| Foster, Mary O-10-2890 | Basa Resources, Inc. only | Iatan, East Howard | Mitchell | 495 | 12.9M | 2.65M | by Jan 1993 – Aug 2026 |
| Mary Ellen O-10-38532 | Diamondback E&P LLC only | Sallie Ann (Spraberry-Wolfcamp) | Ector | 18 | 1.47M | 4.16M | Oct 2007 – Aug 2026 |
| Mary Ann O-10-23870 | Diamondback E&P LLC only | RK (Devonian) | Martin | 3 | 1.45M | 222 | by Jan 1993 – Mar 2019 |
| Mary Krause Unit A O-2-10199 | Burlington Resources O & G Co LP only | Eagleville (Eagle Ford-2) | Live Oak | 4 | 1.28M | 4.55M | Sep 2012 – Aug 2026 |
| Paluxy "B" Sand Unit O-6-14110 | Culver & Cain Production LLC only | Mary Blevins (Paluxy B) | Smith | 8 | 1.16M | 0 | Oct 2001 – Aug 2026 |
| Foster, Mary Acct. #2 O-10-12160 | Basa Resources, Inc. only | Iatan (San Andres) | Mitchell | 74 | 997K | 142K | by Jan 1993 – Aug 2026 |
| Gubbels, Mary Mrs. O-3-4112 | P.o.&g. Operating, LLC only | Thompson | Fort Bend | 17 | 960K | 830K | by Jan 1993 – Jan 2024 |
| Mary Rose A O-9-20971 | Civitas Permian Operating, LLC only | Spraberry (Trend Area) | Reagan | 2 | 952K | 2.3M | Oct 2020 – Aug 2026 |
| Mary 18 O-9-18593 | Pioneer Natural Res. USA, Inc. only | Spraberry (Trend Area) R 40 Exc | Upton | 8 | 937K | 4.93M | Nov 2013 – Aug 2026 |
| Mary O-2-9668 | Magnolia Oil & Gas Operating LLC only | Eagleville (Eagle Ford-2) | Karnes | 4 | 766K | 1.95M | Dec 2010 – Aug 2026 |
| Mary 18-7-G O-9-19483 | Pioneer Natural Res. USA, Inc. only | Spraberry (Trend Area) R 40 Exc | Upton | 1 | 713K | 1.5M | Dec 2016 – Aug 2026 |
| Mary 18-7A-AZ O-9-19484 | Pioneer Natural Res. USA, Inc. only | Spraberry (Trend Area) R 40 Exc | Upton | 1 | 694K | 1.96M | Dec 2016 – Aug 2026 |
| Johnson, Mary B. O-1-15298 | Texian Operating Company, LLC only | Salt Flat (Edwards) | Caldwell | 7 | 687K | 0 | May 2010 – Jul 2026 |
| Mary Scharbauer B7 O-10-48961 | COG Operating LLC only | Parks (Consolidated) | Midland | 1 | 675K | 1.53M | May 2017 – Aug 2026 |
| Maryruth-Anderson 47C O-10-53059 | Pioneer Natural Res. USA, Inc. only | Spraberry (Trend Area) | Martin | 1 | 674K | 821K | Nov 2019 – Aug 2026 |
| Mary O-9-15535 | COG Operating LLC only | Spraberry (Trend Area) | Upton | 8 | 663K | 2.13M | Jun 2004 – Aug 2026 |
| Maryruth-Anderson 47F O-10-53183 | Pioneer Natural Res. USA, Inc. only | Spraberry (Trend Area) | Martin | 1 | 647K | 480K | Nov 2019 – Aug 2026 |
| Maryruth-Bristow 47H O-10-56388 | Pioneer Natural Res. USA, Inc. only | Spraberry (Trend Area) | Martin | 1 | 646K | 692K | Sep 2021 – Aug 2026 |
| Mary Scharbauer B2 O-10-49024 | COG Operating LLC only | Parks (Consolidated) | Midland | 1 | 644K | 1.5M | May 2017 – Aug 2026 |
| Chalk, Mary O-10-19033 | Conocophillips Company only | Howard-Glasscock (Glorieta) | Howard | 29 | 642K | 188K | by Jan 1993 – Nov 2011 |
| Turner, Mary E. -D- O-10-22276 | Pioneer Natural Res. USA, Inc. only | Spraberry (Trend Area) | Midland | 17 | 615K | 1.13M | by Jan 1993 – Dec 2023 |
| Mary Scharbauer B4 O-10-49006 | COG Operating LLC only | Parks (Consolidated) | Midland | 1 | 606K | 1.46M | May 2017 – Aug 2026 |
| Maryruth-Anderson 47D O-10-53082 | Pioneer Natural Res. USA, Inc. only | Spraberry (Trend Area) | Martin | 1 | 555K | 712K | Oct 2019 – Aug 2026 |
| Mary 18-7A-A O-9-19446 | Pioneer Natural Res. USA, Inc. only | Spraberry (Trend Area) R 40 Exc | Upton | 1 | 528K | 1.57M | Dec 2016 – Aug 2026 |
| Bean, Mary B. O-7-6067 | Basa Resources, Inc. only | East Texas | Rusk | 6 | 525K | 277K | by Jan 1993 – Aug 2026 |
| Maryruth-Anderson 47E O-10-53149 | Pioneer Natural Res. USA, Inc. only | Spraberry (Trend Area) | Martin | 1 | 522K | 701K | Oct 2019 – Aug 2026 |
| E. S. H. O-8-27132 | Clear Fork, Incorporated only | Maryneal (Strawn) | Nolan | 6 | 494K | 375K | Mar 1994 – Jun 2005 |
| Mary O-9-17637 | Summit Petroleum LLC only | Spraberry (Trend Area) | Upton | 9 | 488K | 3.12M | Sep 2011 – Jun 2025 |
| Maryruth-Bristow 47I O-10-56449 | Pioneer Natural Res. USA, Inc. only | Spraberry (Trend Area) | Martin | 1 | 486K | 595K | Sep 2021 – Aug 2026 |
| Nielsen O-11-65457 | Whiting Oil and Gas Corporation only | Mary Two (Devonian) | Yoakum | 1 | 459K | 11.4K | by Jan 1993 – Sep 2023 |
| Maryruth-Bristow 47J O-10-56326 | Pioneer Natural Res. USA, Inc. only | Spraberry (Trend Area) | Martin | 1 | 451K | 574K | Sep 2021 – Aug 2026 |
| Mary Rose C O-9-20975 | Civitas Permian Operating, LLC only | Spraberry (Trend Area) | Reagan | 1 | 444K | 2.09M | Oct 2020 – Aug 2026 |
| Mary 18-7-H O-9-19445 | Pioneer Natural Res. USA, Inc. only | Spraberry (Trend Area) R 40 Exc | Upton | 1 | 436K | 1.02M | Dec 2016 – Aug 2026 |
| Maryruth-Bristow 47K O-10-56278 | Pioneer Natural Res. USA, Inc. only | Spraberry (Trend Area) | Martin | 1 | 416K | 573K | Sep 2021 – Aug 2026 |
| Maryland Trust O-4-13353 | Kaler Energy Corp. only | McCampbell (Deep Frio Cons.) | San Patricio | 5 | 405K | 319K | Oct 2004 – Aug 2026 |
| Mary Rose D O-9-20976 | Civitas Permian Operating, LLC only | Spraberry (Trend Area) | Reagan | 2 | 401K | 1.93M | Oct 2020 – Aug 2026 |
| Mary 18-7A-D O-9-20918 | Pioneer Natural Res. USA, Inc. only | Spraberry (Trend Area) R 40 Exc | Upton | 1 | 399K | 2.67M | Nov 2019 – Aug 2026 |
| Mary a Unit O-9-19209 | COG Operating LLC only | Spraberry (Trend Area) | Upton | 1 | 393K | 1.44M | Aug 2015 – Aug 2026 |
| Mary Rose B O-9-20974 | Civitas Permian Operating, LLC only | Spraberry (Trend Area) | Reagan | 2 | 385K | 1.64M | Oct 2020 – Aug 2026 |
| Hubberd, Mary C. -A- O-4-1573 | Hilcorp Energy Company only | Loma Novia | Duval | 16 | 381K | 111 | by Jan 1993 – May 2026 |
| Mary 18D O-9-22060 | Pioneer Natural Res. USA, Inc. only | Spraberry (Trend Area) | Upton | 1 | 374K | 606K | May 2023 – Aug 2026 |
| Lawson, Mary O-7-8045 | Basa Resources, Inc. only | East Texas | Gregg | 24 | 373K | 259K | by Jan 1993 – Aug 2026 |
| Chalk,mary O-10-41221 | Citation Oil & Gas Corp. only | Howard Glasscock (Consolidated) | Howard | 37 | 371K | 131K | Dec 2011 – Aug 2026 |
| Mary Gary O-1-17429 | EOG Resources, Inc. only | Eagleville (Eagle Ford-1) | Atascosa | 2 | 361K | 349K | Jan 2014 – Aug 2026 |
| Mary 18-7A-C O-9-20916 | Pioneer Natural Res. USA, Inc. only | Spraberry (Trend Area) R 40 Exc | Upton | 1 | 349K | 1.07M | Nov 2019 – Aug 2026 |
| Mary Scharbauer B6 O-10-48964 | COG Operating LLC only | Parks (Consolidated) | Midland | 1 | 341K | 1.79M | May 2017 – Aug 2026 |
| Mary Scharbauer B1 O-10-48992 | COG Operating LLC only | Parks (Consolidated) | Midland | 1 | 334K | 2.04M | May 2017 – Aug 2026 |
| Marshall, Mary Ann O-3-17816 | Valence Operating Company only | FT Trinidad-Barrett,e.(dexter) | Madison | 1 | 330K | 86 | by Jan 1993 – Aug 2024 |
| Riddle, Mary Belle, Oil Unit O-6-4908 | HD Operating Co, LLC only | Pittsburg (Sub-Clarksville) | Camp | 4 | 317K | 21 | by Jan 1993 – Jul 2026 |
| Mary O O-9-18246 | Summit Petroleum LLC only | Spraberry (Trend Area) | Upton | 5 | 312K | 970K | Jan 2013 – Aug 2026 |