Historic Oil Field
The North Robertson Unit in Gaines County, Texas is one of the Permian Basin’s benchmark Clear Fork CO2 floods — a shallow-shelf carbonate reservoir that produced modestly under primary and waterflood recovery, then earned a second life through unitization and CO2 injection. The Robertson (Clear Fork) field it sits in still reports well over a million barrels of oil a year, decades after conventional wisdom would have retired it.
Source: Texas Railroad Commission production filings, aggregated across RRC field designations 77318666, 77318900. Reported volumes lag the calendar by several months.
The Robertson field was found in 1949 as operators stepped out across the Northern Shelf of the Midland Basin, proving oil in the low-permeability Clear Fork and Glorieta carbonates that blanket Gaines County. Primary recovery in these "tight" carbonates was famously poor — single-digit percentages of the oil in place — which made the area an early candidate for waterflooding in the decades that followed.
The North Robertson Unit was formed in 1987, consolidating thousands of acres so that infill drilling and flood patterns could be engineered as one project. CO2 injection followed in the 1990s using water-alternating-gas (WAG) cycles, and the unit became a frequently cited case study in Society of Petroleum Engineers literature for how to make CO2 flooding work in a heterogeneous, lower-quality shelf carbonate rather than a premium reef.
Successive operators have continued to develop the flood since, and the broader Robertson (Clear Fork) field remains one of the more productive legacy assets in a county better known today for its San Andres horizontal redevelopment plays.
The unit produces from the Permian-age Clear Fork and Glorieta dolomites at roughly 6,000 to 7,200 feet — thick but low-permeability shelf carbonates whose oil does not flow easily to wellbores. That rock quality is precisely why EOR matters here: without injection support, wells decline quickly and strand the great majority of the oil in place. The play’s heterogeneity rewards dense well spacing and carefully managed injection patterns.
North Robertson’s water-alternating-gas CO2 flood alternates slugs of CO2 and water to control the gas’s tendency to finger through the rock, improving how much of the reservoir each injected ton actually sweeps. It is a working demonstration that CO2 EOR is not just for elite reservoirs like SACROC’s Canyon Reef — engineered patiently, it revives ordinary shelf carbonates too. For royalty owners that has meant a production plateau, and royalty stream, measured in additional decades.
Gaines County minerals carry a double story: legacy Clear Fork flood production like North Robertson, plus the modern San Andres horizontal redevelopment happening across the county. An interest under or near the unit can have value from both. We buy Gaines County minerals and royalties directly — unitized flood interests included — and will show you exactly how we weigh long-tail flood production against nearby redevelopment upside in a written offer.
County-level well data, production charts, and selling guides for the counties this field spans:
An EOR technique that alternates injections of CO2 and water. The CO2 mixes with stranded oil and mobilizes it; the alternating water slugs keep the CO2 from channeling straight to producing wells, so more of the reservoir gets swept. North Robertson is one of the Permian’s reference examples in shelf carbonates.
Yes — the Robertson (Clear Fork) field designations covering the unit still report more than 1.5 million barrels of oil a year to the Texas Railroad Commission, supported by the CO2 flood.
Yes. Unitized interests pay on a tract-participation formula rather than a single lease, which changes the math but not the marketability. Send us a division order or check stub and we will price the interest as it actually pays.