| Bush-Stetz Unit O-3-21694 | Union Pacific Resources Company only | Giddings (Austin Chalk-3) | Brazos | 1 | 23.7K | 206K | by Jan 1993 – Feb 2000 |
| Risinger-Cooke Unit O-3-21796 | Union Pacific Resources Company only | Giddings (Austin Chalk-3) | Brazos | 1 | 23.6K | 31.6K | by Jan 1993 – Sep 1994 |
| Fox Creek Ranch "A" O-2-9465 | Union Gas Operating Company only | Eagleville (Eagle Ford) | McMullen | 1 | 23K | 20.8K | Mar 2010 – Nov 2010 |
| Parker, J. E. "C" O-10-33506 | Union Oil Company of California only | Parker (Pennsylvanian) | Andrews | 1 | 22.9K | 25.5K | by Jan 1993 – Jan 1994 |
| Callis-Miller Lagrange Unit O-3-21474 | Union Pacific Resources Company only | Giddings (Austin Chalk-3) | Fayette | 1 | 22.8K | 37.7K | by Jan 1993 – Dec 1996 |
| Parker, J.E. -P- O-10-30768 | Union Oil Company of California only | Parker (Wolfcamp) | Andrews | 3 | 22.8K | 26.9K | by Jan 1993 – Aug 1994 |
| Rost Unit O-3-20553 | Union Pacific Resources Company only | Giddings (Austin Chalk-3) | Lee | 1 | 22.8K | 535K | by Jan 1993 – Oct 1999 |
| Peters, R. H. 29 O-5-3276 | Union Oil Company of California only | Van (Austin Chalk) | Van Zandt | 3 | 22.6K | 34.4K | by Jan 1993 – Oct 2009 |
| Schkade-Paseur Unit O-3-21308 | Union Pacific Resources Company only | Giddings (Austin Chalk-3) | Fayette | 1 | 22.4K | 83.2K | by Jan 1993 – Mar 1997 |
| J. E. Weedon Unit O-3-21257 | Union Pacific Resources Company only | Giddings (Austin Chalk-3) | Brazos | 1 | 22.1K | 88.8K | by Jan 1993 – Apr 1998 |
| Wendler-Solis Unit O-3-21725 | Union Pacific Resources Company only | Giddings (Austin Chalk-3) | Fayette | 1 | 21.8K | 45.9K | by Jan 1993 – Mar 1995 |
| Clark, Frank O-10-34434 | Union Oil Company of California only | Andrews (Pennsylvanian) | Andrews | 1 | 21.2K | 36.2K | Jan 1995 – Sep 1995 |
| Arco Fee G-3-143979 | Union Oil Company of California only | Felicia Creek (y-6 Sand) | Liberty | 1 | 21.2K | 702K | by Jan 1993 – Aug 1995 |
| Tidwell, Thomas O-5-3753 | Old Union Operating Company only | Just Plain Lucky (Rodessa) | Van Zandt | 1 | 20.7K | 1.23M | Nov 2002 – Aug 2026 |
| Kistner-Hass OL Unit O-3-22320 | Union Pacific Resources Company only | Giddings (Austin Chalk-3) | Fayette | 1 | 20.6K | 31.7K | Dec 1993 – Aug 1997 |
| Dansby-Dansby Unit O-3-21478 | Union Pacific Resources Company only | Giddings (Austin Chalk-3) | Brazos | 1 | 20.4K | 127K | by Jan 1993 – Dec 1994 |
| Bvi-Little Unit O-3-21866 | Union Pacific Resources Company only | Giddings (Austin Chalk-3) | Brazos | 1 | 20.3K | 25.7K | by Jan 1993 – Mar 1997 |
| English O-1-13691 | Union Pacific Resources Company only | Pearsall (Austin Chalk) | Frio | 1 | 20.2K | 36.5K | by Jan 1993 – Sep 1996 |
| Ray, S. R. O-5-3492 | Union Oil Company of California only | Van, West (Travis Peak, E) | Van Zandt | 1 | 20.2K | 231K | Oct 1994 – May 1999 |
| Crim, B. E. 15 O-5-3628 | Union Oil Company of California only | Van (Rodessa) | Van Zandt | 1 | 20.2K | 72.6K | Apr 1998 – Jan 1999 |
| Union Ranch State GU G-4-190647 | Mountain V Texas, LLC only | Tiffany (Wilcox Carrizo) | Webb | 1 | 20.1K | 3.51M | Aug 2002 – Aug 2026 |
| Union-State O-9-10870 | Last Dollar LLC only | Farmer (San Andres) | Crockett | 2 | 19.9K | 2.64K | by Jan 1993 – Aug 2026 |
| Wagner, L.V. O-11-67210 | Northstar Operating Company only | Union School (Penn) | Terry | 1 | 19.9K | 912 | Jan 1994 – Apr 2005 |
| Parker, J. E. -E- O-10-246 | Union Oil Company of California only | Andrews (Pennsylvanian) | Andrews | 3 | 19.8K | 13.7K | Jul 1993 – Nov 1994 |
| Arco-Vastar Unit A-914 O-6-13030 | Union Pacific Resources Company only | Brookeland (Austin Chalk, 8800) | Jasper | 1 | 19.7K | 163K | by Jan 1993 – Apr 1996 |
| Zetka, Josef O-2-3426 | Union Oil Company of California only | Ganado, West (4700 Zone) | Jackson | 3 | 19.7K | 38.5K | by Jan 1993 – Feb 1996 |
| Parker, J. E. "U" (Amoco) O-10-33612 | Union Oil Company of California only | Parker (Wolfcamp) | Andrews | 1 | 19.5K | 36K | by Jan 1993 – Aug 1994 |
| Parker, J.E. -H- O-10-29638 | Union Oil Company of California only | Parker (Wolfcamp) | Andrews | 16 | 19.4K | 16.5K | by Jan 1993 – Aug 1994 |
| Pittman, Oscar Unit O-3-15021 | Union Pacific Resources Company only | Giddings (Austin Chalk-3) | Burleson | 1 | 19.3K | 36.2K | by Jan 1993 – May 1996 |
| Selected Lands - House Unit O-3-22510 | Union Pacific Resources Company only | Giddings (Austin Chalk-3) | Grimes | 1 | 19K | 74.3K | Aug 1994 – Sep 1994 |
| M. Scamardo-Scamardo Unit O-3-21307 | Union Pacific Resources Company only | Giddings (Austin Chalk-3) | Burleson | 1 | 19K | 194K | by Jan 1993 – Mar 1997 |
| Spacek, Frank O-2-7903 | Union Oil Company of California only | Ganado, West (5250) | Jackson | 1 | 18.9K | 17.9K | Sep 1993 – Aug 1994 |
| Mueller-Korth Unit O-3-22269 | Union Pacific Resources Company only | Giddings (Austin Chalk-3) | Lee | 1 | 18.7K | 105K | Nov 1993 – Jan 1994 |
| Parker, J. E. -Y- O-10-28222 | Union Oil Company of California only | Parker (Pennsylvanian) | Andrews | 4 | 18.6K | 20.2K | by Jan 1993 – Aug 1994 |
| Deford, R. K. O-10-9765 | Union Oil Company of California only | Andrews (Wolfcamp) | Andrews | 2 | 18.6K | 37.2K | by Jan 1993 – Sep 1995 |
| BP Stark A-370 G-3-245856 | Union Gas Operating Company only | Dempsey Creek (Wilcox) | Newton | 1 | 18.5K | 930K | Oct 2008 – Jan 2021 |
| Crim, R. C. 28 O-5-3311 | Union Oil Company of California only | Van (Austin Chalk) | Van Zandt | 2 | 18.3K | 35.3K | May 1993 – Jun 2009 |
| Coffman-Coffman Unit O-3-21595 | Union Pacific Resources Company only | Giddings (Austin Chalk-3) | Burleson | 1 | 18.3K | 123K | by Jan 1993 – Mar 1996 |
| Crim, J. F. 16 O-5-3643 | Union Oil Company of California only | Van (James) | Van Zandt | 2 | 18.3K | 12.4K | May 1998 – Dec 1998 |
| Union Ranch G-4-188672 | Mountain V Texas, LLC only | Tiffany (Wilcox Carrizo) | Webb | 1 | 18.2K | 3.27M | Apr 2002 – Aug 2026 |
| Linebery, Evelyn, Etal -A- O-10-11835 | Texland Petroleum, L.P. only | Union | Andrews | 1 | 18.2K | 5.02K | by Jan 1993 – Jun 1996 |
| College Hills Unit O-3-21673 | Union Pacific Resources Company only | Giddings (Austin Chalk-3) | Brazos | 1 | 17.5K | 130K | by Jan 1993 – Jul 1995 |
| Scamardo, Morris O-3-22436 | Union Pacific Resources Company only | Giddings (Buda) | Burleson | 1 | 17.5K | 26.1K | Mar 1994 – Oct 1994 |
| Parker, J. E. -AA- O-10-31930 | Union Oil Company of California only | Parker (Pennsylvanian) | Andrews | 3 | 17.3K | 35.1K | by Jan 1993 – Aug 1994 |
| Waltman-Chance Farms Unit G-3-144378 | Union Pacific Resources Company only | Giddings (Austin Chalk, Gas) | Brazos | 1 | 17.3K | 89K | by Jan 1993 – Feb 1997 |
| Smith 104 O-5-3248 | Union Oil Company of California only | Van (Austin Chalk) | Van Zandt | 2 | 16.9K | 10.9K | by Jan 1993 – Nov 2012 |
| Wardner, G.P. O-4-11734 | Union Pacific Resources Company only | Stratton (Sellers 3, E) | Nueces | 1 | 16.9K | 48.8K | by Jan 1993 – Apr 1996 |
| Davis Heirs G-5-119014 | Old Union Operating Company only | Rischers Store (Davis Sand) | Freestone | 1 | 16.9K | 635K | by Jan 1993 – Aug 2026 |
| Logsdon -C- O-10-13500 | Texland/JMC Joint Venture only | Union | Andrews | 2 | 16.8K | 7.99K | by Jan 1993 – May 1995 |
| Logsdon, C. W. -E- O-10-7036 | Texland/JMC Joint Venture only | Union | Andrews | 6 | 16.7K | 75.3K | by Jan 1993 – May 1995 |