| 1 | S & J Operating Company | Wichita Falls, TX 76301 | Oil & Gas Operator | Mar 2015 |
| 2 | S2 Energy Operating LLC | | Oil & Gas Operator | May 2023 |
| 3 | Sable Minerals, Inc. | | Oil & Gas Operator | Nov 1993 |
| 4 | Samedan Oil Corp. Et Al | | Oil & Gas Operator | Jan 1989 |
| 5 | Samedan Oil Corporation | Houston, TX 77067 | Oil & Gas Operator | Dec 2019 |
| 6 | Samson Contour Energy E&P, LLC | Tulsa, OK 74103 | Oil & Gas Operator | Sep 2017 |
| 7 | Samson Resources Company | Tulsa, OK 74103 | Oil & Gas Operator | Jun 2025 |
| 8 | Samuel Gary Jr. And Assoc., Inc. | | Oil & Gas Operator | Mar 2023 |
| 9 | Sandalwood Exploration, L.P. | Houston, TX 77056 | Oil & Gas Operator | Oct 2025 |
| 10 | Santa Fe Braun, Inc | Dallas, TX 75240-6620 | Oil & Gas Operator | Mar 1995 |
| 11 | Seagull Energy E & P Inc | Houston, TX 77002 | Oil & Gas Operator | Jan 2015 |
| 12 | Seawide Limited | | Oil & Gas Operator | Jul 1983 |
| 13 | Setex Oil And Gas Company | Houston, TX 77002 | Oil & Gas Operator | Feb 2012 |
| 14 | Shale Energy International, LLC | | Oil & Gas Operator | Nov 2024 |
| 15 | Shelf Energy, LLC | | Oil & Gas Operator | Dec 2024 |
| 16 | Shell Oil Company | Houston, TX 77210 | Oil & Gas Operator | Apr 2015 |
| 17 | Shell Western E&P Inc. | Houston, TX 77001 | Oil & Gas Operator | May 2011 |
| 18 | Shenandoah Oil Corporation | | Oil & Gas Operator | Jun 1979 |
| 19 | Shocker Energy, Inc. | | Oil & Gas Operator | Oct 1992 |
| 20 | Shoreline Southeast LLC | | Oil & Gas Operator | Jun 2017 |
| 21 | Signal Petroleum | | Oil & Gas Operator | Jul 1980 |
| 22 | Sklar & Phillips Oil Co. | Shreveport, LA 71101 | Oil & Gas Operator | Dec 2000 |
| 23 | Skyline Oil Company | Salt Lake City, UT 84111 | Oil & Gas Operator | Jan 1987 |
| 24 | Smith Production Co. | Wichita Falls, TX 76308 | Oil & Gas Operator | Oct 2025 |
| 25 | Snyder Oil Company | Fort Worth, TX 76102 | Oil & Gas Operator | Mar 2015 |
| 26 | Snyder Oil Corporation | Houston, TX 77024 | Oil & Gas Operator | Mar 2008 |
| 27 | Sohio Petroleum Co. | Casper, WY 82602 | Oil & Gas Operator | Apr 1986 |
| 28 | Solatex Resources, LTD | Houston, TX 77257 | Oil & Gas Operator | Oct 2025 |
| 29 | Sonat Exploration Co. | Houston, TX 77251 | Oil & Gas Operator | Dec 2021 |
| 30 | South Leeville, LLC | Houston, TX 77069 | Oil & Gas Operator | Oct 2022 |
| 31 | Southern Natural Gas Co | Houston, TX 77001 | Oil & Gas Operator | Dec 2011 |
| 32 | Southern Petroleum Company | | Oil & Gas Operator | Jan 1994 |
| 33 | Southern Production SVC., Inc. | | Oil Operator | Mar 1997 |
| 34 | Southport Exploration Inc | Tulsa, OK 74103-4015 | Oil & Gas Operator | Nov 1998 |
| 35 | Southwestern Energy Prod Co | Houston, TX 77032 | Oil & Gas Operator | Jun 2015 |
| 36 | Square Mile Energy, L.L.C. | Houston, TX 77057 | Oil & Gas Operator | Oct 2025 |
| 37 | St. Mary Energy Company | Houston, TX 77079 | Oil & Gas Operator | Aug 2008 |
| 38 | Star Energy Inc | Dayton, PA 16222-4325 | Oil & Gas Operator | Dec 2024 |
| 39 | Stone Oil Corp & McMoran Expl | | Oil & Gas Operator | Oct 1984 |
| 40 | Stone Petroleum Corporation | | Oil & Gas Operator | Dec 1996 |
| 41 | Stratco Operating Co Inc | Austin, TX 78701 | Oil & Gas Operator | Oct 2025 |
| 42 | Sulphur River Exploration, Inc. | Dallas, TX 75244 | Oil & Gas Operator | Oct 2025 |
| 43 | Sun Exploration-Production Co. | | Oil & Gas Operator | Jan 1990 |
| 44 | Sun Texas Company | | Oil & Gas Operator | Jun 1981 |
| 45 | Sunburst, Inc. | Wheat Ridge, CO 80033 | Oil & Gas Operator | Jul 2025 |
| 46 | Superior - Austral | | Oil & Gas Operator | Mar 1978 |
| 47 | Superior Oil Co. | Denver, CO 80217-5444 | Oil & Gas Operator | Feb 2001 |
| 48 | Sutton Joint Account | | Oil Operator | Mar 1988 |
| 49 | Swift Energy Company | Houston, TX 77060 | Oil & Gas Operator | Mar 2021 |
| 50 | Swift Energy Operating, LLC | Houston, TX 77079 | Oil & Gas Operator | Jun 2017 |