| 1 | Samedan Oil Corporation | Houston, TX 77067 | Oil & Gas Operator | Dec 2019 |
| 2 | Samson Hydrocarbons Company | Tulsa, OK 74103 | Oil & Gas Operator | Nov 2016 |
| 3 | Samson Lone Star LP | Tulsa, OK 74103 | Oil & Gas Operator | Jun 2007 |
| 4 | Samson Resources Company | Tulsa, OK 74103 | Oil & Gas Operator | Jun 2025 |
| 5 | San Isidro Development Co, L. C. | Sandia, TX 78383 | Oil & Gas Operator | Oct 2025 |
| 6 | Sanchez-O'Brien Oil & Gas Corp | Houston, TX 77057 | Oil & Gas Operator | May 1998 |
| 7 | Sandalwood Exploration, L.P. | Houston, TX 77056 | Oil & Gas Operator | Oct 2025 |
| 8 | Sandalwood Oil & Gas, Inc. | Houston, TX 77057 | Oil & Gas Operator | Oct 2025 |
| 9 | Sandia Energy Corporation-NM | Holdenville, OK 74848 | Oil & Gas Operator | Aug 2003 |
| 10 | Sarita Energy Resources, LTD. | Houston, TX 77277 | Oil & Gas Operator | Oct 2025 |
| 11 | Savage Exploration, Inc. | San Marcos, TX 78666 | Oil & Gas Operator | Oct 2025 |
| 12 | Saxet Petroleum, Inc. | Houston, TX 77057 | Oil & Gas Operator | Oct 2025 |
| 13 | Scana Petroleum Resources Inc | Houston, TX 77002 | Oil & Gas Operator | Jun 2013 |
| 14 | Setex Oil And Gas Company | Houston, TX 77002 | Oil & Gas Operator | Feb 2012 |
| 15 | Setex Oil Company, L.P. | Houston, TX 77060 | Oil & Gas Operator | Jan 2000 |
| 16 | Shoreham Oil & Gas Company, Inc. | Katy, TX 77492 | Oil & Gas Operator | Oct 2025 |
| 17 | Sien Operating Company, LLC | San Antonio, TX 78209 | Oil Operator | May 2023 |
| 18 | Sierra Exploration Company | San Antonio, TX 78209 | Oil & Gas Operator | Mar 2008 |
| 19 | Slawson Exploration Company Inc | Oklahoma City, OK 73102 | Oil & Gas Operator | Oct 2025 |
| 20 | Smith Petroleum Company | Spring, TX 77389 | Oil & Gas Operator | Oct 2025 |
| 21 | Sonterra Oil & Gas, Inc. | Wichita, KS 67217 | Oil & Gas Operator | Oct 2025 |
| 22 | Southern Royalty Inc. | Corpus Chrsti, TX 78411 | Oil & Gas Operator | Feb 1997 |
| 23 | Southwest Oil & Land, Inc. | Corpus Chrsti, TX 78460 | Oil & Gas Operator | Dec 1999 |
| 24 | Spartan Operating Company, Inc. | Tyler, TX 75702 | Oil & Gas Operator | Feb 2013 |
| 25 | Stacha, Eddy A. | Rice, TX 75155 | Oil & Gas Operator | Oct 2025 |
| 26 | Stallion Oil Company | Lafayette, LA 70505 | Oil & Gas Operator | Jun 2004 |
| 27 | Star Oil & Gas | Ben Bolt, TX 78342 | Oil & Gas Operator | Oct 2025 |
| 28 | Star Production, Inc. | Dallas, TX 75360 | Oil & Gas Operator | Oct 2025 |
| 29 | Starr Operating, LLC | San Antonio, TX 78209 | Oil & Gas Operator | Oct 2025 |
| 30 | Startex Energy, Inc. | Abilene, TX 79608 | Oil & Gas Operator | Oct 2025 |
| 31 | Sterling Engine Service, Inc. | Alice, TX 78333 | Oil & Gas Operator | Oct 2025 |
| 32 | Sue-Ann Operating, L.C. | Victoria, TX 77903 | Oil & Gas Operator | Oct 2025 |
| 33 | Sue-Ann Production Company | Victoria, TX 77903 | Oil & Gas Operator | Mar 2008 |
| 34 | Suemaur Exploration, Inc. | Corpus Chrsti, TX 78470 | Oil & Gas Operator | Mar 2008 |
| 35 | Sun Exploration, Inc. | Alice, TX 78332 | Oil & Gas Operator | Oct 2025 |
| 36 | SV Energy Company, LLC | Corpus Chrsti, TX 78401 | Oil & Gas Operator | Mar 2017 |
| 37 | Swift Energy Company | Houston, TX 77060 | Oil & Gas Operator | Mar 2021 |
| 38 | Swope Corp. | Austin, TX 78735 | Oil & Gas Operator | Oct 2025 |