WELL · 42-013-35848 · DISTRICT 1
Guajillo Unit 14 South #4H
Atascosa County · Eagleville (Eagle Ford-1) field · Producing · Horizontal
Guajillo Unit 14 South #4H (API 42-013-35848) is a horizontal well in Atascosa County operated by Marathon Oil EF LLC, completed January 19, 2022 and listed as producing on the RRC schedule.
The RRC has issued one drilling permit, issued May 14, 2021, permitted to 22,000 ft.
Completion filings report 10 formation tops, including Queen City, Reklaw, Carrizo, Wilcox.
Its lease has reported 486K barrels of oil and 564K mcf of gas since July 2021, last reporting in July 2026. The lease carries 4 wells, so these are lease totals, not this well alone.
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 LLCMay 14, 2021 |
- 22,000
- total depth, ft
- 1
- permits on file
- May 14, 2021
- last permit issued
- Jan 19, 2022
- completed
- 486K
- cumulative oil, bbl
- 564K
- cumulative gas, mcf
PRODUCTION FROM PDQ LEASE REPORTS · Jul 2021 THROUGH Jul 2026
Regulatory status · RRC wellbore file
- Schedule
- ON SCHEDULE
- Completed
- Jan 19, 2022
- Shut in
- —
- Plugged
- —
Operator's P-5 on the schedule: Active
Surface location
28.673589, -98.304786
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; they carry 4 wells in total, so volumes are shared.Why →
| Lease | Field | Reporting operator | Wells | Oil, bbl | Gas, mcf | Reported |
|---|---|---|---|---|---|---|
| Guajillo Unit 14 South O-1-20461 | Eagleville (Eagle Ford-1) | Marathon Oil EF LLC | 4 | 486K | 564K | Jul 2021 – Jul 2026 |
Oil, barrels lease total
Last 12 months 34,500 · prior 12 46,393(-26%)
Gas, mcf lease total
Last 12 months 48,551 · prior 12 75,216(-35%)
Chain of custody
Every operator that reported production on this well's lease, in order.
- 1Marathon Oil EF LLCNov 2021 → Apr 2026
Permits
| Permit | Type | Operator | Received | Issued | Spud | Depth |
|---|---|---|---|---|---|---|
| 869747-99 | Drill | Marathon Oil EF LLC | May 10, 2021 | May 14, 2021 | Jul 21, 2021 | 22,000 |
Completions
| Completed | Lease | Field | Operator | Status | Depth |
|---|---|---|---|---|---|
| — | — O-1-20461 | — | — | — | — |
Formation tops
As filed on W-2/G-1. Subsea from 269 ft elevation.Download CSV →
| Formation | MD ft | Subsea |
|---|---|---|
| Queen City | 2,505 | -2,236 |
| Reklaw | 3,210 | -2,941 |
| Carrizo | 3,895 | -3,626 |
| WilcoxWILCOX - DISPOSAL | 5,810 | -5,541 |
| AnacachoANACACHO - H2S | 10,422 | -10,153 |
| Austin ChalkAUSTIN CHALK - H2S, DISPOSAL | 10,660 | -10,391 |
| Bartosh | — | — |
| EscondidoESCONDIDO - H2S, DISPOSAL | — | — |
| NavarroNAVARRO - H2S | — | — |
| OlmosOLMOS - DISPOSAL | — | — |
Perforations
Perforated and open-hole intervals.
| From | To | Type |
|---|---|---|
| 11,087 | 17,162 | Perforated |
Casing
Strings as reported, shallowest first.
| Casing in | Set at | Hole in | Cement |
|---|---|---|---|
| 9.625 | 5,183 | 12.25 | 1,483 S |
| 5.5 | 17,162 | 8.75 | 2,489 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 | Feb 28, 2022 | Feb 17, 2022 | Yes |
| 00 | Dec 16, 2021 | Dec 2, 2021 | — |
| 00 | Sep 17, 2021 | Aug 28, 2021 | 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 42-013-35848 → W-2, G-1, plugging reports, as PDFs
- Completion packets for 42-013-35848 → 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.
Guajillo Unit 14 South42-013-35847
0.0 KM · Marathon Oil EF LLC · Section with this well →
| Queen City | 2,505 | -2,236 |
| Reklaw | 3,210 | -2,941 |
| Carrizo | 3,895 | -3,626 |
| Wilcox | 5,810 | -5,541 |
| Anacacho | 10,438 | -10,169 |
| Austin Chalk | 10,674 | -10,405 |
| Bartosh | — | |
| Olmos | — |
10 TOPS · FIRST 8
Guajillo Unit 14 South42-013-35846
0.0 KM · Marathon Oil EF LLC · Section with this well →
| Queen City | 2,505 | -2,237 |
| Reklaw | 3,210 | -2,942 |
| Carrizo | 3,895 | -3,627 |
| Wilcox | 5,125 | -4,857 |
| Anacacho | 10,450 | -10,182 |
| Austin Chalk | 10,686 | -10,418 |
| Navarro | — | |
| Olmos | — |
10 TOPS · FIRST 8
Guajillo Unit 14 South42-013-35845
0.0 KM · Marathon Oil EF LLC · Section with this well →
| Queen City | 2,505 | -2,236 |
| Reklaw | 3,210 | -2,941 |
| Carrizo | 3,895 | -3,626 |
| Wilcox | 5,810 | -5,541 |
| Anacacho | 10,457 | -10,188 |
| Austin Chalk | 10,698 | -10,429 |
| Escondido | — | |
| Navarro | — |
10 TOPS · FIRST 8
Guajillo Unit 13 South42-013-35844
0.5 KM · Marathon Oil EF LLC · Section with this well →
| Queen City | 2,517 | -2,269 |
| Reklaw | 3,212 | -2,964 |
| Carrizo | 3,857 | -3,609 |
| Wilcox | 6,827 | -6,579 |
| Anacacho | 10,458 | -10,210 |
| Austin Chalk | 10,696 | -10,448 |
| Navarro | — | |
| Escondido | — |
10 TOPS · FIRST 8
Guajillo Unit 13 South42-013-35843
0.5 KM · Marathon Oil EF LLC · Section with this well →
| Queen City | 2,517 | -2,268 |
| Reklaw | 3,212 | -2,963 |
| Carrizo | 3,857 | -3,608 |
| Wilcox | 5,817 | -5,568 |
| Anacacho | 10,474 | -10,225 |
| Austin Chalk | 10,719 | -10,470 |
| Eagle Ford | 10,844 | -10,595 |
| Olmos | — |
14 TOPS · FIRST 8
Guajillo Unit 13 South42-013-35842
0.5 KM · Marathon Oil EF LLC · Section with this well →
| Queen City | 2,517 | -2,267 |
| Reklaw | 3,212 | -2,962 |
| Carrizo | 3,857 | -3,607 |
| Wilcox | 5,817 | -5,567 |
| Anacacho | 10,485 | -10,235 |
| Austin Chalk | 10,727 | -10,477 |
| Olmos | — | |
| Navarro | — |
10 TOPS · FIRST 8
Guajillo Unit 13 South42-013-35841
0.5 KM · Marathon Oil EF LLC · Section with this well →
| Queen City | 2,517 | -2,267 |
| Reklaw | 3,212 | -2,962 |
| Carrizo | 3,857 | -3,607 |
| Wilcox | 5,817 | -5,567 |
| Anacacho | 10,494 | -10,244 |
| Austin Chalk | 10,737 | -10,487 |
| Navarro | — | |
| Olmos | — |
10 TOPS · FIRST 8
Heard Bower West Unit42-013-35664
0.5 KM · Teal Operating, LLC · Section with this well →
| Carrizo | 3,900 | -3,641 |
| Anacacho | 10,479 | -10,220 |
| Austin Chalk | 10,775 | -10,516 |
| Queen City | — | |
| Olmos | — | |
| Navarro | — | |
| Reklaw | — | |
| Wilcox | — |
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/01335848, documented in the API reference.