| 1 | S & J Operating Company | Wichita Falls, TX 76301 | Oil & Gas Operator | Mar 2015 |
| 2 | Sage Energy Company | San Antonio, TX 78215 | Oil & Gas Operator | Oct 2025 |
| 3 | Samedan Oil Corporation | Houston, TX 77067 | Oil & Gas Operator | Dec 2019 |
| 4 | Samson Resources Company | Tulsa, OK 74103 | Oil & Gas Operator | Jun 2025 |
| 5 | Schalk Oil Company, Inc. | Wichita Falls, TX 76308 | Oil & Gas Operator | Oct 2025 |
| 6 | Scout Energy Management LLC | Dallas, TX 75240 | Oil & Gas Operator | Oct 2025 |
| 7 | Sha Stephens, Incorporated | Weatherford, TX 76087 | Oil & Gas Operator | Apr 2006 |
| 8 | Shell Western E&P Inc. | Houston, TX 77001 | Oil & Gas Operator | May 2011 |
| 9 | Sidwell Oil & Gas, Inc. | Amarillo, TX 79105 | Oil & Gas Operator | Sep 2014 |
| 10 | Slate Holdings, Inc. | Mineral Wells, TX 76068 | Oil & Gas Operator | Oct 2025 |
| 11 | Smith Operating And MGMT Co. | Shreveport, LA 71161 | Oil & Gas Operator | Jun 2023 |
| 12 | Smith Pipe Of Abilene | Abilene, TX 79608 | Oil & Gas Operator | Oct 2025 |
| 13 | Sonat Exploration Company-MCR | Houston, TX 77251 | Oil & Gas Operator | Dec 1999 |
| 14 | Spartan Operating Company, Inc. | Tyler, TX 75702 | Oil & Gas Operator | Feb 2013 |
| 15 | Spitfire Partners, LLC | Dallas, TX 75225 | Oil Operator | Oct 2025 |
| 16 | Stephens & Johnson Operating Co. | Wichita Falls, TX 76307 | Oil & Gas Operator | Oct 2025 |
| 17 | Strickland, H.W. | Henrietta, TX 76365 | Oil & Gas Operator | Dec 1999 |
| 18 | Suncoast Technical Services Inc | Dallas, TX 75251 | Oil & Gas Operator | Oct 2025 |
| 19 | Sutherland Energy Co., LLC | Bridgeport, TX 76426 | Oil & Gas Operator | Oct 2025 |