WELL · 42-255-31661 · DISTRICT 2
Turnbull Unit A #1H
Karnes County · Horizontal
Turnbull Unit A #1H (API 42-255-31661) is a permitted horizontal well in Karnes County filed by Marathon Oil EF LLC; no completion report is on file yet.
The RRC has issued 3 drilling permits (amended once) between 2010 and 2013, permitted to 16,946 ft.
Completion filings report 4 formation tops, including Anacho, Austin Chalk, Upper Ef, Eagle Ford.
Its 3 leases have reported 757K barrels of oil and 2M mcf of gas since April 2010, last reporting in July 2026. The leases carry 14 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 | none |
| Production reports | Marathon Oil EF LLCthrough Apr 2026 |
| Latest permit | Marathon Oil EF LLCJul 3, 2013 |
- 16,946
- total depth, ft
- 4
- permits on file
- Jul 3, 2013
- last permit issued
- —
- completed
- 757K
- cumulative oil, bbl
- 2M
- cumulative gas, mcf
PRODUCTION FROM PDQ LEASE REPORTS · Apr 2010 THROUGH Jul 2026
Regulatory status · RRC wellbore file
- Schedule
- OFF SCHEDULE
- Completed
- —
- Shut in
- —
- Plugged
- —
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 3 leases this well is completed on; they carry 14 wells in total, so volumes are shared.Why →
| Lease | Field | Reporting operator | Wells | Oil, bbl | Gas, mcf | Reported |
|---|---|---|---|---|---|---|
| Turnbull Unit A O-2-9596 | Eagleville (Eagle Ford-2) | Marathon Oil EF LLC | 9 | 645K | 1.74M | Dec 2010 – Jul 2026 |
| Turnbull O-2-9503 | Eagleville (Eagle Ford) | Marathon Oil EF LLC | 4 | 112K | 242K | Apr 2010 – Sep 2012 |
| Turnbull G-2-259605 | Sugarkane (Cretaceous) | Hilcorp Energy Company | 1 | 0 | 20K | Jun 2010 – Jun 2010 |
Oil, barrels lease total
Last 12 months 2,000 · prior 12 1,635(+22%)
Gas, mcf lease total
Last 12 months 2,963 · prior 12 1,882(+57%)
Chain of custody
Every operator that reported production on this well's lease, in order.
- 1Hilcorp Energy CompanyJun 2010 → Oct 2011
- 2Marathon Oil EF LLCNov 2011 → Apr 2026
Permits
| Permit | Type | Operator | Received | Issued | Spud | Depth |
|---|---|---|---|---|---|---|
| 765685-99 | Recompletion | Marathon Oil EF LLC | Jun 28, 2013 | Jul 3, 2013 | — | 16,946 |
| 723889-99 | Recompletion | Hilcorp Energy Company | Sep 8, 2011 | Sep 12, 2011 | Apr 1, 2010 | 12,500 |
| 693706-98 | Drill | Hilcorp Energy Company | Apr 1, 2010 | Mar 30, 2010 | Apr 1, 2010 | 12,500 |
| 693706-99 | Drill | Hilcorp Energy Company | Mar 30, 2010 | Mar 30, 2010 | Apr 1, 2010 | 12,500 |
Completions
| Completed | Lease | Field | Operator | Status | Depth |
|---|---|---|---|---|---|
| — | — G-2-259605 | — | — | — | — |
| — | — O-2-9503 | — | — | — | — |
| — | — O-2-9596 | — | — | — | — |
Formation tops
As filed on W-2/G-1. Subsea from 392 ft elevation.Download CSV →
| Formation | MD ft | Subsea |
|---|---|---|
| Anacho | 11,155 | -10,763 |
| Austin Chalk | 11,323 | -10,931 |
| Upper EF | 11,444 | -11,052 |
| Eagle Ford | 11,485 | -11,093 |
Perforations
Perforated and open-hole intervals.
| From | To | Type |
|---|---|---|
| 12,640 | 16,533 | Perforated |
Casing
Strings as reported, shallowest first.
| Casing in | Set at | Hole in | Cement |
|---|---|---|---|
| 9.625 | 5,902 | 12.25 | 2,330 S |
| 5.5 | 9,885 | 8.5 | 2,575 S |
| 4.5 | 16,946 | 8.5 | 2,575 S |
| 4.5 | 16,946 | — | — |
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 | Jun 26, 2012 | Sep 16, 2011 | Yes |
| 00 | May 23, 2012 | Sep 16, 2011 | Yes |
| 00 | May 3, 2011 | Jun 17, 2010 | Yes |
| 00 | Apr 20, 2011 | — | — |
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 42-255-31661 → W-2, G-1, plugging reports, as PDFs
- Completion packets for 42-255-31661 → 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.
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/25531661, documented in the API reference.