WELL · 42-013-36187 · DISTRICT 1
Hierholzer Retzloff-McMahon SA1 #1H
Atascosa County · Eagleville (Eagle Ford-1) field · Producing · Horizontal
Hierholzer Retzloff-Mcmahon Sa1 #1H (API 42-013-36187) is a permitted horizontal well in Atascosa County filed by Marathon Oil EF LLC; no completion report is on file yet.
The RRC has issued one drilling permit, issued August 1, 2024, permitted to 24,000 ft.
Completion filings report 10 formation tops, including Queen City, Reklaw, Carrizo, Wilcox.
Its lease has reported 299K barrels of oil and 413K mcf of gas since March 2025, last reporting in July 2026.
Operator of record
Houston, TX · P-5 Y, filed Aug 4, 2025 · 3,191 permits on file · (800) 332-9449
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 LLCAug 1, 2024 |
- 24,000
- total depth, ft
- 1
- permits on file
- Aug 1, 2024
- last permit issued
- —
- completed
- 299K
- cumulative oil, bbl
- 413K
- cumulative gas, mcf
PRODUCTION FROM PDQ LEASE REPORTS · Mar 2025 THROUGH Jul 2026
Regulatory status · RRC wellbore file
- Schedule
- ON SCHEDULE
- Completed
- —
- Shut in
- —
- Plugged
- —
Operator's P-5 on the schedule: Active
Surface location
28.806073, -98.138688
OpenStreetMap → · Google Maps →
Permit surface location from the RRC GIS record, in Atascosa County.
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; this well is the only one on it.Why →
| Lease | Field | Reporting operator | Wells | Oil, bbl | Gas, mcf | Reported |
|---|---|---|---|---|---|---|
| Hierholzer Retzloff-McMahon SA1 O-1-21771 | Eagleville (Eagle Ford-1) | Marathon Oil EF LLC | 1 | 299K | 413K | Mar 2025 – Jul 2026 |
Oil, barrels lease total
Last 12 months 218,949 · prior 12 80,296(+173%)
Gas, mcf lease total
Last 12 months 328,090 · prior 12 85,401(+284%)
Chain of custody
Every operator that reported production on this well's lease, in order.
- 1Marathon Oil EF LLCMar 2025 → Apr 2026
Permits
| Permit | Type | Operator | Received | Issued | Spud | Depth |
|---|---|---|---|---|---|---|
| 901580-99 | Drill | Marathon Oil EF LLC | Jul 25, 2024 | Aug 1, 2024 | Oct 23, 2024 | 24,000 |
Completions
| Completed | Lease | Field | Operator | Status | Depth |
|---|---|---|---|---|---|
| — | — O-1-21771 | — | — | — | — |
Formation tops
As filed on W-2/G-1. Subsea from 450 ft elevation.Download CSV →
| Formation | MD ft | Subsea |
|---|---|---|
| Queen City | 2,721 | -2,271 |
| Reklaw | 3,257 | -2,807 |
| Carrizo | 3,983 | -3,533 |
| WilcoxWILCOX - DISPOSAL | 4,107 | -3,657 |
| AnacachoANACACHO - H2S | 10,243 | -9,793 |
| Austin ChalkAUSTIN CHALK - H2S, DISPOSAL | 10,368 | -9,918 |
| Bartosh | — | — |
| EscondidoESCONDIDO - H2S, DISPOSAL | — | — |
| NavarroNAVARRO - H2S | — | — |
| OlmosOLMOS - DISPOSAL | — | — |
Perforations
Perforated and open-hole intervals.
| From | To | Type |
|---|---|---|
| 10,760 | 24,059 | Perforated |
Casing
Strings as reported, shallowest first.
| Casing in | Set at | Hole in | Cement |
|---|---|---|---|
| 9.625 | 5,048 | 12.25 | 1,405 S |
| 5.5 | 24,059 | 8.75 | 4,744 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. About these reports →
| Suffix | Filed | W-2 / G-1 date | Logs referenced |
|---|---|---|---|
| 00 | Sep 14, 2026 | Aug 25, 2026 | — |
| 00 | Aug 4, 2025 | May 8, 2025 | Yes |
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 42-013-36187 → W-2, G-1, plugging reports, as PDFs
- Completion packets for 42-013-36187 → scanned completion filings
Log images are in archives with no per-well link: the RRC's Neubus archive (2004 onward). then paste it into their search.
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 neighbours, subsea-aligned so they line up regardless of surface terrain.
Hierholzer Retzloff-McMahon SA242-013-36186
0.0 KM · Marathon Oil EF LLC · Section with this well →
| Queen City | 2,721 | -2,270 |
| Reklaw | 3,257 | -2,806 |
| Carrizo | 3,983 | -3,532 |
| Wilcox | 4,107 | -3,656 |
| Anacacho | 10,235 | -9,784 |
| Austin Chalk | 10,362 | -9,911 |
| Navarro | — | |
| Olmos | — |
10 TOPS · FIRST 8
Hierholzer Retzloff-McMahon SA342-013-36185
0.0 KM · Marathon Oil EF LLC · Section with this well →
| Queen City | 2,778 | -2,325 |
| Reklaw | 3,376 | -2,923 |
| Carrizo | 4,083 | -3,630 |
| Wilcox | 4,202 | -3,749 |
| Anacacho | 10,238 | -9,785 |
| Austin Chalk | 10,367 | -9,914 |
| Olmos | — | |
| Navarro | — |
10 TOPS · FIRST 8
Kowrs Allocation #542-013-35543
0.7 KM · XTO Energy Inc. · Section with this well →
| Queen City | 830 | -377 |
| Carrizo | 1,580 | -1,127 |
| Olmos | 1,820 | -1,367 |
| Reklaw | 1,900 | -1,447 |
| Escondido | 2,600 | -2,147 |
| Bartosh | 3,150 | -2,697 |
| Navarro | 3,600 | -3,147 |
| Wilcox | 4,660 | -4,207 |
11 TOPS · FIRST 8
Kowrs Allocation #442-013-35520
0.7 KM · XTO Energy Inc. · Section with this well →
| Queen City | 830 | -377 |
| Carrizo | 1,580 | -1,127 |
| Escondido | 1,820 | -1,367 |
| Reklaw | 1,900 | -1,447 |
| Olmos | 2,600 | -2,147 |
| Bartosh | 3,150 | -2,697 |
| Navarro | 3,600 | -3,147 |
| Wilcox | 4,660 | -4,207 |
10 TOPS · FIRST 8
Kowrs Allocation #342-013-35519
0.7 KM · XTO Energy Inc. · Section with this well →
| Queen City | 830 | -377 |
| Carrizo | 1,580 | -1,127 |
| Escondido | 1,820 | -1,367 |
| Reklaw | 1,900 | -1,447 |
| Olmos | 2,600 | -2,147 |
| Bartosh | 3,150 | -2,697 |
| Navarro | 3,600 | -3,147 |
| Wilcox | 4,660 | -4,207 |
10 TOPS · FIRST 8
Kowrs Allocation #242-013-35542
0.7 KM · XTO Energy Inc. · Section with this well →
| Queen City | 830 | -377 |
| Reklaw | 1,580 | -1,127 |
| Carrizo | 1,580 | -1,127 |
| Olmos | 1,820 | -1,367 |
| Escondido | 2,600 | -2,147 |
| Bartosh | 3,150 | -2,697 |
| Navarro | 3,600 | -3,147 |
| Wilcox | 4,660 | -4,207 |
11 TOPS · FIRST 8
Kowr Allocation #142-013-35521
0.7 KM · XTO Energy Inc. · Section with this well →
| Queen City | 830 | -377 |
| Carrizo | 1,580 | -1,127 |
| Olmos | 1,820 | -1,367 |
| Anacacho | 1,830 | -1,377 |
| Reklaw | 1,900 | -1,447 |
| Escondido | 2,600 | -2,147 |
| Austin Chalk | 3,050 | -2,597 |
| Bartosh | 3,150 | -2,697 |
10 TOPS · FIRST 8
Chapman Rothe Unit42-013-35411
1.5 KM · Marathon Oil EF LLC · Section with this well →
| Queen City | 2,858 | -2,452 |
| Reklaw | 3,433 | -3,027 |
| Bartosh | 3,686 | -3,280 |
| Carrizo | 4,104 | -3,698 |
| Wilcox | 5,520 | -5,114 |
| Navarro | 8,670 | -8,264 |
| Olmos | 9,057 | -8,651 |
| Anacacho | 10,386 | -9,980 |
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
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