| 101 | Reunion Energy Company | Houston, TX 77056 | Oil & Gas Operator | May 1996 |
| 102 | Reveille Resources (Texas), Inc. | Houston, TX 77084 | Oil & Gas Operator | Jan 2013 |
| 103 | Richman Petroleum Corp. | Grapevine, TX 76051 | Oil & Gas Operator | Jul 2006 |
| 104 | Ricochet Energy, Inc. | San Antonio, TX 78258 | Oil & Gas Operator | Apr 2024 |
| 105 | Risco La Sara Operations, LLC | Houston, TX 77056 | Oil & Gas Operator | Aug 2014 |
| 106 | Royal Oil & Gas Corp. | Indiana, PA 15701 | Oil & Gas Operator | Apr 2014 |
| 107 | Saga Petroleum Corp. | Midland, TX 79701 | Oil & Gas Operator | Mar 2008 |
| 108 | Samedan Oil Corporation | Houston, TX 77067 | Oil & Gas Operator | Dec 2019 |
| 109 | Sanchez Oil & Gas Corporation | Houston, TX 77056 | Oil & Gas Operator | Apr 2024 |
| 110 | Sanchez-O'Brien Oil & Gas Corp | Houston, TX 77057 | Oil & Gas Operator | May 1998 |
| 111 | Santos USA Corp. | Houston, TX 77042 | Oil & Gas Operator | Dec 2008 |
| 112 | Sarita Energy Resources, LTD. | Houston, TX 77277 | Oil & Gas Operator | Apr 2024 |
| 113 | Sarita Oil & Gas | Boerne, TX 78006 | Oil & Gas Operator | Apr 2024 |
| 114 | Saxum Oil & Gas, LLC | Beeville, TX 78104 | Oil & Gas Operator | Apr 2024 |
| 115 | Se USA Operating, Inc. | Houston, TX 77002 | Oil & Gas Operator | Dec 2009 |
| 116 | Sedco Resources Inc | Kerrville, TX 78029 | Oil & Gas Operator | Apr 2024 |
| 117 | Shell Trading Us Company | Houston, TX 77210 | Oil & Gas Operator | Jan 2024 |
| 118 | Shell Western E&P Inc. | Houston, TX 77001 | Oil & Gas Operator | May 2011 |
| 119 | Sierra Resources, LLC | Houston, TX 77219 | Oil & Gas Operator | Aug 2021 |
| 120 | Smith Production Inc. | The Woodlands, TX 77381 | Oil & Gas Operator | Apr 2024 |
| 121 | Sonat Exploration Co. - Houston | Houston, TX 77251 | Oil & Gas Operator | Dec 1999 |
| 122 | Sue-Ann Production Company | Victoria, TX 77903 | Oil & Gas Operator | Mar 2008 |
| 123 | Swift Energy Company | Houston, TX 77060 | Oil & Gas Operator | Mar 2021 |
| 124 | Swift Energy Operating, LLC | Houston, TX 77079 | Oil & Gas Operator | Jun 2017 |
| 125 | Synergy Oil & Gas, Inc. (A) | Houston, TX 77024 | Oil & Gas Operator | Aug 2001 |
| 126 | Tallgrass Energy, L.L.C. | Tulsa, OK 74136 | Oil & Gas Operator | Apr 2024 |
| 127 | Tecpetrol Operating LLC | Houston, TX 77027 | Oil & Gas Operator | Dec 2015 |
| 128 | Texaco E & P Inc | Houston, TX 77099 | Oil & Gas Operator | Apr 2024 |
| 129 | Texakoma E & P, LLC | Plano, TX 75024 | Oil & Gas Operator | Apr 2024 |
| 130 | Texakoma Operating, L.P. | Plano, TX 75024 | Oil & Gas Operator | Apr 2024 |
| 131 | Texas Crude, Inc. | Houston, TX 77256 | Oil & Gas Operator | Oct 1995 |
| 132 | Texas Oil And Gas Operating, LLC | Friendswood, TX 77546 | Oil & Gas Operator | Apr 2024 |
| 133 | Texas Western Energy Corporation | Portland, TX 78374 | Oil & Gas Operator | Nov 2002 |
| 134 | Texron Operating, LLC | Bulverde, TX 78163 | Oil & Gas Operator | Apr 2024 |
| 135 | The Houston Exploration Company | Houston, TX 77002 | Oil & Gas Operator | Apr 2017 |
| 136 | Tri-C Resources, Inc. | Houston, TX 77024 | Oil & Gas Operator | Aug 2009 |
| 137 | Tucker Operating Co., Inc. | Victoria, TX 77903 | Oil & Gas Operator | Apr 2024 |
| 138 | U.S. Enercorp, LLC | San Antonio, TX 78217 | Oil & Gas Operator | Jul 2004 |
| 139 | U.S. Enercorp, LTD. | San Antonio, TX 78209 | Oil & Gas Operator | Sep 2019 |
| 140 | Union Oil Co Of California | Midland, TX 79706 | Oil & Gas Operator | Jan 2022 |
| 141 | Urban Oil & Gas Group, LLC | Plano, TX 75074 | Oil & Gas Operator | Apr 2024 |
| 142 | Vaquero Operating | FT Stockton, TX 79735 | Oil & Gas Operator | Apr 2024 |
| 143 | Wagner & Brown, LTD. | Midland, TX 79702 | Oil & Gas Operator | Aug 2014 |
| 144 | Wapiti Operating, LLC | Houston, TX 77043 | Oil & Gas Operator | Apr 2024 |
| 145 | Westlake Energy Consultants Corp | Thousand Oaks, CA 91362 | Oil & Gas Operator | Aug 2003 |
| 146 | Whittington Operating Company | Houston, TX 77069 | Oil & Gas Operator | Apr 2024 |
| 147 | XTO Energy Inc. | Spring, TX 77389 | Oil & Gas Operator | Apr 2024 |
| 148 | Zenergy Inc | Tulsa, OK 74136 | Oil & Gas Operator | Feb 2024 |