| 301 | Wagner Oil Company | Fort Worth, TX 76102 | Oil & Gas Operator | Oct 2025 |
| 302 | Wainoco Oil & Gas Company | Houston, TX 77024 | Oil & Gas Operator | Dec 2005 |
| 303 | Warner Sisters, LLC | Thompsons Sta, TN 37179 | Oil Operator | Oct 2025 |
| 304 | Waters Eng. & Operating, Inc. | Corpus Chrsti, TX 78471 | Oil & Gas Operator | Sep 2013 |
| 305 | Weatherston, George D. | San Antonio, TX 78217 | Oil & Gas Operator | Oct 2001 |
| 306 | Williams, Clayton Energy, Inc. | Houston, TX 77070 | Oil & Gas Operator | Oct 2025 |
| 307 | Williams-Cody, Inc. | Houston, TX 77060 | Oil & Gas Operator | May 1994 |
| 308 | Wilson Hydrocarbon Inc. | Houston, TX 77066 | Oil & Gas Operator | Oct 2025 |
| 309 | Winn Exploration Co., Inc. | Corpus Chrsti, TX 78401 | Oil & Gas Operator | Oct 2025 |
| 310 | WTXR Operating (Texas), Inc. | Carrollton, TX 75007 | Oil Operator | Oct 2025 |
| 311 | Wynn-Crosby Operating, LTD. | Dallas, TX 75201 | Oil & Gas Operator | Oct 2025 |
| 312 | XCL-Texas, Inc. | Lafayette, LA 70503 | Oil & Gas Operator | Nov 2000 |
| 313 | XTO Energy Inc. | Spring, TX 77389 | Oil & Gas Operator | Oct 2025 |
| 314 | Zachry Exploration, Inc. | San Antonio, TX 78205 | Oil & Gas Operator | Oct 2025 |
| 315 | Zachry Exploration, LLC | San Antonio, TX 78224 | Oil & Gas Operator | Oct 2025 |
| 316 | Zachry Exploration, LTD. | San Antonio, TX 78205 | Oil & Gas Operator | Jan 2009 |
| 317 | Zachry, H. B. Company | San Antonio, TX 78205 | Oil & Gas Operator | Apr 1994 |
| 318 | Zinn Petroleum Co. | Houston, TX 77024 | Oil & Gas Operator | Nov 2021 |