| 201 | T-M Well Service | Jefferson, TX 75657 | Oil & Gas Operator | Sep 2004 |
| 202 | T-M Well Service, L.L.C. | Jefferson, TX 75657 | Oil & Gas Operator | Dec 2024 |
| 203 | T. And M. Production | Oil City, LA 71061 | Oil & Gas Operator | Apr 2026 |
| 204 | Talus Inc | Graham, TX 76450-1210 | Oil & Gas Operator | Feb 2017 |
| 205 | Tamarack Petroleum Company, Inc. | Midland, TX 79701 | Oil & Gas Operator | Apr 2026 |
| 206 | Tanos Exploration II, LLC | Tyler, TX 75701 | Oil & Gas Operator | Sep 2023 |
| 207 | Te-Ray Resources, LLC | Oklahoma City, OK 73142 | Oil & Gas Operator | Apr 2026 |
| 208 | Tepee Petroleum Company, Inc. | Houston, TX 77098 | Oil & Gas Operator | Feb 2014 |
| 209 | Texxol Operating Company, Inc. | Fort Worth, TX 76108 | Oil & Gas Operator | Apr 2026 |
| 210 | Three Sisters Petroleum, Inc. | Oil City, LA 71061 | Oil & Gas Operator | Jan 2025 |
| 211 | Thunderbird (Texas) Resources LP | Edmond, OK 73025 | Oil & Gas Operator | Apr 2019 |
| 212 | Tidemark Exploration Inc | Tulsa, OK 74120 | Oil & Gas Operator | Apr 2019 |
| 213 | Torrent Oil LLC | Houston, TX 77002 | Oil & Gas Operator | Apr 2026 |
| 214 | Tracer Energy, Inc. | Graham, TX 76450 | Oil & Gas Operator | Nov 1998 |
| 215 | Tracy Production | Lindale, TX 75771 | Oil & Gas Operator | Apr 2026 |
| 216 | Trek Resources, Inc. | Dallas, TX 75207 | Oil & Gas Operator | Apr 2026 |
| 217 | Tri-State Sales & Production | Rodessa, LA 71069 | Oil & Gas Operator | Dec 2008 |
| 218 | Tri-Union Development Corp. | Houston, TX 77002 | Oil & Gas Operator | Apr 2026 |
| 219 | United Petroleum & Gas, Inc. | Kilgore, TX 75663 | Oil & Gas Operator | Apr 2026 |
| 220 | Uptex Operating Inc. | Dallas, TX 75201 | Oil & Gas Operator | May 2011 |
| 221 | Uptex Operating, L.P. | Dallas, TX 75201 | Oil & Gas Operator | May 2010 |
| 222 | Valence Operating Company | Kingwood, TX 77339 | Oil & Gas Operator | Apr 2026 |
| 223 | Vanco Oil & Gas Corp. | Abilene, TX 79604 | Oil & Gas Operator | Apr 2026 |
| 224 | Vess Oil Corporation | Dallas, TX 75201 | Oil & Gas Operator | Apr 2026 |
| 225 | Vintage Petroleum, Inc. | Houston, TX 77046 | Oil & Gas Operator | Jan 2026 |
| 226 | Vista Resources, Inc. (A) | Midland, TX 79701 | Oil & Gas Operator | Feb 2000 |
| 227 | Wagner, Duer & Co. | Fort Worth, TX 76102 | Oil & Gas Operator | Jan 1999 |
| 228 | West Mountain Operating Co, Inc. | Longview, TX 75604 | Oil & Gas Operator | Feb 2019 |
| 229 | Whatley, O. B. | Kilgore, TX 75662 | Oil & Gas Operator | Jun 1993 |
| 230 | Whatley, O.B. Oil Company, Inc. | Bivins, TX 75555 | Oil & Gas Operator | Apr 2026 |
| 231 | Will-Drill Production Co., Inc. | Shreveport, LA 71105 | Oil & Gas Operator | Apr 2026 |
| 232 | Williamson Oil & Gas, Inc. | Shreveport, LA 71166 | Oil & Gas Operator | Dec 2024 |
| 233 | Williamson Operating Co., LLC | Stamps, AR 71860 | Oil & Gas Operator | Apr 2026 |
| 234 | Wilson Energy Resources LLC | Graham, TX 76450 | Oil Operator | Apr 2026 |
| 235 | XTO Energy Inc. | Spring, TX 77389 | Oil & Gas Operator | Apr 2026 |
| 236 | Zadeck Energy Group | Shreveport, LA 71101 | Oil & Gas Operator | Dec 2011 |