| 1 | S2 Energy Operating LLC | | Oil & Gas Operator | May 2023 |
| 2 | Sabine Corporation | Oklahoma City, OK 73116 | Oil & Gas Operator | Jul 1996 |
| 3 | Sam Jones & Assoc Prod Div Inc | | Oil & Gas Operator | Feb 1999 |
| 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 | Sandefer Petroleum Co. | | Oil & Gas Operator | Apr 1994 |
| 9 | Santa Fe Energy Resources, Inc. | Houston, TX 77024 | Oil & Gas Operator | Mar 2008 |
| 10 | Seahawk Oil & Gas Company | Dallas, TX 75379 | Oil & Gas Operator | Aug 2007 |
| 11 | Sealexco | | Oil & Gas Operator | Jun 1992 |
| 12 | Senior G&A Operating Co Inc | | Oil & Gas Operator | Nov 1991 |
| 13 | Shale Energy International, LLC | | Oil & Gas Operator | Nov 2024 |
| 14 | Shelf Energy, LLC | | Oil & Gas Operator | Dec 2024 |
| 15 | Shell Offshore Inc. | New Orleans, LA 70161 | Oil & Gas Operator | Jan 2008 |
| 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 | Shore Oil Company | | Oil & Gas Operator | May 1998 |
| 19 | Shoreline Southeast LLC | | Oil & Gas Operator | Jun 2017 |
| 20 | Shuteston Oil & Gas | | Oil & Gas Operator | Sep 1997 |
| 21 | Signal Petroleum | | Oil & Gas Operator | Jul 1980 |
| 22 | Smith Production Co. | Wichita Falls, TX 76308 | Oil & Gas Operator | Oct 2025 |
| 23 | Snyder Oil Company | Fort Worth, TX 76102 | Oil & Gas Operator | Mar 2015 |
| 24 | Snyder Oil Corporation | Houston, TX 77024 | Oil & Gas Operator | Mar 2008 |
| 25 | Sohio Petroleum Co. | Casper, WY 82602 | Oil & Gas Operator | Apr 1986 |
| 26 | Solatex | | Oil & Gas Operator | Oct 1978 |
| 27 | Sonat Exploration Co. | Houston, TX 77251 | Oil & Gas Operator | Dec 2021 |
| 28 | Sonora Producing, Inc. | | Oil & Gas Operator | May 2006 |
| 29 | Southport Exploration Inc | Tulsa, OK 74103-4015 | Oil & Gas Operator | Nov 1998 |
| 30 | Southwest Oil Properties, Inc. | | Oil & Gas Operator | Feb 1996 |
| 31 | Southwest Rig Service | | Oil & Gas Operator | Nov 1998 |
| 32 | Southwestern Energy Prod Co | Houston, TX 77032 | Oil & Gas Operator | Jun 2015 |
| 33 | Square Mile Energy, L.L.C. | Houston, TX 77057 | Oil & Gas Operator | Oct 2025 |
| 34 | SRP Production Corp. | | Oil & Gas Operator | Nov 1997 |
| 35 | St. Mary Energy Company | Houston, TX 77079 | Oil & Gas Operator | Aug 2008 |
| 36 | St. Mary Land & Exploration Co | Denver, CO 80201 | Oil & Gas Operator | Jun 2010 |
| 37 | St. Mary Operating Company | Denver, CO 80203 | Oil & Gas Operator | Mar 2019 |
| 38 | Stone Energy Corporation | Denver, CO 80202-2828 | Oil & Gas Operator | Oct 2014 |
| 39 | Stone Petroleum Corporation | | Oil & Gas Operator | Dec 1996 |
| 40 | Strata Energy, Inc. | | Oil & Gas Operator | Sep 1983 |
| 41 | Stratco Operating Co Inc | Austin, TX 78701 | Oil & Gas Operator | Oct 2025 |
| 42 | Summit Energy, Inc. | Littleton, CO 80127 | Oil & Gas Operator | Aug 2013 |
| 43 | Summit Overseas Expl., Inc. | Denver, CO 80226 | Oil & Gas Operator | Apr 2007 |
| 44 | Sun Exploration-Production Co. | | Oil & Gas Operator | Jan 1990 |
| 45 | Sunchase Exploration, Inc. | | Oil & Gas Operator | Oct 1997 |
| 46 | Superior Oil Co. | Denver, CO 80217-5444 | Oil & Gas Operator | Feb 2001 |
| 47 | Swift Energy Company | Houston, TX 77060 | Oil & Gas Operator | Mar 2021 |