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Royalty Clerk

Texas operator · RRC P-5 525398

Marathon Oil Ef LLC

Marathon Oil Ef LLC runs 1,561 producing leases in 8 Texas counties. The Railroad Commission shows 29 million barrels of oil and 104 million mcf of gas in the 12 months through Jul 2026.

Operator dossier · 8 counties

29,216,060bbl oil, last 12 months−32% vs prior year
Producing leases
1,561of 1,980 on record
Counties
8
Biggest county
Karnes County
Biggest field
Eagleville (Eagle Ford-1)

Get checks from Marathon Oil Ef LLC?

Upload a royalty check stub or a phone photo. We compare each month with the state numbers for the lease and tell you what to ask.

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Where they work

fewermore

Atascosa County: 111 producing leasesLavaca County: 19 producing leasesMcMullen County: 2 producing leasesGonzales County: 61 producing leasesKarnes County: 932 producing leasesDe Witt County: 213 producing leasesBee County: 11 producing leasesLive Oak County: 212 producing leasesAtascosaGonzalesKarnes
8 counties with producing leasesClick a county to open it
Gas, last 12 months
104,473,064 mcf
RRC operator no.
525398
Leases on record
1,980
Data through
Jul 2026

Production

Five years of Marathon Oil Ef LLC output

Monthly totals across every lease the Railroad Commission lists under this operator. When the operator buys or sells leases, its total moves with them.

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

29M bbl in the 12 months through Jul 2026, against 43M bbl in the 12 months before. Peak month: Jul 2024, 4.5M bbl.

Oil output from Marathon Oil Ef LLC fell 32% over the last 12 months29M bbl in the 12 months through Jul 2026, against 43M bbl in the 12 months before. Peak month: Jul 2024, 4.5M bbl.Oil, bbl per month01M2M3M4M5MPeak 4.5M (Jul 24)2.1M20222023202420252026
Oil output from Marathon Oil Ef LLC fell 32% over the last 12 months29M bbl in the 12 months through Jul 2026, against 43M bbl in the 12 months before. Peak month: Jul 2024, 4.5M bbl.Oil, bbl per month01M2M3M4M5MPeak 4.5M (Jul 24)2.1M'22'23'24'25'26

Gas output from Marathon Oil Ef LLC fell 34% over the last 12 months

104M mcf in the 12 months through Jul 2026, against 159M mcf in the 12 months before. Peak month: Jul 2023, 16M mcf.

Gas output from Marathon Oil Ef LLC fell 34% over the last 12 months104M mcf in the 12 months through Jul 2026, against 159M mcf in the 12 months before. Peak month: Jul 2023, 16M mcf.Gas, mcf per month05M10M15M20MPeak 16M (Jul 23)7.6M20222023202420252026
Gas output from Marathon Oil Ef LLC fell 34% over the last 12 months104M mcf in the 12 months through Jul 2026, against 159M mcf in the 12 months before. Peak month: Jul 2023, 16M mcf.Gas, mcf per month05M10M15M20MPeak 16M (Jul 23)7.6M'22'23'24'25'26

SourceTexas Railroad Commission, Production Data Query, summed over every lease reported under operator 525398. Reported through Jul 2026, file dated Sep 18, 2026. The newest month is often revised as operators file late.

Leases

Marathon Oil Ef LLC leases, biggest first

Find the lease printed on your statement. Filter by county, sort by output or by change over the year, and open any lease for its ledger.

Showing 25 of 150 (the 150 largest of 1,561 producing leases).

Search by lease name →

SourceTexas Railroad Commission, Production Data Query. Ranked by an approximate value of last-12-month output, so oil and gas wells sort together.

Where they work

Counties and fields where Marathon Oil Ef LLC produces

Every county and field links to the others operating there, so you can see who else is drilling around your lease.

Counties, by Marathon Oil Ef LLC oil

Karnes County leads

  1. Karnes County932 producing leases14Mbbl
  2. Atascosa County111 producing leases8.6Mbbl
  3. Gonzales County61 producing leases3.5Mbbl
  4. De Witt County213 producing leases1.6Mbbl
  5. Live Oak County212 producing leases1.4Mbbl
  6. Lavaca County19 producing leases170kbbl
  7. McMullen County2 producing leases25.2kbbl
  8. Bee County11 producing leases1,872bbl

Fields, by Marathon Oil Ef LLC oil

Eagleville (Eagle Ford-1) leads

  1. Eagleville (Eagle Ford-1)156 producing leases · District 01 · Field 2713570011Mbbl
  2. Eagleville (Eagle Ford-2)388 producing leases · District 02 · Field 2713575010Mbbl
  3. Sugarkane (Eagle Ford)684 producing leases · District 02 · Field 869506006.3Mbbl
  4. De Witt (Eagle Ford Shale)196 producing leases · District 02 · Field 244925001.3Mbbl
  5. Sugarkane (Austin Chalk)135 producing leases · District 02 · Field 86950300785kbbl
  6. Fashing (Austin Chalk)1 producing lease · District 01 · Field 303791002,348bbl
  7. San Marcos (Austin Chalk)1 producing lease · District 02 · Field 8028050051bbl

Recent drilling permits for Marathon Oil Ef LLC

How to read the statement

How to read a Marathon Oil Ef LLC royalty statement

Every operator lays out its stub differently, but the same seven parts are on all of them. This guide is a template, with what public records tell us about Marathon Oil Ef LLC added where they help. We have not catalogued Marathon Oil Ef LLC’s exact layout yet.

  1. The header: who paid you, and for which check

    Look for the payor name, your owner number, the check number and the check date. Keep the owner number: every call or letter to the operator starts with it.

    What we knowMarathon Oil Ef LLC is Railroad Commission operator 525398. The name on your check may be a parent company or a payment subsidiary.

  2. The property line: which lease this is

    Each lease you own in gets its own block, named as the operator names it. That name can be shorter than the state's, or carry a suffix such as a well number or unit letter.

    What we knowMarathon Oil Ef LLC runs 1,561 producing leases across 8 counties, so one check can list many properties. Find yours in the table above by name, or search for the name printed on the stub.

  3. Product and volume: barrels, mcf, and the month

    The stub shows the production month (the production month, not the check month), the product and your share of the volume. Divide your volume by your decimal to get the lease total, then compare it with the lease page.

    What we knowFor example, open MIDDLE MCCOWEN, BARNHART (EF) or RIDLEY 01 and read the “oil sold” and “gas sold” columns.

  4. Price: what the operator says it got

    Oil is usually close to the WTI benchmark for the month. Gas prices vary widely: they depend on where the gas is sold and on what the operator subtracts before it reports a price.

  5. Deductions: gathering, compression, processing

    Costs taken after the well. Some leases allow them and some do not; your lease and division order say which. A deduction that appears in one month and not the next is worth a question.

    What we knowAbout 90% of the gas Marathon Oil Ef LLC reported in the last 12 months went to processing plants, so expect processing and plant-product lines on gas statements. Another 0.0% went straight to a pipeline.

  6. Taxes: severance and ad valorem

    Texas severance tax is taken from your share: 4.6% of oil value and 7.5% of gas value at market. Ad valorem tax may also appear. The rate on your stub should match these.

  7. Net: gross, minus deductions and taxes, times your share

    Check the arithmetic: volume times price gives gross value, then subtract deductions and taxes. If the net does not match your check, or a month is missing, that is the first thing to ask about.

    What we know0.6% of the gas Marathon Oil Ef LLC reported was flared or vented. Flared gas pays no royalty, so a lease that flares heavily will show a smaller gas volume on your stub than on the state's production line.

At a glance

Marathon Oil Ef LLC

RRC operator number (P-5)
525398
Producing leases
1,561
Counties
8
Biggest county
Karnes County
Oil, last 12 months
29,216,060 bbl
Gas sent to plants
90%
Gas sold to pipelines
0.0%
Gas flared or vented
0.6%

Owner relations

Who to call at Marathon Oil Ef LLC

We have not yet added Marathon Oil Ef LLC’s owner relations phone, mailing address or online portal. It is usually printed at the top or bottom of your statement. The Railroad Commission also holds an address for the operator under number 525398.

When there is something to ask

We write the question for you, with the numbers behind it, and a letter you can send.
Check a Marathon Oil Ef LLC statement