TEXAS · WELLS · ATASCOSA COUNTY · MIDDLE MCCOWEN LEASE · API 42-013-35532 · DISTRICT 01
Middle McCowen #166H
Atascosa County · Eagleville (Eagle Ford-1) field · Producing · Horizontal
Middle Mccowen #166H (API 42-013-35532) is a horizontal well in Atascosa County operated by Marathon Oil EF LLC, completed August 15, 2023 and listed as producing on the RRC schedule.
The RRC has issued one drilling permit (amended once), issued September 28, 2017, permitted to 9,884 ft.
Completion filings report 10 formation tops, including Queen City, Reklaw, Bartosh, Carrizo.
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
- 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 schedule | Marathon Oil EF LLC |
| Production reports | Marathon Oil EF LLCthrough Apr 2026 |
| Latest permit | Marathon Oil EF LLCSep 28, 2017 |
- 9,884
- total depth, ft
- 2
- permits on file
- Sep 28, 2017
- last permit issued
- Aug 15, 2023
- 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
- Aug 15, 2023
- Shut in
- —
- Plugged
- —
Operator's P-5 on the schedule: Active – Extension (X)
Surface location
28.702708, -98.382406 NAD27, as filed
28.702970, -98.382697 WGS84
Permit surface location from the RRC GIS record, referenced to NAD27 as the RRC files it; the WGS84 pair is the same point through NOAA's NADCON grid, and the map link uses it, in Atascosa County.
Wells nearby
Every well with a location on file around this one, in any state, nearest first.
Loading the wells nearby…
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 →
| Lease | Field | Reporting operator | Wells | Oil, bbl | Gas, mcf | Reported |
|---|---|---|---|---|---|---|
| Middle McCowen O-1-15638 | Eagleville (Eagle Ford-1) | Marathon Oil EF LLC | 125 | 30.4M | 24.8M | Aug 2011 – Apr 2026 |
Oil, barrels lease total
Last 12 months 4,281,756 · prior 12 5,967,262(-28%)
Gas, mcf lease total
Last 12 months 3,027,282 · prior 12 4,175,011(-27%)
Chain of custody
Every operator that reported production on this well's lease, in order.
- 1Hilcorp Energy CompanySep 2011 → Oct 2011
- 2Marathon Oil EF LLCNov 2011 → Apr 2026
Permits
| Permit | Type | Operator | Received | Issued | Spud | Depth |
|---|---|---|---|---|---|---|
| 831142-98 | Drill | Marathon Oil EF LLC | Nov 1, 2018 | Sep 28, 2017 | Jun 15, 2018 | 19,500 |
| 831142-99 | Drill | Marathon Oil EF LLC | Sep 20, 2017 | Sep 28, 2017 | Mar 27, 2018 | 19,500 |
Completions
| Completed | Lease | Field | Operator | Status | Depth |
|---|---|---|---|---|---|
| Aug 15, 2023 | Middle McCowen O-1-15638 | Eagleville (Eagle Ford-1) | Marathon Oil EF LLC | Producing | 9,884 |
Formation tops
As filed on W-2/G-1. Subsea from 241 ft elevation.Download CSV →
| Formation | MD ft | Subsea |
|---|---|---|
| Queen City | 2,172 | -1,931 |
| Reklaw | 2,612 | -2,371 |
| Bartosh | 3,014 | -2,773 |
| Carrizo | 3,378 | -3,137 |
| WilcoxWILCOX - DISPOSAL | 4,712 | -4,471 |
| NavarroNAVARRO - H2S | 7,754 | -7,513 |
| OlmosOLMOS - DISPOSAL | 8,114 | -7,873 |
| AnacachoANACACHO - H2S | 9,651 | -9,410 |
| Austin ChalkAUSTIN CHALK - H2S, DISPOSAL | 9,851 | -9,610 |
| Bartosh | — | — |
| EscondidoESCONDIDO - H2S, DISPOSAL | — | — |
| NavarroNAVARRO - H2S | — | — |
| OlmosOLMOS - DISPOSAL | — | — |
Perforations
Perforated and open-hole intervals.
| From | To | Type |
|---|---|---|
| 10,242 | 16,981 | Perforated |
Casing
Strings as reported, shallowest first.
| Casing in | Set at | Hole in | Cement |
|---|---|---|---|
| 9.625 | 4,612 | 12.25 | 1,469 S |
| 5.5 | 17,089 | 8.75 | 3,010 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 →
| Suffix | RRC record date | W-2 / G-1 date | Logs referenced |
|---|---|---|---|
| 00 | Nov 13, 2023 | Oct 3, 2023 | — |
| 00 | Mar 4, 2019 | Jan 18, 2019 | Yes |
| 00 | Dec 6, 2018 | Sep 17, 2018 | Yes |
Well logs
2 logs loaded from the RRC's log index, the latest received Jul 13, 2021. Gamma ray. 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 described | Files | Intervalft, as filed | Datereceived | SizeMB |
|---|---|---|---|---|
| Gamma RaySpans Carrizo, Wilcox, Navarro, Olmos, Anacacho, Austin Chalk | TIFF | 4,700 to 17,068 | Jul 13, 2021 | 9.62 |
| Gamma RaySpans Carrizo, Wilcox, Navarro, Olmos, Anacacho, Austin Chalk | TIFF | 4,700 to 17,068 | Apr 12, 2021 | 9.62 |
"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.
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.
- Wellbore filings for 42-013-35532 → W-2, G-1, plugging reports, as PDFs
- Completion packets for 42-013-35532 → scanned completion filings
The logs loaded for this well are under Well logs, with the RRC's log search for it.
Nearby wells and their tops
NEAREST 8 LOCATED WELLS WITH TOPS · WITHIN 16 KM
Draw a cross-section
This well's tops beside its 5 nearest neighbors, subsea-aligned so they line up regardless of surface terrain.
Middle McCowen42-013-35531
0.0 KM · Marathon Oil EF LLC · Section with this well →
| Queen City | 2,172 | 2,278 |
| Reklaw | 2,612 | 1,838 |
| Bartosh | 3,014 | 1,436 |
| Carrizo | 3,378 | 1,072 |
| Wilcox | 4,712 | -262 |
| Navarro | 7,754 | -3,304 |
| Olmos | 8,114 | -3,664 |
| Anacacho | 9,654 | -5,204 |
10 TOPS · FIRST 8
Middle McCowen42-013-35533
0.0 KM · Marathon Oil EF LLC · Section with this well →
| Queen City | 2,172 | -1,931 |
| Reklaw | 2,612 | -2,371 |
| Bartosh | 3,014 | -2,773 |
| Carrizo | 3,378 | -3,137 |
| Wilcox | 4,712 | -4,471 |
| Navarro | 7,754 | -7,513 |
| Olmos | 8,114 | -7,873 |
| Anacacho | 9,367 | -9,126 |
10 TOPS · FIRST 8
Middle McCowen42-013-35530
0.0 KM · Marathon Oil EF LLC · Section with this well →
| Queen City | 2,172 | -1,930 |
| Reklaw | 2,612 | -2,370 |
| Bartosh | 3,014 | -2,772 |
| Carrizo | 3,378 | -3,136 |
| Wilcox | 4,439 | -4,197 |
| Navarro | 7,754 | -7,512 |
| Olmos | 8,114 | -7,872 |
| Anacacho | 9,652 | -9,410 |
10 TOPS · FIRST 8
Middle McCowen42-013-35827
0.0 KM · Marathon Oil EF LLC · Section with this well →
| Queen City | 2,180 | -1,938 |
| Reklaw | 2,619 | -2,377 |
| Bartosh | 3,021 | -2,779 |
| Carrizo | 3,297 | -3,055 |
| Wilcox | 3,477 | -3,235 |
| Olmos | 8,122 | -7,880 |
| Anacacho | 9,611 | -9,369 |
| Austin Chalk | 9,818 | -9,576 |
10 TOPS · FIRST 8
Middle McCowen42-013-35826
0.0 KM · Marathon Oil EF LLC · Section with this well →
| Queen City | 2,180 | -1,938 |
| Reklaw | 2,619 | -2,377 |
| Bartosh | 3,021 | -2,779 |
| Carrizo | 3,297 | -3,055 |
| Wilcox | 3,477 | -3,235 |
| Olmos | 8,122 | -7,880 |
| Anacacho | 9,626 | -9,384 |
| Austin Chalk | 9,837 | -9,595 |
10 TOPS · FIRST 8
Middle McCowen42-013-35825
0.1 KM · Marathon Oil EF LLC · Section with this well →
| Queen City | 2,180 | -1,938 |
| Reklaw | 2,619 | -2,377 |
| Bartosh | 3,021 | -2,779 |
| Carrizo | 3,297 | -3,055 |
| Wilcox | 3,477 | -3,235 |
| Olmos | 8,122 | -7,880 |
| Anacacho | 9,629 | -9,387 |
| Austin Chalk | 9,841 | -9,599 |
10 TOPS · FIRST 8
Middle McCowen42-013-35780
2.0 KM · Marathon Oil EF LLC · Section with this well →
| Queen City | 490 | -250 |
| Reklaw | 2,838 | -2,598 |
| Carrizo | 3,604 | -3,364 |
| Wilcox | 4,938 | -4,698 |
| Anacacho | 9,897 | -9,657 |
| Austin Chalk | 10,088 | -9,848 |
| Olmos | — | |
| Bartosh | — |
10 TOPS · FIRST 8
Middle McCowen42-013-35781
2.0 KM · Marathon Oil EF LLC · Section with this well →
| Queen City | 490 | -241 |
| Reklaw | 2,838 | -2,589 |
| Carrizo | 3,604 | -3,355 |
| Wilcox | 4,938 | -4,689 |
| Anacacho | 9,866 | -9,617 |
| Austin Chalk | 10,089 | -9,840 |
| Escondido | — | |
| Olmos | — |
10 TOPS · FIRST 8
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/01335532, documented in the API reference.