WELL · 42-317-45622 · DISTRICT 8

Cox 12-9 Unit 1 #141

Y

Martin County · Spraberry (Trend Area) field · Producing  · Horizontal

Cox 12-9 Unit 1 #141 (API 42-317-45622) is a horizontal well in Martin County operated by Diamondback E&P LLC, completed November 9, 2024 and listed as producing on the RRC schedule.

The RRC has issued one drilling permit, issued September 25, 2023, permitted to 10,802 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 11 formation tops, including Santa Rosa, Yates, Queen, Grayburg.

Its lease has reported 2.08M barrels of oil and 5.16M mcf of gas since August 2017, last reporting in July 2026. The lease carries 13 wells, so these are lease totals, not this well alone.

Operator of record

Diamondback E&P LLC

Permitted by Endeavor Energy Resources L.P.; the EWA schedule now lists a different operator.

Midland, TX · P-5 Y, filed Mar 4, 2026 · 5,231 permits on file · (855) 247-5920

SOURCE · RRC EWA WELLBORE SCHEDULE

What each RRC source says

Wellbore scheduleDiamondback E&P LLC
Production reportsDiamondback E&P LLCthrough Apr 2026
Latest permitEndeavor Energy Resources L.P.Sep 25, 2023

The sources disagree, which usually means a transfer or a lease-level production filing by a different entity. Petrora goes with the schedule.

10,802
total depth, ft
1
permits on file
Sep 25, 2023
last permit issued
Nov 9, 2024
completed
2.08M
cumulative oil, bbl
5.16M
cumulative gas, mcf

PRODUCTION FROM PDQ LEASE REPORTS · Aug 2017 THROUGH Jul 2026

Regulatory status · RRC wellbore file

Schedule
ON SCHEDULE
Completed
Nov 9, 2024
Shut in
—
Plugged
—

Operator's P-5 on the schedule: X

Surface location

32.302640, -102.005999

OpenStreetMap → ·  Google Maps →

Permit surface location from the RRC GIS record, in Martin 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 13 wells in total, so volumes are shared.Why →

LeaseFieldReporting operatorWellsOil, bblGas, mcfReported
Cox 12-9 Unit 1 O-10-49245Spraberry (Trend Area)Diamondback E&P LLC132.08M5.16MAug 2017 – Jul 2026

Oil, barrels lease total

Last 12 months 498,220 · prior 12 818,801(-39%)

0100K200K300K202420252026

Gas, mcf lease total

Last 12 months 2,481,154 · prior 12 1,502,229(+65%)

0200K400K202420252026

Chain of custody

Every operator that reported production on this well's lease, in order.

  1. 1Endeavor Energy Resources L.P.Aug 2017 → Dec 2024
  2. 2Diamondback E&P LLCJan 2025 → Apr 2026

Permits

PermitTypeOperatorReceivedIssuedSpudDepth
893737-99DrillEndeavor Energy Resources L.P.Sep 14, 2023Sep 25, 2023Jan 27, 202410,802

Completions

CompletedLeaseFieldOperatorStatusDepth
—— O-10-49245————

Formation tops

As filed on W-2/G-1. Subsea from 2,827 ft elevation.Download CSV →

FormationMD ftSubsea
Santa Rosa1,0001,827
Yates2,75671
Queen3,622-795
Grayburg3,975-1,148
San AndresSAN ANDRES - ACTIVE CO2 FLOOD; H4,739-1,912
Clear ForkCLEARFORK, UPPER6,477-3,650
Spraberry7,806-4,979
Cisco——
Dean——
Pennsylvanian——
Wolfcamp——

Perforations

Perforated and open-hole intervals.

FromToType
9,22916,742Perforated

Casing

Strings as reported, shallowest first.

Casing inSet atHole inCement
13.3751,91317.51,515 S
9.6256,71412.251,840 S
5.516,7668.52,000 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 →

SuffixFiledW-2 / G-1 dateLogs referenced
00Oct 1, 2025Mar 14, 2025—
00Oct 11, 2024Jun 27, 2024Yes

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.

Log images are in archives with no per-well link: the RRC's Neubus archive (2004 onward) and the University Lands library. 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 neighbours, subsea-aligned so they line up regardless of surface terrain.

Open the cross-section →

Cox 12-9 Unit 142-317-45621

0.0 KM · Endeavor Energy Resources L.P. · Section with this well →

Santa Rosa1,0001,827
Yates2,75770
Queen3,623-796
Grayburg3,977-1,150
San Andres4,739-1,912
Clear Fork6,476-3,649
Spraberry7,793-4,966
Cisco—

15 TOPS · FIRST 8

Cox 12-9 Unit 142-317-45623

0.0 KM · Endeavor Energy Resources L.P. · Section with this well →

Santa Rosa1,0001,827
Yates2,75770
Queen3,622-795
Grayburg3,977-1,150
San Andres4,735-1,908
Clear Fork6,477-3,650
Spraberry7,799-4,972
Cisco—

10 TOPS · FIRST 8

Cox 12-9 Unit 142-317-45625

0.0 KM · Endeavor Energy Resources L.P. · Section with this well →

Santa Rosa1,0001,827
Yates2,75869
Queen3,621-794
Grayburg3,981-1,154
San Andres4,738-1,911
Clear Fork6,481-3,654
Spraberry7,793-4,966
Dean9,123-6,296

11 TOPS · FIRST 8

Cox 12-9 Unit 142-317-45624

0.0 KM · Endeavor Energy Resources L.P. · Section with this well →

Santa Rosa1,0001,827
Yates2,75770
Queen3,622-795
Grayburg3,976-1,149
San Andres4,737-1,910
Clear Fork6,475-3,648
Spraberry7,801-4,974
Dean—

11 TOPS · FIRST 8

Pier 21-24 D42-317-42246

0.0 KM · Endeavor Energy Resources L.P. · Section with this well →

Santa Rosa1,0001,828
Yates1,861967
Queen2,300528
Grayburg4,258-1,430
San Andres4,481-1,653
Cisco6,491-3,663
Spraberry8,129-5,301
Dean8,775-5,947

10 TOPS · FIRST 8

Pier 21-24 C42-317-42245

0.0 KM · Endeavor Energy Resources L.P. · Section with this well →

Santa Rosa1,0001,828
Yates1,861967
Queen2,300528
Grayburg4,258-1,430
San Andres4,481-1,653
Cisco6,491-3,663
Spraberry8,113-5,285
Pennsylvanian—

10 TOPS · FIRST 8

Pier 21-24 D42-317-42247

0.0 KM · Endeavor Energy Resources L.P. · Section with this well →

Santa Rosa1,0001,828
Yates1,861967
Queen2,300528
Grayburg4,258-1,430
San Andres4,481-1,653
Cisco6,491-3,663
Spraberry8,126-5,298
Wolfcamp—

10 TOPS · FIRST 8

Pier 21-24 C42-317-42244

0.0 KM · Endeavor Energy Resources L.P. · Section with this well →

Santa Rosa1,0001,827
Yates1,861966
Queen2,300527
Grayburg4,258-1,431
San Andres4,481-1,654
Cisco6,491-3,664
Spraberry8,116-5,289
Dean9,180-6,353

10 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

Developers: this page as JSON is GET /v1/data/wells/31745622, documented in the API reference.