FORMATIONS · RRC WELLBORE FILE
Grayburg
Reported as a top in 48,974 wells across 36 counties, at a median depth of 3,957 ft (2,014 to 4,504 ft in most wells). 4,888 of those wells were permitted in the last three years.
A well counts if any of its completion filings report this formation, whether it produces from it or drilled through it. Depths are measured depth as filed; typo depths exist, which is why ranges are percentiles, not extremes. About completion reports →
- 49K
- wells reporting a top
- 4,888
- permitted in last 3 years
- 36
- counties
- 3,957
- median top, ft
COMPUTED OCT 29, 2026 · REBUILT DAILY
Depth by county
Counties with at least five wells reporting the top. Bars are well counts.
| County | Wells | Median, ft | P10–P90 | Last 3 yrs |
|---|---|---|---|---|
| Andrews | 7,866 | 4,258 | 4,022–4,670 | 247 |
| Midland | 7,411 | 4,237 | 3,860–4,602 | 1,165 |
| Martin | 6,246 | 3,950 | 3,345–4,448 | 1,079 |
| Ector | 5,602 | 3,960 | 3,620–4,400 | 79 |
| Upton | 3,640 | 3,980 | 2,622–4,593 | 643 |
| Reagan | 3,280 | 2,770 | 2,079–3,485 | 632 |
| Crane | 2,470 | 2,751 | 2,451–3,258 | 282 |
| Glasscock | 2,442 | 3,342 | 2,354–3,799 | 252 |
| Pecos | 1,948 | 1,398 | 1,162–2,066 | 199 |
| Yoakum | 1,564 | 4,265 | 4,096–4,473 | 20 |
| Gaines | 1,454 | 4,202 | 4,046–4,558 | 117 |
| Irion | 1,169 | 1,500 | 1,070–1,815 | 87 |
| Howard | 1,022 | 2,012 | 1,654–3,017 | 34 |
| Crockett | 721 | 1,790 | 1,216–2,226 | 2 |
| Hockley | 630 | 3,814 | 3,588–3,955 | 0 |
| Winkler | 263 | 3,380 | 3,213–3,650 | 13 |
| Mitchell | 262 | 1,495 | 1,253–1,510 | 1 |
| Cochran | 180 | 3,956 | 3,756–4,018 | 1 |
| Sterling | 180 | 1,842 | 1,481–2,080 | 1 |
| Scurry | 137 | 1,420 | 1,298–1,519 | 1 |
| Dawson | 124 | 4,120 | 3,350–4,313 | 9 |
| Terry | 85 | 4,244 | 3,993–4,428 | 2 |
| Ward | 84 | 3,272 | 2,721–3,451 | 9 |
| Borden | 50 | 3,050 | 2,035–3,140 | 1 |
| Garza | 49 | 2,600 | 2,212–2,670 | 8 |
| Crosby | 37 | 2,619 | 2,545–2,676 | 0 |
| Tom Green | 37 | 440 | 394–566 | 3 |
| Hale | 5 | 4,449 | 3,596–5,877 | 0 |
| Lubbock | 5 | 2,854 | 2,838–2,925 | 0 |
Operators
Current operator of record for wells reporting the top, ranked by wells permitted in the last three years.
| Operator | Last 3 yrs | All |
|---|---|---|
| Pioneer Natural Res. USA, Inc. | 1,209 | 4,882 |
| Diamondback E&P LLC | 563 | 1,808 |
| Endeavor Energy Resources L.P. | 242 | 1,789 |
| Blackbeard Operating, LLC | 226 | 719 |
| COG Operating LLC | 186 | 1,197 |
| Marathon Oil Company | 184 | 1,308 |
| XTO Energy Inc. | 179 | 2,258 |
| Apache Corporation | 173 | 1,655 |
| DE IV Operating, LLC | 169 | 301 |
| DE IV Operating, LLC | 149 | 149 |
| Civitas Permian Operating, LLC | 145 | 145 |
| Chevron U. S. A. Inc. | 138 | 1,410 |
| OXY USA WTP LP | 97 | 517 |
| SM Energy Company | 84 | 346 |
| Firebird Energy II LLC | 81 | 81 |
| Oxyrock Operating, LLC | 80 | 80 |
| Utoco, Ltd. | 77 | 665 |
| Triple Crown Resources, LLC | 75 | 184 |
| Occidental Permian Ltd. | 73 | 1,598 |
| Oxyrock Operating, LLC | 63 | 1,096 |
| Vital Energy, Inc. | 39 | 59 |
| Hannathon Petroleum II, LLC | 37 | 54 |
| Discovery Natural Resources LLC | 34 | 251 |
| Ring Energy, Inc. | 33 | 283 |
| Black Swan Opco, LLC | 32 | 32 |
Recently permitted wells reporting the Grayburg
BY LAST PERMIT ISSUED
| Last permit | Lease | Operator | County | Top, ft | API |
|---|---|---|---|---|---|
| Oct 26, 2026 | West Seminole SA Unit | OXY USA WTP LP | Gaines | 4,430 | 16500636 |
| Oct 21, 2026 | West Seminole SA Unit | OXY USA WTP LP | Gaines | 4,444 | 16538557 |
| Oct 21, 2026 | West Seminole SA Unit | OXY USA WTP LP | Gaines | 4,437 | 16538559 |
| Oct 13, 2026 | Seminole San Andres Unit | OXY USA Inc. | Gaines | 4,383 | 16500032 |
| Oct 13, 2026 | Seminole San Andres Unit | OXY USA Inc. | Gaines | 4,473 | 16501824 |
| Oct 5, 2026 | Seminole San Andres Unit | OXY USA Inc. | Gaines | 4,366 | 16500037 |
| Oct 5, 2026 | Seminole San Andres Unit | OXY USA Inc. | Gaines | 4,409 | 16502072 |
| Sep 25, 2026 | West Seminole SA Unit | OXY USA WTP LP | Gaines | 4,287 | 16538405 |
| Sep 24, 2026 | West Seminole SA Unit | OXY USA WTP LP | Gaines | 4,290 | 16538299 |
| Sep 3, 2026 | Foster, H. C. | Laguna Petroleum Corporation | Ector | 3,693 | 13538408 |
| Sep 1, 2026 | Bennett Ranch Unit | Occidental Permian Ltd. | Yoakum | 4,410 | 50135666 |
| Aug 31, 2026 | Waddell, W. N. Etal | Burlington Res O & G Co-Midland | Crane | 2,521 | 10334611 |
| Aug 21, 2026 | Fullerton Clearfork Unit | XTO Energy Inc. | Andrews | 4,135 | 00346561 |
| Aug 21, 2026 | Seminole San Andres Unit | OXY USA Inc. | Gaines | 4,462 | 16500102 |
| Aug 19, 2026 | Yates Filed Unit | Marathon Oil Company | Pecos | 1,609 | 37133696 |
| Aug 13, 2026 | Edwards, Jack -L- | Pitts Energy Co. | Ward | 3,008 | 47533646 |
| Aug 12, 2026 | Seminole San Andres Unit | OXY USA Inc. | Gaines | 4,576 | 16536958 |
| Aug 10, 2026 | Edwards, C. W. et AL | Pitts Energy Co. | Ward | 3,096 | 47510042 |
| Aug 6, 2026 | Seminole San Andres Unit | OXY USA Inc. | Gaines | 4,530 | 16500100 |
| Aug 3, 2026 | Willard Unit | OXY USA WTP LP | Yoakum | 4,521 | 50136219 |
| Jul 24, 2026 | Bennett Ranch Unit | Occidental Permian Ltd. | Yoakum | 4,434 | 50137551 |
| Jul 17, 2026 | Johnson, J. L. -AB- | Basin Oil & Gas Operating, LLC | Ector | 4,018 | 13532972 |
| Jul 8, 2026 | Seminole San Andres Unit | OXY USA Inc. | Gaines | 4,466 | 16532753 |
| Jul 2, 2026 | Yates Field Unit | Marathon Oil Company | Pecos | 1,048 | 37132317 |
| Jul 2, 2026 | State-Walton | Pennzenergy Exp. & Prod., L.L.C. | Winkler | 3,222 | 49505173 |
About this data
Formation tops, elevations, perforations, and casing from the RRC dbf900 wellbore file, refreshed weekly, with reported names normalized to Petrora's formation registry. County and operator breakdowns are rebuilt nightly.
Developers: this page as JSON is GET /v1/data/formations/grayburg, documented in the API reference.