| 501 | Whittier Operating Inc. | Houston, TX 77002 | Oil & Gas Operator | May 2007 |
| 502 | Williams Prod. Gulf Coast, L.P. | Benbrook, TX 76126 | Oil & Gas Operator | Jan 2012 |
| 503 | Willowbend Investments, Inc. | Wichita Falls, TX 76307 | Oil & Gas Operator | Apr 2025 |
| 504 | Wilson Exploration Co. | Fort Worth, TX 76102 | Oil & Gas Operator | Jul 1996 |
| 505 | Winchester Oil & Gas LLC | Katy, TX 77449 | Oil Operator | Apr 2025 |
| 506 | Winfield Operating Company | Dallas, TX 75214 | Oil & Gas Operator | Apr 2025 |
| 507 | Wise Exploration | Perrin, TX 76486 | Oil & Gas Operator | Apr 2025 |
| 508 | Wise Production Company | Bowie, TX 76230 | Oil & Gas Operator | Apr 2025 |
| 509 | Wise Well Service | Bowie, TX 76230 | Oil & Gas Operator | Jul 2017 |
| 510 | World Producers, Inc. | Dallas, TX 75201 | Oil & Gas Operator | Nov 1994 |
| 511 | WPX Energy Gulf Coast, LP | Benbrook, TX 76126 | Oil & Gas Operator | May 2012 |
| 512 | Wy Woodland Operating, LLC | Covington, TX 76636 | Oil & Gas Operator | Apr 2025 |
| 513 | Xplore Operating, LLC | Arlington, TX 76001 | Oil & Gas Operator | Apr 2025 |
| 514 | XTO Energy Inc. | Spring, TX 77389 | Oil & Gas Operator | Apr 2025 |
| 515 | Young Resources, Inc. | Fort Worth, TX 76102 | Oil & Gas Operator | Aug 1999 |
| 516 | Young, L. M. | Brownwood, TX 76804 | Oil & Gas Operator | Aug 2003 |
| 517 | Young, Marshall R., Oil Co. | Fort Worth, TX 76107 | Oil & Gas Operator | Mar 2011 |