| 1 | S & J Operating Company | Wichita Falls, TX 76301 | Oil & Gas Operator | Mar 2015 |
| 2 | S N D Energy Company, Inc. | Kilgore, TX 75662 | Oil & Gas Operator | Oct 2025 |
| 3 | Sabco Operating Company | Houston, TX 77056 | Oil & Gas Operator | Oct 2011 |
| 4 | Sabco Operating Company, LLC | Houston, TX 77056 | Oil & Gas Operator | Jun 2018 |
| 5 | Salvador Oil, LLC | Dallas, TX 75201 | Oil & Gas Operator | Oct 2025 |
| 6 | Samedan Oil Corporation | Houston, TX 77067 | Oil & Gas Operator | Dec 2019 |
| 7 | Samson Resources Company | Tulsa, OK 74103 | Oil & Gas Operator | Jun 2025 |
| 8 | Samurai Operating Co. L.L.C. | Dayton, TX 77535 | Oil & Gas Operator | Oct 2025 |
| 9 | San Patricio Corporation | Dinero, TX 78350 | Oil & Gas Operator | Sep 2003 |
| 10 | Sanchez-O'Brien Oil & Gas Corp | Houston, TX 77057 | Oil & Gas Operator | May 1998 |
| 11 | Sandia Operating Corp. | San Antonio, TX 78270 | Oil & Gas Operator | May 2010 |
| 12 | Santa Rosa Operating, LLC | Corpus Chrsti, TX 78411 | Oil & Gas Operator | Oct 2025 |
| 13 | Sarita Energy Resources, LTD. | Houston, TX 77277 | Oil & Gas Operator | Oct 2025 |
| 14 | Satex Energy, Inc. | San Antonio, TX 78216 | Oil & Gas Operator | Aug 2003 |
| 15 | Savage Exploration, Inc. | San Marcos, TX 78666 | Oil & Gas Operator | Oct 2025 |
| 16 | Scythian, LTD. | Midland, TX 79701 | Oil & Gas Operator | Dec 2020 |
| 17 | Shana Petroleum Company | Dallas, TX 75206 | Oil & Gas Operator | Aug 2002 |
| 18 | Shell Western E&P Inc. | Houston, TX 77001 | Oil & Gas Operator | May 2011 |
| 19 | Shidler, Mark L., Inc. | Houston, TX 77055 | Oil & Gas Operator | Oct 2025 |
| 20 | Shoco Production LLC | Kilgore, TX 75663 | Oil & Gas Operator | Oct 2025 |
| 21 | Shoreline Production Serv., Inc. | Rockport, TX 78381 | Oil & Gas Operator | Apr 2002 |
| 22 | Silver Fox Oil & Gas LLC | McAllen, TX 78504 | Oil & Gas Operator | Oct 2025 |
| 23 | Situs Oil & Gas, LLC | Corpus Chrsti, TX 78414 | Oil Operator | Oct 2025 |
| 24 | Smith Petroleum Company | Spring, TX 77389 | Oil & Gas Operator | Oct 2025 |
| 25 | South Central Texas Oil & Gas Co | Houston, TX 77060 | Oil & Gas Operator | Oct 2025 |
| 26 | South Leeville, LLC | Houston, TX 77069 | Oil & Gas Operator | Oct 2022 |
| 27 | Southcoast Production Inc | Houston, TX 77010 | Oil & Gas Operator | Oct 2025 |
| 28 | Southern Resource Company | Corpus Chrsti, TX 78404 | Oil & Gas Operator | Mar 2022 |
| 29 | Southern Royalty Inc. | Corpus Chrsti, TX 78411 | Oil & Gas Operator | Feb 1997 |
| 30 | Southland Royalty Company | Houston, TX 77210 | Oil & Gas Operator | Sep 2011 |
| 31 | Southwest Gathering Company | Alice, TX 78332 | Oil & Gas Operator | Oct 2025 |
| 32 | Southwestern Energy Prod Co | Houston, TX 77032 | Oil & Gas Operator | Jun 2015 |
| 33 | Star Production, Inc. | Dallas, TX 75360 | Oil & Gas Operator | Oct 2025 |
| 34 | Starco Exploration, Inc. | Dallas, TX 75360 | Oil & Gas Operator | Oct 2025 |
| 35 | Startex Energy, Inc. | Abilene, TX 79608 | Oil & Gas Operator | Oct 2025 |
| 36 | Stephens & Johnson Operating Co. | Wichita Falls, TX 76307 | Oil & Gas Operator | Oct 2025 |
| 37 | Striper Oil, Inc. | Dallas, TX 75379 | Oil & Gas Operator | Apr 2002 |
| 38 | STS Petroleum LLC | Houston, TX 77289 | Oil & Gas Operator | Oct 2025 |
| 39 | Sue-Ann Operating, L.C. | Victoria, TX 77903 | Oil & Gas Operator | Oct 2025 |
| 40 | Sue-Ann Production Company | Victoria, TX 77903 | Oil & Gas Operator | Mar 2008 |
| 41 | Suemaur Expl. & Prod., LLC | Corpus Chrsti, TX 78401 | Oil & Gas Operator | Jun 2024 |
| 42 | Suemaur Exploration, Inc. | Corpus Chrsti, TX 78470 | Oil & Gas Operator | Mar 2008 |
| 43 | Suemaur Operating LLC | Corpus Chrsti, TX 78401 | Oil & Gas Operator | Oct 2025 |
| 44 | Sulphur River Exploration, Inc. | Dallas, TX 75244 | Oil & Gas Operator | Oct 2025 |
| 45 | Summit Resources, Inc. | Houston, TX 77077 | Oil & Gas Operator | Sep 2016 |
| 46 | Sun Exploration, Inc. | Alice, TX 78332 | Oil & Gas Operator | Oct 2025 |
| 47 | Sure Flow Oil & Gas, Inc. | Victoria, TX 77902 | Oil & Gas Operator | Oct 2025 |
| 48 | Synergy Oil & Gas, Inc. (A) | Houston, TX 77024 | Oil & Gas Operator | Aug 2001 |
| 49 | Synergy Production Company | Houston, TX 77024 | Oil & Gas Operator | Jan 1996 |