| 1 | S & J Operating Company | Wichita Falls, TX 76301 | Oil & Gas Operator | Mar 2015 |
| 2 | Samedan Oil Corporation | Houston, TX 77067 | Oil & Gas Operator | Dec 2019 |
| 3 | Samis Oil Company, Inc. | Oklahoma City, OK 73156 | Oil & Gas Operator | Sep 2000 |
| 4 | Samson Hydrocarbons Company | Tulsa, OK 74103 | Oil & Gas Operator | Nov 2016 |
| 5 | Samson Lone Star LP | Tulsa, OK 74103 | Oil & Gas Operator | Jun 2007 |
| 6 | Samson Lone Star, LLC | Tulsa, OK 74103 | Oil & Gas Operator | Oct 2025 |
| 7 | Samson Resources Company | Tulsa, OK 74103 | Oil & Gas Operator | Jun 2025 |
| 8 | Sanders & Smith, L.C. | Amarillo, TX 79110 | Oil & Gas Operator | Mar 2004 |
| 9 | Sandlot Oil & Gas LLC | Gruver, TX 79040 | Oil & Gas Operator | Oct 2025 |
| 10 | Sanguine Gas Exploration, LLC | Tulsa, OK 74119 | Oil & Gas Operator | Oct 2025 |
| 11 | Santa Fe Energy Oper. Part., LP | Houston, TX 77057 | Oil & Gas Operator | Dec 1994 |
| 12 | Saxet Operating Co.,Inc. | Madisonville, TX 77864 | Oil & Gas Operator | Oct 2025 |
| 13 | Sbog, LLC | Granbury, TX 76048 | Oil & Gas Operator | Feb 2021 |
| 14 | Scout Energy Management LLC | Dallas, TX 75240 | Oil & Gas Operator | Oct 2025 |
| 15 | Seagull Energy E & P Inc | Houston, TX 77002 | Oil & Gas Operator | Jan 2015 |
| 16 | Seagull Midcon Inc. | Houston, TX 77002 | Oil & Gas Operator | Mar 2015 |
| 17 | Shamrock Texas Partners L.P. | San Angelo, TX 76904 | Oil & Gas Operator | Oct 2025 |
| 18 | Shannon Energy | Liberal, KS 67901 | Oil & Gas Operator | Feb 1999 |
| 19 | Sheridan Energy,Inc. | Houston, TX 77002 | Oil & Gas Operator | Feb 2000 |
| 20 | Sidwell Oil & Gas, Inc. | Amarillo, TX 79105 | Oil & Gas Operator | Sep 2014 |
| 21 | Sidwell Operating Company, L.P. | Amarillo, TX 79105 | Oil & Gas Operator | Oct 2025 |
| 22 | Sierra Group, L.L.C. | San Angelo, TX 76904 | Oil & Gas Operator | Jan 2025 |
| 23 | Sierra Resources, Inc. | Oklahoma City, OK 73142 | Oil & Gas Operator | Aug 2025 |
| 24 | Sigma Exploration Corp., The | Dallas, TX 75230 | Oil & Gas Operator | Sep 1998 |
| 25 | Skycap Energy, LLC | Oklahoma City, OK 73118 | Oil & Gas Operator | Jul 2025 |
| 26 | SLT Dakota Operating, Inc. | Yukon, OK 73099 | Oil & Gas Operator | Oct 2025 |
| 27 | SM Energy Company | Midland, TX 79707 | Oil & Gas Operator | Oct 2025 |
| 28 | SMR Natural Gas Ventures Inc | Oklahoma City, OK 73112 | Oil & Gas Operator | Jan 1999 |
| 29 | Snappy Services, Inc. | Pampa, TX 79066 | Oil & Gas Operator | Oct 2025 |
| 30 | Sonat Exploration Co. | Houston, TX 77251 | Oil & Gas Operator | Dec 2021 |
| 31 | Sonat Exploration Company-MCR | Houston, TX 77251 | Oil & Gas Operator | Dec 1999 |
| 32 | Spindletop Drilling Co. | Dallas, TX 75230 | Oil & Gas Operator | Oct 2025 |
| 33 | Spindletop Oil & Gas Co. | Dallas, TX 75230 | Oil & Gas Operator | Oct 2025 |
| 34 | St. Mary Energy Company | Houston, TX 77079 | Oil & Gas Operator | Aug 2008 |
| 35 | St. Mary Land & Exploration Co | Denver, CO 80201 | Oil & Gas Operator | Jun 2010 |
| 36 | St. Mary Operating Company | Denver, CO 80203 | Oil & Gas Operator | Mar 2019 |
| 37 | Stahl Petroleum Co. | Amarillo, TX 79118 | Oil & Gas Operator | Aug 2003 |
| 38 | Staley, Jack C. | Wichita Falls, TX 76308 | Oil & Gas Operator | Jan 2000 |
| 39 | Stallion Energy, Inc. | Houston, TX 77060 | Oil & Gas Operator | Oct 2017 |
| 40 | Statoil Oil & Gas LP | Austin, TX 78730 | Oil & Gas Operator | Oct 2018 |
| 41 | Stephens & Johnson Operating Co. | Wichita Falls, TX 76307 | Oil & Gas Operator | Oct 2025 |
| 42 | Stephens Production Company | The Woodlands, TX 77381 | Oil & Gas Operator | Jul 2025 |
| 43 | Sting Exploration Company | Tulsa, OK 74120 | Oil Operator | Sep 2004 |
| 44 | Striper Oil, Inc. | Dallas, TX 75379 | Oil & Gas Operator | Apr 2002 |
| 45 | Summit Exploration, L.L.C. | Tulsa, OK 74119 | Oil & Gas Operator | Mar 2008 |
| 46 | Summit Overseas Expl., Inc. | Denver, CO 80226 | Oil & Gas Operator | Apr 2007 |
| 47 | Sundown Energy, Inc. | Dallas, TX 75240 | Oil & Gas Operator | May 2025 |
| 48 | Supa Energy, Inc. | Shamrock, TX 79079 | Oil & Gas Operator | Oct 2025 |
| 49 | Swift Energy Company | Houston, TX 77060 | Oil & Gas Operator | Mar 2021 |