ASSESSING THE STATEWIDE CARBON SEQUESTRATION POTENTIAL IN INDIANA

Over the last 20 years, the Indiana Geological and Water Survey (IGWS) has participated in several multi-state research consortia to study the high-level potential to sequester CO₂ in underground saline reservoirs. Outside of the petroliferous Devonian – Mississippian intervals of the Illinois Basin and the Ordovician Trenton field of east-central Indiana, many subsurface reservoirs of Indiana are saline-filled. These deep (>2,500 ft) sandstone and dolomitic intervals provide a unique opportunity for potential carbon sequestration in the state.

According to the Environmental Protection Agency’s 2021 Facility Level Information on Greenhouse Gases Tool (FLIGHT), Indiana ranks No. 3 in the United States, behind Texas and Louisiana, in CO₂e (carbon dioxide equivalent) emissions from stationary sources. The convergence of significant CO₂e emissions in the state, abundant deep saline reservoirs, low structural complexity in many areas of the state, and thick sequences of caprocks, makes Indiana a prime candidate for exploring subsurface carbon sequestration opportunities.

Many aspects of the potential geologic sequestration in Indiana are yet to be understood. Mineralogy data from the most suitable geologic formations – key for creating robust petrophysical models of the reservoir and caprocks – are lacking. Regional understanding of the diagenetic history and porosity distribution also needs improvement to calculate the storage available in these reservoirs reliably. In addition, fluid-rock interactions need to be evaluated because they play a big role within the reservoir and in interactions with the caprock.

The U.S. Department of Energy recently awarded the IGWS a multi-year grant to work on these aspects and collaborate with other Indiana University departments to understand the human impact of geologic sequestration. The expected outcome of this work is a better understanding of the subsurface capacity for carbon storage and identifying the most promising areas for geologic sequestration in Indiana. Collaborative efforts like this grant will encompass surface, subsurface, and societal aspects to plan for potential geologic sequestration development in the state.