WELL · 42-335-31379 · DISTRICT 8

Westbrook Southwest Unit #4-16

Y

Mitchell County · Westbrook field · Shut IN  · Vertical

Westbrook Southwest Unit #4-16 (API 42-335-31379) is a well in Mitchell County operated by Grayrock Energy II LLC, completed March 2, 2017 and listed as shut in on the RRC schedule.

The RRC has issued one drilling permit, issued September 21, 1978, permitted to 3,250 ft.

It was permitted by Union Texas Petroleum Corp. and has since transferred to Grayrock Energy II LLC on the wellbore schedule.

Completion filings report one formation top, including Clear Fork.

Its lease has reported 8.65M barrels of oil and 21 mcf of gas since January 1993, last reporting in July 2026. The lease carries 371 wells, so these are lease totals, not this well alone.

It holds an active disposal or injection permit.

Operator of record

Grayrock Energy II LLC

Permitted by Union Texas Petroleum Corp.; the EWA schedule now lists a different operator.

Fort Worth, TX · P-5 Y, filed Aug 4, 2025 · (214) 234-9115

SOURCE · RRC EWA WELLBORE SCHEDULE

What each RRC source says

Wellbore scheduleGrayrock Energy II LLC
Production reportsGrayrock Energy II, LLCthrough Apr 2026
Latest permitUnion Texas Petroleum Corp.Sep 21, 1978

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

3,250
total depth, ft
1
permits on file
Sep 21, 1978
last permit issued
Mar 2, 2017
completed
8.65M
cumulative oil, bbl
21
cumulative gas, mcf

PRODUCTION FROM PDQ LEASE REPORTS · Jan 1993 THROUGH Jul 2026

Regulatory status · RRC wellbore file

Schedule
ON SCHEDULE
Completed
Mar 2, 2017
Shut in
—
Plugged
—

Operator's P-5 on the schedule: Active

Surface location

No coordinates on the permit record yet. The RRC's GIS record usually lands within days of issuance; historical master-file permits never carry one.

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 371 wells in total, so volumes are shared.Why →

LeaseFieldReporting operatorWellsOil, bblGas, mcfReported
Westbrook Southwest Unit O-10-21120WestbrookGrayrock Energy II, LLC3718.65M21Jan 1993 – Jul 2026

Oil, barrels lease total

Last 12 months 130,319 · prior 12 134,739(-3%)

05K10K15K202420252026

Chain of custody

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

  1. 1Meridian Oil Inc.Jan 1993 → Jul 1996
  2. 2Burlington Resources Oil&gas Co.Aug 1996 → Apr 1997
  3. 3Gruy Petroleum Management Co.May 1997 → Apr 2006
  4. 4Cimarex Energy Co. of ColoradoMay 2006 → Sep 2009
  5. 5Merit Energy CompanyOct 2009 → May 2017
  6. 6Rover Petroleum Operating, LLCJun 2017 → Dec 2023
  7. 7Grayrock Energy II, LLCJan 2024 → Apr 2026

Permits

PermitTypeOperatorReceivedIssuedSpudDepth
34186-99DrillUnion Texas Petroleum Corp.Sep 21, 1978Sep 21, 1978Nov 8, 19783,250

Completions

CompletedLeaseFieldOperatorStatusDepth
—— O-10-21120————

Formation tops

As filed on W-2/G-1. Subsea from 2,132 ft elevation.Download CSV →

FormationMD ftSubsea
Clear ForkTOP CLEARFORK2,455-323
Clear ForkMIDDLE CLEARFORK2,958-826

Perforations

Perforated and open-hole intervals.

FromToType
2,8693,122Perforated
2,8693,124Perforated

Casing

Strings as reported, shallowest first.

Casing inSet atHole inCement
8.62531812.25225 S
8.62531812.5225 S
2.3753,099——
5.53,2507.875750 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 25, 2023May 9, 2023—
00Mar 22, 2012Feb 9, 2012—
00Jun 20, 1984Apr 10, 1984—
00Jan 12, 1984Apr 10, 1984—

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). then paste it into their search.

Beyond the permit record

RRC UIC permits · H-10 reported volumes

Injection

0
bbl, last 12 reported months
2.07M
bbl, all reported
Jan 2026
reported through
UICKindStatusPermitted bbl/dMax psiZone ft
000046317H-1 InjectionActive5001,1502,300–3,300

MONTHLY INJECTED, BBL · H-10 · LAST 24 REPORTED MONTHS

Last 12 months 0 · prior 12 0

0120252026

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/33531379, documented in the API reference.