North Burbank

The North Burbank Unit (NBU) is a CO₂-enhanced oil recovery project located in Osage County, Oklahoma, near Shidler, within the Cherokee Platform of the Anadarko Basin region. Operated by Perdure Petroleum, the project injects CO₂ via Class II wells for miscible EOR, with retained CO₂ providing associated geologic sequestration monitored under EPA Subpart RR. CO₂ injection began in 2013 following earlier primary and secondary recovery phases, and operations are forecast to continue through at least 2060. The reservoir is the Burbank Sandstone, a Pennsylvanian-age fluvial-dominated deltaic (Class 1) system composed of overlapping channel sand bodies deposited along the margin of the Cherokee Sea. The field represents an updip pinch-out trap with heterogeneous lenticular sand bodies trending southeast–northwest. The reservoir lies at an average depth of approximately 2,900–3,000 ft, with average thickness of 45–60 ft, porosity of ~16.8–22%, and permeability ranging from ~32–313 mD. Structural dip is generally west-southwest, and regional geology shows no significant faults or fractures that would provide vertical leakage pathways. Development history includes initial discovery in 1920, followed by extensive primary production and long-term waterflooding using water curtain injection to control fluid migration. The Burbank Field contains approximately 824 million barrels OOIP, with about 39% recovered through primary and secondary operations prior to CO₂ flooding. Current operations employ a water-alternating-gas (WAG) injection strategy combined with water curtain injection along unit boundaries to maintain pressure and prevent lateral migration of CO₂ outside the flood area. As of the end of 2019, approximately 143.8 BCF (~7.58 million tonnes) of CO₂ had been injected, with a significant portion produced and recycled during operations. Forecast modeling indicates cumulative injection and storage of approximately 514 BCF (~27.11 million tonnes) over the life of the project, representing about 46.7% of theoretical storage capacity.