| 601 | White Star Petroleum LLC | Oklahoma City, OK 73116-7906 | Oil & Gas Operator | Dec 2024 |
| 602 | Whiting Oil And Gas Corporation | Houston, TX 77002 | Oil & Gas Operator | Mar 2025 |
| 603 | Whitmar Exploration Company | Denver, CO 80202 | Oil & Gas Operator | Dec 2024 |
| 604 | Whitmar Natural Resources Co | Tulsa, OK 74136-9998 | Oil & Gas Operator | Jun 2004 |
| 605 | Whitmar Operating Company | Tulsa, OK 74103-3515 | Oil & Gas Operator | Apr 2009 |
| 606 | Wildhorse Operating Company | Ardmore, OK 73402 | Oil & Gas Operator | Mar 2025 |
| 607 | Williford Energy Company | Tulsa, OK 74135 | Oil & Gas Operator | Mar 2025 |
| 608 | Windsor Energy Group LLC | Oklahoma City, OK 73118 | Oil & Gas Operator | Aug 2021 |
| 609 | Wise James W | Okmulgee, OK 74447 | Oil & Gas Operator | Oct 1996 |
| 610 | WM KS Energy Resources LLC | Shreveport, LA 71101 | Oil & Gas Operator | Nov 2019 |
| 611 | WN Operating Inc | Okmulgee, OK 74447 | Oil & Gas Operator | Dec 2024 |
| 612 | Wolverine Exploration Company | Houston, TX 77002 | Oil & Gas Operator | May 2019 |
| 613 | Woods Petroleum Corporation | Oklahoma City, OK 73112 | Oil & Gas Operator | Mar 2015 |
| 614 | WR Oil & Gas LLC | Plano, TX 75024-3523 | Oil & Gas Operator | Jan 2025 |
| 615 | Wroten Wiley Jr | Dallas, TX 75252 | Oil & Gas Operator | Jun 1994 |
| 616 | Xanadu Exploration Company | Broken Arrow, OK 74014 | Oil & Gas Operator | Jan 2025 |
| 617 | Xeric Oil & Gas Corporation | Midland, TX 79702 | Oil & Gas Operator | Apr 2014 |
| 618 | Yale Oil Association, Inc. | Oklahoma City, OK 73105 | Oil & Gas Operator | Jan 2025 |
| 619 | Z G Exploration Inc | Oklahoma City, OK 73112 | Oil & Gas Operator | Feb 2005 |
| 620 | Zenergy Inc | Tulsa, OK 74136 | Oil & Gas Operator | Jan 2025 |
| 621 | Zephyr Operating Co LLC | Oklahoma City, OK 73118-6035 | Oil & Gas Operator | Jan 2025 |
| 622 | Zimtex Energy LLC | Perryton, TX 79070-5818 | Oil & Gas Operator | Nov 2017 |
| 623 | Zinke & Trumbo LTD | Tulsa, OK 74105 | Oil & Gas Operator | Sep 2017 |