The Characterization and Carbon Storage Potential of the Paleozoic Ketona Dolomite of Central Alabama

Abstract

This study explores the viability of the Ketona Dolomite, a thick carbonate formation in central Alabama, as a potential reservoir for long-term CO₂ storage through its thorough petrological classification. A variety of analytical methods were employed to assess the formation’s mineral composition, texture, porosity, and reactivity. These include petrographic thin section analysis for structural and mineralogical interpretation, X-ray diffraction to determine bulk mineral composition, and scanning electron microscopy for high-resolution imaging of surface features and post-reaction textures. Controlled dissolution experiments using both hydrochloric acid and carbonic acid simulated fluid-rock interactions to evaluate reactivity and the potential for changes in porosity. Although the Ketona lies well below the depth reached by the well drilled at the location of interest, additional physical samples were collected from outcrops and well bore cuttings across Alabama to support laboratory testing and analysis. The absence of in situ sample material, temperature, and pressure conditions limit the application of resultant data however, the observed low porosities ranging from .07-3.3%, pure dolomitic composition comprising 82%-100% of lithic material, and moderate dissolutive behavior inform the provisional classification of the unit as an unsuitable reservoir and provide strong foundation for further reservoir modeling. The combination of field data, sample-based laboratory experiments, and high-resolution imaging provides a detailed picture of the Ketona Dolomite and its classification as a fine to coarse grained mostly clean fractured crystalline dolomite with minimal calcite & chert inclusions. These findings contribute to a broader understanding of carbonate reservoir dynamics and support ongoing efforts to identify and evaluate viable CCS targets in the southeastern United States.