TEXAS · WELLS · MIDLAND COUNTY · RIO SAN MARCOS 36-45 UNIT 2A LEASE · API 42-329-46866 · DISTRICT 7B
Rio San Marcos 36-45 Unit 2A #251
Midland County · Spraberry (Trend Area) field · Producing · Horizontal
Rio San Marcos 36-45 Unit 2a #251 (API 42-329-46866) is a horizontal well in Midland County operated by Diamondback E&P LLC, completed February 4, 2025 and listed as producing on the RRC schedule.
The RRC has issued one drilling permit, issued March 7, 2024, permitted to 9,647 ft.
It was permitted by Endeavor Energy Resources L.P. and has since transferred to Diamondback E&P LLC on the wellbore schedule.
Completion filings report 10 formation tops, including Santa Rosa, Rustler, Yates, Seven Rivers.
Its lease has reported 1.3M barrels of oil and 3.35M mcf of gas since March 2024, last reporting in July 2026. The lease carries 9 wells, so these are lease totals, not this well alone.
Operator of record
Permitted by Endeavor Energy Resources L.P.; the EWA schedule now lists a different operator.
- Based in
- Midland, TX
- P-5 status
- Active – Extension (X)
- P-5 last filed
- May 4, 2026
- Permits on file
- 5,237
- Phone
- (432) 221-7400
SOURCE · RRC EWA WELLBORE SCHEDULE
What each RRC source says
| Wellbore schedule | Diamondback E&P LLC |
| Production reports | Diamondback E&P LLCthrough Apr 2026 |
| Latest permit | Endeavor Energy Resources L.P.Mar 7, 2024 |
The sources disagree, which usually means a transfer or a lease-level production filing by a different entity. Petrora goes with the schedule.
- 9,647
- total depth, ft
- 1
- permits on file
- Mar 7, 2024
- last permit issued
- Feb 4, 2025
- completed
- 1.3M
- cumulative oil, bbl
- 3.35M
- cumulative gas, mcf
PRODUCTION FROM PDQ LEASE REPORTS · Mar 2024 THROUGH Jul 2026
Regulatory status · RRC wellbore file
- Schedule
- ON SCHEDULE
- Completed
- Feb 4, 2025
- Shut in
- —
- Plugged
- —
Operator's P-5 on the schedule: Active (A)
Surface location
31.791413, -102.008542
Permit surface location from the RRC GIS record, in Midland County.
Lease production
PDQ LEASE REPORTS · REPORTED THROUGH APR 2026
Texas reports oil by lease, not by well. These are the lease this well is completed on; they carry 9 wells in total, so volumes are shared.Why →
| Lease | Field | Reporting operator | Wells | Oil, bbl | Gas, mcf | Reported |
|---|---|---|---|---|---|---|
| Rio San Marcos 36-45 Unit 2A O-10-62127 | Spraberry (Trend Area) | Diamondback E&P LLC | 9 | 1.3M | 3.35M | Mar 2024 – Jul 2026 |
Oil, barrels lease total
Last 12 months 841,202 · prior 12 462,737(+82%)
Gas, mcf lease total
Last 12 months 2,764,913 · prior 12 583,460(+374%)
Chain of custody
Every operator that reported production on this well's lease, in order.
- 1Diamondback E&P LLCFeb 2025 → Apr 2026
Permits
| Permit | Type | Operator | Received | Issued | Spud | Depth |
|---|---|---|---|---|---|---|
| 897848-99 | Drill | Endeavor Energy Resources L.P. | Mar 1, 2024 | Mar 7, 2024 | May 29, 2024 | 10,049 |
Completions
| Completed | Lease | Field | Operator | Status | Depth |
|---|---|---|---|---|---|
| Feb 4, 2025 | Rio San Marcos 36-45 Unit 2A O-10-62127 | Spraberry (Trend Area) | Diamondback E&P LLC | Producing | 9,647 |
Formation tops
As filed on W-2/G-1. Subsea from 2,700 ft elevation.Download CSV →
| Formation | MD ft | Subsea |
|---|---|---|
| Santa Rosa | 1,000 | 1,700 |
| Rustler | 1,608 | 1,092 |
| Yates | 2,608 | 92 |
| Yates | 2,617 | 83 |
| Seven Rivers | 2,978 | -278 |
| Queen | 3,818 | -1,118 |
| Queen | 3,821 | -1,121 |
| Grayburg | 4,384 | -1,684 |
| Grayburg | 4,385 | -1,685 |
| San AndresSAN ANDRES - HIGH FLOWS, H2S, CO | 4,641 | -1,941 |
| San AndresSAN ANDRES - HIGH FLOWS, H2S, CO | 5,108 | -2,408 |
| Glorieta | 5,403 | -2,703 |
| Glorieta | 5,851 | -3,151 |
| Clear ForkCLEARFORK | 6,760 | -4,060 |
| Clear ForkCLEARFORK | 6,774 | -4,074 |
| Spraberry | 7,661 | -4,961 |
| Spraberry | 7,667 | -4,967 |
| Rustler | — | — |
| Santa Rosa | — | — |
| Seven Rivers | — | — |
Perforations
Perforated and open-hole intervals.
| From | To | Type |
|---|---|---|
| 9,807 | 19,828 | Perforated |
Casing
Strings as reported, shallowest first.
| Casing in | Set at | Hole in | Cement |
|---|---|---|---|
| 13.375 | 1,375 | 16 | 875 S |
| 9.625 | 8,622 | 12.25 | 1,255 S |
| 5.5 | 19,845 | 7.875 | 1,105 S |
Completion filings
W-2 and G-1 reports on record in the RRC wellbore file, newest first. The suffix identifies the wellbore or completion event. About these reports →
| Suffix | Filed | W-2 / G-1 date | Logs referenced |
|---|---|---|---|
| 00 | Jul 15, 2025 | Jun 11, 2025 | Yes |
| 00 | Jan 16, 2025 | Oct 16, 2024 | — |
The source documents
Petrora holds the structured record. The scanned filings live at the RRC; these links open its search already filled in for this API.
- Wellbore filings for 42-329-46866 → W-2, G-1, plugging reports, as PDFs
- Completion packets for 42-329-46866 → scanned completion filings
Log images are in archives with no per-well link: the RRC's Neubus archive (2004 onward). then paste it into their search.
Nearby wells and their tops
NEAREST 8 LOCATED WELLS WITH TOPS · WITHIN 16 KM
Draw a cross-section
This well's tops beside its 5 nearest neighbors, subsea-aligned so they line up regardless of surface terrain.
Rio San Marcos 36-45 Unit 2A42-329-46865
0.0 KM · Endeavor Energy Resources L.P. · Section with this well →
| Santa Rosa | 1,000 | 1,700 |
| Rustler | 1,608 | 1,092 |
| Yates | 2,608 | 92 |
| Seven Rivers | 2,977 | -277 |
| Queen | 3,814 | -1,114 |
| Grayburg | 4,385 | -1,685 |
| San Andres | 5,118 | -2,418 |
| Glorieta | 5,853 | -3,153 |
15 TOPS · FIRST 8
Rio San Marcos 36-45 Unit 2A42-329-46868
0.0 KM · Endeavor Energy Resources L.P. · Section with this well →
| Santa Rosa | 1,000 | 1,700 |
| Rustler | 1,608 | 1,092 |
| Yates | 2,608 | 92 |
| Seven Rivers | 2,977 | -277 |
| Queen | 3,816 | -1,116 |
| Grayburg | 4,385 | -1,685 |
| San Andres | 5,105 | -2,405 |
| Glorieta | 5,853 | -3,153 |
10 TOPS · FIRST 8
Rio San Marcos 36-45 Unit 2A42-329-46867
0.0 KM · Endeavor Energy Resources L.P. · Section with this well →
| Santa Rosa | 1,000 | 1,700 |
| Rustler | 1,608 | 1,092 |
| Yates | 2,608 | 92 |
| Seven Rivers | 2,977 | -277 |
| Queen | 3,818 | -1,118 |
| Grayburg | 4,377 | -1,677 |
| San Andres | 5,108 | -2,408 |
| Glorieta | 5,853 | -3,153 |
10 TOPS · FIRST 8
Rio San Marcos 36-45 Unit 2B42-329-46869
0.0 KM · Endeavor Energy Resources L.P. · Section with this well →
| Santa Rosa | 1,000 | 1,700 |
| Rustler | 1,614 | 1,086 |
| Yates | 2,609 | 91 |
| Queen | 3,679 | -979 |
| Grayburg | 4,366 | -1,666 |
| San Andres | 5,161 | -2,461 |
| Glorieta | 5,632 | -2,932 |
| Clear Fork | 6,767 | -4,067 |
11 TOPS · FIRST 8
Rio San Marcos 36-45 Unit 142-329-41960
0.3 KM · Endeavor Energy Resources L.P. · Section with this well →
| Santa Rosa | 1,790 | 906 |
| Yates | 2,597 | 99 |
| Seven Rivers | 2,974 | -278 |
| Queen | 3,742 | -1,046 |
| Grayburg | 4,411 | -1,715 |
| San Andres | 5,035 | -2,339 |
| Glorieta | 5,810 | -3,114 |
| Clear Fork | 6,849 | -4,153 |
10 TOPS · FIRST 8
Rio San Marcos 36-45 Unit 142-329-41934
0.3 KM · Endeavor Energy Resources L.P. · Section with this well →
| Santa Rosa | 1,790 | 906 |
| Yates | 2,597 | 99 |
| Seven Rivers | 2,974 | -278 |
| Queen | 3,742 | -1,046 |
| Grayburg | 4,411 | -1,715 |
| San Andres | 5,035 | -2,339 |
| Glorieta | 5,810 | -3,114 |
| Clear Fork | 6,849 | -4,153 |
10 TOPS · FIRST 8
Rio San Marcos 36-45 Unit 142-329-42323
0.3 KM · Endeavor Energy Resources L.P. · Section with this well →
| Santa Rosa | 1,790 | 906 |
| Yates | 2,597 | 99 |
| Seven Rivers | 2,974 | -278 |
| Queen | 3,742 | -1,046 |
| Grayburg | 4,411 | -1,715 |
| San Andres | 5,035 | -2,339 |
| Glorieta | 5,810 | -3,114 |
| Clear Fork | 6,849 | -4,153 |
10 TOPS · FIRST 8
Rio San Marcos 36-45 Unit 142-329-41958
0.3 KM · Endeavor Energy Resources L.P. · Section with this well →
| Santa Rosa | 1,000 | 1,696 |
| Yates | 2,597 | 99 |
| Seven Rivers | 2,974 | -278 |
| Queen | 3,742 | -1,046 |
| Grayburg | 4,411 | -1,715 |
| San Andres | 5,035 | -2,339 |
| Glorieta | 6,029 | -3,333 |
| Clear Fork | 6,849 | -4,153 |
11 TOPS · FIRST 8
About this data
Permits from the RRC OGA049M master and daily daf420 files; wellbore and operator of record from the EWA schedule, weekly; completions, formation tops, casing, and perforations from the dbf900 wellbore file; production from PDQ lease reports, which lag two to three months; injection from UIC permits, H-10 reports, and TexNet daily volumes; earthquakes from the TexNet catalog.
New to these records? How to read a well page · API numbers · completion reports and tops · why production is by lease
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