FORMATIONS · RRC WELLBORE FILE

Pennsylvanian

Reported as a top in 6,533 wells across 96 counties, at a median depth of 7,903 ft (4,660 to 10,448 ft in most wells). 80 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 →

6.53K
wells reporting a top
80
permitted in last 3 years
96
counties
7,903
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.

CountyWellsMedian, ftP10–P90Last 3 yrs
Crockett
615
7,7847,507–8,0151
Andrews
532
8,8588,680–9,1744
Hemphill
459
6,1145,480–9,5620
Martin
405
9,9259,225–10,60033
Upton
404
10,2949,083–11,0771
Howard
289
8,8097,296–9,1111
Ward
280
7,9882,502–8,2434
Lipscomb
248
5,0304,847–5,2960
Wheeler
248
6,4976,307–7,9080
Ochiltree
242
4,7344,436–5,1171
Midland
202
10,3739,962–10,5971
Crane
158
7,2376,880–7,7786
Ector
153
8,9287,772–10,4031
Glasscock
148
8,5748,166–9,6340
Roberts
136
5,4554,626–6,1020
Dawson
131
9,0858,322–10,2462
Hansford
125
4,1604,003–4,3800
Winkler
117
8,1907,764–8,5030
Reeves
113
11,0009,083–13,7400
Cooke
81
1,666731–7,7473
Pecos
81
8,4845,964–15,1440
Gaines
79
9,3119,023–10,2840
Sterling
71
7,5924,880–8,0251
Yoakum
70
9,7808,798–10,8820
Kent
66
6,4505,020–6,7750
Hartley
64
5,4614,750–7,0983
Borden
62
7,5146,698–8,6811
Terrell
59
10,87210,198–11,3580
King
54
5,2865,199–5,4031
Edwards
51
6,6802,703–8,9800
Loving
50
14,90014,002–15,1020
Scurry
46
6,6464,797–7,0241
Grayson
42
7,0364,681–10,4111
Nolan
38
5,6184,236–6,1690
Sherman
37
3,8903,126–4,2220
Terry
36
9,7369,370–10,6100
Coke
35
4,9703,860–5,6694
Potter
33
5,5364,694–6,7701
Hutchinson
32
4,2873,750–4,6000
Wichita
32
594307–7670
Oldham
29
6,5705,002–7,2052
Sutton
29
5,0654,190–8,3801
Reagan
23
9,7718,163–10,6020
Garza
22
7,6086,980–7,8343
Palo Pinto
19
3,5153,260–3,9600
Schleicher
18
4,8522,321–7,9200
Montague
17
6,1771,416–6,5180
Mitchell
15
7,3746,342–7,9281
Lynn
14
9,3818,328–9,6660
Motley
13
4,2994,026–5,1100
Hudspeth
12
5,1891,730–5,3620
Johnson
12
5,5865,300–6,0460
Hockley
10
9,2969,178–9,8111
Wilbarger
10
5,9245,365–6,1920
Irion
9
7,1425,555–8,8080
Parker
9
5,7703,906–6,2740
Stephens
9
1,350828–3,8900
Tarrant
9
5,6701,984–6,7940
Young
9
1,4001–4,6950
Floyd
8
7,4285,834–9,2790
Hardeman
8
7,2733,331–7,5090
Cochran
7
8,1818,164–9,6340
Dickens
7
5,0174,997–5,0510
Tom Green
7
3,8503,700–5,0360
Val Verde
7
3,3943,315–9,5580
Clay
6
365155–3,1030
Fisher
6
4,8023,913–5,1800
Childress
5
4,1864,127–4,2090
Coleman
5
381366–3880
Culberson
5
9,2006,124–10,5120

Operators

Current operator of record for wells reporting the top, ranked by wells permitted in the last three years.

Recently permitted wells reporting the Pennsylvanian

BY LAST PERMIT ISSUED

Last permitLeaseOperatorCountyTop, ftAPI
Oct 9, 2026Tubb 39Surge Operating, LLCHoward8,80922736348
Jul 6, 2026Clayton, A. M. 'E' NCT-2Yukon Exploration Operating, LLCBorden8,17503300992
Jun 2, 2026Eagle Draw '11'Walsh & Watts, Inc.Crockett5,69010538575
May 15, 2026Parker, J. E. "Z"Union Oil Company of CaliforniaAndrews8,95000337616
Apr 9, 2026Pyote MonitorXTO Energy Inc.Ward11,42047530228
Feb 24, 2026Bivins WestSunlight Exploration, Inc.Oldham7,18635930435
Dec 23, 2025Kirkpatrick 878Yates Energy CorporationGarza7,03416933524
Dec 19, 2025Hamil BHPC Operating, Inc.Dawson9,16611532880
Dec 9, 2025Wm. Howell 'B'SNR Operating, LLCCooke7,74709734529
Oct 13, 2025Poe SWDQEP Energy CompanyMartin10,86531741240
Oct 8, 2025Trew,r.w. 'D'V & H Oil, L.P.Cooke80009734835
Sep 24, 2025Mabee 6 SWDWasser Operating, LLCMartin9,75031741025
Sep 17, 2025PeelerQEP Energy CompanyMartin10,86531741365
Aug 12, 2025AxeKek Exploration LLCSterling5,10043133529
Aug 6, 2025Sixes PickGunn Oil CompanyKing4,56726933063
Jul 22, 2025Flying Fortress 82/81Mewbourne Oil CompanyWard10,90747538994
Jul 15, 2025WD Johnson EWilliams Oil CompanyWard7,62947531727
May 23, 2025University Block 9/Penn/UnitXTO Energy Inc.Andrews8,74000338290
Apr 16, 2025Ratliff, Sallie W.Slant Operating, LLCEctor10,68613505000
Apr 10, 2025Toucan SWDEnvironmental Dspl Systems, LLCMartin10,44831743781
Apr 9, 2025Walker RanchDDD Exploration, Inc.Hartley5,54020530302
Feb 18, 2025Dunn 1McCann CorporationScurry7,24041532547
Feb 13, 2025Voth, TheoFelderhoff Production CompanyCooke1,63009734828
Feb 5, 2025Swepi/Txpo JusticeShell Western E&P Inc.Garza7,42716932444
Feb 5, 2025Swepi/Txpo JusticeShell Western E&P Inc.Garza7,39016932623

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/pennsylvanian, documented in the API reference.