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Royalty Clerk

RRC operator 525398

Marathon Oil Ef LLC

Marathon Oil Ef LLC reported 29 million barrels of oil and 101 million mcf of gas in the last 12 months.

Operator dossier

28,673,899bbl oil, last 12 months−32% vs prior year
Producing leases
1,545of 1,982 on record
Counties
8
Biggest county
Karnes County
Biggest field
Eagleville (Eagle Ford-2)

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Where they work

fewermore

Atascosa County: 112 producing leasesLavaca County: 19 producing leasesMcMullen County: 2 producing leasesGonzales County: 62 producing leasesKarnes County: 928 producing leasesDe Witt County: 200 producing leasesBee County: 11 producing leasesLive Oak County: 211 producing leasesAtascosaGonzalesKarnes
8 counties
Gas, last 12 months
101,014,184 mcf
Fields
7
Data through
Aug 2026
Leases on record
1,982

Where Marathon Oil Ef LLC has wells

Every well the state's map puts on a lease it operates now, and its drilling permits of the last 24 months.
Map of the wells of Marathon Oil Ef LLC in Texas: 3,160 wells and 99 recent drilling locations, in a picture about 126 miles across.
  • Drilling locations99Permits issued in the last two years
  • Producing wells2,693On a lease reporting production now
  • Not producing455Shut in, inactive or no lease on record
  • Plugged12The state's wellbore record says plugged

Each dot is a well on a lease Marathon Oil Ef LLC operates now, where the Railroad Commission's map puts it, or one of its drilling permits of the last 24 months. Wells of other operators are not on this map. The picture is about 126 miles across. The white counties are the ones with a well or drilling permit of its own on the map. Sources: Railroad Commission of Texas well layers and drilling permit files, US Census Bureau county outlines, town points from GeoNames (CC BY 4.0).

See the whole Texas well map

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You may show this map on any site, unchanged. Keep the credit line and its link to Royalty Clerk under the map. The picture updates by itself as the state records new wells and permits.

Download the picture (WebP)
<a href="https://royaltyclerk.com/texas/operators/marathon-oil-ef-llc-525398"><img src="https://royaltyclerk.com/maps/operator-wells/marathon-oil-ef-llc-525398.svg" alt="Map of the wells of Marathon Oil Ef LLC in Texas: 3,160 wells and 99 recent drilling locations, in a picture about 126 miles across." width="1000" height="951" loading="lazy" style="max-width:100%;height:auto;border:0"></a>
<p style="margin:4px 0 0;font-size:14px">Map: <a href="https://royaltyclerk.com/texas/operators/marathon-oil-ef-llc-525398">Oil and gas wells of Marathon Oil Ef LLC in Texas</a> by Royalty Clerk, from Railroad Commission of Texas records</p>

Five years of Marathon Oil Ef LLC output

Oil output from Marathon Oil Ef LLC fell 32% over the last 12 months

29M bbl through Aug 2026, against 42M bbl a year earlier. Peak Jul 2024: 4.5M bbl.

Oil output from Marathon Oil Ef LLC fell 32% over the last 12 months29M bbl through Aug 2026, against 42M bbl a year earlier. Peak Jul 2024: 4.5M bbl.Oil, bbl per month01M2M3M4M5MPeak 4.5M (Jul 24)2.2M20222023202420252026
Oil output from Marathon Oil Ef LLC fell 32% over the last 12 months29M bbl through Aug 2026, against 42M bbl a year earlier. Peak Jul 2024: 4.5M bbl.Oil, bbl per month01M2M3M4M5MPeak 4.5M (Jul 24)2.2M'22'23'24'25'26

Gas output from Marathon Oil Ef LLC fell 35% over the last 12 months

101M mcf through Aug 2026, against 155M mcf a year earlier. Peak Jul 2023: 16M mcf.

Gas output from Marathon Oil Ef LLC fell 35% over the last 12 months101M mcf through Aug 2026, against 155M mcf a year earlier. Peak Jul 2023: 16M mcf.Gas, mcf per month05M10M15M20MPeak 16M (Jul 23)7.6M20222023202420252026
Gas output from Marathon Oil Ef LLC fell 35% over the last 12 months101M mcf through Aug 2026, against 155M mcf a year earlier. Peak Jul 2023: 16M mcf.Gas, mcf per month05M10M15M20MPeak 16M (Jul 23)7.6M'22'23'24'25'26

SourceTexas Railroad Commission Production Data Query, operator 525398, through Aug 2026, file dated Oct 20, 2026.

Marathon Oil Ef LLC leases, biggest first

Under each volume: change on the year before.

Showing 25 of 150 (the 150 largest of 1,545), ranked by output value.

Search by lease name →

SourceTexas Railroad Commission Production Data Query.

Counties and fields where Marathon Oil Ef LLC produces

Counties, by Marathon Oil Ef LLC oil

Karnes County leads

  1. Karnes County928 leases14Mbbl
  2. Atascosa County112 leases8.2Mbbl
  3. Gonzales County62 leases3.5Mbbl
  4. De Witt County200 leases1.6Mbbl
  5. Live Oak County211 leases1.3Mbbl
  6. Lavaca County19 leases161kbbl
  7. McMullen County2 leases24.7kbbl
  8. Bee County11 leases1,656bbl

Fields, by Marathon Oil Ef LLC oil

Eagleville (Eagle Ford-1) leads

  1. Eagleville (Eagle Ford-1)158 leases · District 01 · Field 2713570010Mbbl
  2. Eagleville (Eagle Ford-2)386 leases · District 02 · Field 2713575010Mbbl
  3. Sugarkane (Eagle Ford)681 leases · District 02 · Field 869506005.9Mbbl
  4. De Witt (Eagle Ford Shale)188 leases · District 02 · Field 244925001.4Mbbl
  5. Sugarkane (Austin Chalk)130 leases · District 02 · Field 86950300747kbbl
  6. Fashing (Austin Chalk)1 lease · District 01 · Field 303791002,348bbl
  7. San Marcos (Austin Chalk)1 lease · District 02 · Field 8028050051bbl

Recent drilling permits for Marathon Oil Ef LLC

Where the gas of Marathon Oil Ef LLC went

Plants
90%
Pipelines
0.0%
Lease fuel
9.7%
Flared or vented
0.6%

SourceTexas Railroad Commission Production Data Query, last 12 months. What the codes mean

Marathon Oil Ef LLC address and phone number

This is the mailing address and phone Marathon Oil Ef LLC filed with the Texas Railroad Commission. It is the company’s address of record with the state. It can be a regulatory office and not the desk that pays royalties, so a letter about a payment should name the owner relations or division order department, your owner number and the lease name from your stub.

Mailing address

Marathon Oil Ef LLC
PO Box 2197 Regulatory Dept
Houston, TX 77252

State filing

RRC operator 525398 · P-5 status: Active (extension) · last filing received Oct 13, 2026

Writing about a missing or stopped check? See what to ask first or open the company record for its state registration and who buys its oil and gas.

SourceTexas Railroad Commission, P-5 Organization data, file dated Oct 22, 2026. Royalty Clerk is not affiliated with Marathon Oil Ef LLC.