“INTEGRATED CHARACTERIZATION AND MODELING WORKFLOWS FOR A DEPLETED RESERVOIR IN THE TRENTON-BLACK RIVER PLAY, SOUTHERN MICHIGAN, PART 1: RESERVOIR CHARACTERIZATION”

Ordovician aged carbonates of the Trenton and Black River Groups (TBR) are regionally significant hydrocarbon bearing formations in the Southern Michigan Basin, USA. Fields such as Albion-Scipio, Napoleon, and Stoney Point formed by wrench faulting along reactivated basement faults during the Taconic Orogeny. Hydrothermal fluids flowed up the faults and associated natural fractures and along stratigraphic high permeability zones, dolomitizing the rocks along the fluid flow pathways and forming sucrosic and vugular porosity. Oil and gas later migrated into the hydrothermally altered TBR reservoirs and today form primary target intervals for conventional hydrocarbon exploration.

As part of a United States Department of Energy (DOE) sponsored project evaluating Enhanced Oil recovery (EOR) in these hydrothermally altered carbonates, proprietary 3D seismic was acquired from a local operator to evaluate the structural and stratigraphic features that control the Lee 26 Field, a small producing field within the TBR trend. The data was imported into both Petrel^TM and Geographix^TM software, horizons and faults were interpreted across the seismic volume, and numerous seismic attributes were run on the 3D volume to evaluate which ones most closely tied to productive oil wells in the area. The resulting structural and stratigraphic interpretations were incorporated into a Static Earth Model (SEM) to help identify zones of dolomitization and associated high porosity. Results from the SEM were integrated into a Dynamic Reservoir Model (DRM) in the commercial black-oil simulator CMG-IMEX for history matching and stimulation forecasting.

Part 1 of this two-part talk reviews the reservoir characterization workflow conducted ahead of SEM and DRM efforts. The combined workflows are applicable to this specific DOE project ahead of EOR operations and results can be leveraged to improve resource recovery and inform CO₂ storage potential throughout the conventional TBR hydrocarbon play, as well as hydrothermal dolomite play fairways worldwide.