WELL · 42-255-36040 · DISTRICT 2

S.mcfarland-Challenger C SA #1H

Y

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

S.Mcfarland-Challenger C SA #1H (API 42-255-36040) is a horizontal well in Karnes County operated by Marathon Oil EF LLC, completed May 23, 2024 and listed as producing on the RRC schedule.

The RRC has issued one drilling permit, issued June 22, 2018, permitted to 20,000 ft.

Completion filings report 10 formation tops, including Yegua, Queen City, Reklaw, Carrizo.

Its lease has reported 211K barrels of oil and 211K mcf of gas since November 2018, 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 Mar 2026
Latest permitMarathon Oil EF LLCJun 22, 2018
20,000
total depth, ft
1
permits on file
Jun 22, 2018
last permit issued
May 23, 2024
completed
211K
cumulative oil, bbl
211K
cumulative gas, mcf

PRODUCTION FROM PDQ LEASE REPORTS · Nov 2018 THROUGH Jul 2026

Regulatory status · RRC wellbore file

Schedule
ON SCHEDULE
Completed
May 23, 2024
Shut in
—
Plugged
—

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

Surface location

28.905849, -98.003131

Google Maps ↗

Permit surface location from the RRC GIS record, in Karnes 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
S.mcfarland-Challenger C SA O-2-11657Eagleville (Eagle Ford-2)Marathon Oil EF LLC1211K211KNov 2018 – Jul 2026

Oil, barrels lease total

Last 12 months 880 · prior 12 3,634(-76%)

01K2K202420252026

Gas, mcf lease total

Last 12 months 478 · prior 12 2,045(-77%)

01K2K202420252026

Chain of custody

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

  1. 1Marathon Oil EF LLCFeb 2019 → Mar 2026

Permits

PermitTypeOperatorReceivedIssuedSpudDepth
841566-99DrillMarathon Oil EF LLCJun 21, 2018Jun 22, 2018Jan 25, 201920,000

Completions

CompletedLeaseFieldOperatorStatusDepth
—— O-2-11657————

Formation tops

As filed on W-2/G-1. Subsea from 345 ft elevation.Download CSV →

FormationMD ftSubsea
YeguaYEGUA - DISPOSAL1,294-949
Queen City3,154-2,809
Reklaw3,464-3,119
Carrizo4,179-3,834
WilcoxWILCOX - DISPOSAL5,366-5,021
Austin ChalkAUSTIN CHALK - H2S10,465-10,120
Eagle FordEAGLE FORD - H2S10,705-10,360
Eagle FordEAGLE FORD - H2S——
EdwardsEDWARDS - H2S——
FrioFRIO - DISPOSAL——
SligoSLIGO - H2S——

Perforations

Perforated and open-hole intervals.

FromToType
10,97614,687Perforated

Casing

Strings as reported, shallowest first.

Casing inSet atHole inCement
9.6255,22412.251,534 S
5.514,7958.752,458 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
00Aug 2, 2024Jul 9, 2024—
00Apr 4, 2019Mar 6, 2019Yes
00Feb 20, 2019Jan 16, 2019Yes

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 →

F.janysek-M.hons-S.mcfarland SA42-255-36077

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

Yegua1,294-950
Queen City3,154-2,810
Reklaw3,464-3,120
Carrizo4,179-3,835
Wilcox5,366-5,022
Austin Chalk10,504-10,160
Eagle Ford10,763-10,419
Frio—

10 TOPS · FIRST 8

Mohr-Hons Unit42-255-36038

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

Yegua1,294-951
Queen City3,154-2,811
Reklaw3,464-3,121
Carrizo4,179-3,836
Wilcox5,366-5,023
Austin Chalk10,495-10,152
Eagle Ford10,759-10,416
Frio—

10 TOPS · FIRST 8

Mohr-Hons Unit42-255-36037

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

Yegua1,294-951
Queen City3,154-2,811
Reklaw3,464-3,121
Carrizo4,179-3,836
Wilcox5,366-5,023
Austin Chalk10,524-10,181
Eagle Ford10,785-10,442
Frio—

10 TOPS · FIRST 8

Challenger Unit C AC42-255-36039

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

Yegua1,294-952
Queen City3,154-2,812
Reklaw3,464-3,122
Carrizo4,179-3,837
Wilcox5,366-5,024
Austin Chalk10,518-10,176
Edwards—
Frio—

10 TOPS · FIRST 8

Swize McFarland Unit AC42-255-36651

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

Yegua1,305-937
Queen City3,165-2,797
Reklaw3,475-3,107
Carrizo4,190-3,822
Wilcox5,377-5,009
Austin Chalk10,529-10,161
Edwards—
Eagle Ford—

10 TOPS · FIRST 8

Swize McFarland Unit42-255-36650

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

Yegua1,305-934
Queen City3,165-2,794
Reklaw3,475-3,104
Carrizo4,190-3,819
Wilcox5,377-5,006
Austin Chalk10,524-10,153
Eagle Ford10,763-10,392
Frio—

10 TOPS · FIRST 8

Swize McFarland Unit42-255-36649

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

Yegua1,305-934
Queen City3,165-2,794
Reklaw3,475-3,104
Carrizo4,190-3,819
Wilcox5,377-5,006
Austin Chalk10,546-10,175
Eagle Ford10,783-10,412
Edwards—

10 TOPS · FIRST 8

Swize McFarland Unit42-255-36648

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

Yegua1,305-933
Queen City3,165-2,793
Reklaw3,475-3,103
Carrizo4,190-3,818
Wilcox5,377-5,005
Austin Chalk10,524-10,152
Eagle Ford10,763-10,391
Edwards—

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

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