| O'Connor, Thomas -C- O-2-2876 | Hilcorp Energy Company only | Tom Oconnor (5900 Sand) | Refugio | 59 | 2.99M | 2.17M | Jan 1993 – Apr 2026 |
| Oconnor, Thomas, -C- O-2-2587 | Hilcorp Energy Company only | Tom Oconnor (5500 Sand) | Refugio | 51 | 2.22M | 2.1M | Jan 1993 – Apr 2026 |
| Oconnor, Thomas -A- O-2-1542 | Hilcorp Energy Company only | Tom Oconnor | Refugio | 36 | 650K | 756K | Nov 1993 – Apr 2026 |
| Oconnor, Thomas, -C- O-2-2566 | Hilcorp Energy Company only | Tom Oconnor (4500 Greta Mass.) | Refugio | 18 | 646K | 278K | Jan 1993 – Apr 2026 |
| O'Connor, Thomas "A" O-2-7579 | Hilcorp Energy Company only | Tom O'Connor (5770 U, South) | Refugio | 28 | 538K | 627K | Jan 1993 – Apr 2026 |
| O'Connor, Thomas "A" O-2-3662 | Hilcorp Energy Company only | Tom Oconnor (5400 Sand) | Refugio | 20 | 273K | 1.01M | Jan 1993 – Feb 2023 |
| O'Connor, Thomas -C- O-2-9135 | Hilcorp Energy Company only | Tom Oconnor (5200, East) | Refugio | 12 | 272K | 61.7K | Apr 2007 – Apr 2026 |
| Oconnor, Thomas -A- O-2-4927 | Hilcorp Energy Company only | Tom Oconnor (5450 Sand) | Refugio | 12 | 238K | 685K | Jan 1993 – Sep 2023 |
| O'Conner, Thomas -C- O-2-6234 | Hilcorp Energy Company only | Tom O'Connor (4150) | Refugio | 10 | 186K | 393K | Jan 1993 – May 2004 |
| Oconnor, Thomas, -A- O-2-2627 | Hilcorp Energy Company only | Tom Oconnor (5500 Sand) | Refugio | 9 | 151K | 150K | Jan 1993 – Jan 2022 |
| Oconnor, Thomas O-2-4011 | Greta Operating Company LLC only | Greta, Deep (5620) | Refugio | 2 | 129K | 150K | Jan 1993 – Apr 2026 |
| Oconnor, Thomas -E- O-2-1526 | T-C Oil Company, LLC only | Tom Oconnor | Refugio | 29 | 116K | 317K | Jan 1993 – Nov 2010 |
| Oconnor, Thomas, -A- O-2-2875 | Hilcorp Energy Company only | Tom Oconnor (5900 Sand) | Refugio | 11 | 107K | 236K | Jan 1993 – Oct 2008 |
| O'Connor, Thomas O-2-8827 | Greta Operating Company LLC only | Greta, Deep (5700) | Refugio | 1 | 101K | 170K | Oct 2003 – Apr 2025 |
| Thomas O'Connor O-2-10977 | Greta Operating Company LLC only | Greta (6400) | Refugio | 1 | 74K | 97.6K | Aug 2014 – Jul 2025 |
| O'Connor, Thomas, "D" O-2-1066 | Hilcorp Energy Company only | Melon Creek | Refugio | 6 | 71K | 211K | Jan 1993 – Jun 2015 |
| O'Connor, Thomas "A" O-2-7360 | Hilcorp Energy Company only | Tom O'Connor (4150) | Refugio | 3 | 68.8K | 57K | Jan 1993 – May 2004 |
| Oconnor, Thomas -C- O-2-1543 | Hilcorp Energy Company only | Tom Oconnor | Refugio | 11 | 61.5K | 88.8K | Jan 1993 – Oct 2009 |
| O'Connor, Thomas "A" O-2-8755 | Hilcorp Energy Company only | Tom O'Connor (5350 Sand) | Refugio | 2 | 59K | 141K | Dec 2002 – Mar 2018 |
| O'Connor, Thomas "A" O-2-8686 | Hilcorp Energy Company only | Tom Oconnor (5440) | Refugio | 2 | 55K | 146K | Jan 2002 – Oct 2024 |
| Oconnor, Thomas -D- O-2-1525 | T-C Oil Company, LLC only | Tom Oconnor | Refugio | 7 | 53.8K | 552K | Jan 1993 – Dec 2005 |
| O'Connor, Thomas 'C' O-2-8272 | Hilcorp Energy Company only | Tom Oconnor (5625 Sand) | Refugio | 8 | 45.4K | 200K | Apr 1997 – Feb 2005 |
| Oconnor, Thomas -B- O-2-3660 | T-C Oil Company, LLC only | Tom Oconnor (5400 Sand) | Refugio | 10 | 43K | 133K | Jan 1993 – Jan 2012 |
| O'Connor, Thomas 'B' O-2-8373 | Hilcorp Energy Company only | Tom Oconnor | Refugio | 1 | 42K | 22.9K | Jan 2002 – Apr 2011 |
| Nordan,l. A.-Oconnor,thomas,est. O-2-2869 | T-C Oil Company, LLC only | Tom Oconnor (5900 Sand) | Refugio | 9 | 39.6K | 114K | Jan 1993 – Jun 1998 |
| Oconnor, Thomas -B- O-2-1524 | T-C Oil Company, LLC only | Tom Oconnor | Refugio | 9 | 38.9K | 68.2K | Jan 1993 – Dec 2010 |
| O'Connor, Thomas O-2-9447 | Dorchester Operating Company LLC only | Greta (4400) | Refugio | 1 | 37.8K | 5.39K | Nov 2010 – Apr 2026 |
| Thomas O'Connor "B" O-2-9369 | Hilcorp Energy Company only | Melon Creek, East (5800) | Refugio | 1 | 37.2K | 16.3K | Oct 2009 – Feb 2013 |
| O"connor Thomas "A" O-2-8780 | Hilcorp Energy Company only | Tom O'Connor (5410) | Refugio | 1 | 35.9K | 61.1K | Apr 2003 – Oct 2024 |
| Thomas O'Connor 'B' O-2-10382 | Hilcorp Energy Company only | Mary Ellen Oconnor (Frio 6500) | Refugio | 3 | 28.4K | 67.2K | Oct 2012 – Mar 2018 |
| O'Connor, Thomas "B" O-2-7920 | Hilcorp Energy Company only | Mary Ellen Oconnor (Frio 6500) | Refugio | 1 | 27.7K | 89.3K | Nov 1993 – Mar 1997 |
| Kentucky-Fagan O-2-8371 | Anderson Oil Ltd. only | Fagan (Tilly Thomas) | Refugio | 1 | 27.6K | 18.7K | Mar 1998 – May 1999 |
| Oconnor, Thomas -B- O-2-957 | Hilcorp Energy Company only | Mary Ellen Oconnor (FQ-35 Sd.) | Refugio | 1 | 27.2K | 45.1K | Jan 1993 – Feb 2010 |
| O'Conner, Thomas -A- O-2-6436 | Hilcorp Energy Company only | Tom Oconnor (5425 Sand) | Refugio | 3 | 26.6K | 188K | Sep 1996 – Feb 2005 |
| Thomas O'Connor "B" O-2-9383 | Hilcorp Energy Company only | Melon Creek (5870) | Refugio | 1 | 23.7K | 15.5K | Dec 2009 – Feb 2014 |
| Thomas O'Connor 'A' O-2-11391 | Hilcorp Energy Company only | Tom Oconnor (5200, East) | Refugio | 3 | 22.2K | 17.1K | Aug 2017 – Apr 2026 |
| Kentucky-Fagan O-2-8711 | Anderson Oil Ltd. only | Fagan (Tilly Thomas) | Refugio | 1 | 15.7K | 4.74K | May 2002 – Sep 2004 |
| Oconnor, Thomas, -A- O-2-2864 | T-C Oil Company, LLC only | Tom Oconnor (5900 Sand) | Refugio | 3 | 12.5K | 47.9K | Jan 1993 – Jun 1998 |
| O'Conner, Thomas -B- O-2-5757 | Hilcorp Energy Company only | Mary Ellen Oconnor (5000) | Refugio | 1 | 12.3K | 80.8K | Jan 1993 – Jun 1998 |
| Oconnor, Thomas -A- O-2-3837 | T-C Oil Company, LLC only | Tom Oconnor (5450 Sand) | Refugio | 1 | 12.3K | 42.3K | Jan 1993 – Aug 2008 |
| O'Connor, Thomas -E- O-2-9068 | T-C Oil Company, LLC only | Tom Oconnor (5675 Sand) | Refugio | 1 | 12.2K | 10.6K | Jul 2006 – Feb 2011 |
| O'Connor, Thomas,-C- O-2-9651 | Hilcorp Energy Company only | Tom Oconnor (5450 Sand) | Refugio | 2 | 11.8K | 5.35K | Jul 2011 – Jan 2015 |
| O'Connor, Thomas "A" O-2-7838 | Hilcorp Energy Company only | Tom Oconnor (4600) | Refugio | 1 | 11.6K | 16.4K | Jan 1993 – Oct 2003 |
| O'Connor, Thomas "C" O-2-7753 | Quintana Pet. Corp. only | Tom O'Connor (5770 U, South) | Refugio | 1 | 10.4K | 10K | Jan 1993 – Apr 1997 |
| Oconnor, Thomas -A- O-2-3802 | T-C Oil Company, LLC only | Tom Oconnor (5400 Sand) | Refugio | 2 | 10.2K | 17.6K | Jan 1993 – Jun 1998 |
| O'Connor, Thomas "C" O-2-8969 | Hilcorp Energy Company only | Tom O'Connor (5350 Sand) | Refugio | 1 | 9.09K | 6.58K | May 2005 – Nov 2007 |
| O'Connor, Thomas "B" G-2-143511 | Quintana Pet. Corp. only | Mary Ellen O'Connor (8300) | Refugio | 1 | 8.42K | 108K | Jan 1993 – Jul 1993 |
| O'Connor, Thomas "B" O-2-7841 | Hilcorp Energy Company only | Mary Ellen O'Connor (FS-70) | Refugio | 2 | 8.32K | 74.3K | Jan 1993 – May 1999 |
| Oconnor, Thomas -E- O-2-3661 | T-C Oil Company, LLC only | Tom Oconnor (5400 Sand) | Refugio | 13 | 8.27K | 5.96K | Jan 1993 – Sep 2010 |
| O'Connor, Thomas O-2-8684 | Acock/Anaqua Operating Co., LC only | Greta (5800) | Refugio | 1 | 8.19K | 130K | Jan 2002 – Oct 2003 |