| 1 | S.E.D.I. | Kilgore, TX 75663 | Oil & Gas Operator | Apr 2015 |
| 2 | Samedan Oil Corporation | Houston, TX 77067 | Oil & Gas Operator | Dec 2019 |
| 3 | SDG Operating Company, Inc | Tyler, TX 75701 | Oil & Gas Operator | Dec 2024 |
| 4 | Shelby Production Co. | Kilgore, TX 75663 | Oil & Gas Operator | Mar 2009 |
| 5 | Shell Western E&P Inc. | Houston, TX 77001 | Oil & Gas Operator | May 2011 |
| 6 | Shuler Drilling Co., Inc. | El Dorado, AR 71730 | Oil & Gas Operator | Jul 2024 |
| 7 | Sklar Exploration Company LLC | Shreveport, LA 71101 | Oil & Gas Operator | Dec 2024 |
| 8 | Smith Operating & Management Co. | Shreveport, LA 71161 | Oil & Gas Operator | Dec 2022 |
| 9 | Smith Operating And MGMT Co. | Shreveport, LA 71161 | Oil & Gas Operator | Jun 2023 |
| 10 | Smith, E.N. III Energy Corp. | Marshall, TX 75671 | Oil & Gas Operator | Sep 2006 |
| 11 | Sulphur River Exploration, Inc. | Dallas, TX 75244 | Oil & Gas Operator | Dec 2024 |
| 12 | Sunray Operating Company LLC | Sugar Land, TX 77498 | Oil & Gas Operator | Dec 2024 |