In recent years, the production of anthropogenic carbon dioxide (CO₂) and its potential impact on the global atmospheric carbon budget, and ultimately global climate change, has become a topic of worldwide concern. Carbon sequestration has been proposed as a means of reducing CO₂ emissions by capturing, separating, and storing or reusing large volumes of CO₂ produced by coal-fired power plants and refineries. As part of an effort to identify potential sites for geologic carbon sequestration, the Indiana Geological Survey is evaluating the sequestration potential of several conventional and unconventional geologic reservoirs. This research is part of a larger project, MIDCARB (Mid-continent Interactive Digital Carbon Atlas and Relational DataBase), which was created under the support of U.S. Department of Energy to integrate natural resources databases from five states in the mid-continent region of the United States into a geographic information system (GIS).

Deep saline aquifers are considered important potential CO₂ sinks because many are large, generally contiguous reservoirs and may be capable of storing large volumes of carbon dioxide. In Indiana, the Silurian/Devonian aquifer system is one such candidate for carbon sequestration. This system encompasses the carbonate units of the Bainbridge, New Harmony, and Muscatatuck Groups.

To evaluate the carbon sequestration potential of the Silurian/Devonian aquifer system, information from oil/gas well records including geophysical logs, core analyses, sample descriptions, and brine chemistry data were integrated in a database and analyzed using a GIS. The GIS was used to automate production of a variety of maps (structure, thickness, net porosity, and net permeability), which characterize the aquifer. In addition, data in the GIS were used to calculate hydrostatic potentials and to create a generalized ground-water flow map.