| 601 | Wallis Energy, Inc. | Austin, TX 78746 | Oil & Gas Operator | Apr 2024 |
| 602 | Warbonnet Exploration Company | Houston, TX 77056 | Oil & Gas Operator | Apr 2016 |
| 603 | Waters Eng. & Operating, Inc. | Corpus Chrsti, TX 78471 | Oil & Gas Operator | Sep 2013 |
| 604 | Weaver & Sharp | Corpus Chrsti, TX 78403 | Oil & Gas Operator | Mar 1997 |
| 605 | Weeks Exploration Company | Houston, TX 77063 | Oil & Gas Operator | Aug 1995 |
| 606 | Welhausen Operating Co., Inc. | Beeville, TX 78104 | Oil & Gas Operator | Aug 2003 |
| 607 | Welhausen Operating Company, LP | Beeville, TX 78104 | Oil & Gas Operator | Nov 2016 |
| 608 | West Petroleum Corp. | San Antonio, TX 78205 | Oil & Gas Operator | Oct 2009 |
| 609 | Westport Oil & Gas Company LP | The Woodlands, TX 77380 | Oil & Gas Operator | Feb 2007 |
| 610 | White Marlin Operating Company, LLC | Houston, TX 77002 | Oil & Gas Operator | Apr 2024 |
| 611 | White Oak Operating Company LLC | Houston, TX 77077 | Oil & Gas Operator | Apr 2024 |
| 612 | Whiting Petroleum Corporation | Denver, CO 80290 | Oil & Gas Operator | Feb 2024 |
| 613 | Whittier Operating Inc. | Houston, TX 77002 | Oil & Gas Operator | May 2007 |
| 614 | Wilbanks, Bruce A. Company | Midland, TX 79702 | Oil & Gas Operator | Apr 2024 |
| 615 | Wilmoth Interests, Inc. | Marion Center, PA 15759 | Oil & Gas Operator | Dec 2023 |
| 616 | Wilson Hydrocarbon Inc. | Houston, TX 77066 | Oil & Gas Operator | Apr 2024 |
| 617 | Winchester Production Company | Shreveport, LA 71129 | Oil & Gas Operator | Nov 2008 |
| 618 | Wiseman, B. W., Jr. | Midland, TX 79702 | Oil & Gas Operator | Dec 2002 |
| 619 | World Energy Corporation | Laredo, TX 78041 | Oil & Gas Operator | Aug 2003 |
| 620 | Wright Brothers Energy, Inc. | Boerne, TX 78006 | Oil & Gas Operator | Apr 2024 |
| 621 | Wright Brothers Petroleum, LTD. | San Antonio, TX 78212 | Oil & Gas Operator | May 2002 |
| 622 | XCL-Texas, Inc. | Lafayette, LA 70503 | Oil & Gas Operator | Nov 2000 |
| 623 | Xeric Oil & Gas Corporation | Midland, TX 79702 | Oil & Gas Operator | Apr 2014 |
| 624 | Xog Operating LLC | Midland, TX 79702 | Oil & Gas Operator | Apr 2024 |
| 625 | XTO Energy Inc. | Spring, TX 77389 | Oil & Gas Operator | Apr 2024 |
| 626 | Yarborough Oil & Gas L.P. | Midland, TX 79701 | Oil & Gas Operator | Oct 2000 |
| 627 | Yarborough, W. B. | Midland, TX 79701 | Oil & Gas Operator | Nov 1995 |
| 628 | Zachry Exploration, Inc. | San Antonio, TX 78205 | Oil & Gas Operator | Apr 2024 |
| 629 | Zachry Exploration, LLC | San Antonio, TX 78224 | Oil & Gas Operator | Apr 2024 |
| 630 | Zachry Exploration, LTD. | San Antonio, TX 78205 | Oil & Gas Operator | Jan 2009 |
| 631 | Zaf Oil | San Antonio, TX 78230 | Oil & Gas Operator | Aug 2002 |
| 632 | Zone Energy, LLC | Houston, TX 77251 | Oil & Gas Operator | Dec 2023 |