| Obrien, Reid G-6-225339 | Burk Royalty Co., Ltd. only | Brookeland (Austin Chalk, 8800) | Tyler | 1 | 44.5K | 672K | Feb 2006 – Aug 2026 |
| Obrien, G. W., Etal G-10-291495 | Two P Partners, LLC only | Ward-Estes, North | Ward | 1 | 10K | 3.39K | Oct 2021 – Aug 2026 |
| JM Obrien "A" G-2-214405 | Greta Operating Company LLC only | Greta (6200, South) | Refugio | 1 | 5.78K | 229K | Jun 2005 – Aug 2012 |
| Obrien, G. W., Etal G-10-291549 | Two P Partners, LLC only | Ward-Estes, North | Ward | 1 | 4.6K | 2.45K | Mar 2021 – Aug 2026 |
| Obrien, G. W., Etal G-10-291551 | Two P Partners, LLC only | Ward-Estes, North | Ward | 1 | 2.8K | 1.8K | Oct 2021 – Aug 2026 |
| Obrien, J. J. G-2-225547 | Emerald Oil & Gas LC only | Refugio Old | Refugio | 1 | 2.69K | 19.3K | Mar 2006 – Oct 2008 |
| Harkins - O'Brien "C" G-2-167828 | Charro Operating, L.L.C. only | Obrien Ranch (4500) | Goliad | 1 | 2.48K | 807K | Jan 1998 – Sep 2013 |
| O'Brien-Harkins G-2-169342 | C & E Operating, Inc. only | Obrien Ranch (4500) | Goliad | 1 | 980 | 310K | May 1998 – Dec 2009 |
| Obrien, J. J. -B- G-2-33086 | JTB Oil Company, Inc. only | Blanconia (4700) | Bee | 1 | 931 | 411K | by Jan 1993 – Mar 2012 |
| O'Brien-Harkins G-2-168460 | C & E Operating, Inc. only | Obrien Ranch (3820) | Goliad | 1 | 850 | 1.95M | Mar 1998 – Nov 2006 |
| Harkins-O'Brien "C" G-2-174801 | Charro Operating, L.L.C. only | Obrien Ranch (4500) | Goliad | 1 | 422 | 197K | Jul 1999 – Feb 2007 |
| Obrien, Mick & Dick G-2-173232 | Welder Exploration & Prod., Inc. only | Murphy Sisters (Frio 3600) | Bee | 1 | 265 | 268K | Apr 1999 – Nov 2006 |
| O'Brien-Harkins G-2-173070 | C & E Operating, Inc. only | Obrien Ranch (3820) | Goliad | 1 | 202 | 1.31M | Mar 1999 – Jul 2012 |
| O'Brien, J.M. G-2-162477 | C & E Operating, Inc. only | Obrien Ranch (4420) | Bee | 1 | 185 | 586K | Feb 1997 – Jul 2012 |
| O'Brien, J. M. G-2-160773 | C & E Operating, Inc. only | Obrien Ranch (3820) | Bee | 1 | 182 | 440K | Nov 1996 – Jan 1998 |
| O'Brien-Harkins G-2-175281 | C & E Operating, Inc. only | Obrien Ranch (3820) | Bee | 1 | 173 | 718K | Aug 1999 – Sep 2004 |
| O'Brien-Harkins G-2-173069 | C & E Operating, Inc. only | Obrien Ranch (3820) | Goliad | 1 | 162 | 588K | Mar 1999 – Aug 2004 |
| O'Brien-Harkins G-2-168463 | C & E Operating, Inc. only | Obrien Ranch (3820) | Goliad | 1 | 137 | 345K | Apr 1998 – Sep 1999 |
| Obrien, J. M. III G-2-172422 | Welder Exploration & Prod., Inc. only | Murphy Sisters (Frio 3600) | Bee | 1 | 137 | 1.04M | Dec 1998 – Nov 2006 |
| O'Brien, J. M. G-2-161555 | C & E Operating, Inc. only | Obrien Ranch (3820) | Bee | 1 | 83 | 257K | Jan 1997 – Feb 1998 |
| O'Brien, J. M. G-2-168465 | C & E Operating, Inc. only | Obrien Ranch (3820) | Bee | 1 | 41 | 307K | Mar 1998 – Oct 2011 |
| Powers, J. N. G-2-174749 | C & E Operating, Inc. only | Obrien Ranch (3820) | Goliad | 1 | 39 | 223K | Aug 1999 – Oct 2004 |
| Obrien, J. M. -a-Gas Prod.area-E G-2-65409 | Chilton Energy only | Greta (1080) | Refugio | 1 | 0 | 0 | — |
| Obrien, J. M. G-2-66659 | Dewbre Petroleum Corporation only | Greta (4400) | Refugio | 1 | 0 | 0 | — |
| Obrien, J. J. -C- G-2-68175 | Chilton Energy only | Greta (O-4) | Refugio | 1 | 0 | 0 | — |
| Obrien, J. M. -B- G-2-74461 | Greta Operating Company LLC only | Greta (C-1) | Refugio | 1 | 0 | 408K | by Jan 1993 – May 2020 |
| Obrien,j.m.-B-(gas Prod.area-B-) G-2-74593 | Greta Operating Company LLC only | Greta (L-13) | Refugio | 1 | 0 | 0 | — |
| Obrien, J. M. -B- G-2-76329 | Exxon Corp. only | Greta (C-1) | Refugio | 1 | 0 | 0 | — |
| Obrien, J. M. -B- G-2-82795 | Greta Operating Company LLC only | Greta (1250) | Refugio | 1 | 0 | 0 | — |
| Obrien, J. M. -B- G-2-85106 | Greta Operating Company LLC only | Greta (1300) | Refugio | 1 | 0 | 0 | — |
| Obrien, J. M. -A- G-2-85208 | Greta Operating Company LLC only | Greta (900) | Refugio | 1 | 0 | 0 | — |
| Obrien, J. M. -A- G-2-85256 | Greta Operating Company LLC only | Greta (1250) | Refugio | 1 | 0 | 28.9K | Jan 1997 – Jan 2018 |
| Obrien J. M. -B- G-2-86196 | Acock/Anaqua Operating Co., LP only | Greta (700) | Refugio | 1 | 0 | 14.2K | by Jan 1993 – Jun 1997 |
| Obrien, J. M. -B- G-2-86197 | Acock/Anaqua Operating Co., LP only | Greta (800) | Refugio | 1 | 0 | 0 | — |
| Obrien, J. M. G-2-86779 | Primrose Operating Company only | Greta (800) | Refugio | 1 | 0 | 0 | — |
| Obrien, J. M. G-2-98519 | Primrose Operating Company only | Greta (900) | Refugio | 1 | 0 | 33.5K | by Jan 1993 – Apr 2005 |
| Obrien, J. M. -B- G-2-99595 | Greta Operating Company LLC only | Greta (900) | Refugio | 1 | 0 | 0 | — |
| Obrien, J. M. G-2-101793 | Acock/Anaqua Operating Co., LP only | Greta (C-5) | Refugio | 1 | 0 | 755K | by Jan 1993 – Mar 2009 |
| Obrien, J. M. D & E G-2-106112 | Greta Operating Company LLC only | Greta, Deep (5600) | Refugio | 1 | 0 | 0 | — |
| Obrien, J. M. -B- G-2-108307 | Dorchester Operating Company LLC only | Greta (C-5) | Refugio | 1 | 0 | 0 | — |
| Obrien, J. M. -A- G-2-112910 | Dewbre Petroleum Corporation only | Greta (3500) | Refugio | 1 | 0 | 162K | by Jan 1993 – Sep 1999 |
| Obrien, J. M. G-2-115243 | Exxon Corp. only | Greta (O-6) | Refugio | 1 | 0 | 15.3K | Oct 1993 – Dec 1993 |
| Obrien, J.M. G-2-125476 | Primrose Operating Company only | Greta (O-4) | Refugio | 1 | 0 | 0 | — |
| Obrien, J.M. G-2-127502 | Acock/Anaqua Operating Co., LP only | Greta (L- 4) | Refugio | 1 | 0 | 16.5K | by Jan 1993 – May 2004 |
| Obrien, J.M. -H- G-2-132945 | Greta Operating Company LLC only | Greta (L- 8) | Refugio | 1 | 0 | 988 | Feb 1993 – Jun 1993 |
| Harkins-O'Brien "B" G-2-167770 | Charro Operating, L.L.C. only | Obrien Ranch (4500) | Goliad | 1 | 0 | 19.6K | Dec 1997 – Aug 1999 |
| Harkins - O'Brien "C" G-2-168785 | Charro Operating, L.L.C. only | Obrien Ranch (Frio 4650) | Goliad | 1 | 0 | 50.6K | Jan 1998 – Jun 1999 |
| O'Brien-Harkins G-2-169343 | C & E Operating, Inc. only | Obrien Ranch (Frio 4650) | Goliad | 1 | 0 | 291K | May 1998 – Oct 2007 |
| O'Brien-Harkins G-2-170010 | C & E Operating, Inc. only | Obrien Ranch (Frio 4650) | Goliad | 1 | 0 | 240K | Jun 1998 – Dec 2009 |
| O'Brien-Harkins G-2-170012 | C & E Operating, Inc. only | Obrien Ranch (4500) | Goliad | 1 | 0 | 247K | Jun 1998 – Dec 2009 |