WELL · 42-255-35196 · DISTRICT 2
Challenger Unit C AC #1H
Karnes County · Sugarkane (Austin Chalk) field · Producing · Horizontal
Challenger Unit C AC #1H (API 42-255-35196) is a horizontal well in Karnes County operated by Marathon Oil EF LLC, completed October 26, 2017 and listed as producing on the RRC schedule.
The RRC has issued one drilling permit, issued December 14, 2016, permitted to 17,500 ft.
Completion filings report 10 formation tops, including Yegua, Queen City, Reklaw, Carrizo.
Its lease has reported 1.38M barrels of oil and 3.42M mcf of gas since June 2017, last reporting in July 2026. The lease carries 3 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 LLCDec 14, 2016 |
- 17,500
- total depth, ft
- 1
- permits on file
- Dec 14, 2016
- last permit issued
- Oct 26, 2017
- completed
- 1.38M
- cumulative oil, bbl
- 3.42M
- cumulative gas, mcf
PRODUCTION FROM PDQ LEASE REPORTS · Jun 2017 THROUGH Jul 2026
Regulatory status · RRC wellbore file
- Schedule
- ON SCHEDULE
- Completed
- Oct 26, 2017
- Shut in
- —
- Plugged
- —
Operator's P-5 on the schedule: Active (A)
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 3 wells in total, so volumes are shared.Why →
| Lease | Field | Reporting operator | Wells | Oil, bbl | Gas, mcf | Reported |
|---|---|---|---|---|---|---|
| Challenger Unit C AC O-2-11418 | Sugarkane (Austin Chalk) | Marathon Oil EF LLC | 3 | 1.38M | 3.42M | Jun 2017 – Jul 2026 |
Oil, barrels lease total
Last 12 months 33,522 · prior 12 47,135(-29%)
Gas, mcf lease total
Last 12 months 150,573 · prior 12 195,843(-23%)
Chain of custody
Every operator that reported production on this well's lease, in order.
- 1Marathon Oil EF LLCOct 2017 → Apr 2026
Permits
| Permit | Type | Operator | Received | Issued | Spud | Depth |
|---|---|---|---|---|---|---|
| 820514-99 | Drill | Marathon Oil EF LLC | Nov 17, 2016 | Dec 14, 2016 | Jul 15, 2017 | 17,500 |
Completions
| Completed | Lease | Field | Operator | Status | Depth |
|---|---|---|---|---|---|
| — | — O-2-11418 | — | — | — | — |
Formation tops
As filed on W-2/G-1. Subsea from 341 ft elevation.Download CSV →
| Formation | MD ft | Subsea |
|---|---|---|
| YeguaYEGUA - DISPOSAL | 1,318 | -977 |
| Queen City | 3,253 | -2,912 |
| Reklaw | 3,573 | -3,232 |
| Carrizo | 3,929 | -3,588 |
| WilcoxWILCOX - DISPOSAL | 4,176 | -3,835 |
| Austin ChalkAUSTIN CHALK - H2S | 10,539 | -10,198 |
| Eagle FordEAGLE FORD - H2S | — | — |
| EdwardsEDWARDS - H2S | — | — |
| FrioFRIO - DISPOSAL | — | — |
| SligoSLIGO - H2S | — | — |
Perforations
Perforated and open-hole intervals.
| From | To | Type |
|---|---|---|
| 10,717 | 16,442 | Perforated |
Casing
Strings as reported, shallowest first.
| Casing in | Set at | Hole in | Cement |
|---|---|---|---|
| 9.625 | 5,843 | 12.25 | 1,698 S |
| 5.5 | 16,542 | 8.75 | 2,860 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 | Jul 16, 2018 | May 3, 2018 | Yes |
| 00 | Apr 20, 2018 | Oct 12, 2017 | 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 42-255-35196 → W-2, G-1, plugging reports, as PDFs
- Completion packets for 42-255-35196 → 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/25535196, documented in the API reference.