Regional Variability of Michigan Niagaran Reefs and the Impact on CO2 Storage Resources

Abstract

There are over 800 identified Silurian-aged (Niagaran) pinnacle reefs in the Northern Niagaran Pinnacle Reef Trend (NNPRT) of the Michigan Basin. These fields provide an opportunity to evaluate the geologic variability in complex carbonate reservoirs and its impact on carbon dioxide (CO2) storage configurations. Analyses of the reefs included: 1) geologic characterization using wireline logs, whole core, and production records; 2) assessment of enhanced oil recovery (EOR)/carbon capture, utilization, and storage (CCUS) feasibility and comparison between the reefs via simplified modeling; and 3) estimates of CO2 storage resources across the NNPRT. A comprehensive dataset collected on this project was used to identify trends in the NNPRT and to characterize variability while also providing a resource and guide for future CCUS activities. New methodologies and techniques were developed to analyze hundreds of fields. These methods include image analysis techniques to statistically derive porosity indicators and to quantify diagenetic features in whole core using computerized tomography (CT) scan data as well as petrophysical techniques for complex carbonates to identify reefs better suited for CCUS. Results from simplified modeling and storage resource calculations were used to rank the reefs by CCUS feasibility. Future geomechanical anayses will assess the effectiveness of CCUS in reefs.