Assessment of Geological Carbon Storage Capacity in the Cambrian Mt Simon Sandstone; Regional Assessment to Site Characterization and Feasibility, an Example from the Michigan Basin

David A. Barnes¹ and Diana H. Bacon^2
1MGRRE/Western Michigan University, Kalamazoo, MI, 49008
²Battelle Pacific Northwest Division, Richland, WA

Geological carbon storage (GCS) capacity in the Michigan basin, in excess of 86 billion metric tons of CO₂, was reported in the DOE/NETL Carbon Sequestration Atlas of the US and Canada (CSAUS&C). Investigations were undertaken to refine estimates in the Cambrian Mt Simon Sandstone and establish the feasibility of GCS for a large, stationary emissions source, although capture facilities are not now in place. The Mt Simon may have little effective porosity in the central basin below approximately 1.8 to 2.0km due to diagenetic alteration. Lateral and vertical facies changes in the basin also result in substantial variation in fundamental rock properties and petrophysics. Using methodology modified from the CSAUS&C, estimates of storage capacity of the Mt. Simon Sandstone in Ottawa Co. are between 5000 and 14000 metric tons per acre. Numerical simulations of CO₂ injection were conducted using the STOMP-CO₂ simulator to assess the potential for geologic sequestration at maximum theoretical injection rates. Injecting CO₂ for 4 years at a rate limited by a fracture pressure gradient of 0.8 psi/ft results in injection rates that vary between 16 and 29 MMT/yr. After 4 years, the total amount of CO₂ injected is 102.7 MMT, with 99 MMT as supercritical CO₂ and 3.7 MMT dissolved into the brine. After 4 years of injection, the maximum radius of the supercritical CO₂ is 3 km and injection pressures at the bottom of the caprock (Eau Claire Formation) are below the fracture pressure limit. Although these results suggest that the Mt. Simon has the capacity to accept the large volume, CO₂ output of a typical coal-fired power plant in a small number of injection wells, further sensitivity analysis and field validation will be needed before such high injection potential can be verified.

Presented AAPG Eastern Section Meeting, Pittsburgh, Pennsylvania 2008 © AAPG Eastern Section