| 301 | Western Chief Operating, L.L.C. | Graham, TX 76450 | Oil & Gas Operator | Apr 2024 |
| 302 | Westland Oil Development Corp. | Conroe, TX 77305 | Oil & Gas Operator | Mar 2008 |
| 303 | Wheeler Operating Corporation | Fort Worth, TX 76101 | Oil & Gas Operator | Apr 2024 |
| 304 | Will-Drill Production Co., Inc. | Shreveport, LA 71105 | Oil & Gas Operator | Apr 2024 |
| 305 | Williams, Clayton W., Jr., Inc. | Midland, TX 79705 | Oil & Gas Operator | Mar 2008 |
| 306 | Wilson Hydrocarbon Inc. | Houston, TX 77066 | Oil & Gas Operator | Apr 2024 |
| 307 | Wilson, Don H., Inc. | Elkhart, TX 75839 | Oil & Gas Operator | May 2019 |
| 308 | Wing Corporation | Houston, TX 77002 | Oil & Gas Operator | Jun 2000 |
| 309 | Winn Exploration Co., Inc. | Corpus Chrsti, TX 78401 | Oil & Gas Operator | Apr 2024 |
| 310 | Xeric Oil & Gas Corporation | Midland, TX 79702 | Oil & Gas Operator | Apr 2014 |
| 311 | XTO Energy Inc. | Spring, TX 77389 | Oil & Gas Operator | Apr 2024 |