| 1 | S&B Petroleum Corporation | | Oil & Gas Operator | Jun 1994 |
| 2 | Samson Resources Company | Tulsa, OK 74103 | Oil & Gas Operator | Aug 2025 |
| 3 | Sandefer Petroleum Co. | | Oil & Gas Operator | Apr 1994 |
| 4 | Sandhill Production Inc | Shongaloo, LA 71072 | Oil & Gas Operator | Dec 2019 |
| 5 | Santa Fe Braun Inc | Dallas, TX 75240-6620 | Oil & Gas Operator | Mar 1995 |
| 6 | Santa Fe Energy Operg Parts LP | | Oil & Gas Operator | Nov 1993 |
| 7 | Santa Fe Energy Resources, Inc. | Houston, TX 77024 | Oil & Gas Operator | Mar 2008 |
| 8 | Se USA Operating, Inc. | Houston, TX 77002 | Oil & Gas Operator | Dec 2009 |
| 9 | Senior G&A Operating Co Inc | | Oil & Gas Operator | Nov 1991 |
| 10 | Shell Oil Co. | Houston, TX 77001 | Oil & Gas Operator | Jun 1985 |
| 11 | Shell Western E&P Inc. | Houston, TX 77001 | Oil & Gas Operator | May 2011 |
| 12 | Shore Oil Company | | Oil & Gas Operator | May 1998 |
| 13 | Shoreline Southeast LLC | | Oil & Gas Operator | Jun 2017 |
| 14 | Smith Petroleum Company | Spring, TX 77389 | Oil & Gas Operator | Dec 2025 |
| 15 | Smith Production Co. | Wichita Falls, TX 76308 | Oil & Gas Operator | Dec 2025 |
| 16 | Sohio Petroleum Co. | Casper, WY 82602 | Oil & Gas Operator | Apr 1986 |
| 17 | Sohio Petroleum Co. Et Al | | Oil & Gas Operator | May 1979 |
| 18 | Sonat Exploration Co. | Houston, TX 77251 | Oil & Gas Operator | Dec 2021 |
| 19 | Source Petroleum Inc. | San Antonio, TX 78265 | Oil & Gas Operator | Dec 2025 |
| 20 | South Oak Production Company | | Oil & Gas Operator | Jun 2010 |
| 21 | Southern G Holdings, LLC | Houston, TX 77002 | Oil & Gas Operator | Dec 2007 |
| 22 | Southern Production & Expl Co. | | Oil & Gas Operator | Apr 2008 |
| 23 | Southwest Oil Properties, Inc. | | Oil & Gas Operator | Feb 1996 |
| 24 | Square Mile Energy, L.L.C. | Houston, TX 77057 | Oil & Gas Operator | Dec 2025 |
| 25 | St. Mary Energy Company | Houston, TX 77079 | Oil & Gas Operator | Aug 2008 |
| 26 | St. Mary Land & Exploration Co | Denver, CO 80201 | Oil & Gas Operator | Jun 2010 |
| 27 | Stone Oil Corp - Strata Energy | | Oil & Gas Operator | Mar 1982 |
| 28 | Stone Petroleum Corporation | | Oil & Gas Operator | Dec 1996 |
| 29 | Sun Exploration And Production Co | | Oil & Gas Operator | Jan 1990 |
| 30 | Sun Texas Company | | Oil & Gas Operator | Jun 1981 |
| 31 | Superior Oil Co. | Denver, CO 80217-5444 | Oil & Gas Operator | Feb 2001 |
| 32 | SWD, Inc. | | Oil Operator | Jan 2025 |
| 33 | Synergy Oil & Gas, L.P. | Houston, TX 77024 | Oil & Gas Operator | May 2012 |