| 1 | S & D Energy Associates Inc. | | Gas Operator | Dec 1986 |
| 2 | S & S Oil Company LLC | | Oil Operator | Sep 2025 |
| 3 | S. A. Camp Companies | | Oil & Gas Operator | Dec 1998 |
| 4 | S. H. Montgomery | | Oil & Gas Operator | Dec 1996 |
| 5 | Sacramento Energy Inc. | | Oil & Gas Operator | Sep 2025 |
| 6 | Samson Resources Company | Tulsa, OK 74103 | Oil & Gas Operator | Aug 2025 |
| 7 | San Joaquin Facilities Management Inc. | | Oil & Gas Operator | Oct 2025 |
| 8 | Say Energy Inc. | | Oil & Gas Operator | Dec 2004 |
| 9 | Second Wind Production Company Inc. | | Oil Operator | Dec 2013 |
| 10 | Seneca Resources Co LLC | Cranberry Township, PA 16066 | Oil & Gas Operator | Sep 2025 |
| 11 | Seneca Western Minerals Corp. | | Oil & Gas Operator | Dec 2009 |
| 12 | Sentinel Peak Resources California LLC | | Oil & Gas Operator | Oct 2025 |
| 13 | Sequoia Exploration Inc. | | Oil & Gas Operator | Sep 2025 |
| 14 | Shadow Wolf Energy LLC | | Oil Operator | Sep 2025 |
| 15 | Shell Calif. Prod. Inc. | | Oil Operator | Dec 1980 |
| 16 | Shell Western E&P Inc. | Houston, TX 77001 | Oil & Gas Operator | May 2011 |
| 17 | Shelly Energy Inc | Berwyn, PA 19312 | Oil & Gas Operator | Sep 2025 |
| 18 | Sherman Havens | | Oil & Gas Operator | Sep 2025 |
| 19 | Sierra Resources, Inc. | Oklahoma City, OK 73142 | Oil & Gas Operator | Sep 2025 |
| 20 | Signal Hill Petroleum Inc. | | Oil & Gas Operator | Oct 2025 |
| 21 | SJM Oil LLC | | Oil & Gas Operator | Dec 2009 |
| 22 | Soc Resources Inc. | | Oil & Gas Operator | Dec 2024 |
| 23 | Sojitz Energy Venture, Inc. | Houston, TX 77042 | Oil & Gas Operator | Feb 2018 |
| 24 | Solimar Energy LLC | | Oil & Gas Operator | Sep 2025 |
| 25 | Son Petroleum | Bakersfield, CA 93309 | Oil & Gas Operator | Mar 1994 |
| 26 | Source Energy Corp. | | Gas Operator | Aug 2022 |
| 27 | Southern California Gas Company | | Oil & Gas Operator | Sep 2025 |
| 28 | Standing Bear Petroleum Inc. | | Oil & Gas Operator | Dec 2005 |
| 29 | Stockdale Oil & Gas Inc. | | Oil & Gas Operator | Dec 2001 |
| 30 | Stowe Killingsworth | | Oil & Gas Operator | Apr 2023 |
| 31 | Strata-X Inc. | | Oil & Gas Operator | Sep 2025 |
| 32 | Stream Energy, Inc. | Oklahoma City, OK 73102 | Oil & Gas Operator | Sep 2025 |
| 33 | Summit Energy LLC | | Oil & Gas Operator | Sep 2025 |
| 34 | Sun Mountain Oil & Gas | | Oil & Gas Operator | Dec 2020 |
| 35 | Sunray Petroleum Inc. | | Oil & Gas Operator | Sep 2025 |
| 36 | Superior Oil Co. | Denver, CO 80217-5444 | Oil & Gas Operator | Feb 2001 |
| 37 | Superior Well Service Inc. | | Oil & Gas Operator | Sep 2007 |
| 38 | Synergy Resources | Artesia, NM 88210 | Oil & Gas Operator | Jan 2015 |