A Comparison of Resource Estimate Methodologies to Assess CO₂ Storage Capacity across the Northern Niagaran Pinnacle Reef Trend

Abstract

The Northern Niagaran Pinnacle Reef Trend (NNPRT) has over 800 identified Silurian-aged pinnacle reefs in the Michigan Basin. The reefs have a long history of oil and gas production, gas storage, and more recently successful CO₂-EOR operations. These fields provide an excellent opportunity to evaluate the geologic variability in complex carbonate reservoirs and its impact on carbon capture utilization and storage (CCUS) feasibility. Because the reefs are individual, compartmentalized reservoirs which have variable reservoir characteristics from reef to reef, traditional methodologies cannot easily be applied to estimate CO₂ storage capacity. Novel methodologies and techniques were developed to analyze hundreds of fields for CO₂ storage and enhanced oil recovery options. Multiple scenarios were explored to fully utilize the NNPRT, including (1) CO₂ storage without EOR, (2) CO₂-EOR, and (3) CO₂-EOR with enhanced storage. This included a regional static earth model to compute volumetric based resource estimates, fluid substitution to estimate storage resources from oil and gas production, proximity analysis based weighting of reefs to predict reservoir performance metrics and estimate enhanced oil recovery, and finally an enhanced storage scenario of maximizing a reefs storage potential at the end of a CO₂-EOR life cycle. Under scenario 1, more than 230 million MT of CO₂ storage is possible, with 73 million MT in oil reefs and 160+ million MT in gas reefs. Scenario 2 explored traditional CO₂-EOR, which would store 49 million MT at the end of the life cycle. Finally, scenario 3 would consider repressurizing a reef following CO₂-EOR to maximize CO₂ storage, resulting in nearly 250 million MT of possible storage. The results of the study compared different calculation approaches and ranges of potential resource estimates for the entire NNPRT. The study is part of the Midwestern Regional Carbon Sequestration Partnership (MRCSP) Michigan Basin Large-Scale Injection Project under DOE/NETL Cooperative Agreement # DE-FC26-0NT42589 with co-funding by Core Energy, LLC, and several other partners.

AAPG Datapages/Search and Discovery Article #90373 © 2019 AAPG Eastern Section Meeting, Energy from the Heartland, Columbus, Ohio, October 12-16, 2019