| Company Name | Company Location | Company Type | Most Recent Production | |
|---|---|---|---|---|
| 601 | WRT Energy Corporation | Oklahoma City, OK 73118 | Oil & Gas Operator | May 1998 |
| 602 | Xplor Energy Operating Co. | Houston, TX 77079 | Oil & Gas Operator | Jan 2012 |
| 603 | XTO Energy Inc. | Spring, TX 77389 | Oil & Gas Operator | Jul 2025 |
| 604 | Yentzen Investments, Inc. | Sugar Land, TX 77478 | Oil Operator | May 1993 |
| 605 | Zadeck Energy Group Inc | Oil & Gas Operator | Dec 2011 | |
| 606 | Zenergy Inc | Tulsa, OK 74136 | Oil & Gas Operator | May 2025 |
| 607 | Zinn Petroleum Co. | Houston, TX 77024 | Oil & Gas Operator | Nov 2021 |