THE POTENTIAL FOR DEEP CO2 STORAGE ALONG THE OHIO RIVER INDUSTRIAL CORRIDOR

The Midwest Regional Carbon Sequestration Partnership covers 10 states, which vary in geology and stratigraphic nomenclature. In order to visualize the changing subsurface stratigraphy of the region, multiple cross sections were constructed. One of these follows the important industrial corridor of the Ohio River. The section extends from the eastern margin of the Illinois Basin to the Appalachian Basin and the Allegheny Front, northeast of Pittsburgh, Pa. Subsurface units in the section are color-coded based on a unit’s potential as a (1) storage interval (regional saline reservoir), (2) confining interval with local potential reservoirs, (3) confining zone, or (4) organic-rich shale. Units are also color-coded at depths greater than 2,600 ft, which is the approximate depth needed for CO₂ to be in a dense supercritical phase for storage. The cross section is based on 25 deep wells with the best downhole geophysical logs to illustrate the depth to potential carbon-storage intervals along the section. Four of these are CO₂-injection test wells and two are Class 1 waste-injection wells, so significant data are available to characterize subsurface reservoirs and confining zones along the section.

Precambrian basement shallows from –7,000 ft subsea on the western end of the cross section to less than –2,000 ft subsea on the Cincinnati Arch to nearly –15,000 ft subsea in the Appalachian Basin. Cambrian Knox carbonates and sandstones were primary test horizons in several CO₂ wells in both basins. The Cambrian Mount Simon Sandstone was the primary injection zone of the Battelle No. 1 Duke Energy well in northern Kentucky, southwest of Cincinnati on the Cincinnati Arch, where the Knox shallows to less than 2,600 ft depth. Eastward in the Appalachian Basin, where Cambrian and Ordovician horizons are more than 10,000 ft beneath the surface, shallower reservoirs in the Silurian Clinton-Medina Group and Devonian Oriskany Sandstone might be considered for future storage. Known Silurian through Mississippian oil and gas reservoirs may have potential for using CO₂ in enhanced recovery applications. Likewise, the Ordovician Utica Shale and Devonian Ohio Shale are being investigated for their potential use in CO₂-enhanced gas recovery with ultimate storage.