Northeastern Arizona is underlain by the southwestern part of the Colorado Plateau, an area of gently dipping to slightly folded Paleozoic and Mesozoic strata that include porous and permeable sandstone units. Three Paleozoic sandstone units, the Cambrian Tapeats Sandstone, Devonian McCracken Sandstone, and Permian De Chelly Sandstone, were identified for study as potential targets for CO2 sequestration in order to reduce anthropogenic emissions to the atmosphere. Well logs for 755 drill holes were used to evaluate the extent, depth, and thickness of these sandstone units. Esri® ArcMap™ software was then used to calculate the volume of each sandstone unit where the top of each unit is below 800 m depth, which is the minimum necessary for CO2 sequestration so that the CO2 remains in a dense, near-liquid state. Well logs were used to evaluate porosity, which was then used to calculate effective porosity that is theoretically available for CO2 storage. We calculate that there are 9.7 km3 of effective pore space in the De Chelly Sandstone in Black Mesa basin, with 0.43 km3 and 0.72 km3 effective pore space in the Tapeats and McCracken sandstone units, respectively, in the same area. The total mass of CO2 that, potentially, could be stored in Colorado Plateau sandstone units is calculated at 8.28 billion metric tons. Qualitative information available from well logs suggests that the Tapeats and McCracken sandstones contain saline formation waters, but the character of formation waters in the De Chelly Sandstone remains poorly known.
Rauzi, S.L. and Spencer, J.E., An Evaluation of CO2 Sequestration Potential of Paleozoic Sandstone Units, Northeastern Arizona. Arizona Geological Survey Open File Report, OFR-12-10, 12 p.
The title was altered slightly on 27 June 2013; CO2 was changed to Carbon Dioxide to facilitate word searches.