LEASES · O-1-16060 · OIL · DISTRICT 01
Mark & Sandra Unit
ReportingAtlas Operating LLC · Zavala County · Briscoe Ranch (Eagleford) field
Mark & Sandra Unit is an RRC oil lease (O-1-16060) in Zavala County operated by Atlas Operating LLC, with 2 wells completed on it.
It has reported 272K barrels of oil and 64K mcf of gas since June 2012, last reporting volume in March 2026 (statewide data runs through April 2026).
The last 12 reported months total 4.18K barrels of oil, down 39% on the year before; the lease peaked at 11.1K barrels in August 2012.
5 operators have filed production on it, most recently Atlas Operating LLC since April 2021.
- 272K
- bbl oil, all reported
- 64K
- mcf gas incl. casinghead
- 4.18K
- bbl oil, last 12 reported
- -39%
- vs the 12 before
- 2
- wells completed on it
- 11.1K
- peak month, bbl (Aug 2012)
PDQ LEASE REPORTS · FIRST JUN 2012 · LAST VOLUME MAR 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 4,181 · prior 12 6,905(-39%)
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 0 · prior 12 0
Decline curve
A MODEL FITTED TO THE REPORTS, NOT A REPORT
An Arps exponential curve fitted to the 118 reporting months of oil since the peak in Jun 2016. 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.
- 11%
- first-year decline from the peak (nominal Di 11%)
- 0.0
- b factor (exponential)
- 0.74
- fit R²
- 46.1K
- 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 4,181 · prior 12 6,905(-39%)
Fitted exponential curve from the Jun 2016 peak, dashed 24 months past the last report
| Projected month | Oct 2026 | Apr 2027 | Oct 2027 | Apr 2028 |
|---|---|---|---|---|
| On the curve, bbl per month | 419 | 395 | 373 | 352 |
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.
- Sanchez Oil & Gas CorporationJun 2012 → Apr 2014 · 23 mo
- SN Operating, LLCMay 2014 → Oct 2016 · 30 mo
- Sanchez Oil & Gas CorporationNov 2016 → Dec 2020 · 50 mo
- Catarina Midstream, LLCJan 2021 → Mar 2021 · 3 mo
- Atlas Operating LLCApr 2021 → Jul 2026 · 64 mo
Wells on the lease
FROM COMPLETION REPORTS · PRODUCTION ABOVE IS THEIR TOTAL
2
wells completed on the lease
- Producing
- 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-1-16060, documented in the API reference.