TEXAS · WELLS · ATASCOSA COUNTY · MIDDLE MCCOWEN LEASE · API 42-013-34570 · DISTRICT 01

Middle McCowen #20H

On schedule

Atascosa County · Eagleville (Eagle Ford-1) field · Producing  · Horizontal

Middle Mccowen #20H (API 42-013-34570) is a horizontal well in Atascosa County operated by Marathon Oil EF LLC, completed December 18, 2021 and listed as producing on the RRC schedule.

The RRC has issued one drilling permit, issued July 27, 2012, permitted to 10,749 ft.

Completion filings report 5 formation tops, including Wilcox, Olmos, Anacacho, Austin Chalk.

Its lease has reported 30.4M barrels of oil and 24.8M mcf of gas since August 2011, last reporting volume in April 2026. The lease carries 125 wells, so these are lease totals, not this well alone.

Operator of record

Marathon Oil EF LLC

Based in
Houston, TX
P-5 status
Active (A)
P-5 last filed
Sep 26, 2025
Permits on file
3,191
Phone
(832) 486-2737

SOURCE · RRC EWA WELLBORE SCHEDULE

What each RRC source says

Wellbore scheduleMarathon Oil EF LLC
Production reportsMarathon Oil EF LLCthrough Apr 2026
Latest permitMarathon Oil EF LLCJul 27, 2012
10,749
total depth, ft
1
permits on file
Jul 27, 2012
last permit issued
Dec 18, 2021
completed
30.4M
cumulative oil, bbl
24.8M
cumulative gas, mcf

PRODUCTION FROM PDQ LEASE REPORTS · SEP 2011 THROUGH APR 2026

Regulatory status · RRC wellbore file

Schedule
ON SCHEDULE
Completed
Dec 18, 2021
Shut in
—
Plugged
—

Operator's P-5 on the schedule: Active – Extension (X)

Surface location

No coordinates on the permit record yet. The RRC's GIS record usually lands within days of issuance; historical master-file permits never carry one.

Wells nearby

Every well with a location on file around this well, in any state, nearest first.

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Texas locations come from drilling permits, so most older Texas wells have none and are not listed.

Lease production

PDQ LEASE REPORTS · REPORTED THROUGH APR 2026

Texas reports oil by lease, not by well. These are the lease this well is completed on; they carry 125 wells in total, so volumes are shared.Why →

LeaseFieldReporting operatorWellsOil, bblGas, mcfReported
Middle McCowen O-1-15638Eagleville (Eagle Ford-1)Marathon Oil EF LLC12530.4M24.8MAug 2011 – Apr 2026

Oil, barrels lease total

Last 12 months 4,281,756 · prior 12 5,967,262(-28%)

0500K1M202420252026

Gas, mcf lease total

Last 12 months 3,027,282 · prior 12 4,175,011(-27%)

0200K400K600K202420252026

Wells named Middle McCowen

Marathon Oil EF LLC's other wells filed under this lease name in Atascosa County, newest permit first. The RRC gives a gas well its own lease number, so the name is what joins the wells of a unit.

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Chain of custody

Every operator that reported production on this well's lease, in order.

  1. 1Hilcorp Energy CompanySep 2011 → Oct 2011
  2. 2Marathon Oil EF LLCNov 2011 → Apr 2026

Permits

PermitTypeOperatorReceivedIssuedSpudDepth
744906-99DrillMarathon Oil EF LLCJul 18, 2012Jul 27, 2012Mar 4, 201318,200

Completions

CompletedLeaseFieldOperatorStatusDepth
Dec 18, 2021Middle McCowen O-1-15638Eagleville (Eagle Ford-1)Marathon Oil EF LLCProducing10,749

Formation tops

As filed on W-2/G-1. Subsea from 292 ft elevation.Download CSV →

FormationMD ftSubsea
Wilcox5,111-4,819
Olmos8,841-8,549
Anacacho10,442-10,150
Austin Chalk10,696-10,404
Eagle Ford10,792-10,500

Perforations

Perforated and open-hole intervals.

FromToType
11,04917,274Perforated

Casing

Strings as reported, shallowest first.

Casing inSet atHole inCement
9.6255,22012.251,280 S
5.517,4508.51,900 S

Completion filings

W-2 and G-1 reports on record in the RRC wellbore file, newest first. The suffix identifies the wellbore or completion event. The record date is the RRC's own date on the record, not the day the report was filed: 462,034 of the state's filings carry 1984-01-12. About these reports →

SuffixRRC record dateW-2 / G-1 dateLogs referenced
00Feb 10, 2022Jan 21, 2022—
00Oct 5, 2016Sep 29, 2016—
00Oct 4, 2016Sep 29, 2016—
00Sep 9, 2013Jul 3, 2013Yes
00Aug 8, 2013Jun 17, 2013Yes

Well logs

2 logs loaded from the RRC's log index, the latest received May 9, 2016. Resistivity. These are the logs loaded into Petrora from the Railroad Commission's inventories, not necessarily every log run on the well. The RRC holds the files; each opens from its log search for the well. The kind is the RRC's description of the log; the interval is the one filed for it.

Open the RRC's log search for this well ↗
Logas describedFiles Intervalft, as filedDatereceivedSizeMB
RESISTIVITYSpans Olmos, Anacacho, Austin Chalk, Eagle FordTIFF9,990 to 17,450May 9, 2016run Mar 16, 20132.20
RESISTIVITYSpans Olmos, Anacacho, Austin Chalk, Eagle Ford3 TIFF9,990 to 17,450May 2, 2016run Mar 16, 20130.63 + 0.48 + 0.67

"Spans" is by this well's own filed formation tops: a formation runs from its top to the next deeper top filed, and the deepest runs to the bottom of the log. Depths are measured along the wellbore, so on a horizontal the lateral counts in the formation it was landed in.

Find logs withinmiles of this well:List →Map →

Search the well logs loaded into Petrora →

The source documents

Petrora holds the structured record. The scanned filings live at the RRC; these links open its search already filled in for this API.

The logs loaded for this well are under Well logs, with the RRC's log search for it.

About this data

Permits from the RRC OGA049M master and daily daf420 files; wellbore and operator of record from the EWA schedule, weekly; completions, formation tops, casing, and perforations from the dbf900 wellbore file; production from PDQ lease reports, which lag two to three months; injection from UIC permits, H-10 reports, and TexNet daily volumes; earthquakes from the TexNet catalog.

New to these records? How to read a well page · API numbers · completion reports and tops · why production is by lease

Developers: this page as JSON is GET /v1/data/wells/01334570, documented in the API reference.