| 1 | S & L Oil Field Services | Carrizo SPGS, TX 78834 | Oil & Gas Operator | Jan 1999 |
| 2 | Sabco Operating Company | Houston, TX 77056 | Oil & Gas Operator | Oct 2011 |
| 3 | Sabco Operating Company, LLC | Houston, TX 77056 | Oil & Gas Operator | Jun 2018 |
| 4 | Sabinal Resources, Inc. | Kingwood, TX 77339 | Oil & Gas Operator | Oct 2025 |
| 5 | Sage Energy Company | San Antonio, TX 78215 | Oil & Gas Operator | Oct 2025 |
| 6 | San Antonio Gas & Oil, Inc. | San Antonio, TX 78209 | Oil & Gas Operator | Feb 2000 |
| 7 | Sanchez Oil & Gas Corporation | Houston, TX 77056 | Oil & Gas Operator | Oct 2025 |
| 8 | Saxet Petroleum, Inc. | Houston, TX 77057 | Oil & Gas Operator | Oct 2025 |
| 9 | Seagull Operating Co., Inc. | Shreveport, LA 71101 | Oil & Gas Operator | Jan 2025 |
| 10 | Setex Oil And Gas Company | Houston, TX 77002 | Oil & Gas Operator | Feb 2012 |
| 11 | Shell Western E&P | Houston, TX 77001 | Oil & Gas Operator | Oct 2025 |
| 12 | Showdown Energy Corporation | Dallas, TX 75230 | Oil & Gas Operator | Aug 2003 |
| 13 | Silver Anchor Resources LLC | Azle, TX 76020 | Oil & Gas Operator | Oct 2025 |
| 14 | Silver Rock Energy, LLC | Terrell, TX 75160 | Oil Operator | Oct 2025 |
| 15 | Skidmore Energy,Inc. | Salado, TX 76571 | Oil & Gas Operator | Jun 1999 |
| 16 | SN Operating, LLC | Houston, TX 77002 | Oil & Gas Operator | May 2023 |
| 17 | Snyder Oil Corporation | Houston, TX 77024 | Oil & Gas Operator | Mar 2008 |
| 18 | Sojourner Drilling Corporation | Abilene, TX 79604 | Oil & Gas Operator | Oct 2025 |
| 19 | Southern Union Exploration Co. | Austin, TX 78701 | Oil & Gas Operator | Feb 2002 |
| 20 | Southwest Oil & Land, Inc. | Corpus Chrsti, TX 78460 | Oil & Gas Operator | Dec 1999 |
| 21 | Southwest Royalties Inc | Midland, TX 79710 | Oil & Gas Operator | Oct 2025 |
| 22 | Spartan Operating Company, Inc. | Tyler, TX 75702 | Oil & Gas Operator | Feb 2013 |
| 23 | Spiller Operating Co., Inc. | Round Rock, TX 78665 | Oil & Gas Operator | May 2015 |
| 24 | Spiller, H. G. | San Antonio, TX 78213 | Oil & Gas Operator | Oct 1993 |
| 25 | Spiller, J.A. | Austin, TX 78735 | Oil & Gas Operator | Jan 2016 |
| 26 | Spiller, Robert S. | San Antonio, TX 78213 | Oil & Gas Operator | Oct 1995 |
| 27 | Spur Operating Co. | Austin, TX 78701 | Oil & Gas Operator | Oct 2025 |
| 28 | Square One Corporation | Giddings, TX 78942 | Oil & Gas Operator | Dec 2012 |
| 29 | Stephens Production Company | The Woodlands, TX 77381 | Oil & Gas Operator | Jul 2025 |
| 30 | Stonegate Operators, Inc. | Addison, TX 75001 | Oil Operator | Oct 2025 |
| 31 | Strand Energy, L.C. | Houston, TX 77002 | Oil & Gas Operator | Oct 2025 |
| 32 | Strata Star Petroleum Corp. | Uvalde, TX 78801 | Oil Operator | Oct 2025 |
| 33 | Stratco Operating Co Inc | Austin, TX 78701 | Oil & Gas Operator | Oct 2025 |
| 34 | Stratex Oil & Gas Holdings, Inc. | Watertown, CT 06795 | Oil Operator | Jun 2015 |
| 35 | Stringer Oil & Gas Co., Inc. | San Angelo, TX 76902 | Oil & Gas Operator | Oct 1996 |
| 36 | Swift Energy Company | Houston, TX 77060 | Oil & Gas Operator | Mar 2021 |