| 1 | S & L Oil Field Services | Carrizo SPGS, TX 78834 | Oil & Gas Operator | Jan 1999 |
| 2 | Seagull Operating Co., Inc. | Shreveport, LA 71101 | Oil & Gas Operator | Jan 2025 |
| 3 | Seeker Oil Company II, Inc. | San Antonio, TX 78209 | Oil Operator | Jan 2016 |
| 4 | Seeker Oil Company, Incorporated | San Antonio, TX 78209 | Oil & Gas Operator | Jun 2025 |
| 5 | Seismotech Energy, Incorporated | Plano, TX 75075 | Oil & Gas Operator | Aug 2003 |
| 6 | Short Oil Co. | Luling, TX 78648 | Oil & Gas Operator | Mar 2025 |
| 7 | Simco Oil, LLC | Lytle, TX 78052 | Oil Operator | Jun 2025 |
| 8 | Sinclair Energy Corporation | Fort Worth, TX 76177 | Oil & Gas Operator | Jun 2025 |
| 9 | Somerset Oil & Gas Company | Portland, TX 78374 | Oil & Gas Operator | Dec 2006 |
| 10 | Sorto, Peters God | Somerset, TX 78069 | Oil Operator | Jun 2025 |
| 11 | South Loop Operating, L.C. | San Antonio, TX 78279 | Oil & Gas Operator | Apr 2009 |
| 12 | South Sam Operating Company, LLC | Lakehills, TX 78063 | Oil Operator | Jun 2025 |
| 13 | Southwest Loop 1604, LTD. | San Antonio, TX 78209 | Oil Operator | Sep 2022 |
| 14 | Spain Oil Company | Somerset, TX 78069 | Oil & Gas Operator | Jun 2025 |
| 15 | Spiller, Robert S. | San Antonio, TX 78213 | Oil & Gas Operator | Oct 1995 |
| 16 | Starr Operating Company | Austin, TX 78759 | Oil & Gas Operator | Jun 2025 |
| 17 | Sterling Inv. Group & Assc., Inc | Baytown, TX 77522 | Oil & Gas Operator | Jun 2025 |
| 18 | Stone, M. L. | Kerrville, TX 78029 | Oil & Gas Operator | Aug 2003 |
| 19 | Success Oil Company, Inc. | Beverly Hills, CA 90211 | Oil & Gas Operator | Jun 2025 |
| 20 | Syj Oil & Gas | San Antonio, TX 78209 | Oil Operator | Sep 2000 |
| 21 | Syj Oil & Gas, Inc. | San Antonio, TX 78209 | Oil & Gas Operator | Jun 2025 |