The Postle field in Texas County, deep in the Oklahoma Panhandle about 120 miles north of Amarillo, is the state’s standout example of full-cycle recovery engineering. Discovered in 1958 and developed by Mobil in the early 1960s, its Morrow sands at roughly 6,100 feet were unitized for waterflood in 1967 and then converted to miscible CO2 flooding beginning in 1996 — a project that lifted field output from about 3,000 to more than 11,000 barrels a day within a few years. Postle remains one of the few active CO2 floods in Oklahoma.
Postle was discovered in 1958 on the Panhandle shelf of the Anadarko Basin, and the former Mobil Oil Corporation developed it through the early 1960s as a Morrow sandstone oil field — an oil accumulation in a region better known for the giant Guymon-Hugoton gas field that surrounds it. Mobil unitized Postle for waterflooding in 1967, organizing the field into injection units that would define its operations for the next half century.
The waterflood carried the field for three decades, but the transformative step came in 1996, when CO2 injection started in three units on roughly the eastern half of the field. The response was emphatic: output climbed by about 8,000 barrels a day, exceeding 11,000 barrels daily by 1999, and subsequent operators expanded the flood across additional units with fresh CO2 purchases and infill drilling. Pipeline-delivered CO2 made the Panhandle location workable, tying Postle into the regional CO2 infrastructure serving the Permian and mid-continent floods.
Postle also became a science bed: the Reservoir Characterization Project ran time-lapse multicomponent seismic surveys over the flood in the 2000s, using the field to test whether CO2 movement through Morrow sands could be tracked seismically — work that fed both EOR practice and carbon-storage research. Operatorship has changed hands over the years, but the flood itself has remained the field’s engine, with cumulative recovery on the order of 130 million barrels.
Postle produces from upper Morrow sandstones of Pennsylvanian age at about 6,100 feet — fluvial and valley-fill sands encased in shale on the northwestern shelf of the Anadarko Basin. The sands are discontinuous and channelized, which makes reservoir mapping the central engineering challenge: injected water or CO2 follows the sand fairways, and sweep efficiency depends on knowing exactly where they run. That geometry is why the field rewarded decades of characterization work, from Mobil’s unit mapping to modern time-lapse seismic monitoring of the CO2 flood.
Postle is Oklahoma’s flagship CO2 story. Miscible CO2 injection, begun in 1996 after nearly thirty years of waterflooding, mixes with the Morrow oil and strips it from pore space water cannot reach; the field’s output roughly tripled within three years of startup. Operated as a water-alternating-gas flood with purchased, pipeline-delivered CO2, the project has sustained meaningful production decades past the field’s natural life. For royalty owners, that means checks backed by continuing injection investment — production that exists because an operator keeps buying CO2 to make it exist.
Postle-area royalties behave like utility income with commodity exposure: long-lived, flood-supported production whose pace reflects CO2 purchase economics and operator investment rather than steep natural decline. Valuing such interests requires modeling the flood’s remaining performance — not applying shale-style decline curves, which badly misprice CO2-flood tails in both directions. We buy minerals and royalties in Texas County directly, and we provide free written offers that show how we model flood-supported production.
County-level well data, production charts, and selling guides for the counties this field spans:
CO2 flooding has been the field’s core recovery method since injection began in 1996, expanded across units by successive operators. As with any EOR project, injection pace varies with economics, but the flood is the reason Postle still produces at scale more than sixty years after discovery.
Your royalty is paid on production sold, and the flood is what sustains that production. How certain costs are treated depends on your lease language, so it is worth reviewing — but the dominant effect of CO2 at Postle has been decades of additional paying production that waterflooding alone would not have delivered.
Flood-supported production declines slowly and responds to injection investment, so its value sits in a long tail that simple decline-curve pricing understates. A method-aware buyer models the flood’s history and remaining response. Request a free written offer and we will walk you through exactly that analysis for your interest.