| 1 | S. S. Tatum | | Oil Operator | Aug 1999 |
| 2 | Sabine Oil & Gas Corporation | Houston, TX 77002 | Oil & Gas Operator | Oct 2025 |
| 3 | Samson Contour Energy E&P, LLC | Tulsa, OK 74103 | Oil & Gas Operator | Sep 2017 |
| 4 | Samson Resources Company | Tulsa, OK 74103 | Oil & Gas Operator | Jun 2025 |
| 5 | San Miguel Oil & Gas, Inc. | | Oil & Gas Operator | Jan 1993 |
| 6 | Sepulvado Oilfield Service Inc | | Oil & Gas Operator | Jul 2010 |
| 7 | Shufflin Energy | | Oil & Gas Operator | Sep 2011 |
| 8 | Sierra Industries, Inc. | | Oil & Gas Operator | Apr 1989 |
| 9 | Smith Oil & Gas Co., Inc. | Wichita Falls, TX 76310 | Oil Operator | Dec 2010 |
| 10 | Smith Operating And MGMT Co. | Shreveport, LA 71161 | Oil & Gas Operator | Jun 2023 |
| 11 | Sonat Exploration Co. | Houston, TX 77251 | Oil & Gas Operator | Dec 2021 |
| 12 | Steaua Romana (Us) Inc. | | Oil & Gas Operator | Apr 1987 |
| 13 | Strike Energy Corp | Blackwell, OK 74631 | Oil & Gas Operator | Jul 2023 |
| 14 | Sun Exploration-Production Co. | | Oil & Gas Operator | Jan 1990 |
| 15 | Suncoast Investments Co., Inc. | Plano, TX 75074 | Oil & Gas Operator | Oct 2001 |
| 16 | Suncoast Technical SVCS., Inc. | | Oil & Gas Operator | Dec 2011 |
| 17 | Super Energy Inc. | | Oil & Gas Operator | Oct 1993 |
| 18 | Superior Resources Corporation | | Oil Operator | Apr 2006 |
| 19 | SV Energy Company, LLC | Corpus Chrsti, TX 78401 | Oil & Gas Operator | Mar 2017 |
| 20 | Swepi LP | Houston, TX 77079 | Oil & Gas Operator | Jul 2020 |
| 21 | Swift Energy Company | Houston, TX 77060 | Oil & Gas Operator | Mar 2021 |
| 22 | Swift Energy Operating, LLC | Houston, TX 77079 | Oil & Gas Operator | Jun 2017 |
| 23 | SWN Production (Louisiana), LLC | | Oil & Gas Operator | Dec 2024 |