TEXAS · WELLS · ZAPATA COUNTY · API 42-505-35921 · DISTRICT 04
Cuellar-Graves Gas Unit #1
Zapata County · Exsun (Lobo Cons.) field · Producing · Directional
Cuellar-Graves Gas Unit #1 (API 42-505-35921) is a well in Zapata County operated by Hilcorp Energy Company, completed November 10, 2008 and listed as producing on the RRC schedule.
The RRC has issued one drilling permit, issued July 17, 2007, permitted to 10,941 ft.
It was permitted by Chesapeake Operating, Inc. and has since transferred to Hilcorp Energy Company on the wellbore schedule.
Completion filings report 3 formation tops, including Queen City, Big Blue, Lobo Unconformity.
Its 2 leases have reported 792 barrels of oil and 912K mcf of gas since December 2007, last reporting volume in April 2026. The leases carry 2 wells, so these are lease totals, not this well alone.
Operator of record
Permitted by Chesapeake Operating, Inc.; the EWA schedule now lists a different operator.
- Based in
- Houston, TX
- P-5 status
- Active – Extension (X)
- P-5 last filed
- Mar 27, 2026
- Permits on file
- 3,458
- Phone
- (713) 209-2400
SOURCE · RRC EWA WELLBORE SCHEDULE
What each RRC source says
| Wellbore schedule | Hilcorp Energy Company |
| Production reports | Hilcorp Energy Companythrough Apr 2026 |
| Latest permit | Chesapeake Operating, Inc.Jul 17, 2007 |
The sources disagree, which usually means a transfer or a lease-level production filing by a different entity. Petrora goes with the schedule.
- 10,941
- total depth, ft
- 1
- permits on file
- Jul 17, 2007
- last permit issued
- Nov 10, 2008
- completed
- 792
- cumulative oil, bbl
- 912K
- cumulative gas, mcf
PRODUCTION FROM PDQ LEASE REPORTS · Dec 2007 THROUGH Apr 2026
Regulatory status · RRC wellbore file
- Schedule
- ON SCHEDULE
- Completed
- Nov 10, 2008
- 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 2 leases this well is completed on; they carry 2 wells in total, so volumes are shared.Why →
| Lease | Field | Reporting operator | Wells | Oil, bbl | Gas, mcf | Reported |
|---|---|---|---|---|---|---|
| Cuellar-Graves Gas Unit G-4-234480 | Exsun (Lobo Cons.) | Hilcorp Energy Company | 1 | 792 | 912K | Dec 2007 – Apr 2026 |
| Cuellar-Graves Gas Unit G-4-235926 | Zapata, SE. (Wilcox) | Hilcorp Energy Company | 1 | 0 | 0 | Dec 2007 – — |
Gas, mcf lease total
Last 12 months 11,825 · prior 12 14,746(-20%)
Chain of custody
Every operator that reported production on this well's lease, in order.
- 1Chesapeake Operating, Inc.Dec 2007 → Aug 2014
- 2Hilcorp Energy CompanySep 2014 → Apr 2026
Permits
| Permit | Type | Operator | Received | Issued | Spud | Depth |
|---|---|---|---|---|---|---|
| 642096-99 | Drill | Chesapeake Operating, Inc. | Jul 9, 2007 | Jul 17, 2007 | Oct 27, 2007 | 12,000 |
Completions
| Completed | Lease | Field | Operator | Status | Depth |
|---|---|---|---|---|---|
| Nov 10, 2008 | Cuellar-Graves Gas Unit G-4-234480 | Exsun (Lobo Cons.) | Hilcorp Energy Company | Producing | 10,941 |
| Dec 2, 2007 | Cuellar-Graves Gas Unit G-4-235926 | Zapata SE. (Wilcox) | Hilcorp Energy Company | SWR-10-Well · shut in May 1, 2009 | 10,941 |
Formation tops
As filed on W-2/G-1. Subsea from 342 ft elevation.Download CSV →
| Formation | MD ft | Subsea |
|---|---|---|
| Queen City | 1,910 | -1,568 |
| Big Blue | 6,330 | -5,988 |
| Lobo Unconformity | 8,555 | -8,213 |
Perforations
Perforated and open-hole intervals.
| From | To | Type |
|---|---|---|
| 6,910 | 10,474 | Perforated |
| 7,442 | 10,474 | Perforated |
Casing
Strings as reported, shallowest first.
| Casing in | Set at | Hole in | Cement |
|---|---|---|---|
| 9.625 | 762 | 12.25 | 312 S |
| 7 | 6,629 | 8.75 | 352 S |
| 4.5 | 10,930 | 6.25 | 545 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 | Jun 19, 2009 | Feb 4, 2009 | — |
| 00 | Jul 1, 2008 | Mar 5, 2008 | Yes |
| 00 | Jun 11, 2008 | — | — |
| 00 | Apr 30, 2008 | Jan 16, 2008 | Yes |
| 00 | Apr 23, 2008 | — | — |
Well logs
1 log loaded from the RRC's log index, the latest received Dec 20, 2010. Density, Neutron, Resistivity. 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 |
|---|---|---|---|---|
| COMBINATION: RESISTIVITY/NEUTRON/DENSITY POROSITYSpans Big Blue, Lobo Unconformity | TIFF | 6,620 to 10,931 | Dec 20, 2010run Nov 17, 2007 | 0.62 |
"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 42-505-35921 → W-2, G-1, plugging reports, as PDFs
- Completion packets for 42-505-35921 → 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/50535921, documented in the API reference.