstone bodies represent the most promising reservoir units based on their lateral continuity and stacking geometries (ranging from ~40- to 115-m [~130- to 377-ft] wide × 4- to 6.5-m [13- to 20-ft] thick), as well as measured porosityand permeability relationships. Quantified dimensions of sandstone bodies and characterization of their lateral and vertical connectivity are significantly aided by a digital outcrop model. This model was generated by ground-based LIDAR, and results were exported as spatial and geologic constraints for geocellular modeling. Such quantitative outcrop-based modeling provides guidelines for predicting sub-surface reservoir quality and dimensions,and may be extrapolated to analogous fluviodeltaic and lacustrine hydrocarbon prospects.

Abstract This chapter presents three groups of reservoir simulation models that address aspects of fluid flow in deltaic systems of lacustrine basins. These models are based on companion field-based geologic investigations of the Eocene Green River Formation in Nine Mile Canyon of the Uinta Basin, Utah ( Taylor and Ritts, 2004 ; Moore et al., 2012 ). The first group consists of models based on two-dimensional (2-D) geologic descriptions of outcrops in Parley Canyon ( Taylor and Ritts, 2004 ). These descriptions, combined with petrophysical data from measured sections to produce a three-dimensional (3-D) model based on one-dimensional (1-D) and 2-D data. Because results of the first simulation models demonstrated the importance of channels in the plumbing of such lacustrine deltaic systems, a second group of simulation models was constructed to address the impact of heterogeneity within individual channels on flow across and along channels. The data used to generate these channel models are entirely synthetic, although the geometries involved were digitized from sketches drawn by a geologist and guided by relationships observed in the Uinta Basin study area. The third group of models represents the northwest Argyle Canyon area and, unlike the Parley Canyon model, was constructed from a third geologic data set that was produced by integrating light detection and ranging (LIDAR) scanning and correlation with geologic description of multiple cliff outcrops of varying orientation in the field ( Moore et al., 2012 ). Together, these models demonstrate dominant characteristics that control production efficiency of reservoirs in lacustrine deltaic settings and also demonstrate how improving geologic characterization improves the 3-D modeling of such systems.