LEASES · O-1-7875 · OIL · DISTRICT 01
Sun Mark Exploration
ReportingCastillo Oil Company LLC · Caldwell County · Salt Flat, West field
Sun Mark Exploration is an RRC oil lease (O-1-7875) in Caldwell County operated by Castillo Oil Company LLC, with 6 wells completed on it.
It has reported 20.9K barrels of oil and 24.6K mcf of gas since January 1993, last reporting volume in April 2026 (statewide data runs through April 2026).
The last 12 reported months total 234 barrels of oil, down 55% on the year before; the lease peaked at 385 barrels in December 2007.
8 operators have filed production on it, most recently Castillo Oil Company LLC since March 2007.
- 20.9K
- bbl oil, all reported
- 24.6K
- mcf gas incl. casinghead
- 234
- bbl oil, last 12 reported
- -55%
- vs the 12 before
- 6
- wells completed on it
- 385
- peak month, bbl (Dec 2007)
PDQ LEASE REPORTS · FIRST JAN 1993 · 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 234 · prior 12 524(-55%)
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
None shown. Petrora fits an Arps curve only when the last ten years of oil reports follow one decline closely enough to project (R² of 0.7 or better over at least a year since the peak). This lease's recent history does not, so a projection would be a guess dressed as a number.
Who reported it
Each run of months one operator filed the production report, oldest first.
- Polo Petroleum, Inc.Jan 1993 → Jul 1993 · 7 mo
- Mitchell Production, Inc.Aug 1993 → Jan 1997 · 42 mo
- Thomas Oil & Gas CompanyFeb 1997 → Jul 1998 · 18 mo
- LTS Energy, L.P.Aug 1998 → Jan 2000 · 18 mo
- Thomas Oil & Gas CompanyFeb 2000 → Apr 2003 · 39 mo
- LTS Energy, L.P.May 2003 → Nov 2006 · 43 mo
- Castillo Oil Co.Dec 2006 → Feb 2007 · 3 mo
- Castillo Oil Company LLCMar 2007 → Jul 2026 · 233 mo
Wells on the lease
FROM COMPLETION REPORTS · PRODUCTION ABOVE IS THEIR TOTAL
6
wells completed on the lease
- NO Type on File
- 6
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-1-7875, documented in the API reference.