| 1 | Samedan Oil Corp. Et Al | | Oil & Gas Operator | Jan 1989 |
| 2 | Samedan Oil Corporation | Houston, TX 77067 | Oil & Gas Operator | Dec 2019 |
| 3 | Samson Resources Company | Tulsa, OK 74103 | Oil & Gas Operator | Jun 2025 |
| 4 | Sandefer Petroleum Co. | | Oil & Gas Operator | Apr 1994 |
| 5 | Sandridge Exploration And Production LLC | Oklahoma City, OK 73104 | Oil & Gas Operator | Oct 2025 |
| 6 | Sandridge Onshore, LLC | Houston, TX 77010 | Oil & Gas Operator | Jun 2014 |
| 7 | Santa Fe Braun, Inc | Dallas, TX 75240-6620 | Oil & Gas Operator | Mar 1995 |
| 8 | Santa Fe Minerals, Inc. | Dallas, TX 75240 | Oil & Gas Operator | Sep 2013 |
| 9 | Santana Exploration, Inc. | | Oil & Gas Operator | Dec 1985 |
| 10 | Senior G&A Operating Co Inc | | Oil & Gas Operator | Nov 1991 |
| 11 | Serio Exploration Company | | Oil Operator | Jan 1992 |
| 12 | Settco Oil & Gas | | Oil & Gas Operator | May 1994 |
| 13 | Shell Oil Company | Houston, TX 77210 | Oil & Gas Operator | Apr 2015 |
| 14 | Shell Western E&P Inc. | Houston, TX 77001 | Oil & Gas Operator | May 2011 |
| 15 | Shield Energy Resources, LLC | | Oil Operator | Dec 2024 |
| 16 | Single Barrel Oil And Gas LLC | Granbury, TX 76048 | Oil & Gas Operator | Oct 2025 |
| 17 | Smith Production Co. | Wichita Falls, TX 76308 | Oil & Gas Operator | Oct 2025 |
| 18 | SMK-La, Inc. | | Oil & Gas Operator | Sep 1999 |
| 19 | Sohio Petroleum Co. | Casper, WY 82602 | Oil & Gas Operator | Apr 1986 |
| 20 | Sonat Exploration Co. | Houston, TX 77251 | Oil & Gas Operator | Dec 2021 |
| 21 | Source Petroleum Inc. | San Antonio, TX 78265 | Oil & Gas Operator | Oct 2025 |
| 22 | South Oak Production Company | | Oil & Gas Operator | Jun 2010 |
| 23 | Southeastern Public Service Co | | Oil & Gas Operator | Sep 1982 |
| 24 | Southern Bay Operating, L.L.C. | Houston, TX 77002 | Oil & Gas Operator | Jun 2013 |
| 25 | Southern Natural Gas Co | Houston, TX 77001 | Oil & Gas Operator | Dec 2011 |
| 26 | Southern Natural Gas Company LLC | | Oil & Gas Operator | Nov 2024 |
| 27 | Southwest Rig Service | | Oil & Gas Operator | Nov 1998 |
| 28 | Spartan Operating Company, Inc. | Tyler, TX 75702 | Oil & Gas Operator | Feb 2013 |
| 29 | Square One Corporation | Giddings, TX 78942 | Oil & Gas Operator | Dec 2012 |
| 30 | Ssi Energy LLC | | Oil & Gas Operator | Jul 2021 |
| 31 | Standard Operating Company, LLC | | Oil & Gas Operator | May 2022 |
| 32 | Sugar Bowl Industrial Gas Corp | | Oil Operator | Dec 1983 |
| 33 | Sun Exploration-Production Co. | | Oil & Gas Operator | Jan 1990 |
| 34 | Sunchase Exploration, Inc. | | Oil & Gas Operator | Oct 1997 |
| 35 | Superior Oil Co. | Denver, CO 80217-5444 | Oil & Gas Operator | Feb 2001 |
| 36 | Sydson D'Oro Expl. Co. | Houston, TX 77079 | Oil & Gas Operator | Jan 1992 |