| 401 | Triumph Resources Inc | Oklahoma City, OK 73114 | Oil & Gas Operator | Nov 2004 |
| 402 | Trout Disposal Well Inc | Hammon, OK 73650-0292 | Oil & Gas Operator | Jul 2016 |
| 403 | Tucker Ron & Co | Norman, OK 73069-8511 | Gas Operator | Sep 2017 |
| 404 | Txo Production Corp. | Ganado, TX 77962 | Oil & Gas Operator | Aug 2022 |
| 405 | Txok Energy Resources Company | Tulsa, OK 74172-0140 | Oil & Gas Operator | Feb 2017 |
| 406 | Umc Petroleum Corporation | Houston, TX 77002 | Oil & Gas Operator | Mar 2015 |
| 407 | Union Oil Co Of California | Midland, TX 79706 | Oil & Gas Operator | Jan 2022 |
| 408 | Unit Drilling & Exploration Co | Tulsa, OK 74132-5300 | Oil & Gas Operator | Dec 2023 |
| 409 | Unit Petroleum Company | Tulsa, OK 74170 | Oil & Gas Operator | May 2024 |
| 410 | Universal Drilling Co., Inc. | Denver, CO 80203 | Oil & Gas Operator | Sep 2003 |
| 411 | Vastar Resources Inc | Houston, TX 77253 | Oil & Gas Operator | Jan 2024 |
| 412 | Vintage Gas Inc | Tulsa, OK 74119-1029 | Oil & Gas Operator | Jun 2007 |
| 413 | Vintage Petroleum, Inc. | Houston, TX 77046 | Oil & Gas Operator | Jan 2024 |
| 414 | W S Crude Oil Purchasing Inc | Oklahoma City, OK 73129-7613 | Oil & Gas Operator | May 2008 |
| 415 | Wagner Oil Company | Fort Worth, TX 76102 | Oil & Gas Operator | May 2024 |
| 416 | Ward Petroleum Corporation | Enid, OK 73702 | Oil & Gas Operator | Jan 2024 |
| 417 | Wentworth Operating Company | Oklahoma City, OK 73162-1863 | Oil & Gas Operator | Mar 2024 |
| 418 | Western Oil And Gas Development Corp | Oklahoma City, OK 73103-3735 | Oil & Gas Operator | Feb 2024 |
| 419 | WFD Oil Corporation | Edmond, OK 73012-0619 | Oil & Gas Operator | Feb 2024 |
| 420 | Wheeler Energy Co. | Tulsa, OK 74101 | Oil & Gas Operator | Jan 2024 |
| 421 | Wheeler Energy, LLC | Tulsa, OK 74101 | Oil & Gas Operator | May 2024 |
| 422 | White Wolf Energy LLC | | Oil & Gas Operator | Oct 2022 |
| 423 | Whitmar Exploration Company | Denver, CO 80202 | Oil & Gas Operator | Jan 2024 |
| 424 | Whitmar Natural Resources Co | Tulsa, OK 74136-9998 | Oil & Gas Operator | Jun 2004 |
| 425 | Whitmar Operating Company | Tulsa, OK 74103-3515 | Oil & Gas Operator | Apr 2009 |
| 426 | Wildhorse Operating Company | Ardmore, OK 73402 | Oil & Gas Operator | May 2024 |
| 427 | Williford Energy Company | Tulsa, OK 74135 | Oil & Gas Operator | May 2024 |
| 428 | Williford Petroleum LLC | Green CV SPGS, FL 32043 | Oil & Gas Operator | May 2024 |
| 429 | Windward Development LLC | Tulsa, OK 74136-7007 | Oil & Gas Operator | Jul 2019 |
| 430 | Wohlford Properties Inc | | Gas Operator | Apr 2022 |
| 431 | Wolf Howard Lee | Burneyville, OK 73430-9617 | Oil & Gas Operator | Jun 2000 |
| 432 | Wolverine Exploration Company | Houston, TX 77002 | Oil & Gas Operator | May 2019 |
| 433 | Wood Oil Company | Tulsa, OK 74103 | Gas Operator | Oct 1997 |
| 434 | Woodward Iodine Corporation | Woodward, OK 73802-1245 | Oil & Gas Operator | Feb 2024 |
| 435 | WPX Energy Mid-Continent Co | Oklahoma City, OK 73102-5010 | Oil & Gas Operator | Apr 2016 |
| 436 | Wynn-Crosby Operating LP | Dallas, TX 75201 | Oil & Gas Operator | Jan 2024 |
| 437 | Wytex Production Corporation | Fort Smith, AR 72903 | Oil & Gas Operator | Jan 2020 |
| 438 | Xeric Oil & Gas Corporation | Midland, TX 79702 | Oil & Gas Operator | Apr 2014 |
| 439 | Xog Operating LLC | Midland, TX 79702 | Oil & Gas Operator | May 2024 |
| 440 | XTO Energy Inc. | Spring, TX 77389 | Oil & Gas Operator | May 2024 |
| 441 | Z G Exploration Inc | Oklahoma City, OK 73112 | Oil & Gas Operator | Feb 2005 |
| 442 | Zeiders Bros Oil & Gas Co LLC | Edmond, OK 73003 | Oil & Gas Operator | Jan 2024 |
| 443 | Zimet Brothers Inc | | Oil Operator | Mar 2008 |
| 444 | Zinke & Trumbo LTD | Tulsa, OK 74105 | Oil & Gas Operator | Sep 2017 |