LEASES · O-10-44546 · OIL · DISTRICT 08
Calverley 4
ReportingCOG Operating LLC · Glasscock County · Spraberry (Trend Area) field
Calverley 4 is an RRC oil lease (O-10-44546) in Glasscock County operated by Cog Operating LLC, with 3 wells completed on it.
It has reported 71.2K barrels of oil and 428K mcf of gas since August 2013, last reporting volume in October 2025 (statewide data runs through April 2026).
The last 12 reported months total 552 barrels of oil, down 54% on the year before; the lease peaked at 3.06K barrels in May 2014.
3 operators have filed production on it, most recently Cog Operating LLC since August 2018.
- 71.2K
- bbl oil, all reported
- 428K
- mcf gas incl. casinghead
- 552
- bbl oil, last 12 reported
- -54%
- vs the 12 before
- 3
- wells completed on it
- 3.06K
- peak month, bbl (May 2014)
PDQ LEASE REPORTS · FIRST AUG 2013 · LAST VOLUME OCT 2025 · 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 552 · prior 12 1,213(-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 6,891 · prior 12 15,407(-55%)
Decline curve
A MODEL FITTED TO THE REPORTS, NOT A REPORT
An Arps hyperbolic curve fitted to the 103 reporting months of oil since the peak in Feb 2017. 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.
- 48%
- first-year decline from the peak (nominal Di 84%)
- 0.7
- b factor (hyperbolic)
- 0.75
- fit R²
- 9.54K
- 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 552 · prior 12 1,213(-54%)
Fitted hyperbolic curve from the Feb 2017 peak, dashed 24 months past the last report
| Projected month | Oct 2026 | Apr 2027 | Oct 2027 | Apr 2028 |
|---|---|---|---|---|
| On the curve, bbl per month | 56 | 53 | 50 | 47 |
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.
- Adventure Expl Partners II, LLCAug 2013 → Aug 2014 · 13 mo
- RSP Permian, LLCSep 2014 → Jul 2018 · 47 mo
- COG Operating LLCAug 2018 → Jul 2026 · 96 mo
Wells on the lease
FROM COMPLETION REPORTS · PRODUCTION ABOVE IS THEIR TOTAL
3
wells completed on the lease
- Shut IN
- 1
- Plugged
- 1
- NO Type on File
- 1
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-10-44546, documented in the API reference.