| 1 | Sabine Corporation | Oklahoma City, OK 73116 | Oil & Gas Operator | Jul 1996 |
| 2 | Samedan Oil Corporation | Houston, TX 77067 | Oil & Gas Operator | Dec 2019 |
| 3 | Samson Resources Company | Tulsa, OK 74103 | Oil & Gas Operator | Jun 2025 |
| 4 | Santana Exploration, Inc. | | Oil & Gas Operator | Dec 1985 |
| 5 | Shelf Energy, LLC | | Oil & Gas Operator | Dec 2024 |
| 6 | Shell Oil Company | Houston, TX 77210 | Oil & Gas Operator | Apr 2015 |
| 7 | Shenandoah Oil Corporation | | Oil & Gas Operator | Jun 1979 |
| 8 | Silver Oak Operating, Inc. | Longview, TX 75601 | Oil & Gas Operator | Dec 2009 |
| 9 | Silver Oak Operating, LLC | Longview, TX 75604 | Oil & Gas Operator | Oct 2025 |
| 10 | Skelly Oil Co | | Oil & Gas Operator | Mar 2005 |
| 11 | Smith Production Co. | Wichita Falls, TX 76308 | Oil & Gas Operator | Oct 2025 |
| 12 | South Oak Production Company | | Oil & Gas Operator | Jun 2010 |
| 13 | Southwest Oil Properties, Inc. | | Oil & Gas Operator | Feb 1996 |
| 14 | Southwestern Energy Prod Co | Houston, TX 77032 | Oil & Gas Operator | Jun 2015 |
| 15 | Spindletop Drilling Co. | Dallas, TX 75230 | Oil & Gas Operator | Oct 2025 |
| 16 | SRP Production Corp. | | Oil & Gas Operator | Nov 1997 |
| 17 | St. Mary Energy Company | Houston, TX 77079 | Oil & Gas Operator | Aug 2008 |
| 18 | St. Mary Land & Exploration Co | Denver, CO 80201 | Oil & Gas Operator | Jun 2010 |
| 19 | State Energy & Investment Inc. | | Oil & Gas Operator | Mar 1990 |
| 20 | Sun Exploration-Production Co. | | Oil & Gas Operator | Jan 1990 |