Arizona Geological Society: Arizona’s Deep Subsurface – Exploring Energy Resiliency through Gas Storage, Mineral-Sequestration, and Geothermal Resources

The U.S. and other countries are making major investments to evaluate the deep-subsurface for storage and energy options to meet growing demands for clean and alternative energy, energy resiliency, and management of energy-related wastes. In Arizona, deep, subsurface geology has excellent potential to accommodate the energy transition through salt cavern gas storage, energy byproduct disposal and sequestration, and enhanced geothermal energy.

Forty-seven percent of Arizona’s energy comes from natural gas, with the remainder divided between nuclear (27%), solar & wind (11%), coal (10%), and hydroelectric (5%). Arizona’s major power utility companies are committed to providing 100% clean and carbon-free energy by 2050. Thus, Arizona must diversify its energy supply, transport, and storage options, while managing emissions through storage and utilization safely and with minimal risks.

Arizona Geological Survey’s Basin Analysis research team manages subsurface datasets, provides data to the public; conducts basin-scale research; develops basin models; and collaborates with stakeholders, industry, and neighboring states to advance our understanding of subsurface resources and data deficiencies. In this presentation, we highlight recent and ongoing projects aimed at evaluating primarily subsurface geology in the state, including regional-scale carbon management through utilization and storage, research in bedded salt deposits for different types of gas storage, carbon dioxide mineralization in mafic rocks, 3D basin modeling, and basin characterization through new acquisition of geophysics and stratigraphic test well drilling.  Education and outreach to Arizona’s stakeholders, public, regulatory agencies, and industry are critical to these efforts.

Exploration, research, and collaboration are key to evaluating subsurface energy and storage options at the local and regional scale. A single sedimentary basin or subbasin can provide one or more options, including but not limited to: deep-enhanced geothermal energy in dry basement rocks, gas storage in bedded salt deposits, pore space and alkaline rocks for carbon dioxide sequestration and mineralization in hypersaline aquifers, and pore space for saltwater and produced water disposal. As part of the energy transition over the next 20 to 30 years, we anticipate regional and site-scale research and collaboration to identify resources in the deep subsurface through drilling, geophysics, risk assessment, and stakeholder engagement.

Presented by

Tawnya Wilson and Brian Gootee

Arizona Geological Survey