| 1 | Sandalwood Exploration, L.P. | Houston, TX 77056 | Oil & Gas Operator | Oct 2025 |
| 2 | Sandefer Petroleum Co. | | Oil & Gas Operator | Apr 1994 |
| 3 | Sandridge Exploration And Production LLC | Oklahoma City, OK 73104 | Oil & Gas Operator | Oct 2025 |
| 4 | Sandridge Onshore, LLC | Houston, TX 77010 | Oil & Gas Operator | Jun 2014 |
| 5 | Seahawk Oil & Gas Company | Dallas, TX 75379 | Oil & Gas Operator | Aug 2007 |
| 6 | Sealexco | | Oil & Gas Operator | Jun 1992 |
| 7 | Sealexco-Crescent Drilling | | Oil & Gas Operator | May 1986 |
| 8 | Shell Oil Company | Houston, TX 77210 | Oil & Gas Operator | Apr 2015 |
| 9 | Shell Western E&P Inc. | Houston, TX 77001 | Oil & Gas Operator | May 2011 |
| 10 | Shoreline Offshore LLC | | Oil & Gas Operator | Jun 2017 |
| 11 | Shoreline Southeast LLC | | Oil & Gas Operator | Jun 2017 |
| 12 | Skelly Oil Co | | Oil & Gas Operator | Mar 2005 |
| 13 | Sonora Producing, Inc. | | Oil & Gas Operator | May 2006 |
| 14 | Sound Resources Corporation | | Oil & Gas Operator | Dec 2003 |
| 15 | Source Petroleum Inc. | San Antonio, TX 78265 | Oil & Gas Operator | Oct 2025 |
| 16 | South Oak Production Company | | Oil & Gas Operator | Jun 2010 |
| 17 | Southern Bay Operating, L.L.C. | Houston, TX 77002 | Oil & Gas Operator | Jun 2013 |
| 18 | Spirit Petroleum Company | | Oil & Gas Operator | Apr 1999 |
| 19 | Spooner Petroleum Company | | Oil & Gas Operator | Jul 2025 |
| 20 | Square Mile Energy, L.L.C. | Houston, TX 77057 | Oil & Gas Operator | Oct 2025 |
| 21 | SRP Production Corp. | | Oil & Gas Operator | Nov 1997 |
| 22 | St. Croix Corporation | | Oil & Gas Operator | Apr 1990 |
| 23 | Stone Energy Corporation | Denver, CO 80202-2828 | Oil & Gas Operator | Oct 2014 |
| 24 | Stone Oil Corp-Forest Oil Corp | | Oil & Gas Operator | Jan 1983 |
| 25 | Stone Oil-Lamson-Onshore Pet. | | Oil & Gas Operator | May 1985 |
| 26 | Stone Petroleum Corporation | | Oil & Gas Operator | Dec 1996 |
| 27 | Stratco Operating Co Inc | Austin, TX 78701 | Oil & Gas Operator | Oct 2025 |
| 28 | Summit Energy Company | | Oil & Gas Operator | Mar 2009 |
| 29 | Sun Exploration-Production Co. | | Oil & Gas Operator | Jan 1990 |
| 30 | Superior Oil Co. | Denver, CO 80217-5444 | Oil & Gas Operator | Feb 2001 |
| 31 | Swift Energy Operating, LLC | Houston, TX 77079 | Oil & Gas Operator | Jun 2017 |