The Illinois Basin–Decatur Project (IBDP) site, located at the Archer Daniels Midland Corn Processing Plant in Decatur, Illinois, is part of the Midwest Geological Sequestration Consortium’s effort to demonstrate large-scale carbon capture and storage (CCS). The Cambrian Mt. Simon Sandstone, which this project injects into, is a brine-saturated sandstone reservoir that underlies a large part of the Midwestern United States and is a primary target for CCS in the region. To determine basic rock properties, including permeability, a commercial laboratory analyzed whole core samples from Verification Well #1 (VW#1), a 7,272 ft (2,216.5 m) deep IBDP monitoring well in the Mt. Simon Sandstone. Whole core analysis yielded numerous examples of vertical permeability (kv) larger than horizontal permeability (kh) by several orders of magnitude. Generally, permeability of geologic formations is anisotropic (higher kh than kv) because of depositional effects and the in-situ stress field in the crust. Porosity and permeability were measured on core plugs as a means of verifying and improving whole core data for IBDP reservoir models. Anomalous permeability data was most pronounced in the lower Mt. Simon Sandstone, which is a poorly sorted, course-grained sandstone to pebble conglomerate. To compare horizontal and vertical plug and whole core permeability, the selection of core plug sample depths included those depths with anomalous and normal whole core kv/kh values. Horizontally and vertically oriented core plugs from each sample depth revealed kh values generally greater than whole core kh (average relative difference of 75%), indicating a suppression of the original whole core kh values. Three main lithologic groups occur (fine- to course-grained, poorly to well sorted, and sandstone to conglomerate) in the core plugs; these groups were used to select data to fit transform equations to correct the whole core horizontal permeability data. Correlation between the permeability results of the core plug analysis and lithology indicated that whole core values less than 10 millidarcies (md) (9.87*10-15 m2) or kv/kh values less than 0.25 did not need a correction.
- Illinois Basin - Decatur Project