Storage Resource Estimates and Seal Evaluation of Cambrian-Ordovician Units in the MRCSP Region

Abstract

To evaluate the carbon storage potential of the Midwest Regional Carbon Sequestration Partnership (MRCSP) region, petrophysical analyses of Cambrian-Ordovician strata were conducted, resulting in new estimates of the reservoir targets for carbon storage and the effectiveness of overlying units to serve as seals. The carbon storage resource estimates (SRE) were evaluated using a hierarchy of methods that resulted in different SRE values based on a series of increasingly complex portrayals of the pore system. The simplest analysis follows the United States Department of Energy (USDOE) methodology, whereby a SRE is calculated using a single ‘best estimate’ of the average porosity of the assessed formations. Additional estimates employ variable porosity models based on a depth-based diagenesis function and effective porosity values derived from geophysical logs. Results from this approach not only illuminate the magnitude of uncertainty that should be expected in SREs as a function of data availability, but also suggest a high potential for storage in deeper Cambrian-Ordovician units. Capillary pressure data from mercury porosimetry (MICP) were used to evaluate the seal capacity of the Upper Ordovician Maquoketa Group and equivalent units. Geophysical logs (gamma-ray, density, and neutron porosity logs) from multiple well locations in the MRCSP region were used to develop a lithofacies model consisting of five units, revealing a high degree of regional variability within the Maquoketa Group. The distribution of clay-rich lithofacies defines areas having higher potential for effective confinement. Further characterization of porosity, permeability, and the micro- and meso-pore size distribution from MICP suggest high sealing and capillary trapping potential of the Maquoketa Group. The research was performed under the MRCSP program led by Battelle and funded under USDOE/NETL Cooperative Agreement # DE-FC26-0NT42589.

AAPG Datapages/Search and Discovery Article #90335 © 2018 AAPG 47th Annual AAPG-SPE Eastern Section Joint Meeting, Pittsburgh, Pennsylvania, October 7-11, 2018