| Foster, J. R. O-4-1183 | Hilcorp Energy Company only | Hagist Ranch ( Queen City Sand) | Duval | 15 | 79.9K | 351K | by Jan 1993 – Dec 2024 |
| Foster Lumber Co. "D" G-3-97266 | Oretta Holdings LLC only | Cold Springs (Wilcox, Cons.) | San Jacinto | 1 | 78.9K | 1.63M | by Jan 1993 – Jul 2022 |
| Mobil-Foster O-13-28296 | Nortex Production Co., LLC only | Wichita County Regular | Wichita | 12 | 78.2K | 21 | by Jan 1993 – May 2016 |
| Gaskins O-8-25383 | Rjkb Foster Operating LLC only | Scranton | Eastland | 9 | 75K | 1.1K | by Jan 1993 – Aug 2026 |
| Judkins, Charlie, Etal O-10-1555 | Aghorn Operating, Inc. only | Foster | Ector | 7 | 70K | 10.2K | by Jan 1993 – Jun 2026 |
| Foster et Al O-6-12590 | Mosbacher Energy Company only | Fairway (Massive Anhydrite) | Anderson | 1 | 69.2K | 21.4K | by Jan 1993 – Jan 2025 |
| Foster Lumber Co. A O-3-25819 | Oretta Holdings LLC only | Cold Springs (Wilcox 7,800) | San Jacinto | 2 | 68.5K | 434K | Nov 2011 – Aug 2026 |
| Foster H. S. "E" O-10-22238 | Par Development only | Cowden, South (Canyon 8900) | Ector | 2 | 68.3K | 69.7K | by Jan 1993 – Aug 2026 |
| Foster, W. L. Jr. -27- O-10-34835 | Owl Ops LLC only | Conger (Penn) | Sterling | 6 | 67.5K | 1.51M | Sep 1996 – Jun 2026 |
| Jones-Foster Unit O-3-22302 | Enervest Operating, L.L.C. only | Kurten (Buda) | Brazos | 1 | 66K | 173K | Dec 1993 – Aug 2010 |
| Foster, W. L., Estate O-10-14616 | Baylor Operating, LLC only | Iatan, East Howard | Mitchell | 35 | 63.3K | 65 | by Jan 1993 – Aug 2020 |
| Palmer, R. G. O-10-33652 | Bustamante Oil Company only | Foster | Ector | 1 | 63.3K | 16K | by Jan 1993 – Aug 2026 |
| Foster 'A' O-11-68294 | MWL Energy LLC only | Foster Ranch (Tannehill) | King | 1 | 62.6K | 0 | Apr 2001 – Aug 2026 |
| Foster Lumber Co. "D" G-3-156950 | Famcor Oil, Inc. only | Cold Springs (Wilcox, Cons.) | San Jacinto | 1 | 61.4K | 910K | Dec 1995 – Feb 2001 |
| Foster -D- O-10-21856 | Occidental Permian Ltd. only | Cowden, South (Canyon 8790) | Ector | 2 | 61.2K | 64.1K | by Jan 1993 – Aug 2021 |
| Michie O-13-19254 | R2Q Operating LLC only | Kempner (Foster Sand) | Wichita | 2 | 61.1K | 24.8K | by Jan 1993 – Aug 2026 |
| Foster Lumber Co G-3-163249 | Hilcorp Energy Company only | Mercy (10400 Wilcox) | San Jacinto | 1 | 61K | 1.27M | May 1997 – Aug 2026 |
| Foster, Ethel O-10-20180 | Stephens & Johnson Operating Co. only | W. A. M., South (Fusselman) | Sterling | 1 | 60.5K | 56 | by Jan 1993 – Aug 2026 |
| Foster, Henry L. O-6-10228 | King Operating Corporation only | Alpine (Pettit) | Gregg | 1 | 60.2K | 450K | by Jan 1993 – Aug 2026 |
| Foster Farms Deep G-3-226909 | Proline Energy Resources Inc only | Fulshear, S. (Cons.) | Fort Bend | 1 | 59.3K | 2.37M | Feb 2007 – Aug 2026 |
| Foster F O-10-50281 | OXY USA WTP LP only | Cowden, South (Dev.) | Ector | 1 | 58.6K | 239K | Jun 2018 – Aug 2026 |
| Foster Farms, Inc G-3-208026 | Vaquero Operating only | Fulshear, S. (Cons.) | Fort Bend | 1 | 55.4K | 2.87M | Feb 2005 – Feb 2013 |
| Foster E O-10-37190 | OXY USA Inc. only | Cowden, South | Ector | 1 | 52.1K | 5.9K | Aug 2003 – Aug 2026 |
| Foster "A" O-3-24718 | Oretta Holdings LLC only | Cold Springs (Wilcox, Cons.) | San Jacinto | 2 | 52K | 674K | Jul 2005 – Nov 2016 |
| Foster O-10-39363 | Southwest Royalties, Inc. only | Spraberry (Trend Area) | Glasscock | 5 | 51.9K | 33.6K | Mar 2009 – Aug 2026 |
| Foster "F" O-10-22703 | Baker Operating, Inc. only | Cowden, South (Canyon 8900) | Ector | 1 | 51.3K | 65K | by Jan 1993 – May 2016 |
| Foster Lumber Co. "D" G-3-199422 | Oretta Holdings LLC only | Cold Springs (Wilcox, Cons.) | San Jacinto | 1 | 51K | 1.09M | Jan 2004 – Mar 2023 |
| Manning-Foster (AW) O-6-16015 | Barrow-Shaver Resources Co. only | Hidden Rock (Cotton Valley Lime) | Cass | 1 | 51K | 45K | Jan 2024 – Aug 2026 |
| Foster "34" O-10-24818 | Bolding Energy, LLC only | Conger (Penn) | Sterling | 11 | 49.6K | 3.06M | by Jan 1993 – Aug 2026 |
| Foster, J. R. -B- O-4-1184 | Hilcorp Energy Company only | Hagist Ranch ( Queen City Sand) | Duval | 1 | 48.6K | 148K | by Jan 1993 – Sep 2017 |
| Foster Lumber Co. "D" O-3-23977 | Famcor Oil, Inc. only | Cold Springs (Wilcox, Cons.) | San Jacinto | 1 | 45.9K | 208K | Mar 2001 – Oct 2007 |
| Foster Unit 248 G-14-276329 | BE Anadarko II, LLC only | Lipscomb, S.E. (Cleveland) | Lipscomb | 1 | 44.8K | 847K | Aug 2013 – Aug 2026 |
| Foster "41" O-10-41925 | Ovintiv USA Inc. only | Spraberry (Trend Area) | Dawson | 1 | 44.4K | 39.5K | Oct 2011 – Jun 2026 |
| Foster & Allen O-13-5259 | Texas Green Energy Services LLC only | Wichita County Regular | Wichita | 35 | 44.4K | 21 | by Jan 1993 – Feb 2026 |
| Foster Lumber Co. "A" G-3-148412 | Alta Mesa Services, LP only | Cold Springs (Wilcox, Cons.) | San Jacinto | 1 | 44.4K | 911K | Feb 1994 – Sep 2011 |
| Foster, Mary O-10-38598 | Basa Resources, Inc. only | Coahoma, N. (Wolfcamp) | Mitchell | 2 | 44.3K | 40.1K | Dec 2007 – Aug 2026 |
| Foster, W. L. -A- O-10-2931 | Royalty Resources, L.L.C. only | Iatan, North | Howard | 8 | 43.8K | 30 | by Jan 1993 – May 2017 |
| L. Foster -8- O-10-25183 | Burk Royalty Co., Ltd. only | Conger (Penn) | Sterling | 7 | 43K | 1.68M | by Jan 1993 – Aug 2026 |
| Foster O-6-15342 | Machin & Associates, Inc. only | Iron Lake | Cass | 1 | 40.9K | 0 | Oct 2014 – Jul 2026 |
| Foster "33" O-10-24817 | Bolding Energy, LLC only | Conger (Penn) | Sterling | 13 | 40.8K | 3.67M | by Jan 1993 – Aug 2026 |
| Foster O-10-40747 | COG Operating LLC only | Spraberry (Trend Area) | Midland | 1 | 40.7K | 69.2K | Dec 2010 – Jul 2020 |
| Foster, H. -A- O-10-30325 | Endeavor Energy Resources L.P. only | Cowden, South (Canyon 8790) | Ector | 1 | 40.5K | 74.7K | by Jan 1993 – May 2006 |
| Foster, W. L., Jr., -B- O-10-4666 | D & D Well Service, L.L.C. only | Parochial-Bade (Queen Sand) | Sterling | 10 | 39.8K | 1.48K | by Jan 1993 – Aug 2019 |
| Foster, B. J. O-10-19466 | Baker Operating, Inc. only | Cowden, South | Ector | 3 | 39.6K | 9 | by Jan 1993 – Aug 2026 |
| Foster Mineral Ltd G-3-148160 | Oretta Holdings LLC only | Cold Springs (Wilcox, Cons.) | San Jacinto | 1 | 39.4K | 785K | Jan 1994 – Apr 2003 |
| Foster O-13-16615 | Horansky Burrell Revocable Trust only | Wichita County Regular | Wichita | 4 | 39.1K | 20 | by Jan 1993 – Jul 2026 |
| Fosters G-2-229787 | Lgdc Corporation only | Tiger Bend (Wilcox) | Lavaca | 1 | 39.1K | 5.07M | Feb 2007 – Jul 2018 |
| Foster Lumber Co. "D" G-3-154051 | Famcor Oil, Inc. only | Cold Springs (Wilcox, Cons.) | San Jacinto | 1 | 38.1K | 655K | Dec 1994 – Jun 1997 |
| Foster 6 O-10-46053 | Basin Oil & Gas Operating, LLC only | Spraberry (Trend Area) | Gaines | 2 | 37.7K | 4.26K | Feb 2015 – Aug 2026 |
| Foster, Mary Lou O-6-14113 | Valence Operating Company only | Yantis (Hill Zone) | Wood | 1 | 37.7K | 187K | Aug 2001 – Jan 2013 |