(685c) Evaluating the Feasibility and Scale of Geologic CO2 Storage Potential in Ohio’s Appalachian Region

Authors: 
Ravi Ganesh, P. - Presenter, Battelle Memorial Institute
Haagsma, A., Battelle Memorial Institute
Fukai, I., Battelle Memorial Institute
Main, J., Battelle Memorial Institute
Scharenberg, M., Battelle Memorial Institute
Gupta, N., Battelle
Evaluating the feasibility and scale of geologic CO2 storage potential in Ohioâ??s Appalachian Region

Priya Ravi Ganesh*, Autumn Haagsma, Glenn Larsen, Isis Fukai, Joel Main, Mackenzie Scharenberg, Neeraj Gupta

Battelle, Columbus, OH

Around the world, various industrial-scale carbon dioxide (CO2) geologic storage (GS) demonstration projects have been or are being conducted in deep saline formations. To fully tap into the overall potential of CO2 GS resources, comprehensive research focusing on the detailed geologic characterization of potential regions, such as the Appalachian Basin in the Midwestern United States, needs to be completed. The project described here is part of a long-term program to investigate CO2 GS potential in Ohio and adjacent areas. Here, we apply an integrated multi-scale approach to evaluate the possible implications of basin-scale pressure buildup on storage capacity estimation. The reservoir analysis task is divided into two main efforts: (1) Static capacity assessment to help provide regional estimates as well as specific site estimates for selected saline storage site(s) and (2) Dynamic capacity and injectivity assessments of selected saline storage site(s) as illustrative examples for the evaluation of injectivity and capacity from the study area. The static and dynamic estimates for CO2 storage shall be compared to highlight the effects of dynamic operational constraints such as rates, well locations, etc. typical of realistic CO2GS site conditions.

Our study region consists of ~61,000 sq.km of complex geology in eastern Ohio, with a primary emphasis on the strata that underlie the Lower Ordovician Knox unconformity erosional surface. These strata are the Beekmantown dolomite through the Mt. Simon/basal sandstone where many of these deeper porous layers contain highly saline brines that have remained isolated from shallower zones. Key inputs to this feasibility study draw from the geologic characterization and fracture gradient assessment activities in the study area done as part of other tasks in this project. The static resource capacity estimation shall be determined with considerations for the total storage efficiency of CO2 in these modeled saline formations. The potential storage sites determined from the geologic characterization exercise shall be evaluated to understand dynamic CO2 GS performance metrics of interest, namely, injectivity, pressure buildup and spatial distribution of injected CO2volume through time.

This study aims to help evaluate the feasibility and scale of CO2 GS in regions in Ohio with respect to performance metrics of storage capacity and CO2 injectivity. We work to evaluate different scales such as the regional or formation scale, plume or site-scale, as well as local-scale or near-well effects of CO2 injection. This multi-scale study considers different resolution of input detail such as porosity and permeability distributions and uses key performance metrics, such distribution of injected CO2 and pressure, to provide insights into acceptable site spacing, pressure buildup and CO2plume distribution.

At the formation or regional level, we begin by mapping static storage resource estimates for each formation to create a roadmap to CO2 GS in eastern Ohio. CO2 GS resource is defined as the mass estimate of CO2 that can be stored in a given geologic formation. We use different levels of data resolution for input formation properties (e.g., porosity and thickness) for this exercise. These range from the knowledge of average formation properties to the availability of the spatial distribution of these properties. Results show that, in descending order, the Mt. Simon/ basal sandstone, Kerbel sandstone, and Rose Run sandstone have the highest specific CO2GS resource capacities. We investigate the subsurface dynamics by considering multiple simultaneous operational storage sites scenarios in selected study areas with high storage potential for these formations. The dynamic numerical modeling scenarios that consider multiple operational sites in a given formation or region shall provide in insights into acceptable site spacing from the extent of the pressure front to minimize pressure interference between sites.

The study areas for CO2 GS in Cambrian formations in the eastern Ohio study area were determined from the formation maps created for the study area. Locations where the petrophysical indicators for storativity (porosity-feet) and transmissivity (permeability-feet) highs overlap are considered for further detailed study for CO2 storage with dynamic assessment. The top three sandstone units identified from the static storage resource estimation exercise have been analyzed to identify â??sweet spotsâ??. At the plume or local-scale examination for a given formation, these individual sites shall be modeled with possible CO2 injection well patterns simulated. The results from this exercise test the effect of pressure buildup and potential interference issues (well spacing), as well as tracking the injected CO2plume extent.

On a finer scale, a single well at the center of the possible well patterns for each site in a given formation are simulated for 30 years of CO2injection, followed by 50 years of post-injection monitoring, to get insights into local-scale near-wellbore dynamics. These simplified well models with equivalent average site properties in radial configurations are being tested to help with preliminary sensitivity analysis to relate to monitoring aspects during injection operations. This exercise establishes sensitivity to well configurations, relative permeability etc. representative of local-site conditions in the chosen detailed study site(s).

The integration of results from these different scales are expected to bring together insights into the practical feasibility of commercial CO2 GS storage in our study region. Our study aims to provide insight into the CO2 GS potential for deep saline formations in eastern Ohio while reflecting the effects of dynamic operational constraints typical of realistic CO2GS site conditions in the study region.

This work was supported by the Ohio Development Services Agency OCDO Grant OOE-CDO-D-13-22 and the U.S. Department of Energy through the Midwest Regional Carbon Sequestration Partnership award number DE-FC26-05NT42589. In-kind contributions and well access was provided by a number of well operators in the region.