WELL · 42-177-34703 · DISTRICT 1

Barnhart (Ef)-J.M. Preston SA1 #115H

Y

Gonzales County · Eagleville (Eagle Ford-1) field · Producing  · Horizontal

Barnhart (EF)-J.M. Preston Sa1 #115H (API 42-177-34703) is a horizontal well in Gonzales County operated by Marathon Oil EF LLC, completed January 27, 2025 and listed as producing on the RRC schedule.

The RRC has issued one drilling permit, issued April 25, 2024, permitted to 22,000 ft.

Completion filings report 10 formation tops, including Eagle Ford, Queen City, Sparta, Carrizo.

Its lease has reported 220K barrels of oil and 135K mcf of gas since January 2025, last reporting in July 2026.

Operator of record

Marathon Oil EF LLC

Based in
Houston, TX
P-5 status
Active (A)
P-5 last filed
Sep 26, 2025
Permits on file
3,191
Phone
(832) 486-2737

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 LLCApr 25, 2024
22,000
total depth, ft
1
permits on file
Apr 25, 2024
last permit issued
Jan 27, 2025
completed
220K
cumulative oil, bbl
135K
cumulative gas, mcf

PRODUCTION FROM PDQ LEASE REPORTS · Jan 2025 THROUGH Jul 2026

Regulatory status · RRC wellbore file

Schedule
ON SCHEDULE
Completed
Jan 27, 2025
Shut in
—
Plugged
—

Operator's P-5 on the schedule: Active (A)

Surface location

29.301911, -97.506399

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 SA1 O-1-21712Eagleville (Eagle Ford-1)Marathon Oil EF LLC1220K135KJan 2025 – Jul 2026

Oil, barrels lease total

Last 12 months 143,799 · prior 12 75,812(+90%)

010K20K30K202420252026

Gas, mcf lease total

Last 12 months 91,572 · prior 12 43,697(+110%)

010K20K202420252026

Chain of custody

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

  1. 1Marathon Oil EF LLCJan 2025 → Apr 2026

Permits

PermitTypeOperatorReceivedIssuedSpudDepth
898916-99DrillMarathon Oil EF LLCApr 16, 2024Apr 25, 2024Aug 9, 202422,000

Completions

CompletedLeaseFieldOperatorStatusDepth
—— O-1-21712————

Formation tops

As filed on W-2/G-1. Subsea from 228 ft elevation.Download CSV →

FormationMD ftSubsea
Eagle FordEAGLE FORD - H2S943-715
Queen City1,167-939
Sparta1,167-939
Carrizo1,722-1,494
Reklaw2,102-1,874
WilcoxWILCOX - DISPOSAL2,896-2,668
Austin ChalkAUSTIN CHALK - H2S8,782-8,554
BudaBUDA - H2S, DISPOSAL——
EdwardsEDWARDS - H2S——
Navarro——

Perforations

Perforated and open-hole intervals.

FromToType
9,68020,089Perforated

Casing

Strings as reported, shallowest first.

Casing inSet atHole inCement
9.6254,72312.251,770 S
5.520,0908.753,525 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
00May 12, 2025Mar 31, 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 neighbors, subsea-aligned so they line up regardless of surface terrain.

Open the cross-section →

Barnhart (EF)42-177-34702

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

Queen City1,722-1,494
Reklaw2,102-1,874
Carrizo2,643-2,415
Wilcox2,896-2,668
Austin Chalk8,737-8,509
Eagle Ford9,197-8,969
Buda—
Navarro—

9 TOPS · FIRST 8

Barnhart (EF)42-177-34701

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

Reklaw2,102-1,874
Carrizo2,643-2,415
Wilcox2,896-2,668
Austin Chalk8,779-8,551
Eagle Ford9,216-8,988
Edwards—
Navarro—
Buda—

Barnhart (Ef)-J.M. Preston SA342-177-34611

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

Sparta1,168-945
Queen City1,817-1,594
Reklaw2,104-1,881
Carrizo2,648-2,425
Wilcox2,901-2,678
Anacacho8,670-8,447
Austin Chalk8,773-8,550
Eagle Ford9,262-9,039

10 TOPS · FIRST 8

Barnhart (Ef)-J.M. Preston SA442-177-34612

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

Sparta1,168-945
Queen City1,817-1,594
Reklaw2,104-1,881
Carrizo2,648-2,425
Wilcox2,901-2,678
Austin Chalk8,829-8,606
Eagle Ford9,274-9,051
Navarro—

10 TOPS · FIRST 8

Barnhart (Ef)-J.M. Preston SA542-177-34613

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

Sparta1,168-945
Queen City1,817-1,594
Reklaw2,104-1,881
Carrizo2,648-2,425
Wilcox2,901-2,678
Anacacho8,697-8,474
Austin Chalk8,831-8,608
Eagle Ford9,283-9,060

10 TOPS · FIRST 8

Barnhart (EF)42-177-34287

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

Carrizo2,781-2,525
Wilcox3,783-3,527
Austin Chalk8,793-8,537
Eagle Ford9,281-9,025
Edwards—
Navarro—
Reklaw—
Buda—

Barnhart (EF)42-177-34286

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

Carrizo2,781-2,525
Wilcox3,783-3,527
Austin Chalk8,823-8,567
Eagle Ford9,303-9,047
Navarro—
Edwards—
Reklaw—
Buda—

Barnhart (EF)42-177-34285

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

Reklaw113143
Carrizo2,781-2,525
Wilcox3,783-3,527
Austin Chalk8,849-8,593
Eagle Ford9,316-9,060
Edwards—
Navarro—
Buda—

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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