Beneath Utah’s Surface: Harnessing Geologic Carbon Storage for a Sustainable Future
by Gabriela St. Pierre, Ph.D
The project team at our kickoff meeting in April 2024. The team consists of an interdisciplinary mix of geologists from the UGS, subsurface geology experts from the University of Utah Geology and Geophysics Department and Energy and Geoscience Institute, and environmental justice experts from the University of Utah Anthropology and Sociology Departments.
In early 2024, the Utah Geological Survey (UGS) was awarded a $1.1 million cooperative agreement from the U.S. Department of Energy (DOE) Office of Fossil Energy & Carbon Management to study geologic carbon storage in Utah. So, what is carbon storage and what does it mean for Utah and its residents? Geologic carbon storage, a crucial component of Carbon Capture, Utilization, and Storage (CCUS; see Survey Notes, v. 54, no. 2), offers a promising solution to the challenge of reducing CO2 emissions worldwide. Carbon dioxide [CO2] emissions can be captured at a source (i.e., from industrial, manufacturing, and energy generation processes) and then either used in a commercial product or injected underground for permanent storage. This innovative approach not only promises to mitigate environmental impacts by reducing greenhouse gases, but also holds the potential to transform Utah’s energy landscape. The goal of our project is to provide a detailed assessment of the geologic carbon storage resources available in Utah and make this information available in a web application that can be used by industry, government officials, and the public.
Project Overview
Utah has a variety of rock formations that may be suitable for long-term carbon storage. The UGS has partnered with the University of Utah Energy & Geoscience Institute and Department of Geology & Geophysics to research and assess potential geologic storage sites in the state. Our study will begin by compiling geologic data about Utah’s rock reservoirs (i.e., porous rock formations such as sandstones) and their associated sealing formations (i.e., impermeable rocks such as mudstones that can “trap” liquid CO2 and other fluids) into a geodatabase while also identifying regions with data gaps. Once all relevant data are collected, the project team will examine the carbon storage potential by “geo-region,” or areas of the state with similar geologic histories and structural styles (e.g., southern Basin and Range, Uinta Basin, etc.). This research will also draw on findings and data from over two decades of carbon storage projects in Utah, including a newly funded Carbon-SAFE Phase II project in the Uinta Basin (see all UGS CCUS projects at geology.utah.gov/energy-minerals/ccus).
Risk maps consider geologic parameters around geologic rock reservoirs and their associated seals. This map of southwest Utah shows a hypothetical risk map of the Navajo Sandstone in the Escalante Desert and is an example of the kind of map that will be displayed in the web application along with its associated metadata available for download.
Within the geo-regions that are determined to be best suited for geologic carbon storage, the project team will complete a more detailed analysis of key reservoir and seal pairs. These reservoir and seal pairs will be ranked by “geologic risk” to identify specific areas that are highly favorable for carbon storage. “Geologic risks” can include less-favorable factors, such as whether a rock reservoir has low porosity but high permeability (a higher risk reservoir because there is little pore space to hold carbon, and stored CO2 may quickly leak out); and whether faults create pathways within a sealing rock that may cause the CO2 to leak back to the surface (also high risk). Reservoirs with high carbon storage potential could include rocks like basalt, sandstones deposited in river or near-shore environments, eolian (wind-blown) sandstones, and limestones. Areas that have the greatest number of low-risk reservoirs and seals will be ranked as being highly favorable for carbon storage activities. The project team will also identify areas that need more geologic information to understand the reservoir quality and/or seal leakage risk and will fill in data gaps by analyzing rock samples from outcrops and rock core samples housed within the Utah Core Research Center.
The final product will be a publicly accessible interactive website application and database that allows users to visualize and download the UGS carbon storage assessments and their associated geological metadata. The website application will be a useful tool for everyone to learn more about CCUS opportunities in the state, and the detailed geologic information will provide a bank of reliable data to assist scientists, businesses, and government agencies seeking to research and potentially build regional carbon management hubs.
“Geo-regions” and CO2 emissions by energy sector (emissions data from EPA 2022). The geo-regions represent areas in Utah with similar geologic histories, basin histories, and/or structural styles and each will be evaluated for carbon storage potential. The largest CO2 emitters in Utah are coal and natural gas power plants, which tend to be concentrated along the Wasatch Front and in Emery County. With the increase in subsidies from the Inflation Reduction Act 45Q tax credits, nearly all CO2-emitting facilities qualify for 45Q tax credits in Utah.
Where would the CO2 come from?
Understanding where sources of CO2 are, and how far they are from possible geologic storage sites, is key to understanding the economic viability of future CCUS in Utah. So where would CO2 in Utah come from? In general, three types of CO2 sources are targeted for sequestration: 1) industrial facilities, 2) energy facilities, and 3) direct air capture. Existing facilities such as power plants, chemical plants or refineries, and materials processing plants are considered point sources of emissions because they emit a relatively dense volume of CO2 into the atmosphere at a single location. These facilities could be retrofitted with carbon capture technology to gather CO2 for transportation and storage in nearby underground rock reservoirs. Currently, most Utah industrial and energy facilities qualify for significant 45Q tax credits (see Survey Notes v. 55, no. 1) based on 2022 EPA greenhouse gas emissions data.
CO2 can also be removed from the atmosphere through a new technology called direct air capture (DAC). Although this is an energy-intensive process, the advantage of DAC is that it can be placed anywhere, such as directly over ideal subsurface storage reservoirs, which lessens the need for transporting CO2 over long distances. Additionally, DAC technology could be powered by carbon-free energy sources such as solar, wind, or geothermal, making it a potential carbon neutral technology.
Involving the Utah Community
An integral part of this project’s mission is to engage with people who may be impacted by future CCUS development in Utah. As part of this project, the UGS is collaborating with the Anthropology and Sociology Departments at the University of Utah, who will lead outreach efforts including assessing potential environmental justice issues as well as opportunities for economic progress in communities impacted by carbon storage development. Project tasks will include surveying communities that may be impacted by CCUS projects, planning educational events, and publishing in accessible peer-reviewed journals. The proposed community engagement plan aims to address the needs of stakeholders across the state and to understand how future CCUS projects may play a role in the anticipated economic advancement of Utah.
Looking Forward
CCUS has the potential to fit in well with Utah’s current energy landscape. By completing this study, the UGS and its partners will provide a detailed assessment of the geologic factors that affect carbon storage resources in the state and help reduce the risks and uncertainties of subsurface carbon storage. Looking to the future, this project could help Utah meet national decarbonization goals by facilitating low-risk, economic, commercial-scale CCUS projects and highlighting opportunities for economic revitalization and job creation in Utah communities.
