| 1 | Sabio Oil & Gas Inc. | Dallas, TX 75206 | Oil & Gas Operator | Jan 1998 |
| 2 | Samedan Oil Corporation | Houston, TX 77067 | Oil & Gas Operator | Dec 2019 |
| 3 | Samson Hydrocarbons Company | Tulsa, OK 74103 | Oil & Gas Operator | Nov 2016 |
| 4 | Samson Lone Star LP | Tulsa, OK 74103 | Oil & Gas Operator | Jun 2007 |
| 5 | Samson Lone Star, LLC | Tulsa, OK 74103 | Oil & Gas Operator | Oct 2025 |
| 6 | Samson Resources Company | Tulsa, OK 74103 | Oil & Gas Operator | Jun 2025 |
| 7 | Scout Energy Management LLC | Dallas, TX 75240 | Oil & Gas Operator | Oct 2025 |
| 8 | SDG Operating Company, Inc | Tyler, TX 75701 | Oil & Gas Operator | Oct 2025 |
| 9 | Seagull Energy E & P Inc | Houston, TX 77002 | Oil & Gas Operator | Jan 2015 |
| 10 | Seistech Development, Inc. | Midland, TX 79701 | Oil & Gas Operator | May 2007 |
| 11 | Shelby Production Co. | Kilgore, TX 75663 | Oil & Gas Operator | Mar 2009 |
| 12 | Shelby, Michael H. | Shreveport, LA 71101 | Oil & Gas Operator | Oct 2025 |
| 13 | Shidler, Mark L., Inc. | Houston, TX 77055 | Oil & Gas Operator | Oct 2025 |
| 14 | Shifflett Operating Company | Snyder, TX 79550 | Oil & Gas Operator | Oct 2025 |
| 15 | Shoco Production LLC | Kilgore, TX 75663 | Oil & Gas Operator | Oct 2025 |
| 16 | Shoco Production, L.P. | Kilgore, TX 75663 | Oil & Gas Operator | May 2020 |
| 17 | SHWJ Oil & Gas Co., Inc. | Oil City, LA 71061 | Oil Operator | Oct 2025 |
| 18 | Sikes Operating, Inc. | Tyler, TX 75711 | Oil & Gas Operator | Jun 2003 |
| 19 | Siroco Operating Co., Inc. | Kilgore, TX 75663 | Oil & Gas Operator | Apr 2010 |
| 20 | Skidmore Exploration, Inc. | Dallas, TX 75219 | Oil & Gas Operator | Jul 1997 |
| 21 | Sklar & Phillips Oil Co. | Shreveport, LA 71101 | Oil & Gas Operator | Dec 2000 |
| 22 | SND Operating, L.L.C. | Kilgore, TX 75663 | Oil & Gas Operator | Oct 2025 |
| 23 | Snyder Oil Corporation | Houston, TX 77024 | Oil & Gas Operator | Mar 2008 |
| 24 | Southern Union Exploration Co. | Austin, TX 78701 | Oil & Gas Operator | Feb 2002 |
| 25 | Southwest Operating, Inc.-Tyler | Tyler, TX 75701 | Oil & Gas Operator | Oct 2025 |
| 26 | Southwestern Energy Prod Co | Houston, TX 77032 | Oil & Gas Operator | Jun 2015 |
| 27 | Spartan Operating Company, Inc. | Tyler, TX 75702 | Oil & Gas Operator | Feb 2013 |
| 28 | Spence, Ralph Oil Company, Inc. | Tyler, TX 75701 | Oil & Gas Operator | Jun 2023 |
| 29 | St. Mary Land & Exploration Co | Denver, CO 80201 | Oil & Gas Operator | Jun 2010 |
| 30 | Staub, Larry | Richardson, TX 75080 | Oil & Gas Operator | Aug 2003 |
| 31 | Staub, Larry, Inc. | Azle, TX 76020 | Oil & Gas Operator | Oct 2025 |
| 32 | Strago Petroleum Corporation | Houston, TX 77002 | Oil & Gas Operator | Aug 1994 |
| 33 | Stratco Operating Co Inc | Austin, TX 78701 | Oil & Gas Operator | Oct 2025 |
| 34 | Stroud Petroleum, Inc. | Shreveport, LA 71162 | Oil & Gas Operator | Oct 2025 |
| 35 | Suemaur Expl. & Prod., LLC | Corpus Chrsti, TX 78401 | Oil & Gas Operator | Jun 2024 |
| 36 | Sunland Production Company, Inc. | Shreveport, LA 71101 | Oil & Gas Operator | Jun 2025 |
| 37 | Supreme Energy Company, Inc. | Abilene, TX 79601 | Oil & Gas Operator | Oct 2025 |
| 38 | SW Operating, Inc. | Kilgore, TX 75662 | Oil & Gas Operator | Sep 2000 |
| 39 | Swanson Operating, Inc. | Holliday, TX 76366 | Oil Operator | Oct 2025 |
| 40 | Swanson, Tom | Electra, TX 76360 | Oil & Gas Operator | Oct 2004 |