| Old Ocean Unit G-3-133678 | Hilcorp Energy Company only | Old Ocean (Armstrong) | Brazoria | 1 | 88.5K | 1.3M | Jan 1993 – Jul 2001 |
| Colby, E. H., Etal O-3-9082 | Argent Energy (US) Holdings Inc. only | Manvel (5100) | Brazoria | 1 | 88.3K | 39.8K | Jan 1993 – Dec 2011 |
| Old Ocean Unit G-3-257089 | Hilcorp Energy Company only | Old Ocean (F-26) | Brazoria | 1 | 87.6K | 1.48M | Feb 2010 – Apr 2026 |
| Harrison O-3-25180 | Slawson Exploration Company, Inc only | Angleton, South (12,600) | Brazoria | 1 | 85K | 378K | May 2008 – Nov 2009 |
| Smith Heirs Unit G-3-232250 | Bluestem Natural Gas LLC only | Four Corners (Frio F-28) | Brazoria | 1 | 84.4K | 1.96M | Sep 2007 – Apr 2026 |
| Williamson G-3-176024 | Timberwolf Energy, Inc. only | Angleton, S. (F-4 FB-AZ) | Brazoria | 1 | 84.2K | 3.1M | Jan 2000 – Mar 2026 |
| Wieting, A. M. Gas Unit G-3-198102 | Dune Operating Company only | Chocolate Bayou ( Frio P) | Brazoria | 1 | 83.6K | 2.62M | Oct 2003 – Jul 2008 |
| Switzer Trust G-3-201218 | Noble Energy Inc only | Bartman (11050 Sand) | Brazoria | 1 | 82.2K | 3.08M | Mar 2004 – Jul 2005 |
| Farms, I. P. Unit A G-3-163888 | Proline Energy Resources Inc only | Chocolate Bayou (Andrau) | Brazoria | 1 | 81.8K | 2.43M | May 1997 – May 2001 |
| Old Ocean Unit G-3-42235 | Hilcorp Energy Company only | Old Ocean (Larsen) | Brazoria | 1 | 81.5K | 8.56M | Jan 1993 – Sep 2006 |
| Farms, I. P. G-3-181539 | Elliott Oil & Gas Operating Co. only | Chocolate Bayou, N. (10400) | Brazoria | 1 | 79.2K | 1.96M | Dec 2000 – Oct 2023 |
| Blackstone Hlavinka G-3-282213 | Elliott Oil & Gas Operating Co. only | Chocolate Bayou (11050) | Brazoria | 1 | 78.2K | 605K | Dec 2016 – Jan 2025 |
| Knape, J. O-3-24135 | McGowan Working Partners, Inc. only | Walk Man (Frio 7550) | Brazoria | 1 | 77.9K | 89.1K | Feb 2002 – Sep 2014 |
| Kentzelman O-3-13183 | Alegre Energy, Inc. only | Chocolate Bayou (10570) | Brazoria | 1 | 77.6K | 27 | Jan 1993 – Aug 2012 |
| Old Ocean Unit G-3-125946 | Hilcorp Energy Company only | Old Ocean (Armstrong) | Brazoria | 1 | 77.4K | 657K | Jan 1993 – Sep 2004 |
| Hall Bayou G-3-280683 | Kaler Energy Corp. only | Pegasus Gulf Coast (Big Gas Sd.) | Brazoria | 1 | 77.1K | 256K | Dec 2015 – Sep 2016 |
| Farms, I. P. PG O-3-23813 | Elliott Oil & Gas Operating Co. only | Pegasus Gulf Coast (Grubbs) | Brazoria | 1 | 76.3K | 596K | Apr 2000 – Apr 2025 |
| Cozby G-3-136387 | Quantum Resources Management,llc only | Chocolate Bayou (Andrau) | Brazoria | 1 | 76K | 2.45M | Jan 1993 – Jun 2003 |
| H. O. F. A. O-3-24352 | Denbury Onshore, LLC only | Manvel (4000) | Brazoria | 1 | 75K | 118K | May 2003 – May 2014 |
| Fite Fee O-3-12281 | Channa Operating, LLC only | Sandy Point, West (6480) | Brazoria | 1 | 74.6K | 163 | Jan 1993 – Feb 2008 |
| Sponsel/Price O-3-23570 | Corum Production Company only | Rowan, N. (Frio, Upper 9600) | Brazoria | 1 | 74.3K | 29 | Jul 1998 – Mar 2015 |
| Schenck G-3-283765 | Elliott Oil & Gas Operating Co. only | Chocolate Bayou (Frio, First) | Brazoria | 1 | 72.5K | 147K | Feb 2018 – Feb 2026 |
| H. Blackstone G-3-296708 | Cimarron Engineering, LLC only | Pegasus Gulf Coast (Grubbs) | Brazoria | 1 | 72K | 1.24M | Jan 2024 – Apr 2026 |
| Grubbs O-3-22686 | Elliott Oil & Gas Operating Co. only | Chocolate Bayou (Frio, First) | Brazoria | 1 | 71.6K | 48.7K | Apr 1995 – Jul 2024 |
| Bennett Estate O-3-24706 | HG Operating LLC only | Danbury Dome (2780) | Brazoria | 1 | 71.4K | 93.8K | Jun 2005 – Apr 2026 |
| Korenek O-3-23215 | Houston Petroleum Company only | Danbury Dome (F-2-B) | Brazoria | 2 | 71.1K | 26.1K | Jan 1997 – Mar 2001 |
| Mound Company Lease NCT-1 O-3-24478 | Linc Gulf Coast Petroleum, Inc. only | Hoskins Mound | Brazoria | 2 | 71K | 57.5K | Mar 2004 – Dec 2012 |
| Belcher, W.T. "B" O-3-22726 | Denbury Onshore, LLC only | Manvel (Miocene) | Brazoria | 2 | 70.4K | 67.5K | Nov 2002 – Feb 2013 |
| Blount, C. H., Etux O-3-5610 | Denbury Onshore, LLC only | Hastings, East | Brazoria | 5 | 69.7K | 87.4K | Jan 1993 – Apr 2014 |
| Brown, Cecil O-3-5591 | Exxon Corp. only | Hastings, East | Brazoria | 10 | 67.4K | 248K | Jan 1993 – May 1998 |
| Wilson, R. K. Gas Unit No. 1 G-3-158958 | Dune Operating Company only | Chocolate Bayou (12,000) | Brazoria | 1 | 66.8K | 2.33M | Mar 1996 – May 2008 |
| Halligan, O. M. O-3-23364 | Denbury Onshore, LLC only | Manvel (Miocene 3900) | Brazoria | 1 | 66.6K | 8.68K | Sep 1997 – Sep 2013 |
| Colby, O.C. O-3-22262 | Josey Oil Company, Ltd. only | Manvel (5100) | Brazoria | 1 | 65.9K | 23.8K | Jan 1994 – Nov 2010 |
| Beers, W.F.-A- O-3-5576 | Exxon Corp. only | Hastings, East | Brazoria | 1 | 65.7K | 134K | Jan 1993 – May 1998 |
| Blackstone Hlavinka G-3-282363 | Elliott Oil & Gas Operating Co. only | Persimmon Bayou (Grubbs) | Brazoria | 1 | 65.1K | 659K | Jun 2017 – Jan 2025 |
| Knape O-3-20781 | McGowan Working Partners only | Walk Man (Frio 8000) | Brazoria | 1 | 64.2K | 39.6K | Jan 1993 – Mar 1997 |
| Old Ocean Unit G-3-7673 | Hilcorp Energy Company only | Old Ocean (Larsen) | Brazoria | 1 | 64K | 5.88M | Jan 1993 – Dec 2009 |
| O'Leary Unit G-3-210096 | Bluestem Natural Gas LLC only | Four Corners (Helmuth A) | Brazoria | 1 | 63K | 1.12M | Apr 2004 – Jul 2020 |
| Hofa NCT-1 O-3-16731 | Denbury Onshore, LLC only | Manvel (Miocene 3300) | Brazoria | 1 | 61.9K | 44.7K | Jan 1993 – Mar 2013 |
| Randall-Whiton Miocene Unit O-3-22390 | Denbury Onshore, LLC only | Hastings (M-14-A) | Brazoria | 1 | 61.9K | 85.5K | Apr 1994 – Nov 2003 |
| Old Ocean Unit G-3-7653 | Hilcorp Energy Company only | Old Ocean (Larsen) | Brazoria | 1 | 61.4K | 7.6M | Jan 1993 – Jan 2008 |
| Wilson, R. K. -B- NCT-1 O-3-680 | White Marlin Operating Co, LLC only | Chocolate Bayou ( Frio Upper) | Brazoria | 4 | 60.2K | 292K | May 1996 – Apr 2026 |
| Price, J.E. O-3-19014 | Elliott Oil & Gas Operating Co. only | Arcola (7400 Frio) | Brazoria | 1 | 60K | 48.3K | Jan 1993 – May 2021 |
| Black Stone Ivory G-3-206987 | Elliott Oil & Gas Operating Co. only | Chocolate Bayou,n.(andrau Stray) | Brazoria | 1 | 60K | 886K | Dec 2004 – Jan 2026 |
| Price, J.E. O-3-19383 | Whiting Oil and Gas Corporation only | Rowan, N. (Frio, Upper 9600) | Brazoria | 2 | 59.4K | 6.51K | Jan 1993 – May 2005 |
| Texasgulf, Inc. Fee Unit G-3-159406 | Texas Independent Explor., Inc. only | Old Ocean North (10150) | Brazoria | 1 | 59.3K | 321K | Mar 1996 – Dec 1997 |
| Worrell-Northrup O-3-21103 | Proline Energy Resources Inc only | Chenango, North (Frio 10500) | Brazoria | 1 | 58.9K | 12.2K | Jan 1993 – Dec 2019 |
| Banfield G-3-158351 | Phillips Petroleum Company only | Chocolate Bayou (12,000-S) | Brazoria | 1 | 58.8K | 1.86M | Mar 1996 – Oct 1998 |
| Tri-Wallinder O-3-25598 | Elliott Oil & Gas Operating Co. only | Chocolate Bayou ( Frio Upper) | Brazoria | 1 | 57.7K | 37.3K | Oct 2007 – Jul 2024 |
| Poole G-3-197643 | Arcadia Operating, LLC only | Reasoner (12600) | Brazoria | 1 | 57.6K | 946K | Aug 2003 – Apr 2026 |