LEASES · O-10-53693 · OIL · DISTRICT 08
Rio San Marcos 36-45 Unit 1A
ReportingDiamondback E&P LLC · Midland County · Spraberry (Trend Area) R 40 Exc field
Rio San Marcos 36-45 Unit 1a is an RRC oil lease (O-10-53693) in Midland County operated by Diamondback E&P LLC, with 5 wells completed on it.
It has reported 1.25M barrels of oil and 4.25M mcf of gas since February 2020, last reporting volume in April 2026 (statewide data runs through April 2026).
The last 12 reported months total 73.3K barrels of oil, down 12% on the year before; the lease peaked at 51.8K barrels in April 2020.
2 operators have filed production on it, most recently Diamondback E&P LLC since January 2025.
- 1.25M
- bbl oil, all reported
- 4.25M
- mcf gas incl. casinghead
- 73.3K
- bbl oil, last 12 reported
- -12%
- vs the 12 before
- 5
- wells completed on it
- 51.8K
- peak month, bbl (Apr 2020)
PDQ LEASE REPORTS · FIRST FEB 2020 · 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 73,252 · prior 12 83,627(-12%)
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 832,959 · prior 12 681,394(+22%)
Decline curve
A MODEL FITTED TO THE REPORTS, NOT A REPORT
An Arps hyperbolic curve fitted to the 73 reporting months of oil since the peak in Apr 2020. 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.
- 43%
- first-year decline from the peak (nominal Di 61%)
- 0.3
- b factor (hyperbolic)
- 0.93
- fit R²
- 236K
- 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 73,252 · prior 12 83,627(-12%)
Fitted hyperbolic curve from the Apr 2020 peak, dashed 24 months past the last report
| Projected month | Oct 2026 | Apr 2027 | Oct 2027 | Apr 2028 |
|---|---|---|---|---|
| On the curve, bbl per month | 3,536 | 3,086 | 2,708 | 2,388 |
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.
- Endeavor Energy Resources L.P.Feb 2020 → Dec 2024 · 59 mo
- Diamondback E&P LLCJan 2025 → Jul 2026 · 19 mo
Wells on the lease
FROM COMPLETION REPORTS · PRODUCTION ABOVE IS THEIR TOTAL
5
wells completed on the lease
- Producing
- 3
- Shut IN
- 2
Operates them now
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-10-53693, documented in the API reference.