TEXAS · WELLS · ATASCOSA COUNTY · GUAJILLO EAST LEASE · API 42-013-34951 · DISTRICT 01
Guajillo East #31H
Atascosa County · Eagleville (Eagle Ford-1) field · Producing · Horizontal
Guajillo East #31H (API 42-013-34951) is a horizontal well in Atascosa County operated by Marathon Oil EF LLC, completed October 13, 2022 and listed as producing on the RRC schedule.
The RRC has issued one drilling permit, issued March 22, 2014, permitted to 10,972 ft.
Completion filings report 14 formation tops, including Queen City, Carrizo, Olmos, Reklaw.
Its lease has reported 10.9M barrels of oil and 14.6M mcf of gas since March 2014, last reporting volume in April 2026. The lease carries 61 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 LLCMar 22, 2014 |
- 10,972
- total depth, ft
- 1
- permits on file
- Mar 22, 2014
- last permit issued
- Oct 13, 2022
- completed
- 10.9M
- cumulative oil, bbl
- 14.6M
- cumulative gas, mcf
PRODUCTION FROM PDQ LEASE REPORTS · Jun 2014 THROUGH Apr 2026
Regulatory status · RRC wellbore file
- Schedule
- ON SCHEDULE
- Completed
- Oct 13, 2022
- 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.
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 61 wells in total, so volumes are shared.Why →
| Lease | Field | Reporting operator | Wells | Oil, bbl | Gas, mcf | Reported |
|---|---|---|---|---|---|---|
| Guajillo East O-1-17741 | Eagleville (Eagle Ford-1) | Marathon Oil EF LLC | 61 | 10.9M | 14.6M | Mar 2014 – Apr 2026 |
Oil, barrels lease total
Last 12 months 192,543 · prior 12 317,175(-39%)
Gas, mcf lease total
Last 12 months 274,310 · prior 12 537,477(-49%)
Chain of custody
Every operator that reported production on this well's lease, in order.
- 1Marathon Oil EF LLCJun 2014 → Apr 2026
Permits
| Permit | Type | Operator | Received | Issued | Spud | Depth |
|---|---|---|---|---|---|---|
| 780627-99 | Drill | Marathon Oil EF LLC | Feb 25, 2014 | Mar 22, 2014 | Jun 11, 2014 | 19,000 |
Completions
| Completed | Lease | Field | Operator | Status | Depth |
|---|---|---|---|---|---|
| Oct 13, 2022 | Guajillo East O-1-17741 | Eagleville (Eagle Ford-1) | Marathon Oil EF LLC | Producing | 10,972 |
Formation tops
As filed on W-2/G-1. Subsea from 261 ft elevation.Download CSV →
| Formation | MD ft | Subsea |
|---|---|---|
| Queen City | 830 | -569 |
| Carrizo | 1,580 | -1,319 |
| Olmos | 1,820 | -1,559 |
| OlmosOLMOS - DISPOSAL | 1,820 | -1,559 |
| Reklaw | 1,900 | -1,639 |
| Escondido | 2,600 | -2,339 |
| EscondidoESCONDIDO - H2S, DISPOSAL | 2,600 | -2,339 |
| Bartosh | 3,150 | -2,889 |
| Navarro | 3,600 | -3,339 |
| NavarroNAVARRO - H2S | 3,600 | -3,339 |
| Wilcox | 4,660 | -4,399 |
| WilcoxWILCOX - DISPOSAL | 4,660 | -4,399 |
| Edwards | 7,080 | -6,819 |
| Buda | 7,380 | -7,119 |
| Georgetown | 7,390 | -7,129 |
| Anacacho | 10,707 | -10,446 |
| AnacachoANACACHO - H2S | 10,707 | -10,446 |
| Austin Chalk | 10,989 | -10,728 |
| Austin ChalkAUSTIN CHALK - H2S, DISPOSAL | 10,989 | -10,728 |
| Eagle Ford | 11,096 | -10,835 |
Perforations
Perforated and open-hole intervals.
| From | To | Type |
|---|---|---|
| 11,317 | 17,860 | Perforated |
Casing
Strings as reported, shallowest first.
| Casing in | Set at | Hole in | Cement |
|---|---|---|---|
| 9.625 | 5,355 | 12.25 | 1,818 S |
| 5.5 | 18,000 | 8.5 | 2,813 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 | Jan 10, 2023 | Dec 15, 2022 | — |
| 00 | Nov 22, 2016 | Nov 15, 2016 | Yes |
| 00 | Mar 30, 2015 | Nov 14, 2014 | Yes |
| 00 | Jan 21, 2015 | Oct 3, 2014 | Yes |
Well logs
2 logs loaded from the RRC's log index, 2 of them with a digital LAS file, the latest received Oct 3, 2017. 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 Anacacho, Austin Chalk, Eagle Ford | LAS + TIFF | 10,737 to 18,000 | Oct 3, 2017 | 0.44 + 4.01 |
| Gamma RaySpans Anacacho, Austin Chalk, Eagle Ford | LAS + TIFF | 10,737 to 18,000 | Jun 26, 2017 | 0.44 + 4.01 |
"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 42-013-34951 → W-2, G-1, plugging reports, as PDFs
- Completion packets for 42-013-34951 → scanned completion filings
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/01334951, documented in the API reference.