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Royalty Clerk

Texas oil lease · RRC district 01 · Lease 07875

Producing

SUN MARK EXPLORATION

Sun Mark Exploration is an oil lease in Caldwell County, Texas, operated by Castillo Oil Company LLC in the Salt Flat, West field. The Railroad Commission shows 275 bbl of oil in the 12 months through Jul 2026.

Oil lease dossier · 6 wells

275bbl oil, last 12 months−33% vs prior year
Operator
Castillo Oil Company LLC
County
Caldwell County
Field
Salt Flat, West
RRC lease
01-07875

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Where it sits

This county

Caldwell CountyCaldwellComalGonzalesFayetteTravisBastropLeeHaysGuadalupeCaldwell County
Caldwell County · RRC district 01Open Caldwell County →
Oil in Jul 2026
19 bbl
Reporting to the state
since Jan 2020
Wells
6
Data through
Jul 2026

Production

Month by month, from the state record

What the Railroad Commission says this oil lease produced. Oil is in barrels (bbl). Gas is in thousand cubic feet (mcf).

Oil output fell 33% over the last 12 months

275 bbl in the 12 months through Jul 2026, against 408 bbl in the 12 months before.

  • Oil (bars, left axis)
  • Last 12 months
Oil output fell 33% over the last 12 monthsMonthly oil production for SUN MARK EXPLORATION, Aug 2023 to Jul 2026. Oil output fell 33% over the last 12 months. 275 bbl in the 12 months through Jul 2026, against 408 bbl in the 12 months before.Last 12 months: 275 bblbbl per month050100150200Oct 23Jan 24AprJulOctJan 25AprJulOctJan 26AprJul
Oil output fell 33% over the last 12 monthsMonthly oil production for SUN MARK EXPLORATION, Aug 2023 to Jul 2026. Oil output fell 33% over the last 12 months. 275 bbl in the 12 months through Jul 2026, against 408 bbl in the 12 months before.Last 12 monthsbbl per month050100150200Jan 24JulJan 25JulJan 26Jul

SourceTexas Railroad Commission Production Data Query, oil lease 07875, district 01. Reported through Jul 2026. The state revises recent months.

Gas disposition

Where the gas went

Every month the operator tells the state where each mcf of gas went, using a code. The code decides how your gas is paid.

No gas disposition reported for this lease

The operator has not reported where the gas went in the months we hold.

Operator history

Who has run this lease

The operator runs the wells and pays your royalty. When the operator changes, payments often slip for a month or two.

Castillo Oil Company LLC has reported this lease for the whole period

No change of operator in the months we hold.

Operators of this lease over timeCastillo Oil Company LLC, Jan 2020 to Jul 20262020202120222023202420252026Castillo Oil Company LLCJan 2020 to nowthrough Jul 2026
Operators of this lease over timeCastillo Oil Company LLC, Jan 2020 to Jul 20262020202120222023202420252026Castillo Oil Company LLCJan 2020 to nowthrough Jul 2026

SourceTexas Railroad Commission Production Data Query, operator by month. Reported through Jul 2026.

Wells

6 wells on this lease

Every well the Railroad Commission links to oil lease 07875 in district 01. The API number is the state’s ID for a well.
Wells on SUN MARK EXPLORATION
API numberWell no.Status
42-055-322682CActive
42-055-322691CActive
42-055-322702BActive
42-055-322711BActive
42-055-322722AActive
42-055-322731AActive

SourceTexas Railroad Commission Wellbore Query, district 01, lease 07875.

Who buys and gathers

Who moves and buys this lease's production

The operator files a Form P-4 with the Railroad Commission naming the companies authorised to gather and buy the oil and gas. The buyer's price is the one your royalty is figured on.

  • Oil

    Ace Gathering, Inc. gathers it.

    100% of it, on the list since Jan 1, 2018

SourceRailroad Commission of Texas, Form P-4 file, dated Sep 24, 2026 (source). A listed company is authorised to move or buy the production; the state does not say what it paid.

Who buys my oil and gasIs my oil price fair?

Unit and wells

22 acres on the newest permit

Acres and wells as the operator filed them on its Railroad Commission drilling permits. Your decimal is your net acres over the unit acres, so this is the number to hold your division order against.
Wells on the permits
88 not plugged
Horizontal
0
First completion
Nov 7, 1981
Latest permit
Feb 18, 1982

8 wells are listed on this lease

Each well can have its own unit. The decimal for one well does not have to equal the decimal for another.

Wells and acres on the permits for Sun Mark Exploration
API numberWell no.Acreson the permit
42-055-322682C22
42-055-322691C22
42-055-322702B22
42-055-32272222
42-055-322722A22
42-055-32273122
42-055-322731A22
42-055-322711B22

SourceRailroad Commission of Texas, drilling permits and wellbore file, Sep 26, 2026 (source 1, source 2). The acres are what the operator filed; they are not a survey.

Check my decimal against the unit

Estimator

Estimate your royalty for this lease

A rough check before you look at a statement: the state volumes times your decimal, priced at WTI and Henry Hub.

Estimator

What could your check be?

Your decimal interest is the small number on your division order that says what share of the whole lease (8/8ths) is yours. Type it in and we apply it to what the state says SUN MARK EXPLORATION sold each month.

For example 0.00097656, or a fraction like 1/1024.

Dollars per barrel. Your statements show the gap your operator uses. Leave 0 to price oil at WTI.

Your estimate appears here

Enter your decimal to see an estimated royalty for each of the last 12 months this lease reported. Nothing you type leaves your browser.

An estimate, not your check

It ignores gathering and processing fees, taxes, plant products and the price your operator actually gets, so your statement will differ. Use it as a ceiling to compare against.

Ledger

36 months, newest first

Compare these numbers with your statements. Your share of a month is the “Oil sold” volume times your decimal. Scroll sideways on a phone.
Monthly production, disposition and prices for SUN MARK EXPLORATION
MonthOil producedbblOil soldbblWTI$ per bblHenry Hub$ per MMBtu
Jul 2026Castillo Oil190$80.46$2.89
Jun 2026Castillo Oil180$84.81$3.15
May 2026Castillo Oil150$102.13$2.94
Apr 2026Castillo Oil16160$100.32$2.77
Mar 2026Castillo Oil250$91.38$3.04
Feb 2026Castillo Oil430$64.51$3.62
Jan 2026Castillo Oil340$60.04$7.72
Dec 2025Castillo Oil280$57.97$4.26
Nov 2025Castillo Oil60$60.06$3.79
Oct 2025Castillo Oil300$60.89$3.19
Sep 2025Castillo Oil23162$63.96$2.97
Aug 2025Castillo Oil180$64.86$2.91
Jul 2025Castillo Oil100$68.39$3.20
Jun 2025Castillo Oil00$68.17$3.02
May 2025Castillo Oil10$62.17$3.12
Apr 2025Castillo Oil31174$63.54$3.42
Mar 2025Castillo Oil400$68.24$4.12
Feb 2025Castillo Oil260$71.53$4.19
Jan 2025Castillo Oil320$75.74$4.13
Dec 2024Castillo Oil360$70.12$3.01
Nov 2024Castillo Oil21161$69.95$2.12
Oct 2024Castillo Oil360$71.99$2.20
Sep 2024Castillo Oil1380$70.24$2.28
Aug 2024Castillo Oil370$76.68$1.99
Jul 2024Castillo Oil300$81.80$2.07
Jun 2024Castillo Oil49174$79.77$2.54
May 2024Castillo Oil480$80.02$2.12
Apr 2024Castillo Oil450$85.35$1.60
Mar 2024Castillo Oil520$81.28$1.49
Feb 2024Castillo Oil40171$77.25$1.72
Jan 2024Castillo Oil680$74.15$3.18
Dec 2023Castillo Oil300$71.90$2.52
Nov 2023Castillo Oil40172$77.69$2.71
Oct 2023Castillo Oil320$85.64$2.98
Sep 2023Castillo Oil140$89.43$2.64
Aug 2023Castillo Oil100$81.39$2.58

No report filed More than 3% of gas flared

SourceVolumes: Texas Railroad Commission Production Data Query, reported through Jul 2026. Prices: EIA WTI Cushing spot and Henry Hub spot, monthly, through Aug 2026. “Gas sold” is gas sent to a transmission line (code 2) or a plant (code 3).

Check your statements

Do your checks match this lease?

Upload your statements for SUN MARK EXPLORATION. We compare volumes, prices, deductions and timing with the state record and give you the exact question to ask Castillo Oil Company LLC.

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  • Fees taken on gas
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Around this lease

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Everything on this page connects to the operator, field and county records. Start from any of them.

This lease belongs to

OperatorCastillo Oil Company LLCFieldSalt Flat, WestCountyCaldwell County

Castillo Oil Company LLC in Caldwell County

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Salt Flat, West field

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Found by the location of their wells.

Drilling permits within 10 km

How to read this page

Questions owners ask

What is a decimal interest?

It is your share of the whole lease, written as a decimal. A 1/4 royalty on 5 net acres in a 1,280-acre unit is 1/4 × 5 ÷ 1,280 = 0.00097656. Your division order states yours.

How do I use this page to check a royalty check?

Take the “Oil sold” volume for the month the check covers and multiply it by your decimal. The answer should match the barrels on your statement. If it does not, upload the statement and we will show where the two differ.

Why is the newest month Jul 2026?

The Railroad Commission publishes production two to three months after the fact and revises recent months. We re-pull the latest three months on every update.

Does this page show what my check should be?

No. It shows what the state recorded. Prices, fees and taxes depend on your lease and on what your operator gets for the oil and gas. The estimator gives a ceiling to compare against.

Sources and method

Where these numbers come from

  • Production and disposition by month: Texas Railroad Commission Production Data Query, oil lease 07875, district 01, reported through Jul 2026.
  • Wells: Texas Railroad Commission Wellbore Query.
  • Prices: U.S. Energy Information Administration, WTI Cushing spot and Henry Hub spot, monthly.
  • Page updated Sep 28, 2026.

We show the state’s numbers as filed. Where the state has no report for a month, we say so instead of guessing.