South Midland Facility

The Milestone Carbon Midland CCS Hub, South Midland Facility is a proposed UIC Class VI carbon storage project in Upton County, Texas, on the eastern Midland Basin (Permian). Operator Milestone Carbon Midland CCS Hub, LLC is seeking authorization for a single injection well, Midland CCS #2, to sequester CO₂ captured from nearby gas processing, power, cement, and potential DAC sources (~16.1 MMt/yr of emissions within 30 miles). The well is designed to inject 1 MMt of CO₂ per year (~54.5 MMSCF/day) over 12 years. Reservoir modeling shows ~223 Bcf (~11.8 Mt) cumulative injection, with the plume stabilizing at roughly an 11,800 ft radius 50 years after injection. Storage targets a stacked dual interval, the Siluro-Devonian and Ellenburger units, running from the top of the Devonian (~12,200 ft) down to 100 ft above Precambrian basement (~−11,052 ft TVD SS). The Ellenburger is a fractured, karst-modified dolomite; the Simpson Group acts as an internal baffle between the two units. Porosity is low (~1.5% Devonian, ~4% Ellenburger), with flow driven by fractures rather than matrix. The Woodford Shale is the primary top seal, backed by the Barnett, Atoka, Cisco, and Canyon shales as secondary seals, giving about 10,950 ft of confinement between the injection interval and the base of the USDW (~1,250 ft). No aquifer exemption is required.