42-389-32772
Final CompletionBIG CHIEF
REEVES County · District 8 · COG OPERATING LLC · WOLFBONE (TREND AREA)
Permits
6
Max Depth
14,500 ft
First Permit
2011-03-01
Latest Activity
2015-10-27
Lifespan
5 yrs
Regulatory Status
Schedule
OFF SCHEDULE
Completion
2011-06-03
Shut-In
—
Plugged
2020-01-27
EWA / Production operator mismatch
Scheduling: COG OPERATING LLC ≠ Production: SCOUT ENERGY MANAGEMENT LLC (reported 2026-04)
Resolved via: production → SCOUT ENERGY MANAGEMENT LLC
Production Summary Production data is a work in progress — still being validated against RRC filings. Spot something off or have questions? [email protected]
Cum Oil
— bbl
Cum Gas
— mcf
First Production
2011-06
Last Production
2026-07
Operator History
Chain of Custody
Lease Production
Production is reported at the lease level. View production data, decline curves, and history on the lease page.
Formation Tops (13) Elevation 2,936 ft (GL)
CSV| Formation | Top Depth (MD) | Subsea (+above / −below SL) |
|---|---|---|
| FORD-DELAWARE (Delaware) | 2,500 ft | +436 ft |
| CASTILLE (Castile) | 2,800 ft | +136 ft |
| BELL CANYON | 4,800 ft | -1,864 ft |
| DELAWARE | 4,850 ft | -1,914 ft |
| BONE SPRING | 7,836 ft | -4,900 ft |
| WOLFCAMP | 9,990 ft | -7,054 ft |
| BONE SPRINGS (Bone Spring) | — | — |
| CHERRY CANYON | — | — |
| DELAWARE | — | — |
| DELAWARE CONSOLIDATED GAS (Delaware) | — | — |
| PENNSYLVANIAN | — | — |
| PERMIAN (Permian (undifferentiated)) | — | — |
| WOLFCAMP | — | — |
As reported by operators on W-2/G-1 completion filings (RRC wellbore records). Depths are measured depth; names appear as filed. Subsea = reported elevation − measured depth (negative = below sea level; vertical wellbores only). View filings & logs at RRC ↗
Perforations (3)
| Interval | Type |
|---|---|
| 6,900–7,910 ft | Perforated |
| 8,524–10,380 ft | Perforated |
| 10,830–10,850 ft | Perforated |
Casing (6)
| Size | Set Depth | Cement |
|---|---|---|
| 13.375" | 1,447 ft | 1,250 sx |
| 13.375" | 1,447 ft | 1,250 sx |
| 9.625" | 5,110 ft | 1,950 sx |
| 7" | 9,858 ft | 900 sx |
| 4.5" | 14,000 ft | 550 sx |
| 7" | — | 400 sx |
Permit History (6)
BIG CHIEF · 8,180 ft
2015-10-27
Spud 2014-04-25
BIG CHIEF · 7,340 ft
2013-09-10
BIG CHIEF · 14,500 ft
2013-09-10
BIG CHIEF · 12,000 ft
2013-09-10
Spud 2013-04-02
BIG CHIEF '148' · 14,500 ft
2011-03-01
Spud 2011-04-18
BIG CHIEF "148" · 13,500 ft
2011-03-01
Applications (6)
Records & Logs
4 completion filings on record · 3 with log images at RRC.
Completion packets open directly (post-2011 filings include attached logs). Log images and the UL library can't be deep-linked — clicking copies the API for you to paste.
No GPS coordinates yet
Well Details
- Well Number
- 4801
- Max Depth
- 14,500 ft
- Drill Type
- Vertical
- County
- REEVES
- District
- 8
- Operator
- COG OPERATING LLC
- Completed
- 2011-06-03
Operator
- Name
- COG OPER LLC
- Location
- MIDLAND
- P-5 Status
- X (filed 2026-06-02)
- Cum Oil (all leases)
- 645,285,792 bbl
- Cum Gas (all leases)
- 305,183,488 mcf
- Activities
- OPRS/G, OPRS/O
- Total Permits
- 4,547