Petrora

OPERATORS · RRC 525398  · P-5 STATUS Y

Marathon Oil EF LLC

Houston, TX · most active in Karnes County

Watch this operator

Marathon Oil EF LLC was issued 68 drilling permits in the past 12 months, up 28% on the prior year, across 5 counties led by Karnes with 34. 100% were horizontal.

15 were issued in the past 90 days, down 56% on the prior quarter. 2 were issued in the past week.

The RRC wellbore file lists 3,133 wells under its operatorship (2,309 producing, 273 shut in).

Lease reports credit it with 23.1M barrels of oil and 117M mcf of gas in the 12 months reported through April 2026, down 26% on the year before.

It holds 2 active disposal or injection permits, injecting 2.05M barrels in the 12 months reported through June 2025.

3,190 drilling permits have been issued to this operator number since 2010; its P-5 organization report was last filed August 4, 2025.

68
permits, last 12 months
+28%
vs prior 12 months (53)
5
counties, 12 months
2.31K
producing wells, of 3.13K of record
2.1K
leases it reports
100%
horizontal, 12 months

WINDOWS ON THE RRC ISSUE DATE · COMPUTED OCT 29, 2026

From permit to spud

FROM THE DATES ON ITS W-1 PERMITS · ALL TIME

A permit is a plan, not a well. These figures count only permits old enough to have spudded, six months and more, and read the spud, cancel, and expiry dates the RRC records on each one.

90%
spud rate · 2,833 of 3,149 mature permits
84
median days permit to spud · middle half 41–153
3
spuds, last 180 days
0%
cancelled · 0 permits
355
expired undrilled
188
permits a year over 17 active years

Permits issued by month

LAST 50 MONTHS · BY ISSUE DATE

Last 12 months 75 · prior 12 137(-45%)

0204020222023202420252026

Where

Counties by permits in the last 12 months, with all-time permits and current wells of record there.

County12 moAll timeWellsLast
Karnes county →341,8751,753Oct 27, 2026
DE Witt county →1189284Jul 1, 2026
Atascosa county →8640483May 6, 2026
Live Oak county →8217347Sep 21, 2026
Gonzales county →7281198Jul 21, 2026
McMullen county →—6137Jan 28, 2019
Lavaca county →—2219Apr 13, 2022
Wilson county →—31May 10, 2012
Frio county →—20Sep 25, 2013

All 3,190 permits, searchable → · Leases it reports → · On the map →

Formations in its completed wells

Tops reported on completion filings for wells it operates. RRC wellbore file. About tops →

FormationWellsPermitted last 3 yrs
Austin Chalk2,328152
Eagle Ford1,875118
Wilcox1,784149
Queen City1,564104
Carrizo1,547135
Reklaw1,543136
Anacacho1,08442
Yegua94410
Frio4247
Olmos3074
Navarro2501
Bartosh1900
Cook Mountain1335
Escondido1190
Jackson920

Production by month

PDQ LEASE REPORTS · REPORTED THROUGH APR 2026

Barrels on leases where this operator filed the production report. Lease-level by design; the latest months are revised upward as late reports arrive. How production is reported →

23.1M
bbl oil, last 12 reported months
-26%
vs the 12 months before
117M
mcf gas incl. casinghead, last 12
409M
bbl oil since reporting began

Oil, barrels

Last 12 months 23,122,132 · prior 12 31,178,737(-26%)

01M2M3M202420252026

Gas, mcf

Last 12 months 116,680,080 · prior 12 170,106,471(-31%)

010M20M202420252026

Beyond the permit record

RRC wellbore file

Wells of record

3,133
on the schedule
2,309
producing
273
shut in
9
injection
207
temp. abandoned
21
plugged

How it got them

2,289
permitted itself
844
acquired from others
27
permitted, now run by others

Acquired means the well's permit names a different operator than the schedule does today. Transfers and operator numbers →

RRC UIC permits · H-10 reported volumes

Disposal and injection

2
active UIC permits of 29
25K
permitted bbl/day, active
2.05M
bbl injected, last 12 reported months
Jun 2025
reported through

By county

Karnes1 active25K bbl/d
Atascosa1 active0 bbl/d
Gonzales0 active0 bbl/d

Permitted volume is a ceiling, not throughput. How to read it →

Permit types

Last 12 months against the prior 12, and all time. A type opens the permit history filtered to it. What the types mean →

Type12 moPrior 12All time
Drill68523,151
Recompletion1023
Field transfer0015
Reclass002

Fields

RRC regulatory fields with the most wells of record under this operator. The field opens its page; the count opens this operator's wells in it.

FieldWellsProducing
Eagleville (Eagle Ford-2)271357501,083805
Sugarkane (Eagle Ford)86950600936652
Eagleville (Eagle Ford-1)27135700671532
DE Witt (Eagle Ford Shale)24492500248208
Sugarkane (Austin Chalk)86950300175108
Eagleville (Eagle Ford)2713550070
First Shot (Austin Chalk)3096710040
Wildcat400120
Flintstone (Cretaceous Chalk)3148750022
Pilgrim (Austin Chalk)7148610010
San Marcos (Austin Chalk)8028050011
Sugarkane (Cretaceous)8695050010

P-5 organization report

As registered with the RRC. About the P-5 →

Registration
Status code Y
Last filed Aug 4, 2025
CSGD/GCSGD/PG/PURCondensate gatheringGas gatheringOil gatheringGas operatorOil operator
Address
PO Box 2197 Regulatory Dept
Houston, TX 77252
(800) 332-9449
Officers and agents
CSC-Lawyers Incor Serv. Co · Texas Resident Agent
Gasch, Jeffry M · Vice President
Lisowksi, Alexandra P · Treasurer
Hamilton, Leslie D · Assistant Tax Administration Off
Gresh, Philip M III · Vice President
Hoang, Lily N · General Tax Counsel
Thomas, Richard J · Vice President
King, Wendy D · President
All 14 on the P-5 →

Latest permits

NEWEST FIRST BY ISSUE DATE · FILED OR ON WELLS IT NOW OPERATES

PermitSeenIssuedOperatorCountyLease / wellDepthAPI
919591Nov 1, 2026Oct 30, 2026Marathon Oil EF LLCKarnesRodriguez-Medina SA A #1H17,50025538486
919593Oct 29, 2026Oct 27, 2026Marathon Oil EF LLCKarnesRodriguez-Medina SA C #1H17,50025538488
919592Oct 29, 2026Oct 27, 2026Marathon Oil EF LLCKarnesRodriguez-Medina SA B #1H17,50025538487
919107Oct 10, 2026Oct 8, 2026Marathon Oil EF LLCKarnesSprencel-Peck Unit #3HH11,42825533515
918433Oct 3, 2026Oct 1, 2026Marathon Oil EF LLCKarnesHaus-Jau-Chris SA B #1H17,50025538460
918432Oct 3, 2026Oct 1, 2026Marathon Oil EF LLCKarnesHaus Quad SA A #1H17,50025538459
918398Oct 28, 2026Sep 21, 2026Marathon Oil EF LLCLive OakWhitsett-Taylor-Mass SA C #1H17,50029736602
918391Oct 28, 2026Sep 21, 2026Marathon Oil EF LLCLive OakWhitsett-Taylor-Mass SA B #1H17,50029736600
918399Oct 25, 2026Sep 21, 2026Marathon Oil EF LLCLive OakWhitsett-Taylor-Mass SA D #1H17,50029736601
918390Oct 25, 2026Sep 21, 2026Marathon Oil EF LLCLive OakWhitsett-Taylor-Mass SA A #1H17,50029736599
918399Sep 23, 2026Sep 21, 2026Marathon Oil EF LLCLive OakWhitsett-Taylor-Mass SA D #1H17,50029736601
918398Sep 23, 2026Sep 21, 2026Marathon Oil EF LLCLive OakWhitsett-Taylor-Mass SA C #1H17,50029736602
918391Sep 23, 2026Sep 21, 2026Marathon Oil EF LLCLive OakWhitsett-Taylor-Mass SA B #1H17,50029736600
918390Sep 23, 2026Sep 21, 2026Marathon Oil EF LLCLive OakWhitsett-Taylor-Mass SA A #1H17,50029736599
918436Sep 12, 2026Sep 10, 2026Marathon Oil EF LLCKarnesHaus-Chris SA D #1H17,50025538462

Full permit history →

About this data

Registration from the RRC P-5 organization report, refreshed weekly. Permits from the OGA049M master and daily daf420 files; wells of record from the EWA wellbore schedule; production from PDQ lease reports at the last vintage; disposal from UIC permits and H-10 reports. Summary figures are rebuilt nightly.

Developers: this page as JSON is GET /v1/data/operators/tx/525398, documented in the API reference.