| 1 | American Exploration Company | Houston, TX 77010 | Oil & Gas Operator | Jan 2000 |
| 2 | Amoco Production Co. | Houston, TX 77253 | Oil & Gas Operator | Jun 2015 |
| 3 | Anr Production Company | Houston, TX 77046 | Oil & Gas Operator | Aug 2017 |
| 4 | Apache Corporation | Houston, TX 77042 | Oil & Gas Operator | Oct 2025 |
| 5 | Araxas Exploration, Inc. | The Woodlands, TX 77380 | Oil & Gas Operator | Apr 1998 |
| 6 | Arco Oil & Gas Company | Plano, TX 75086 | Oil & Gas Operator | Mar 2006 |
| 7 | Bandera Oil & Gas Inc | Fulshear, TX 77441 | Oil & Gas Operator | Oct 2025 |
| 8 | BP America Production Company | Denver, CO 80202 | Oil & Gas Operator | Jun 2025 |
| 9 | Chevron USA Inc | Midland, TX 79706 | Oil & Gas Operator | Oct 2025 |
| 10 | CNG Producing Company | New Orleans, LA 70112 | Oil & Gas Operator | Dec 2015 |
| 11 | Coastland Operations, LLC | Dallas, TX 75287 | Oil & Gas Operator | Oct 2025 |
| 12 | Contango Operators, Inc. | Houston, TX 77098 | Oil & Gas Operator | Dec 2022 |
| 13 | Delmar Operating, Inc. | Houston, TX 77010 | Oil & Gas Operator | Oct 1996 |
| 14 | Devon Energy Production Company LP | Oklahoma City, OK 73102 | Oil & Gas Operator | Oct 2025 |
| 15 | Devon Louisiana Corporation | Houston, TX 77002 | Oil & Gas Operator | Oct 2019 |
| 16 | Dominion Oklahoma Texas E&P, Inc | Richmond, VA 23219 | Oil & Gas Operator | Sep 2018 |
| 17 | Dreyfus, Louis Natural Gas Corp | Oklahoma City, OK 73134 | Oil & Gas Operator | Nov 2001 |
| 18 | Dynamic Offshore Resources, LLC | Houston, TX 77042 | Oil & Gas Operator | Oct 2025 |
| 19 | Eclipse Petroleum Corporation | La Grange, TX 78945 | Oil & Gas Operator | Aug 2003 |
| 20 | Energy Development Corporation | Houston, TX 77067 | Oil & Gas Operator | Dec 2024 |
| 21 | Enron Oil & Gas Company | Houston, TX 77210 | Oil & Gas Operator | Dec 1999 |
| 22 | Exxon Corporation | Houston, TX 77210 | Oil & Gas Operator | Jun 2024 |
| 23 | Fieldwood Energy Offshore LLC | Houston, TX 77042 | Oil & Gas Operator | Oct 2025 |
| 24 | Forest Oil Corporation | Houston, TX 77002 | Oil & Gas Operator | Mar 2015 |
| 25 | Global Natural Resources Corp. | Houston, TX 77002 | Oil & Gas Operator | May 1998 |
| 26 | Goldking Operating Company, Inc. | Houston, TX 77002 | Oil & Gas Operator | Jun 2007 |
| 27 | Gulf Coast Operations, LLC | Farmers BRNCH, TX 75234 | Oil & Gas Operator | Oct 2025 |
| 28 | Gulf Energy Exploration Corp. | Austin, TX 78716 | Gas Operator | Oct 2025 |
| 29 | Houston Oil & Minerals Corp. | Houston, TX 77002 | Oil & Gas Operator | Aug 1996 |
| 30 | Hunt Oil Company | Dallas, TX 75201 | Oil & Gas Operator | Oct 2025 |
| 31 | Hunt Petroleum (Aec), Inc. | Dallas, TX 75201 | Oil & Gas Operator | Nov 2008 |
| 32 | Inexco Oil Company | Houston, TX 77210 | Oil & Gas Operator | Mar 2013 |
| 33 | Jefferson Block 24 Oil & Gas LLC | Dallas, TX 75287 | Oil & Gas Operator | Oct 2025 |
| 34 | Kerr-McGee Corporation | Dallas, TX 75380 | Oil & Gas Operator | May 2025 |
| 35 | Llog Exploration Offshore, Inc. | Covington, LA 70433 | Oil & Gas Operator | Aug 2004 |
| 36 | Llog Exploration Texas, L.P. | Covington, LA 70433 | Oil & Gas Operator | Oct 2025 |
| 37 | Maritech Resources, Inc. | The Woodlands, TX 77380 | Oil & Gas Operator | Nov 2009 |
| 38 | Meridian Resource & Expl LLC,The | Houston, TX 77094 | Oil & Gas Operator | Nov 2012 |
| 39 | Mesa Operating Co. | Irving, TX 75039 | Oil & Gas Operator | Aug 1997 |
| 40 | Mesa Operating LTD Partnership | Amarillo, TX 79189 | Oil & Gas Operator | May 1994 |
| 41 | Mitchell Energy Corp | Houston, TX 77002 | Oil & Gas Operator | Aug 2013 |
| 42 | Noble Energy Inc | Midland, TX 79706 | Oil & Gas Operator | Oct 2025 |
| 43 | Norcen Explorer, Inc. | Houston, TX 77079 | Oil & Gas Operator | May 1998 |
| 44 | Ocean Energy, Inc. | Houston, TX 77002 | Oil & Gas Operator | Aug 2003 |
| 45 | Offshore Oil & Gas Inc | Houston, TX 77063 | Oil & Gas Operator | Sep 1994 |
| 46 | Palace Operating Company | Tulsa, OK 74136 | Oil & Gas Operator | Aug 2009 |
| 47 | Pioneer Natural Res. USA, Inc. | Spring, TX 77389 | Oil & Gas Operator | Oct 2025 |
| 48 | Rutherford Oil Corporation | Houston, TX 77046 | Oil & Gas Operator | Jun 2019 |
| 49 | Samedan Oil Corp. -Offshore Div. | Houston, TX 77067 | Oil & Gas Operator | Dec 2002 |
| 50 | Santos USA Corp. | Houston, TX 77042 | Oil & Gas Operator | Dec 2008 |
| 51 | Seagull Energy E & P Inc | Houston, TX 77002 | Oil & Gas Operator | Jan 2015 |
| 52 | Seiran E & P Company, LLC | Friendswood, TX 77546 | Oil & Gas Operator | Oct 2025 |
| 53 | Seneca Resources Corporation | Houston, TX 77002 | Oil & Gas Operator | Dec 2017 |
| 54 | Shell Offshore Inc. | New Orleans, LA 70161 | Oil & Gas Operator | Jan 2008 |
| 55 | Shell Western E&P | Houston, TX 77001 | Oil & Gas Operator | Oct 2025 |
| 56 | Snyder Oil Corporation | Houston, TX 77024 | Oil & Gas Operator | Mar 2008 |
| 57 | Sonat Exploration Gom Inc. | Houston, TX 77251 | Oil & Gas Operator | Dec 1999 |
| 58 | Sterling Expl. & Prod. Co., LLC | Houston, TX 77057 | Oil & Gas Operator | Oct 2025 |
| 59 | Torch Operating Company | Houston, TX 77010 | Oil & Gas Operator | Mar 2015 |
| 60 | Tri-C Resources, Inc. | Houston, TX 77024 | Oil & Gas Operator | Aug 2009 |
| 61 | Tri-C Resources, LLC | Houston, TX 77024 | Oil & Gas Operator | Oct 2025 |
| 62 | Umc Petroleum Corporation | Houston, TX 77002 | Oil & Gas Operator | Mar 2015 |
| 63 | Union Oil Co Of California | Midland, TX 79706 | Oil & Gas Operator | Jan 2022 |
| 64 | Vastar Resources Inc | Houston, TX 77253 | Oil & Gas Operator | Jun 2025 |
| 65 | Vintage Petroleum, Inc. | Houston, TX 77046 | Oil & Gas Operator | May 2025 |
| 66 | Vintage Petroleum, LLC | Houston, TX 77210 | Oil & Gas Operator | Dec 2019 |
| 67 | W & T Offshore, Inc. | Houston, TX 77057 | Oil & Gas Operator | Oct 2025 |
| 68 | Walter Oil & Gas Corporation | Houston, TX 77002 | Oil & Gas Operator | Oct 2025 |
| 69 | Weeks Exploration Company | Houston, TX 77063 | Oil & Gas Operator | Aug 1995 |
| 70 | Whiting Oil And Gas Corporation | Houston, TX 77002 | Oil & Gas Operator | Oct 2025 |
| 71 | Whiting Petroleum Corporation | Denver, CO 80290 | Oil & Gas Operator | Jan 2025 |
| 72 | Xplor Energy Operating Co. | Houston, TX 77079 | Oil & Gas Operator | Jan 2012 |
| 73 | Zilkha Energy Company | Houston, TX 77046 | Oil & Gas Operator | Oct 2002 |