WELL · 42-177-34746 · DISTRICT 2

Barnhart (Ef)-J.M. Preston SA6 #123H

Y

Gonzales County · Eagleville (Eagle Ford-2) field · Producing  · Horizontal

Barnhart (EF)-J.M. Preston Sa6 #123H (API 42-177-34746) is a horizontal well in Gonzales County operated by Marathon Oil EF LLC, completed June 18, 2025 and listed as producing on the RRC schedule.

The RRC has issued one drilling permit, issued December 9, 2024, permitted to 22,000 ft.

Completion filings report 8 formation tops, including Reklaw, Carrizo, Wilcox, Navarro.

Its lease has reported 65.8K barrels of oil and 38.1K mcf of gas since April 2025, last reporting in July 2026.

Operator of record

Marathon Oil EF LLC

Houston, TX · P-5 Y, filed Aug 4, 2025 · 3,191 permits on file · (800) 332-9449

SOURCE · RRC EWA WELLBORE SCHEDULE

What each RRC source says

Wellbore scheduleMarathon Oil EF LLC
Production reportsMarathon Oil EF LLCthrough Apr 2026
Latest permitMarathon Oil EF LLCDec 9, 2024
22,000
total depth, ft
1
permits on file
Dec 9, 2024
last permit issued
Jun 18, 2025
completed
65.8K
cumulative oil, bbl
38.1K
cumulative gas, mcf

PRODUCTION FROM PDQ LEASE REPORTS · Apr 2025 THROUGH Jul 2026

Regulatory status · RRC wellbore file

Schedule
ON SCHEDULE
Completed
Jun 18, 2025
Shut in
—
Plugged
—

Operator's P-5 on the schedule: Active

Surface location

29.312311, -97.500937

OpenStreetMap → ·  Google Maps →

Permit surface location from the RRC GIS record, in Gonzales 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; this well is the only one on it.Why →

LeaseFieldReporting operatorWellsOil, bblGas, mcfReported
Barnhart (Ef)-J.M. Preston SA6 O-2-13129Eagleville (Eagle Ford-2)Marathon Oil EF LLC165.8K38.1KApr 2025 – Jul 2026

Oil, barrels lease total

Last 12 months 65,798 · prior 12 0

010K20K202420252026

Gas, mcf lease total

Last 12 months 38,101 · prior 12 0

05K10K202420252026

Chain of custody

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

  1. 1Marathon Oil EF LLCSep 2025 → Apr 2026

Permits

PermitTypeOperatorReceivedIssuedSpudDepth
904358-99DrillMarathon Oil EF LLCDec 3, 2024Dec 9, 2024Feb 26, 202522,000

Completions

CompletedLeaseFieldOperatorStatusDepth
—— O-2-13129————

Formation tops

As filed on W-2/G-1. Subsea from 240 ft elevation.Download CSV →

FormationMD ftSubsea
Reklaw2,068-1,828
Carrizo2,628-2,388
WilcoxWILCOX - DISPOSAL2,863-2,623
Navarro3,563-3,323
Austin ChalkAUSTIN CHALK - H2S8,845-8,605
Eagle FordEAGLE FORD - H2S9,282-9,042
BudaBUDA - H2S, DISPOSAL——
EdwardsEDWARDS - H2S——
Navarro——

Perforations

Perforated and open-hole intervals.

FromToType
9,79919,460Perforated

Casing

Strings as reported, shallowest first.

Casing inSet atHole inCement
9.6254,74212.251,551 S
5.519,4428.753,175 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
00Jan 15, 2026Sep 3, 2025Yes
00Nov 4, 2025Oct 20, 2025Yes

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.

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 →

Barnhart (Ef)-J.M. Preston SA1042-177-34747

0.0 KM · Marathon Oil EF LLC · Section with this well →

Reklaw2,068-1,828
Carrizo2,628-2,388
Wilcox2,863-2,623
Austin Chalk8,800-8,560
Eagle Ford9,240-9,000
Edwards—
Buda—
Navarro—

Barnhart (Ef)-HFS SA142-177-34748

0.0 KM · Marathon Oil EF LLC · Section with this well →

Reklaw2,068-1,828
Carrizo2,628-2,388
Wilcox2,863-2,623
Austin Chalk8,804-8,564
Eagle Ford9,246-9,006
Edwards—
Buda—
Navarro—

Barnhart (Ef)-HFS SA242-177-34749

0.0 KM · Marathon Oil EF LLC · Section with this well →

Reklaw2,068-1,827
Carrizo2,628-2,387
Wilcox2,863-2,622
Austin Chalk8,799-8,558
Eagle Ford9,248-9,007
Navarro—
Buda—
Edwards—

Barnhart (Ef)-HFS SA342-177-34750

0.0 KM · Marathon Oil EF LLC · Section with this well →

Reklaw2,068373
Carrizo2,628-187
Wilcox2,863-422
Austin Chalk8,808-6,367
Eagle Ford9,253-6,812
Edwards—
Navarro—
Buda—

Barnhart (Ef)-HFS SA842-177-34755

0.4 KM · Marathon Oil EF LLC · Section with this well →

Reklaw2,375-2,097
Carrizo2,516-2,238
Wilcox2,824-2,546
Austin Chalk8,840-8,562
Eagle Ford9,269-8,991
Edwards—
Buda—
Navarro—

Barnhart (Ef)-HFS SA742-177-34754

0.4 KM · Marathon Oil EF LLC · Section with this well →

Reklaw2,372-2,135
Carrizo2,513-2,276
Wilcox2,820-2,583
Austin Chalk8,841-8,604
Austin Chalk8,841-8,604
Eagle Ford9,279-9,042
Eagle Ford9,279-9,042
Buda—

10 TOPS · FIRST 8

Barnhart (Ef)-HFS SA642-177-34753

0.4 KM · Marathon Oil EF LLC · Section with this well →

Reklaw2,368-2,131
Carrizo2,509-2,272
Wilcox2,814-2,577
Austin Chalk8,702-8,465
Eagle Ford9,134-8,897
Buda—
Edwards—
Navarro—

Barnhart (Ef)-HFS SA542-177-34752

0.4 KM · Marathon Oil EF LLC · Section with this well →

Reklaw2,367-2,130
Carrizo2,507-2,270
Wilcox2,811-2,574
Austin Chalk8,667-8,430
Eagle Ford9,100-8,863
Edwards—
Buda—
Navarro—

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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