COUNTIES · TEXAS GULF COAST · DISTRICT 04 · CODE 427
Starr County, Texas
Starr County has had no new drilling permits in the past 90 days; the most recent permit on record was issued April 23, 2026.
Killam Oil Co., Ltd. leads with 1 permit in the past 12 months, one of 5 operators active in the county.
2 operators filed a first Starr County permit in the past year.
Median permitted depth over the past year is 5,000 ft (prior year: 6,690 ft); 0% of the past year's permits are horizontal.
The county has 49 active disposal and injection permits, with 4.16M barrels injected in the 12 months reported through June 2025.
7,111 drilling permits have been issued in Starr County since 1977.
7,111 permits on file since 1977 · last issued Apr 23, 2026
Watch Starr CountyAlso: every Starr County well in the statewide list, searchable → · a year of permits on the map →
- 0
- permits issued, 90d
- —
- vs prior 90d (0)
- 0
- operators filing
- —
- horizontal
- —
- avg permitted depth, ft
- 527
- operators, all time
WINDOWS ON THE RRC ISSUE DATE · COMPUTED NOV 5, 2026 · WHY ISSUE AND SEEN DATES DIFFER
Permits issued by month
LAST 120 MONTHS · BY ISSUE DATE
Last 12 months 5 · prior 12 7(-29%)
Top operators, last 12 months
By permits issued. Wells are the operator’s current inventory here from the RRC wellbore file.
| Operator | Permits | Wells |
|---|---|---|
| Killam Oil Co., Ltd. | 1 | 149 |
| Petrovybe Opco LLC | 1 | 89 |
| Triad O&G, LLC | 1 | 7 |
| Mueller Exploration, Inc. | 1 | 3 |
| Ilex Energy Corporation | 1 | 0 |
New entrants, last 12 months
Operators whose first permit in Starr County came in the last year. 2 in total.
- Petrovybe Opco LLC1 permitApr 23, 2026 · active elsewhere first
- Ilex Energy Corporation1 permitMar 10, 2026 · new to Texas permits
Formations in completed wells
RRC WELLBORE FILE · ≥10 WELLS
Tops reported on completion filings for wells in Starr County. A well counts for every formation it reports, so this reads as the county's stratigraphic column. About tops →
In Starr County the Jackson is reported in 62 wells, median top 2,640 ft, highlighted below. Back to the formation →
| Formation | Wells | Permitted last 3 yrs | Median top, ft | P10–P90 |
|---|---|---|---|---|
| Vicksburg | 1,027 | 12 | 5,996 | 4,540–8,535 |
| Frio | 573 | 1 | 3,770 | 2,300–4,909 |
| Queen City | 261 | 0 | 3,832 | 2,350–7,881 |
| Yegua | 145 | 1 | 3,602 | 1,100–6,593 |
| Catahoula | 110 | 11 | 2,000 | 970–3,901 |
| Miocene (undifferentiated) | 86 | 5 | 1,000 | 34–2,900 |
| Reklaw | 80 | 0 | 5,457 | 5,043–8,338 |
| Wilcox | 74 | 0 | 6,447 | 5,535–8,900 |
| Jackson | 62 | 0 | 2,640 | 234–9,838 |
| Cook Mountain | 51 | 0 | 3,600 | 2,300–8,095 |
Beyond the permit record
RRC UIC permits · H-10 reported volumes
Disposal and injection
- 49
- active UIC permits of 424
- 193K
- permitted bbl/day, active
- 4.16M
- bbl injected, last 12 reported months
- Jun 2025
- reported through
Every active well, operator, and daily reporter in Starr County →
Permitted volume is a ceiling, not throughput. How to read it →
TexNet catalog via USGS
Seismicity, last 2 years
- 0
- M2+ events in the area
- —
- largest
Monthly counts, magnitudes, and every recent event in the area →
Events are not tagged with a county; this counts M2+ events inside the bounding box of the county’s located permits, padded 0.1°. About TexNet →
Latest permits
NEWEST FIRST BY ISSUE DATE
| Permit | Seen | Issued | Operator | Lease / well | Depth | API |
|---|---|---|---|---|---|---|
| 915027 | Apr 23, 2026 | Apr 23, 2026 | Petrovybe Opco LLC | Richmond #17 | 5,000 | 42734823 |
| 914356 | Mar 27, 2026 | Mar 27, 2026 | Triad O&G, LLC | Montalvo, N. R. #62 | 8,500 | 42734817 |
| 913943 | Mar 10, 2026 | Mar 10, 2026 | Ilex Energy Corporation | Brock #5 | 10,500 | 42734822 |
| 913510 | Feb 20, 2026 | Feb 20, 2026 | Killam Oil Co., Ltd. | I.V. Montalvo 'A' #20 | 4,990 | 42734762 |
| 912483 | Jan 5, 2026 | Jan 5, 2026 | Mueller Exploration, Inc. | Alberto Alaniz #1R | 4,500 | 42734821 |
| 911186 | Oct 20, 2025 | Oct 20, 2025 | Killam Oil Co., Ltd. | I.V. Montalvo 'C' #49 | 5,435 | 42734736 |
| 911185 | Oct 20, 2025 | Oct 20, 2025 | Killam Oil Co., Ltd. | I.V. Montalvo 'C' #58 | 5,822 | 42734743 |
| 910180 | Sep 2, 2025 | Sep 2, 2025 | Mueller Exploration, Inc. | Alberto Alaniz #1 | 4,500 | 42734820 |
| 907671 | May 1, 2025 | May 1, 2025 | Killam Oil Co., Ltd. | Hall, J. F. State #30 | 6,690 | 42734791 |
| 906366 | Mar 7, 2025 | Mar 7, 2025 | Triad O&G, LLC | Montalvo, N. R. #62 | 8,500 | 42734817 |
Questions about Starr County
How many drilling permits were issued in Starr County in the last 12 months?
5 permits were issued in Starr County in the last 12 months, down 29% from 7 in the 12 months before. 0% were for horizontal wells. The most recent was issued Apr 23, 2026. 7,111 are on file since 1977.
Every Starr County permit →Who is the most active operator in Starr County?
By drilling permits filed in the last 12 months, Killam Oil Co., Ltd. is the most active operator in Starr County, with 1 of 5, followed by Petrovybe Opco LLC (1) and Triad O&G, LLC (1). 0 operators filed permits here in the last 90 days.
Operators in Starr County →How many oil and gas wells are in Starr County?
6,216 wells are on file in Starr County: 1,007 active, 3,349 plugged, and 2 permitted and not yet drilled. 11 are horizontal, and 48 operators hold them.
Every well in Starr County →How much oil and gas does Starr County produce?
The Railroad Commission files oil and gas production by lease, not by well or by county. Each lease with wells in Starr County is listed with its reported production on the county's Leases tab.
Leases in Starr County →How much water is injected in Starr County?
4.2 million barrels of water were injected in Starr County in the 12 months through June 2025, reported on form H-10. 49 of the county's 424 disposal and injection permits are active.
Disposal and injection in Starr County →What formations are drilled in Starr County?
Completion filings for wells in Starr County report tops for 10 formations in at least ten wells each. The most reported are the Vicksburg (1,027 wells, median top 5,996 ft), the Frio (573 wells, median top 3,770 ft), and the Queen City (261 wells, median top 3,832 ft).
Formations in Starr County →What basin is Starr County in?
Petrora lists Starr County in the Texas Gulf Coast. It is in the Railroad Commission's District 04.
The Texas Gulf Coast →Have there been earthquakes in Starr County?
TexNet located no earthquakes of magnitude 2 or more in the area of Starr County's permitted wells in the last 2 years.
Earthquakes in Starr County →About this data
Drilling permits from the RRC OGA049M master and daily daf420 files, rebuilt nightly into per-county figures; windows are on the date issued. Disposal from UIC permits and H-10 reports at the last settled month; earthquakes from the TexNet catalog inside the county's located-permit footprint.
Developers: this page as JSON is GET /v1/data/counties/tx/starr?days=90, documented in the API reference.