West Ranch

The West Ranch CO₂ enhanced oil recovery (EOR) project is part of the Petra Nova carbon capture and storage initiative in Texas, integrating post-combustion carbon capture at NRG Energy’s W.A. Parish coal power plant with EOR operations at the West Ranch oil field in Jackson County. The capture facility uses amine-based technology to remove up to approximately 4,700 tonnes of CO₂ per day from a flue gas slipstream, which is then compressed and transported via an approximately 81-mile pipeline to the oil field for injection. CO₂ flooding began in December 2016, targeting depleted Oligocene-age reservoirs within the Frio Formation, primarily the 98-A and 41-A sands, with plans to expand into additional reservoirs including Greta, Glasscock, and Ward. The project is operated through partnerships between NRG Energy, JX Nippon, and Hilcorp, with Hilcorp managing field operations. Injected CO₂ supports tertiary oil recovery while enabling permanent geologic storage within structurally trapped reservoirs sealed by low-permeability layers including the Anahuac Shale. Monitoring, reporting, and verification procedures use mass balance accounting and risk-based monitoring to quantify stored CO₂ and evaluate potential leakage pathways. Between 2017 and 2020, approximately 3.6 million tonnes of CO₂ were delivered to the field, with roughly 3.56 million tonnes estimated as sequestered.