Petrora

FORMATIONS · RRC WELLBORE FILE

Jo Mill

Reported as a top in 1,907 wells across 15 counties, at a median depth of 7,660 ft (6,158 to 8,689 ft in most wells). 68 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 →

1.91K
wells reporting a top
68
permitted in last 3 years
15
counties
7,660
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
Reagan
635
6,6236,100–7,2568
Martin
483
8,4467,617–9,11347
Upton
240
8,3788,085–8,5363
Midland
187
8,4908,047–8,8524
Irion
85
5,9545,671–6,0370
Dawson
68
7,6707,390–8,3552
Borden
56
7,1986,702–7,3600
Glasscock
50
7,6847,303–7,7550
Howard
44
7,2206,334–7,5530
Andrews
28
8,9148,878–9,2493
Crockett
15
5,2925,287–5,5400
Garza
6
6,0625,976–6,2050
Lynn
5
7,6687,624–7,6870

Operators

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

OperatorLast 3 yrsAll
Diamondback E&P LLC4077
Endeavor Energy Resources L.P.7176
Civitas Permian Operating, LLC55
Pioneer Natural Res. USA, Inc.36
XTO Energy Inc.211
Ovintiv USA Inc.24
DE IV Operating, LLC22
Permian Resources Operating, LLC22
Hibernia Resources IV, LLC1189
Petroplex Energy Inc.15
Firebird Energy II LLC11
Vital Energy, Inc.11
Pinon Operating II, LLC11
Sable Permian Resources, LLC0137
Hallwood Petroleum, Inc.0108
Atkins Petroleum Corp.074
Concho Resources Inc.057
QEP Energy Company056
Hugoton Energy Corporation055
Saxon Oil Company044
Usenco042
EP Energy E&P Company, L.P.032
Lewis & Atkins Oil & Gas, Inc.032
BTA Oil Producers030
Brazos Petroleum Co.028

Recently permitted wells reporting the Jo Mill

BY LAST PERMIT ISSUED

Last permitLeaseOperatorCountyTop, ftAPI
Jan 21, 2026Mary '84'Hibernia Resources IV, LLCDawson8,39011531938
Dec 2, 2025Nature Boy 11-37 ADiamondback E&P LLCMidland8,06532948021
Nov 12, 2025Black Caiman 21-24 DDiamondback E&P LLCMartin8,34931747050
Nov 12, 2025Black Caiman 21-24 DDiamondback E&P LLCMartin8,36031747051
Nov 12, 2025Black Caiman 21-24 CDiamondback E&P LLCMartin8,35331747052
Nov 12, 2025Black Caiman 21-24 DDiamondback E&P LLCMartin8,35231747053
Nov 12, 2025Black Caiman 21-24 EDiamondback E&P LLCMartin8,35531747055
Oct 9, 2025Thumper 48-24 KDiamondback E&P LLCEctor8,42713544136
Sep 11, 2025Halfmann BPermian Resources Operating, LLCReagan6,65938342195
Aug 27, 2025UL Monty East 46-32 ADiamondback E&P LLCAndrews8,91600349210
Aug 27, 2025UL Monty East 46-32 DDiamondback E&P LLCAndrews8,91100349212
Aug 11, 2025Greystoke 1-5 GDiamondback E&P LLCMartin8,27731746905
Jul 23, 2025Piranha 6-3 CDiamondback E&P LLCMartin8,32031746939
Jul 23, 2025Piranha 6-3 CDiamondback E&P LLCMartin8,32731746940
Jul 22, 2025Piranha 6-3 DDiamondback E&P LLCMartin8,32031746928
Jul 22, 2025Piranha 6-3 DDiamondback E&P LLCMartin8,32131746929
Jul 22, 2025Piranha 6-3 EDiamondback E&P LLCMartin8,31831746931
Jul 17, 2025Heidelberg 30-31 MDiamondback E&P LLCMartin7,49731746865
Jul 17, 2025Heidelberg 30-31 NDiamondback E&P LLCMartin7,50831746866
Jul 17, 2025Heidelberg 30-31 ODiamondback E&P LLCMartin7,49931746867
Jul 17, 2025Heidelberg 30-31 PDiamondback E&P LLCMartin7,50631746868
Jul 10, 2025Greystoke 1-5 ADiamondback E&P LLCMartin8,28331746894
Jul 10, 2025Greystoke 1-5 BDiamondback E&P LLCMartin8,27531746898
Jul 10, 2025Greystoke 1-5 BDiamondback E&P LLCMartin8,28031746899
Jul 10, 2025Greystoke 1-5 CDiamondback E&P LLCMartin8,29231746902

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/jo-mill, documented in the API reference.