| 501 | Warren American Oil Company LLC | Tulsa, OK 74147 | Oil & Gas Operator | Apr 2025 |
| 502 | Warrior Exploration LLC | Sapulpa, OK 74067-1912 | Oil & Gas Operator | Dec 2024 |
| 503 | Westland Oil Development Corp. | Conroe, TX 77305 | Oil & Gas Operator | Mar 2008 |
| 504 | Westport Oil & Gas Company LP | The Woodlands, TX 77380 | Oil & Gas Operator | Feb 2007 |
| 505 | Weststar Oil & Gas Inc | Edmond, OK 73013 | Oil & Gas Operator | Feb 2025 |
| 506 | WG Oil, LLC | Wichita Falls, TX 76308 | Oil Operator | Apr 2025 |
| 507 | White Rock Oil & Gas, LLC | Plano, TX 75024 | Oil & Gas Operator | Apr 2025 |
| 508 | White Stride LLC | Piedmont, OK 73078 | Oil & Gas Operator | Apr 2025 |
| 509 | Whiting Oil And Gas Corporation | Houston, TX 77002 | Oil & Gas Operator | Apr 2025 |
| 510 | Whiting Petroleum Corporation | Denver, CO 80290 | Oil & Gas Operator | Jan 2025 |
| 511 | Wilbanks Exploration, Inc. | Denver, CO 80202 | Oil & Gas Operator | May 2002 |
| 512 | Wilbanks Reserve Corporation | Denver, CO 80203 | Oil & Gas Operator | Apr 2025 |
| 513 | Williamson, J. C. | Midland, TX 79701 | Oil & Gas Operator | Jan 2001 |
| 514 | Williamson, Ralph E. | Midland, TX 79702 | Oil & Gas Operator | Jan 2012 |
| 515 | Wilson Operating Service Inc | Brownfield, TX 79316 | Oil & Gas Operator | Aug 2003 |
| 516 | Wilson, Don H., Inc. | Elkhart, TX 75839 | Oil & Gas Operator | May 2019 |
| 517 | Windy Cove Energy II, LLC | Houston, TX 77079 | Oil & Gas Operator | Sep 2020 |
| 518 | Wiser Oil Co | Denver, CO 80202 | Oil & Gas Operator | Dec 2023 |
| 519 | Wishbone Texas Operating Co LLC | Houston, TX 77064 | Oil & Gas Operator | Jul 2019 |
| 520 | Woodbine Production Corporation | Kilgore, TX 75663 | Oil & Gas Operator | Apr 2025 |
| 521 | WTG Exploration Inc | Midland, TX 79705 | Oil & Gas Operator | Dec 2023 |
| 522 | Wynn-Crosby Energy, Inc. | Houston, TX 77002 | Oil & Gas Operator | May 2005 |
| 523 | Xog Operating LLC | Midland, TX 79702 | Oil & Gas Operator | Apr 2025 |
| 524 | XTO Energy Inc. | Spring, TX 77389 | Oil & Gas Operator | Apr 2025 |
| 525 | Young, Marshall R., Oil Co. | Fort Worth, TX 76107 | Oil & Gas Operator | Mar 2011 |
| 526 | Yucca Energy, Inc. | Midland, TX 79702 | Oil & Gas Operator | Apr 2025 |
| 527 | Yuma E & P Company, Inc. | Houston, TX 77027 | Oil & Gas Operator | Apr 2025 |