The Wasson Field, spanning Yoakum and Gaines counties on the Permian’s Northwest Shelf, is one of the largest oil fields in the United States — a San Andres giant discovered in the late 1930s that has produced well over two billion barrels. Its Denver Unit hosts one of the largest CO2 enhanced oil recovery projects in the world, and the field as a whole still reports close to fifteen million barrels of oil a year.
Source: Texas Railroad Commission production filings, aggregated across RRC field designations 95397001, 95431001. Reported volumes lag the calendar by several months.
Wasson was discovered in 1936-37 as the San Andres play swept across the Northwest Shelf, and development through the 1940s proved a single accumulation of enormous extent. Like most West Texas carbonate giants, primary recovery left the large majority of the oil behind, and the field was progressively unitized through mid-century so waterfloods could be engineered at scale — the Denver Unit, ODC Unit, Willard Unit, and Cornell Unit among them.
CO2 injection began in the Denver Unit in 1983 and grew into one of the flagship CO2 floods on earth, recovering hundreds of millions of barrels beyond what waterflooding could reach. Occidental Petroleum, the largest CO2 EOR operator in the Permian, has long been associated with the Denver Unit and the field’s other major floods.
Wasson’s scale keeps it central to the modern conversation as well: large, well-characterized CO2 floods like these are the foundation of the Permian’s carbon-management infrastructure, and decades of injection history make the field one of the most studied CO2 storage complexes anywhere.
Wasson produces from the Permian San Andres dolomite at roughly 5,000 feet, with secondary Clear Fork pays beneath. The San Andres here is thick and relatively continuous, which is what allowed floods the size of the Denver Unit (tens of thousands of acres under a single engineering program) to work. Shallow depth, moderate temperatures, and miscibility with CO2 at achievable pressures make it close to ideal EOR rock.
The Denver Unit CO2 flood is the reference project for large-scale miscible flooding: begun in 1983, it has added a recovery tail measured in decades and hundreds of millions of barrels. Purchased and recycled CO2 is injected in engineered patterns, mixes with residual oil, and drives it to producing wells; the CO2 itself is separated and reinjected in a closed loop that permanently stores a large fraction of every ton brought in. Royalty owners in the unit have effectively received a second field-life on top of the original waterflood.
Wasson-area royalty interests combine scale, operating history, and an operator class deeply committed to CO2 infrastructure — the production forecast behind a Denver Unit royalty has decades of flood data underneath it. Valuing that long tail correctly is exactly the kind of work we do: if you own minerals or royalties in Yoakum or Gaines County, unitized or not, we will price them directly with the flood’s history in the model, not a generic decline curve.
County-level well data, production charts, and selling guides for the counties this field spans:
The largest unit in the Wasson Field and one of the largest CO2 EOR projects in the world. CO2 injection began there in 1983 and continues today, recovering oil that the original waterflood left stranded in the San Andres dolomite.
Cumulative production is well over two billion barrels, and the field designations still report nearly fifteen million barrels a year to the Texas Railroad Commission — remarkable for a 1930s discovery.
The field’s CO2 floods already store most injected CO2 permanently as part of normal operations, and large Permian floods are increasingly integrated with carbon-management projects. For royalty owners the near-term effect is continuity: the same infrastructure that stores CO2 also sustains the oil production royalties are paid on.