West Hastings Unit

The West Hastings Unit is a large-scale CO₂-enhanced oil recovery (CO₂-EOR) project located in the historic Hastings Oilfield in Brazoria and Galveston Counties, Texas, south of Houston. The field, discovered in 1934, produces from multiple Oligocene sandstone reservoirs within the Frio Formation associated with a salt-dome structural system. After decades of primary and waterflood production, Denbury initiated a major tertiary redevelopment using miscible CO₂ injection beginning around 2010–2012, supplied via the Gulf Coast CO₂ pipeline network (“Green Pipeline”). The project targets remaining oil in high-permeability stacked sands through continuous CO₂ injection and water-alternating-gas (WAG) processes, re-pressurizing the reservoir and improving sweep efficiency across multiple fault blocks and stratigraphic intervals. The West Hastings flood represents a large Gulf Coast CO₂-EOR redevelopment of a mature, water-drive sandstone reservoir, combining incremental oil recovery with significant subsurface CO₂ storage.