| Acock BP Johnson 21 G-3-285577 | Shoco Production LLC only | Castillo, West (Y-2) | Jasper | 1 | 35.3K | 52K | Dec 2018 – Jul 2026 |
| De Austin-Castillo GU G-4-165693 | Merit Energy Company only | Jeffress, NE. (T, Lo.-Fb,a) | Hidalgo | 1 | 34.8K | 2.35M | Oct 1997 – Aug 2026 |
| Johnson O-10-39814 | WPX Energy Permian, LLC only | Tunstill | Loving | 5 | 33.8K | 12.9K | Dec 2009 – Nov 2019 |
| Tunstill Oil & Land Co. O-10-28952 | Mayjac I, LLC only | Matthews (Lower Cherry Canyon) | Reeves | 3 | 33.4K | 43.5K | by Jan 1993 – Sep 2007 |
| Still, A. L. O-7-7190 | Exzena Oil Corp. only | East Texas | Gregg | 18 | 32.9K | 26 | by Jan 1993 – Jun 2008 |
| Blackwell, Raymond O-1-1111 | Castillo Oil Company LLC only | Luling-Branyon | Caldwell | 31 | 30.5K | 21 | by Jan 1993 – Jul 2026 |
| Books '21' O-10-33920 | Costilla Energy, Inc. only | Patterson Lake (Wolfcamp) | Glasscock | 2 | 29.6K | 107K | Aug 1993 – Oct 1994 |
| Hamlin-L- O-10-35287 | Costilla Energy, Inc. only | Talbot (Canyon) | Howard | 1 | 29.4K | 39.7K | Feb 1997 – Jul 1998 |
| Talbot-Fuller Canyon Unit G-10-151298 | Costilla Petroleum Corporation only | Talbot (Canyon) | Howard | 1 | 28.2K | 91.8K | Aug 1994 – Feb 1995 |
| Santa FE Ranch Mula Pasture G-4-200372 | Hughes, Dan A. Company, L.P. only | Stillman (Deep Cons.) | Kenedy | 1 | 27.8K | 8.32M | Mar 2004 – Aug 2026 |
| Santa FE Ranch Mula Pasture G-4-286736 | Hughes, Dan A. Company, L.P. only | Stillman (Deep Cons.) | Kenedy | 1 | 27.7K | 13.5M | Feb 2019 – Aug 2026 |
| Still, R. H. O-7-6850 | Chevron U. S. A. Inc. only | East Texas | Gregg | 26 | 27.4K | 7.9K | by Jan 1993 – Aug 2000 |
| Fraser, TXL -D- O-10-6866 | WPX Energy Permian, LLC only | Tunstill | Loving | 3 | 26.5K | 4.97K | by Jan 1993 – Nov 2011 |
| Stillwell O-13-21515 | Circle B Oil & Gas only | Queens Peak, W. (Caddo Congl) | Montague | 1 | 26.4K | 5.13K | by Jan 1993 – Aug 2018 |
| Stilly O-13-26797 | Bto Venture, Inc. only | K-M-A | Wichita | 1 | 26.3K | 20 | by Jan 1993 – Oct 2007 |
| Sullivan, D.J. "B" O-4-12412 | Costilla Energy, Inc. only | Pita (D-5-U) | Brooks | 2 | 26.2K | 115K | Sep 1994 – Jul 1998 |
| Koehler, Frank O-1-2685 | Castillo Oil Company LLC only | Luling-Branyon | Caldwell | 2 | 25.7K | 15 | Jan 1994 – Jul 2026 |
| TXL -AV- /NCT-A/ O-10-14316 | Synergy Oil & Gas, Inc. (A) only | Tunstill, East (Delaware) | Loving | 5 | 25.3K | 11.9K | by Jan 1993 – Jan 2001 |
| Caldwell County O-1-3560 | Castillo Oil Company LLC only | Luling-Branyon | Caldwell | 2 | 24.9K | 88 | by Jan 1993 – Jul 2026 |
| Acock BP Johnson 21 O-3-25908 | Daylight Petroleum LLC only | Castillo, W. (Yegua 12A) | Jasper | 1 | 24.3K | 15.2K | May 2012 – Jul 2018 |
| Still, C. C. O-7-8173 | Miken Oil, Inc. only | East Texas | Rusk | 12 | 24.3K | 36.8K | by Jan 1993 – Nov 2022 |
| McKeown, Vera O-10-31119 | Pearce, Roy F., Jr. only | Tunstill | Reeves | 3 | 22.8K | 13.9K | by Jan 1993 – Jan 2017 |
| Hughes, M. B. O-3-22222 | Hanson Production Company only | Castillo (Yegua #5) | Jasper | 1 | 22.7K | 13 | Sep 1993 – Oct 2000 |
| Kleberg, R.j.jr.tr.stillman G-4-269049 | EOG Resources, Inc. only | Tordilla (Deep Cons.) | Willacy | 1 | 22.5K | 740K | Apr 2019 – Jun 2025 |
| Dillard "O" O-10-35381 | Costilla Energy, Inc. only | Talbot (Canyon) | Howard | 1 | 22.5K | 200K | May 1997 – Sep 1999 |
| Kleberg, R J Jr TR Stillman G-4-261761 | EOG Resources, Inc. only | Tordilla (Deep Cons.) | Willacy | 1 | 22.2K | 2.91M | Feb 2016 – Jun 2024 |
| Stillwagon, J. O-3-20083 | American Energy Texas Inc only | Madisonville (Woodbine) | Madison | 1 | 21.8K | 2.77K | by Jan 1993 – Aug 2021 |
| Still, W.W. GU #1 G-6-145073 | Faulconer Energy, LLC only | Rosewood (Cotton Valley) | Upshur | 1 | 21.3K | 1.77M | Mar 1993 – Aug 2026 |
| Sun Mark Exploration O-1-7875 | Castillo Oil Company LLC only | Salt Flat, West | Caldwell | 6 | 21K | 24.6K | by Jan 1993 – Jul 2026 |
| Fraser TXL C O-10-39207 | WPX Energy Permian, LLC only | Tunstill (Cherry Canyon -F-) | Loving | 3 | 20.9K | 19.2K | Nov 2008 – Jan 2020 |
| De Austin-Castillo Gas Unit G-4-200050 | Merit Energy Company only | Jeffress, NE. (T, Lo.-Fb,a) | Hidalgo | 1 | 20.6K | 1.47M | Feb 2004 – Aug 2026 |
| Castillo-Flores GU G-4-174002 | Merit Energy Company only | Jeffress, NE. (Vicksburg T) | Hidalgo | 1 | 20.4K | 4.42M | Jul 1999 – Aug 2026 |
| Arco Hughes O-3-18910 | Hanson Production Company only | Castillo (Yegua #8-A) | Jasper | 1 | 20.3K | 617 | by Jan 1993 – Jun 1996 |
| Callihan, W. M. -A- O-1-987 | Castillo Oil Company LLC only | Luling-Branyon | Caldwell | 5 | 19.8K | 8.3K | by Jan 1993 – Jul 2026 |
| Tunstill, Jack O-10-6878 | WPX Energy Permian, LLC only | Tunstill | Reeves | 8 | 19.7K | 30.8K | by Jan 1993 – Dec 2007 |
| Koehler, Frank -C- O-1-3531 | Castillo Oil Company LLC only | Luling-Branyon | Caldwell | 4 | 19.4K | 29 | by Jan 1993 – Jul 2026 |
| Kleberg, R J Jr TR Stillman G-4-267364 | EOG Resources, Inc. only | Stillman (Deep Cons.) | Kenedy | 1 | 19.3K | 7.74M | Mar 2012 – Jun 2022 |
| Stilley Shallow O-13-5252 | R2Q Operating LLC only | Wichita County Regular | Wichita | 5 | 18.1K | 20 | by Jan 1993 – Feb 2026 |
| Link, Sarah A., Etal O-10-19342 | Synergy Oil & Gas, Inc. (A) only | Tunstill, East (Delaware) | Loving | 10 | 17.9K | 66.5K | by Jan 1993 – Jan 2001 |
| Mingus, V. P. O-10-16249 | Synergy Oil & Gas, Inc. (A) only | Tunstill, East (Delaware) | Loving | 5 | 17K | 16.9K | by Jan 1993 – Jan 2001 |
| Guitar Costilla 5 O-10-39373 | Pioneer Natural Res. USA, Inc. only | Spraberry (Trend Area) | Howard | 1 | 16.5K | 30.8K | May 2008 – Jan 2025 |
| Guitar Costilla 5 O-10-34323 | Fasken, Barbara only | Big Spring, W. (Penn) | Howard | 1 | 16.5K | 22.6K | Nov 1994 – Sep 1995 |
| Fraser TXL E O-10-38021 | WPX Energy Permian, LLC only | Tunstill (Cherry Canyon -F-) | Loving | 2 | 16.5K | 143K | Apr 2005 – Jan 2020 |
| Ziffle, Arnold O-10-34793 | Costilla Energy, Inc. only | Talbot (Canyon) | Howard | 2 | 16.3K | 218K | Dec 1995 – Aug 1999 |
| Atlantic-Castillo O-3-22181 | XTO Energy Inc. only | Bessmay (Wilcox 2B) | Jasper | 2 | 16.2K | 98K | Aug 1993 – Feb 2005 |
| Hughes, M. B. G-3-180120 | Jay Management Company, LLC only | Castillo (Yegua #5) | Jasper | 1 | 15.7K | 308K | Nov 2000 – May 2022 |
| Sullivan, D. J. -B- O-4-11109 | Costilla Energy, Inc. only | Pita (C-7) | Brooks | 1 | 15.6K | 83K | Apr 1994 – Jul 1998 |
| Roberts, Jesse I. O-1-1958 | Castillo Oil Company LLC only | Kaye (Navarro) | Wilson | 6 | 15.5K | 39 | by Jan 1993 – Jun 2017 |
| Castillo-Flores GU G-4-176036 | Merit Energy Company only | Jeffress, NE. (T, Lo.-Fb,a) | Hidalgo | 1 | 15.5K | 1.65M | Nov 1999 – Aug 2026 |
| Castillo Deep Gas Unit G-4-164146 | Merit Energy Company only | Jeffress, NE. (Vicksburg, Lo.) | Hidalgo | 1 | 15.4K | 1.52M | May 1997 – Dec 2002 |