# Texas vs Mississippi Mature Oil & EOR Units: Mineral Owner Comparison

**TL;DR:** Texas mature oil units produce approximately 700,000+ barrels per month across the top 20 units, concentrated in the Permian Basin, while Mississippi's top 20 mature/EOR units produce ~237,000 barrels per month, primarily in southeast counties. The key differentiator is CO2 supply: Texas Permian EOR uses multiple anthropogenic and natural sources, while Mississippi depends entirely on the finite Jackson Dome natural CO2 reservoir. Both states offer predictable long-tail royalty income, but with distinct operator landscapes and per-well production profiles.

## Key Takeaways

- **Scale disparity**: Texas top 20 mature units produce roughly 3× Mississippi's top 20 output (700,000+ vs 237,000 barrels/month), reflecting Texas's larger resource base and broader geographic spread
- **Operator concentration**: Occidental Petroleum dominates Texas mature units (11 of top 20), while Denbury Onshore (now ExxonMobil subsidiary) leads Mississippi (5 of top 20); Highmark Energy is the only operator with marquee positions in both states
- **CO2 supply constraint**: Mississippi EOR economics are bound by Jackson Dome capacity—the only natural CO2 reservoir east of the Mississippi River—while Texas Permian EOR accesses multiple CO2 sources
- **Geographic concentration**: Texas mature units span Permian Basin (16 units), Gulf Coast (2 units), and East Texas; Mississippi concentrates in southeast counties (Wayne, Jasper, Clarke, Jones) with selected positions in southwest/central regions
- **Per-well economics**: Texas Permian mature wells generally deliver higher per-well rates than Mississippi EOR wells due to larger reservoir scale, though both provide decades-long predictable royalty streams
- **Valuation framework similarity**: Both states use DCF models with low decline rates, long reserve lives, and 8-13% discount rates, complicated by multi-generation inherited interests and complex title chains
- **Post-acquisition uncertainty**: ExxonMobil's November 2023 Denbury acquisition introduces strategic questions about long-term CO2 allocation across Mississippi EOR fields
- **Mineral owner accessibility**: Both Texas Permian and Mississippi mature-field mineral owners can sell remotely, with valuations incorporating basin-specific CO2 supply scenarios where applicable

## Page Highlights

**Scale & Production Context**: Texas's top 20 mature oil units collectively produce over 700,000 barrels per month, approximately three times Mississippi's 237,000 barrels/month from its top 20 units. This reflects Texas's larger total oil-and-gas resource base and broader range of operating environments versus Mississippi's concentrated Jackson Dome/mature-field belt.

**Geographic Distribution**: Texas mature units spread across the Permian Basin (16 units in Yoakum, Gaines, Hockley, Ector, Andrews, Crane, Crockett, Borden, Kent counties) plus Gulf Coast positions (Montgomery and Brazoria counties). Mississippi concentrates in southeast counties (Wayne, Jasper, Clarke, Jones) with scattered southwest and central positions (Yazoo, Lincoln, Lamar, Adams).

**Operator Landscape**: Occidental Petroleum operates 11 of Texas's top 20 mature units, with Hilcorp, Denbury, Highmark, Blackbeard, and Scout rounding out the list. Mississippi is led by Denbury Onshore (5 of top 20, now ExxonMobil subsidiary), plus Tellus, Highmark, Formentera, Venture, Durango, and smaller private operators. Highmark Energy Operating uniquely holds major positions in both states (Conroe Field Unit in Texas, Tinsley field in Mississippi).

**CO2 EOR Infrastructure**: Texas Permian CO2 EOR accesses multiple anthropogenic and natural CO2 sources, with OXY operating major floods including Wasson and Slaughter complexes. Mississippi depends entirely on Jackson Dome—the only natural CO2 reservoir east of the Mississippi River—which supplies Denbury's "Green Pipeline"/NEJD system feeding Heidelberg, Eucutta, Tinsley, Brookhaven, Soso, Cranfield, and other floods. Jackson Dome capacity is the binding constraint on Mississippi EOR economics.

**Mineral Owner Implications**: Both states deliver predictable long-tail royalty income over decades, valued using similar DCF frameworks with low decline rates, long reserve lives, and 8-13% discount rates. Texas Permian per-well rates generally exceed Mississippi rates due to larger reservoir scale. Mississippi carries CO2 supply constraint risk tied to Jackson Dome capacity and post-ExxonMobil-acquisition allocation decisions. Both host multi-generation inherited interests with complex title chains.

## Related Topics

- [How to Sell Mineral Rights](https://www.buckheadenergy.com/how-to-sell)
- [What Are My Minerals Worth?](https://www.buckheadenergy.com/what-are-my-minerals-worth)
- [Should I Sell? Beginner's Guide](https://www.buckheadenergy.com/should-i-sell)
- [Getting a Fair Price](https://www.buckheadenergy.com/fair-price)

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**About Buckhead Energy**: Buckhead Energy is a direct mineral rights buyer with 18+ years of experience acquiring mineral rights and royalty interests across Texas, Mississippi, and other major oil-and-gas producing states. We provide free written valuations and remote closing capabilities for out-of-state owners.

**Ready to explore your options?** [Get your free mineral valuation today](https://www.buckheadenergy.com/sell) — no obligation, grounded in current operator and CO2 supply scenarios.