Reservoir Characterization and Petrofacies Model for the Devonian Grosmont and Upper Ireton Formations, Northeastern Alberta, Canada

摘要

The Devonian Grosmont and Upper Ireton formations are composed of dolomitized carbonates and shales respectively, and contain significant volumes of bitumen. To date, little work has been done to characterize the depositional facies and reservoir potential of these formations. The objectives of this study include the identification of depositional facies and associated karst overprint in the Grosmont and Upper Ireton formations and the determination of what (if any) control they may have on reservoir quality. All available core from the study area (approximately 4000 meters total within 83 wells) was described in detail and integrated with all associated digital core analysis porosity, permeability, and fluid saturation data. The Grosmont and Upper Ireton formations are composed of 10 depositional facies that accumulated within open marine subtidal to intertidal flat environments. Intertidal deposits are considered to have the most favorable reservoir quality owing to their highest overall porosity and associated storage capacity. Petrophysical transforms were developed that allow facies prediction at the 85% confidence level in wells that lack core control Petrophysical logs from all Upper Ireton and Grosmont wells across the study area (171 total wells) were correlated within a grid of 12 cross sections.