42-255-32965

Horizontal

CHALLENGER UNIT A

KARNES County · District 2 · MARATHON OIL EF LLC

Permits

Max Depth

17,000 ft

First Permit

2013-01-25

Latest Activity

2013-08-09

Lifespan

< 1 yr

Regulatory Status

Schedule

OFF SCHEDULE

Completion

—

Shut-In

—

Plugged

—

Production Summary

Cum Oil

— bbl

Cum Gas

— mcf

First Production

2012-02

Last Production

2026-07

Lease Production

Production is reported at the lease level. View production data, decline curves, and history on the lease page.

Oil

production & DCA →

Formation Tops (7) Elevation 314 ft (GR)

CSV

Formation	Top Depth (MD)	Subsea (+above / −below SL)
ANACACHO	10,336 ft	-10,022 ft
AUSTIN CHALK	10,457 ft	-10,143 ft
EAGLE FORD	10,748 ft	-10,434 ft
EAGLE FORD	11,032 ft	-10,718 ft
LOWER EAGLE FORD (Eagle Ford)	11,082 ft	-10,768 ft
EAGLE FORD	11,108 ft	-10,794 ft
BUDA	11,189 ft	-10,875 ft

As reported by operators on W-2/G-1 completion filings (RRC wellbore records). Depths are measured depth; names appear as filed. Subsea = reported elevation − measured depth (negative = below sea level; vertical wellbores only). View filings & logs at RRC ↗

Perforations (1)

Interval	Type
11,067–16,258 ft	Perforated

Casing (2)

Size	Set Depth	Cement
9.625"	5,246 ft	1,530 sx
5.5"	16,435 ft	2,475 sx

Permit History (2)

#767573 Recompletion

CHALLENGER UNIT A · 16,435 ft

2013-08-09

#755055 Drill Final Completion

CHALLENGER UNIT A · 17,000 ft

2013-01-25

Spud 2013-04-22

Applications (2)

#767573 A MARATHON OIL EF LLC

received 2013-08-02

#755055 A MARATHON OIL EF LLC

received 2013-01-17

Records & Logs

4 completion filings on record · 1 with log images at RRC.

W-2/G-1 2021-05-26

W-2/G-1 2016-08-22

W-2/G-1 2013-05-30

W-2/G-1 2013-05-15 log on file

Completion packets + logs ↗ Wellbore filings ↗

Completion packets open directly (post-2011 filings include attached logs). Log images can't be deep-linked — clicking copies the API for you to paste.

No GPS coordinates yet

Coordinates come from the RRC GIS backfill and usually appear within days of permit issuance. Located in KARNES County.

Well Details

Well Number: 2H
Max Depth: 17,000 ft
Drill Type: Horizontal
County: KARNES
District: 2
Operator: MARATHON OIL EF LLC

Operator

Name: MARATHON OIL EF LLC
Location: HOUSTON
P-5 Status: Active (filed 2025-09-26)
Cum Oil (all leases): 409,189,156 bbl
Cum Gas (all leases): 1,029,735,602 mcf
Activities: CSGD/G, CSGD/P, G/PUR, GTHS/C, GTHS/G, GTHS/O, OPRS/G, OPRS/O
Total Permits: 3,168