LEASES · O-1-21224 · OIL · DISTRICT 01
Barnhart (Ef)-J.M. Preston SA4
ReportingMarathon Oil EF LLC · Gonzales County · Eagleville (Eagle Ford-1) field
Barnhart (EF)-J.M. Preston Sa4 is an RRC oil lease (O-1-21224) in Gonzales County operated by Marathon Oil EF LLC, with one well completed on it.
It has reported 340K barrels of oil and 227K mcf of gas since October 2023, last reporting volume in April 2026 (statewide data runs through April 2026).
The last 12 reported months total 53.8K barrels of oil, down 54% on the year before; the lease peaked at 46.6K barrels in November 2023.
- 340K
- bbl oil, all reported
- 227K
- mcf gas incl. casinghead
- 53.8K
- bbl oil, last 12 reported
- -54%
- vs the 12 before
- 1
- wells completed on it
- 46.6K
- peak month, bbl (Nov 2023)
PDQ LEASE REPORTS · FIRST OCT 2023 · LAST VOLUME APR 2026 · STATEWIDE DATA THROUGH APR 2026
Oil by month
Barrels reported on Form PR for the whole lease. The latest months are revised upward as late reports arrive.
Last 12 months 53,841 · prior 12 116,062(-54%)
Gas by month
Gas-well gas plus casinghead gas, mcf. On an oil lease all gas is reported as casinghead. The latest months are revised upward as late reports arrive.
Last 12 months 40,540 · prior 12 83,067(-51%)
Decline curve
A MODEL FITTED TO THE REPORTS, NOT A REPORT
An Arps hyperbolic curve fitted to the 30 reporting months of oil since the peak in Nov 2023. The dashed line below is that curve, drawn over the months it was fitted to and then 24 months past the last report; where it parts from the columns is where the model stops describing the lease. It describes the trend of past reports. It does not know about recompletions, shut-ins, or new wells, and it is shown only when the lease reported within the last year and the curve explains most of the history.
- 81%
- first-year decline from the peak (nominal Di 183%)
- 0.1
- b factor (hyperbolic)
- 0.85
- fit R²
- 9.95K
- bbl remaining on the curve, to 1 per month
Oil, barrels reported months since the peak, with the fitted curve and its projection
Last 12 months 53,841 · prior 12 116,062(-54%)
Fitted hyperbolic curve from the Nov 2023 peak, dashed 24 months past the last report
| Projected month | Oct 2026 | Apr 2027 | Oct 2027 | Apr 2028 |
|---|---|---|---|---|
| On the curve, bbl per month | 513 | 287 | 166 | 99 |
Quoting a projected figure as if it were reported would be wrong; the reported figures are the ones in the charts and the table view. How production is reported →
Who reported it
Each run of months one operator filed the production report, oldest first.
- Marathon Oil EF LLCOct 2023 → Jul 2026 · 34 mo
Wells on the lease
FROM COMPLETION REPORTS · PRODUCTION ABOVE IS THEIR TOTAL
About this data
Monthly oil, gas, and casinghead from the RRC PDQ production dump, which lags the reporting month by two to three months; figures shown through Apr 2026. Wells from completion reports; operator runs from who filed each month's report.
Developers: this page as JSON is GET /v1/data/leases/tx/o-1-21224, documented in the API reference.