| 201 | Tryvest, Inc. | | Oil & Gas Operator | Sep 1991 |
| 202 | Turnkey E&P Corporation | | Oil & Gas Operator | Dec 2010 |
| 203 | Union Gas Operating Company | Spring, TX 77391 | Oil & Gas Operator | Feb 2026 |
| 204 | Unit Petroleum Company | Tulsa, OK 74170 | Oil & Gas Operator | Feb 2026 |
| 205 | United Gas Pipe Line Co. | | Oil Operator | Aug 1993 |
| 206 | Urban Oil & Gas Group, LLC | Plano, TX 75074 | Oil & Gas Operator | Feb 2026 |
| 207 | Vernon E. Faulconer, Inc. | Tyler, TX 75711 | Oil & Gas Operator | Dec 2024 |
| 208 | Vinbar Oil & Gas, LLC | | Oil & Gas Operator | Jan 2018 |
| 209 | Vintage Petroleum, Inc. | Houston, TX 77046 | Oil & Gas Operator | Oct 2025 |
| 210 | Wainoco Oil & Gas Company | Houston, TX 77024 | Oil & Gas Operator | Dec 2005 |
| 211 | Warhorse Oil & Gas, LLC | | Oil & Gas Operator | Dec 2018 |
| 212 | Wes-Tex Drilling Company | Abilene, TX 79604 | Oil & Gas Operator | Jan 2000 |
| 213 | White Oak Operating Company LLC | Houston, TX 77077 | Oil & Gas Operator | Feb 2026 |
| 214 | Will-Drill Operating, L.L.C. | Shreveport, LA 71105 | Oil & Gas Operator | Feb 2026 |
| 215 | Will-Drill Production Co., Inc. | Shreveport, LA 71105 | Oil & Gas Operator | Feb 2026 |
| 216 | Windrush Operating Co., L.L.C. | Longville, LA 70652 | Oil & Gas Operator | Feb 2026 |
| 217 | Windrush Operating Company | | Oil & Gas Operator | Jan 2009 |
| 218 | Woods Petroleum Corporation | Oklahoma City, OK 73112 | Oil & Gas Operator | Mar 2015 |
| 219 | Woolf & Magee, Inc. | | Oil & Gas Operator | Oct 1991 |
| 220 | Zachry Exploration, Inc. | San Antonio, TX 78205 | Oil & Gas Operator | Feb 2026 |
| 221 | Zachry Exploration, LLC | San Antonio, TX 78224 | Oil & Gas Operator | Feb 2026 |
| 222 | Zachry Exploration, LTD. | San Antonio, TX 78205 | Oil & Gas Operator | Jan 2009 |