ENERGY & MINERALS

CCUS Project

Basin Analysis and Reservoir Characterization for Geologic Carbon (CO2) Sequestration Associated with a Direct Reduced Iron Plant, Iron County, Utah

Funded by the U.S. Department of Energy (Award DE-FE0031837), the goal of this work in Iron County, Utah, is to develop a detailed geological assessment of the feasibility to sequester carbon in geologic strata beneath the site of a proposed direct reduced iron (DRI) processing plant that is projected to emit upwards of 0.5 million tons of CO2 annually. In partnership with the Energy & Geoscience Institute (EGI) and Utah Iron, LLC, the Utah Geological Survey (UGS) is conducting rigorous site characterization (Phase 1) to assess the CO2 sequestration potential of subsurface geologic strata near the proposed plant to accommodate its carbon-rich byproducts on a commercial scale. Key contributors from the UGS include Mr. Michael Vanden Berg (UGS Energy & Minerals Program Manager), Dr. Eugene Szymanski (Geologic Characterization Project Lead), Dr. Julia Mulhern (CUSP Regional Characterization Lead), and Dr. Elliot Jagniecki (Seismic Data Interpretation and Petrography Specialist). Although more work needs to be conducted, preliminary calculations indicate that current reservoir targets can store industrial volumes of CO2, and saline water geochemical models yield encouraging results.

Project Overview

The Iron Springs district in southwest Utah is one of the largest iron producing regions in the western United States. A local mine recently proposed building a direct reduced iron plant to optimize their operations and increase the domestic supply of steel. We are conducting rigorous site characterization to assesses the CO2 sequestration potential of subsurface geologic strata near the proposed plant to accommodate carbon-rich byproducts on a commercial scale. The region possesses world-class reservoir/seal packages at depths suitable for CO2 storage and lacks evidence of an active petroleum system which lowers the risk of occluded pore space and overpressure, but considerable geologic uncertainty remains due to complex and poorly constrained subsurface conditions. Our characterization approach leverages new and existing geological and geophysical data for analysis of CO2 storage capacity, reservoir and seal quality, and drilling hazards. Primary injection targets lie within eolian sequences of the Jurassic Navajo Sandstone (ɸ: ≤15%; μ: ≤156 mD), overlain by stacked confining units that include anhydrite-carbonate beds in the Temple Cap Fm. (Manganese Wash Mbr.) and gypsiferous shale and limestone of the Carmel Fm. (Co-Op Creek Mbr.), which itself was intruded by the Three Peaks quartz monzonite. Locally, the Navajo Sandstone lies entirely in the subsurface and few well penetrations provide only cutting samples. Preliminary thin section petrography work on cuttings from the ARCO Three Peaks #1 well reveals a range of lithofacies and fabrics that appear promising for CO2 injection and storage. Reservoir analog data from nearby outcrop locations at Parowan Gap and Thunderbird Gardens exhibit different structural and depositional realms but rock mechanics and petrographic data from these locations provide potential end-member values for reducing reservoir quality uncertainties in our risk assessment. Attribute analysis of reprocessed 2D seismic data indicates laterally continuous subsurface reflectors and viable structural, stratigraphic, and volcano-stratigraphic trap styles, suggesting favorable reservoir / seal presence and continuity. A new gravity survey reveals an igneous intrusion sealing unit with greater volume and more complex geometry than previously identified. Each of these data inputs will be combined into a geomodel to simulate flow and CO2 storage potential. Preliminary calculations indicate that current reservoir targets can store industrial volumes of CO2 and saline water geochemical models yield encouraging results to greenlight eventual CO2 injection. This study highlights how integrated basin analysis and reservoir characterization can provide key inputs for site selection and facility design, a first step on the path toward onsite CO2 sequestration on new build industrial projects.

Contact

For more information contact Michael Vanden Berg, 801-538-5419; michaelvandenberg@utah.gov