| 1 | Sabine Corporation | Oklahoma City, OK 73116 | Oil & Gas Operator | Jul 1996 |
| 2 | Samson Contour Energy E&P, LLC | Tulsa, OK 74103 | Oil & Gas Operator | Sep 2017 |
| 3 | Samson Resources Company | Tulsa, OK 74103 | Oil & Gas Operator | Jun 2025 |
| 4 | Santa Fe Braun, Inc | Dallas, TX 75240-6620 | Oil & Gas Operator | Mar 1995 |
| 5 | Santos USA Corp. | Houston, TX 77042 | Oil & Gas Operator | Dec 2008 |
| 6 | Secondary Recovery, Inc. | | Oil & Gas Operator | Dec 1991 |
| 7 | Sevarg Company, Inc. | | Oil & Gas Operator | Feb 2016 |
| 8 | Shale Energy International, LLC | | Oil & Gas Operator | Nov 2024 |
| 9 | Shelf Energy, LLC | | Oil & Gas Operator | Dec 2024 |
| 10 | Shell Oil Company | Houston, TX 77210 | Oil & Gas Operator | Apr 2015 |
| 11 | Shell Western E&P Inc. | Houston, TX 77001 | Oil & Gas Operator | May 2011 |
| 12 | Shuteston Oil & Gas | | Oil & Gas Operator | Sep 1997 |
| 13 | SKZ Inc. | | Oil Operator | Mar 1988 |
| 14 | Sohio Petr Co-Gulf Oil Corp | | Oil & Gas Operator | Dec 1979 |
| 15 | Sohio Petroleum Co. | Casper, WY 82602 | Oil & Gas Operator | Apr 1986 |
| 16 | Sooner Resources, Inc. | | Oil & Gas Operator | Mar 1987 |
| 17 | Source Petroleum Inc. | San Antonio, TX 78265 | Oil & Gas Operator | Oct 2025 |
| 18 | South La. Production Co., Inc. | | Oil & Gas Operator | Jun 1982 |
| 19 | Southern Wells, Inc. | | Oil Operator | Sep 2002 |
| 20 | Southwest Oil Properties, Inc. | | Oil & Gas Operator | Feb 1996 |
| 21 | Southwest Rig Service | | Oil & Gas Operator | Nov 1998 |
| 22 | Southwestern Energy Prod Co | Houston, TX 77032 | Oil & Gas Operator | Jun 2015 |
| 23 | SRP Production Corp. | | Oil & Gas Operator | Nov 1997 |
| 24 | St. Paul Oil And Gas Corp. | | Oil & Gas Operator | Aug 1991 |
| 25 | Star Energy Inc | Dayton, PA 16222-4325 | Oil & Gas Operator | Dec 2024 |
| 26 | Strand Energy, L.C. | Houston, TX 77002 | Oil & Gas Operator | Oct 2025 |
| 27 | Stratco Operating Co Inc | Austin, TX 78701 | Oil & Gas Operator | Oct 2025 |
| 28 | Sun Exploration-Production Co. | | Oil & Gas Operator | Jan 1990 |
| 29 | Sunchase Exploration, Inc. | | Oil & Gas Operator | Oct 1997 |
| 30 | Superior Oil Co. | Denver, CO 80217-5444 | Oil & Gas Operator | Feb 2001 |
| 31 | Synergy Oil & Gas, L.P. | Houston, TX 77024 | Oil & Gas Operator | May 2012 |