Texas vs Mississippi Mature Oil Units: A Mineral Owner's Comparison

Scale

Texas's top 20 mature oil units collectively produce approximately 700,000+ barrels per month. Mississippi's top 20 mature/EOR units produce approximately 237,000 barrels per month — about one-third the size of the Texas total. The difference reflects (1) the much larger total Texas oil-and-gas resource base, and (2) the broader range of Texas operating environments (Permian Basin shelves + Texas Gulf Coast + East Texas) compared with Mississippi's concentrated Jackson Dome / mature-field belt.

For per-unit comparisons, see our Top 20 Texas Oil Units 2026 hub or browse the individual Mississippi unit pages.

Geographic Profile

Texas: top 20 spread across Permian Basin (16 units in Yoakum, Gaines, Hockley, Ector, Andrews, Crane, Crockett, Borden, Kent counties) plus Texas Gulf Coast (2 units in Montgomery and Brazoria counties)

Mississippi: top 20 concentrated in southeast Mississippi (Wayne, Jasper, Clarke, Jones counties dominate) plus selected positions across southwest and central Mississippi (Yazoo, Lincoln, Lamar, Adams)

Operator Landscape

Texas: dominated by Occidental Petroleum (OXY) — 11 of the top 20 — plus Hilcorp, Denbury, Highmark, Blackbeard, Scout, and several long-tenured private operators

Mississippi: dominated by Denbury Onshore — 5 of the top 20 — plus Tellus, Highmark, Formentera, Venture, Durango, and several smaller private operators

Both states have significant ExxonMobil exposure: OXY's Permian portfolio carries the Texas concentration, and ExxonMobil's November 2023 acquisition of Denbury made the Mississippi portfolio an ExxonMobil subsidiary. Highmark Energy Operating is the only operator that runs marquee positions in BOTH states (Conroe Field Unit in Texas's Montgomery County and Tinsley field in Mississippi's Yazoo County).

CO2 EOR Profile

Texas: Permian Basin CO2 EOR is supplied by multiple anthropogenic and natural CO2 sources; OXY operates several major Permian CO2 floods including the Wasson and Slaughter complexes; CO2 supply is generally adequate

Mississippi: Jackson Dome — the only natural CO2 reservoir east of the Mississippi River — supplies the Denbury "Green Pipeline" / NEJD CO2 pipeline system that feeds Heidelberg, Eucutta, Tinsley, Brookhaven, Soso, Cranfield, and other CO2 floods. Jackson Dome CO2 supply is the binding economic constraint on Mississippi EOR economics.

Mineral Owner Implications

Mineral interests on both Texas and Mississippi mature units typically deliver predictable long-tail royalty income for many decades. The valuation framework is similar (DCF with low decline rates, long reserve lives, and 8-13% discount rates). Key differences:

Texas Permian per-well rates are generally higher than Mississippi mature/EOR per-well rates due to larger Permian reservoir scale

Mississippi CO2 EOR fields have CO2 supply constraint risk — Jackson Dome capacity is finite and post-Exxon-acquisition strategy decisions could affect long-term CO2 allocation

Both states host multi-generation inherited interests with complex chains of title

Get a Free Valuation in Either State

Buckhead Energy buys mineral rights and royalty interests across both Texas and Mississippi mature-field positions.