GUAJILLO UNIT 13 SOUTH
GUAJILLO UNIT 13 SOUTH is a Texas oil lease in Atascosa County, Railroad Commission district 01, operated by Marathon Oil Ef LLC. It has 4 wellbores on file with the Commission. Reported production runs from July 2021 to August 2026, totalling 753,375 barrels. The lease is currently producing. Fitting a decline curve to that history and pricing the remaining production at today's forward curve values the whole lease — a 100% undivided interest — at about $6.1M, with roughly $2.5M expected over the next twelve months. An individual royalty owner receives their own decimal interest times that figure. Over the last twelve months on file it averaged 4,369 barrels a month, about 1,092 per wellbore. Its strongest month on the record we hold was November 2021, at 87,947 barrels. In our own backtest, leases producing at this rate are forecast to within about 17% of what they went on to produce, and that measured error is the range shown on the page rather than a confidence of our own devising.
Key facts about GUAJILLO UNIT 13 SOUTH
- Who operates GUAJILLO UNIT 13 SOUTH?
- GUAJILLO UNIT 13 SOUTH is operated by Marathon Oil Ef LLC, Railroad Commission of Texas operator number 525398.
- Where is GUAJILLO UNIT 13 SOUTH?
- GUAJILLO UNIT 13 SOUTH is a Texas oil lease in Atascosa County, Texas, in Railroad Commission district 01. Its Railroad Commission lease number is 20460.
- Is GUAJILLO UNIT 13 SOUTH still producing?
- GUAJILLO UNIT 13 SOUTH is currently producing. The most recent month of production reported to the Railroad Commission of Texas for GUAJILLO UNIT 13 SOUTH is August 2026.
- How much has GUAJILLO UNIT 13 SOUTH produced?
- GUAJILLO UNIT 13 SOUTH has reported 753,375 barrels of oil (bbl) to the Railroad Commission of Texas between July 2021 and August 2026, from 4 wellbores.
- How much is GUAJILLO UNIT 13 SOUTH worth?
- The remaining production from GUAJILLO UNIT 13 SOUTH is estimated to be worth about $6.1M in total as of 27 August 2026, within a range of $5.0M to $7.1M. That figure is the whole lease, undivided — not any one owner's share. A royalty interest in GUAJILLO UNIT 13 SOUTH is a fraction of it. The estimate fits an Arps decline curve to the production GUAJILLO UNIT 13 SOUTH has already reported, prices the remaining production at the current forward strip, and discounts it at 12% a year. The figure shown for GUAJILLO UNIT 13 SOUTH is an estimate of value, not an offer and not an appraisal.
- How much income does GUAJILLO UNIT 13 SOUTH generate in a year?
- GUAJILLO UNIT 13 SOUTH is forecast to net about $2.5M across the whole undivided lease over the twelve months following 27 August 2026, before income tax. A royalty owner in GUAJILLO UNIT 13 SOUTH receives a fraction of that, set by the decimal interest printed on their check stub.
Lease record
| Operator | Marathon Oil Ef LLC |
|---|---|
| Field | Eagleville (Eagle Ford-1) |
| County | Atascosa County, Texas |
| RRC district | 01 |
| Lease number | 20460 |
| Wellbores | 4 |
| Reported production | 753,375 bbl |
| First reported | |
| Last reported | |
| Estimated royalty value | $6.1M |
Where GUAJILLO UNIT 13 SOUTH sits
Source: Railroad Commission of Texas lease production records, complete through . Figures on this page were computed on .
Production figures are as reported to the Railroad Commission of Texas. The value shown is an estimate produced by fitting a decline curve to that reported history; it is not an offer or an appraisal. How this estimate is calculated.