Regional Cross section beneath the Ohio River Valley for carbon storage evaluation
The Ohio River Valley is a major industrial and electric-generation corridor. A cross section using logs from 25 deep wells is constructed from western Kentucky eastward to Pittsburgh, Pennsylvania to illustrate the changing depths of potential carbon storage units and confining strata within the valley in the Midwest Regional Carbon Sequestration Partnership region. All stratigraphic units from the surface to basement are correlated. Intervals below 2,500 ft. depth are color coded as (1) regional saline aquifers, (2) potential local reservoirs within larger confining intervals, (3) confining intervals, and (4) organic-rich shales, which are confining intervals, but also have potential for enhanced gas recovery with CO2. The 2,500 ft depth approximates conditions at which injected CO2 would be in its supercritical state for optimal geologic storage and for miscibility if used for enhanced oil production. Immiscible CO2 could be used in some cases to repressure depleted reservoirs at shallower depths. The Ohio River cross section extends from the western margin of the Illinois Basin, across the Cincinnati Arch, eastward into the Appalachian Basin. Precambrian basement shallows from –7,000 ft (subsea) on the western edge of the section, to less than –3,000 ft on the Arch, to more than –14,000 ft north of Pittsburgh. The section includes four Class V CO2-test wells (Kentucky Geological Survey No. 1 Marvin Blan, Battelle No. 1 Duke Energy, AEP No. 1 Mountaineer, and First Energy Generation No. 1 FEGENCO), and two Class I wells previously drilled for underground waste injection. Carbon storage tests targeted the Mount Simon Sandstone where shallow on the Cincinnati Arch and the Gunter/New Richmond Sandstone, Rose Run Sandstone, and Copper Ridge Dolomite of the Knox Group in the basins. Additional local reservoirs occur in Silurian and Devonian limestones and sandstones in the Appalachian Basin. Parts of the Ohio, Rhinestreet, and Marcellus Shales might also be suitable to inject CO2 for enhanced gas recovery. Results from testing show large-volume storage is possible in certain units in some areas, but in other areas, stacked reservoirs or pipelines would be required. More analyses are needed to quantify actual reservoir characteristics away from the test wells for any of the potential reservoirs shown, but the section allows easy visualization of critical storage units, extent of confining intervals, and location of faults for future carbon storage planning.
AAPG Datapages/Search and Discovery Article #90335 © 2018 AAPG 47th Annual AAPG-SPE Eastern Section Joint Meeting, Pittsburgh, Pennsylvania, October 7-11, 2018