The McElroy Field in Crane and Upton counties, Texas is one of the Permian Basin’s original giants — a shallow Grayburg dolomite reservoir opened by the J.T. McElroy No. 1 in July 1926 and still pumping a full century later. More than 1,800 wells have been drilled across the field, which sits on the eastern edge of the Central Basin Platform and has produced hundreds of millions of barrels. For mineral owners, McElroy is the textbook case of a waterflood-supported royalty stream that has outlived every prediction of its decline, which makes careful valuation essential before any sale.
Source: Texas Railroad Commission production filings, aggregated across RRC field designations 59337001. Reported volumes lag the calendar by several months.
The field came in during the summer of 1926, when the J.T. McElroy No. 1 opened shallow Grayburg pay outside the townsite that became Crane. The discovery, drilled amid the same 1926 wave that produced Yates and Hendrick, turned Crane County from open ranchland into an oil economy almost overnight. Development spread north into Upton County through the late 1920s and 1930s, with dense drilling on the shallow, low-cost pay defining one of the largest contiguous oilfields on the Central Basin Platform.
Gulf Oil became the dominant developer, and the field was eventually organized into large operated units to support secondary recovery. Waterflooding began in the early 1960s and grew into one of the biggest injection operations in the Permian Basin, with operators refining patterns, infill spacing, and injection volumes over the following decades. Reservoir-management case studies of McElroy became standard reading in petroleum engineering precisely because the flood kept coaxing oil from rock that primary production had left behind.
Chevron, as Gulf’s corporate successor, ran McElroy for decades as a cornerstone conventional asset. In the mid-2020s the field transitioned to Dallas-based Scout Energy Partners, which has publicly discussed sustaining production through advanced recovery methods for decades to come. The field marked 100 years of continuous production in 2026 — a century of royalty checks flowing from the same rock, and a reminder that giant carbonate waterfloods retire slowly.
McElroy produces from the Grayburg dolomite and upper San Andres at depths of roughly 2,900 to 3,000 feet along the eastern margin of the Central Basin Platform. The reservoir formed as stacked, shallowing-upward carbonate cycles on a Permian shelf, leaving dolomitized intervals whose moderate permeability traps large volumes of oil in place. That rock character is why the field responded so well to waterflooding: enormous original oil in place, shallow drilling depths, and continuous pay across tens of thousands of acres reward patient, pattern-based injection rather than rapid depletion.
McElroy has been under waterflood since the early 1960s, and studies of the greater McElroy–Dune–Waddell trend estimate hundreds of millions of barrels of mobile oil still unrecovered along this stretch of the platform. Successive operators have re-engineered injection patterns, drilled infill wells, and tested enhanced-recovery concepts to chase that remaining oil. For royalty owners, the practical meaning is longevity: a flood-supported field with a stated operating horizon extending decades further is a long-duration income stream, not a played-out relic.
If you own minerals or royalties in the McElroy area, your interest sits in a field that has paid for a hundred years and is being managed for decades more. Flood-supported production declines gently, so valuations based on a few recent check stubs routinely understate what a century-old giant can still deliver. Understanding unit participation, injection activity, and remaining recovery matters before you consider selling. We buy minerals and royalties in Crane and Upton counties and provide free written offers.
County-level well data, production charts, and selling guides for the counties this field spans:
Yes. The field celebrated 100 years of continuous production in 2026, with more than 1,800 wells drilled since 1926 and an active waterflood sustaining output. Its current operator has publicly discussed keeping the field productive for decades to come.
The field was developed largely by Gulf Oil and then operated for decades by Chevron, Gulf’s successor. In the mid-2020s it transitioned to Scout Energy Partners, a Dallas-based operator that specializes in mature, long-life conventional assets.
Value rests on your decimal interest in the producing units, current production and pricing, and the shallow decline profile typical of mature waterfloods. Because flood-supported wells hold their rates for years, a fair offer should reflect long-term performance — request a free written offer to see the math.