Chester21-29N-02W Storage Facility

The Chester 21-29N-02W Storage Facility, operated by Riverside Energy Michigan, LLC, is a dedicated CO₂ geologic storage project located in Otsego County, Michigan, within the Northern Niagaran Pinnacle Reef Trend (NNPRT) of the Michigan Basin. Unlike many Midwestern projects, this is not an EOR flood; the explicit purpose is permanent disposal and sequestration of CO₂ captured from natural gas processing associated with the Antrim Shale biogenic gas play. Injected CO₂ will be transported approximately two miles from the Turtle Lake capture facility and injected via a permitted Class II injection well (Smith 3-21) into a depleted Silurian-age Niagaran pinnacle reef reservoir at depths of roughly 6,000–7,000 ft, where CO₂ exists in a dense gas phase. The reservoir consists of dolomitized reefal carbonates (Brown Niagaran and A1 Carbonate formations) with porosity averaging about 5.4% and localized higher-quality intervals associated with reef core facies. The reef is a laterally isolated buildup approximately 90 acres in extent and about 550 ft tall, encased by thick evaporite and carbonate sealing formations. The primary seal is the A2 Evaporite, overlain by more than 1,300 ft of evaporites and low-permeability strata of the Salina Group, providing strong vertical containment. The reef was discovered in 1970 and produced limited oil and gas before depletion and abandonment, leaving available pore space for storage.