West Ranch Field occupies the southwestern corner of Jackson County, Texas, on the coastal plain between Victoria and the bays. Magnolia Petroleum completed the discovery well of the main field in August 1938, and development followed across roughly ten thousand acres and nine producing zones, most of them Oligocene Frio sands. After a long mature phase, West Ranch became nationally known as the destination for carbon dioxide captured at a coal-fired power plant northwest of Houston, making it one of the most closely monitored enhanced recovery projects in the United States.
Source: Texas Railroad Commission production filings, aggregated across RRC field designations 96545691, 96545364, 96545351, 96545403, 96545520. Reported volumes lag the calendar by several months.
Magnolia Petroleum Company completed the West Ranch No. 3-A in August 1938, opening the main part of a field that would ultimately produce from nine separate zones. Development moved quickly along the Frio trend, and within four years several hundred wells were producing across about 10,400 acres. The principal reservoirs, known in field usage by their sand names including the 41-A, 98-A and Greta sands, sit around 5,000 to 6,000 feet and were prolific enough to support decades of production before secondary recovery became necessary.
Like most Gulf Coast Frio fields, West Ranch matured through water injection and infill drilling and settled into a long decline. Hilcorp Energy became the operator of the field areas in later years, and by the 2010s the remaining oil was largely residual saturation of the kind that only a miscible flood can move. That is what made West Ranch attractive as the receiving field for captured carbon dioxide, since the reservoirs were well characterized, the depth was suitable and the ownership was consolidated.
The Petra Nova project, a joint venture between NRG Energy and JX Nippon, captured carbon dioxide from a slipstream of flue gas at the W.A. Parish power station and moved it about eighty miles by pipeline to West Ranch for injection. Operations began in early 2017. NRG shut the capture facility down in May 2020 amid low oil prices and mechanical issues. JX Nippon acquired full ownership in 2022 and restarted the capture plant on September 5, 2023, resuming carbon dioxide supply to the field.
West Ranch produces from Oligocene Frio sandstones deposited as barrier-bar and shoreface sands along the ancient Gulf shoreline, the same Greta trend that produced Tom O’Connor to the southwest. Structure is a broad, faulted anticlinal nose rather than a piercement salt dome, and the field contains nine stacked producing zones at depths near 5,000 to 6,000 feet. The reservoir sands are porous, permeable and laterally extensive, with individual zones separated by shale seals that create distinct pressure compartments. That layered, well-sealed geometry made the field a good candidate for monitored carbon dioxide injection.
After primary depletion and waterflooding, West Ranch entered a tertiary phase using carbon dioxide delivered by pipeline from the Petra Nova capture facility. Injected CO2 becomes miscible with residual oil at reservoir conditions and mobilizes crude that water leaves behind, while a portion of the carbon dioxide remains stored in the formation and is tracked under a federal monitoring plan. The project ran from 2017 until it was idled in May 2020, and it resumed operation in September 2023 under new ownership. Tertiary volumes therefore reflect capture plant availability as much as reservoir behavior.
A West Ranch interest is a mature Frio royalty with an unusual tertiary overlay. When carbon dioxide is flowing, unit production can hold up; when the capture facility is down, as it was from 2020 into 2023, volumes fall back toward the waterflood baseline. Owners should expect variability rather than a smooth decline, and should value the tertiary component separately from the base production. At Pointer Minerals we buy minerals and royalties in Jackson County and provide free written offers.
County-level well data, production charts, and selling guides for the counties this field spans:
The carbon dioxide supply to the field came from a capture facility that was shut down in May 2020 and restarted in September 2023. When injection pauses, the tertiary production it supports declines, and unit royalty falls with it. Volumes typically improve again once injection resumes.
A nonoperating royalty owner does not operate the injection wells or hold the permits, and monitoring obligations rest with the project operator. That said, storage and pore space rights are an evolving area of Texas law, and it is worth having a landman or attorney review your instruments if you own the minerals outright.
Look at the base decline separately from the tertiary uplift, then ask what happens to each if carbon dioxide supply stops. A written offer should let you see those pieces. We provide ours in writing at no cost and will walk through the assumptions with you.