| Obrien, G. W., Etal O-10-7338 | Two P Partners, LLC only | Ward-Estes, North | Ward | 2,066 | 31.5M | 30.6M | by Jan 1993 – Aug 2026 |
| Obrien-Brunson 43A O-10-52078 | Pioneer Natural Res. USA, Inc. only | Spraberry (Trend Area) | Midland | 1 | 554K | 1.56M | Jan 2019 – Aug 2026 |
| Obrien, E., Unit 6 O-3-7174 | Big Lake Corporation only | High Island | Galveston | 2 | 302K | 175K | by Jan 1993 – Aug 2026 |
| Obrien, J. J., -B- O-2-3960 | Greta Operating Company LLC only | Greta (4400) | Refugio | 4 | 273K | 40.8K | by Jan 1993 – Nov 2024 |
| Obrien -E- O-3-2651 | Gemarmi Inc. only | Liberty, South | Liberty | 4 | 233K | 67.7K | by Jan 1993 – Jul 2026 |
| State University A&d O-10-22945 | Primal Energy Corporation only | Leon Valley (Obrien) | Pecos | 29 | 231K | 394K | by Jan 1993 – Jun 2012 |
| Obrien, J. M. O-2-4921 | South Texas Operating Company only | Greta, Deep (5660) | Refugio | 1 | 174K | 137K | by Jan 1993 – Aug 2026 |
| Obrien, Erin, Etal, Unit 1 O-3-6121 | Big Lake Corporation only | High Island | Galveston | 2 | 167K | 68.9K | by Jan 1993 – Dec 2016 |
| Obrien, J. J., -A- O-2-3959 | Greta Operating Company LLC only | Greta (4400) | Refugio | 7 | 124K | 48.1K | by Jan 1993 – Apr 2017 |
| Obrien, J. M. O-2-3997 | Primrose Operating Company only | Greta (4400) | Refugio | 6 | 116K | 98.9K | by Jan 1993 – May 2005 |
| Obrien Strawn Unit O-8-10184 | Scout Energy Management LLC only | Obrien (Strawn) | Haskell | 36 | 114K | 17.7K | by Jan 1993 – Aug 2026 |
| Obrien, J. J., -A- O-2-3970 | Greta Operating Company LLC only | Greta (4400) | Refugio | 4 | 108K | 1.34K | by Jan 1993 – Apr 2017 |
| Obrien, J. M. O-2-3984 | South Texas Operating Company only | Greta (4400) | Refugio | 5 | 100K | 123K | by Jan 1993 – Dec 2012 |
| Obrien,j.m.,-A- East 101 Ac. 6 O-2-3992 | Dewbre Petroleum Corporation only | Greta (4400) | Refugio | 4 | 76.5K | 46.6K | by Jan 1993 – Aug 2026 |
| State University A&d O-10-42020 | Xhorizons Energy LLC only | Leon Valley (Obrien) | Pecos | 21 | 76.1K | 709 | Jul 2012 – Jun 2026 |
| Obrien, J. M., -B- O-2-3980 | Acock/Anaqua Operating Co., LP only | Greta (4400) | Refugio | 5 | 65.9K | 173K | by Jan 1993 – Mar 2003 |
| Westenhover O-8-18257 | Iron Bell Operating, LLC only | Obrien (Strawn) | Haskell | 1 | 57.8K | 24 | by Jan 1993 – Jul 2019 |
| Obrien, J. J. O-2-1409 | Eagleford Operating, Inc. only | Refugio Old | Refugio | 4 | 55.1K | 134K | Dec 1993 – Jan 2006 |
| Ellis, M.C. O-8-7551 | Iron Bell Operating, LLC only | Obrien (Strawn) | Haskell | 3 | 51.2K | 22 | by Jan 1993 – May 2009 |
| Redwine O-8-14890 | Iron Bell Operating, LLC only | Obrien (Strawn) | Haskell | 2 | 49.9K | 24 | by Jan 1993 – Aug 2026 |
| Tahoe-University "B" O-10-28285 | Xhorizons Energy LLC only | Leon Valley (Obrien) | Pecos | 4 | 47.5K | 37.8K | by Jan 1993 – Jun 2026 |
| Griffith O-8-16000 | Foundation Energy Management LLC only | Obrien (Strawn) | Haskell | 1 | 46.4K | 24 | by Jan 1993 – Dec 2017 |
| Fly, Florence O-8-15919 | Foundation Energy Management LLC only | Obrien (Strawn) | Haskell | 2 | 38.6K | 24 | by Jan 1993 – Aug 2017 |
| Head-Johnson O-8-24760 | Texoma Oil Tools, Inc. only | Obrien, South (Strawn) | Haskell | 2 | 36.4K | 264 | by Jan 1993 – Nov 2023 |
| University "B" O-10-20718 | Xhorizons Energy LLC only | Leon Valley, E. (Obrien -B- Sd.) | Pecos | 5 | 35.4K | 52.6K | by Jan 1993 – Jun 2026 |
| Logan, H. B. O-8-19223 | Taylor, J. S. Inc. only | Obrien, North (Strawn) | Haskell | 2 | 32.1K | 236 | by Jan 1993 – Nov 1997 |
| O'Brien "A" O-8-25599 | Chap Operating, Inc. only | Obrien, West (Strawn) | Haskell | 1 | 29.6K | 35 | by Jan 1993 – Aug 2026 |
| North O'Brien Unit O-8-27268 | Wilco Properties, Inc. only | Obrien, North (Strawn) | Haskell | 9 | 25.4K | 1 | Sep 1994 – Aug 2001 |
| Hughes, Lera B. O-8-16997 | Scout Energy Management LLC only | Obrien (Strawn) | Haskell | 1 | 22.9K | 0 | Oct 1993 – Jun 2017 |
| University O-10-25904 | Flamingo Operating, LLC only | Leon Valley (Obrien) | Pecos | 3 | 22.6K | 17.6K | by Jan 1993 – Jul 2012 |
| Obrien, G. W., Etal O-10-20910 | Two P Partners, LLC only | Ward-Estes, North (Holt) | Ward | 24 | 18.9K | 341K | by Jan 1993 – Aug 2024 |
| Scott, S.A. O-8-20727 | Chisholm Operating, Inc. only | Obrien (Strawn) | Haskell | 2 | 15.9K | 8.25K | by Jan 1993 – Jan 2008 |
| O'Brien "B" O-8-25646 | Chap Operating, Inc. only | Obrien, West (Strawn) | Haskell | 1 | 15.7K | 35 | by Jan 1993 – Aug 2026 |
| Behrens-Obrien #3 O-3-21132 | Trivista Operating LLC only | Serbin (Taylor Sand) | Bastrop | 2 | 14.6K | 184K | by Jan 1993 – Feb 2026 |
| Obrien, G. W., et al -C- O-10-19236 | Chevron U. S. A. Inc. only | Ward-Estes, North | Winkler | 6 | 13.7K | 12.2K | by Jan 1993 – Jan 1995 |
| Holiman, O. M. O-10-28604 | Cuervo, Inc. only | Leon Valley (Obrien) | Pecos | 2 | 12.2K | 171K | by Jan 1993 – Apr 2019 |
| Tahoe-University "A" O-10-28284 | Xhorizons Energy LLC only | Leon Valley (Obrien) | Pecos | 2 | 9.22K | 85.4K | by Jan 1993 – Jun 2026 |
| Obrien, J. M., -D- O-2-3982 | Exxon Corp. only | Greta (4400) | Refugio | 1 | 6.59K | 20.5K | Aug 1993 – Jul 1996 |
| Waldrip, Ancel O-8-8020 | Wilco Properties, Inc. only | Obrien, North (Strawn) | Haskell | 3 | 6.17K | 20 | by Jan 1993 – Aug 1994 |
| Scott, S.A. "B" O-8-22347 | Petra Oleum Corp. only | Obrien (Strawn) | Haskell | 1 | 5.82K | 3.26K | by Jan 1993 – Aug 1997 |
| Mathis O-8-14874 | Chaparral Energy, L.L.C. only | Obrien (Strawn) | Haskell | 2 | 4.43K | 24 | by Jan 1993 – Jan 1998 |
| Hester, Floyd O-8-18848 | Bristol Resources Corporation only | Obrien (Strawn) | Haskell | 1 | 3.62K | 24 | by Jan 1993 – May 1996 |
| University -A- O-10-25832 | Primal Energy Corporation only | Leon Valley (Obrien) | Pecos | 2 | 3.03K | 9.44K | by Jan 1993 – Apr 2008 |
| Holiman O-10-26230 | Primal Energy Corporation only | Leon Valley (Obrien) | Pecos | 1 | 1.99K | 2.63K | by Jan 1993 – Mar 2008 |
| Obrien, J. M., -B- O-2-3993 | Dewbre Petroleum Corporation only | Greta (4400) | Refugio | 2 | 1.57K | 1.57K | by Jan 1993 – Jan 1994 |
| University 8A O-10-26545 | Primal Energy Corporation only | Leon Valley (Obrien) | Pecos | 3 | 1.54K | 2.24K | by Jan 1993 – Nov 1998 |
| Obrien-Harkins "A" O-2-4866 | Charro Operating, L.L.C. only | Obrien Ranch (Frio 4650) | Goliad | 1 | 882 | 0 | Jan 1997 – May 1997 |
| Halley, S. M. O-10-31255 | Southwest Royalties, Inc. only | Halley (Obrien) | Winkler | 1 | 730 | 60 | by Jan 1993 – Jul 1996 |
| F & J Unit -B- O-8-8660 | Wilco Properties, Inc. only | Obrien, North (Strawn) | Haskell | 1 | 423 | 20 | by Jan 1993 – Aug 1994 |
| Obrien, J. J., -A- O-2-4022 | Chilton Energy only | Greta, Deep (5900) | Refugio | 2 | 85 | 3 | Sep 1993 – Nov 1993 |