| 1 | Amoco Production Company | Houston, TX 77253 | Oil & Gas Operator | Jun 2015 |
| 2 | Ballard Exploration Company,Inc. | Houston, TX 77002 | Oil & Gas Operator | May 2026 |
| 3 | Barrow-Shaver Resources Co. | Tyler, TX 75703 | Oil & Gas Operator | May 2026 |
| 4 | Chesapeake Operating LLC | Oklahoma City, OK 73154 | Oil & Gas Operator | May 2026 |
| 5 | Chesapeake Operating, Inc. | Oklahoma City, OK 73154 | Oil & Gas Operator | Jan 2026 |
| 6 | Cole, Frank W Engineering | Dallas, TX 75254 | Oil & Gas Operator | Mar 2006 |
| 7 | Comanche Well Service Corp. | Plano, TX 75093 | Oil & Gas Operator | May 2026 |
| 8 | Concho Exploration Inc | Oklahoma City, OK 73154 | Oil & Gas Operator | Mar 2015 |
| 9 | Continental Operating Co. | Houston, TX 77024 | Oil & Gas Operator | May 2026 |
| 10 | Dallas Production, Inc. | Dallas, TX 75206 | Oil & Gas Operator | Mar 2021 |
| 11 | Dyersdale Production Co, Inc. | Houston, TX 77019 | Oil & Gas Operator | May 2026 |
| 12 | Eagle Rock Operating Company,LLC | Houston, TX 77252 | Oil & Gas Operator | Oct 2015 |
| 13 | Egl Oil And Gas Corporation | Tyler, TX 75703 | Oil & Gas Operator | Aug 2003 |
| 14 | Exxon Corporation | Houston, TX 77210 | Oil & Gas Operator | Jan 2026 |
| 15 | M. E. Operating & Services, Inc. | Fort Worth, TX 76104 | Oil & Gas Operator | May 2026 |
| 16 | Majestic Petroleum Corporation | Dallas, TX 75230 | Oil & Gas Operator | Oct 1996 |
| 17 | Penwell Energy, Inc. | Houston, TX 77057 | Oil & Gas Operator | May 2026 |
| 18 | Phillips Petroleum Company | Houston, TX 77251 | Oil & Gas Operator | Mar 2013 |
| 19 | Pioneer Natural Res. USA, Inc. | Spring, TX 77389 | Oil & Gas Operator | May 2026 |
| 20 | Redman Operating Company | Houston, TX 77042 | Oil & Gas Operator | May 2008 |
| 21 | Ricks Exploration, Inc. | Oklahoma City, OK 73154 | Oil & Gas Operator | Mar 2008 |
| 22 | Rockwall Marketing Corporation | Benbrook, TX 76126 | Oil & Gas Operator | Dec 2007 |
| 23 | Santa Fe Energy Oper. Part., LP | Houston, TX 77057 | Oil & Gas Operator | Dec 1994 |
| 24 | SND Operating, L.L.C. | Kilgore, TX 75663 | Oil & Gas Operator | May 2026 |
| 25 | Spence Energy Company | Dallas, TX 75360 | Oil & Gas Operator | May 2026 |
| 26 | Tactical Operating Company, LLC | Houston, TX 77042 | Oil & Gas Operator | May 2026 |
| 27 | Tensas Delta Explo. Co., LLC | Shreveport, LA 71101 | Oil & Gas Operator | Dec 2011 |
| 28 | Union Oil Co Of California | Midland, TX 79706 | Oil & Gas Operator | Jan 2022 |
| 29 | Valence Operating Company | Kingwood, TX 77339 | Oil & Gas Operator | May 2026 |
| 30 | Vanguard Operating, LLC | Houston, TX 77057 | Oil & Gas Operator | Aug 2019 |
| 31 | Vintage Petroleum, Inc. | Houston, TX 77046 | Oil & Gas Operator | Jan 2026 |
| 32 | Vintage Petroleum, LLC | Houston, TX 77210 | Oil & Gas Operator | Dec 2019 |
| 33 | Weatherly Oil & Gas, LLC | Dallas, TX 75206 | Oil & Gas Operator | May 2026 |
| 34 | WGR, Inc. | Houston, TX 77046 | Gas Operator | Jul 2007 |