| 31501 | Zilkha Energy Company | Houston, TX 77046 | Oil & Gas Operator | Oct 2002 |
| 31502 | Zilkha Energy Inc | Houston, TX 77002-5223-5223 | Oil & Gas Operator | Dec 2008 |
| 31503 | Zim Energy Corporation | Tulsa, OK 74153 | Oil & Gas Operator | Jan 1998 |
| 31504 | Zimco (Robt A Zimmerman) | Wolf Point, MT 59201 | Oil Operator | Apr 2009 |
| 31505 | Zimet Brothers Inc | | Oil Operator | Mar 2008 |
| 31506 | Zimmerman Oil & Gas Exploration, Inc. | Lovington, NM 88260 | Oil & Gas Operator | Dec 2020 |
| 31507 | Zimmerman, Aaron W. | Penn Yan, NY 14527 | Gas Operator | Dec 2022 |
| 31508 | Zimmerman, IVan L. & Lois N. | Penn Yan, NY 14527 | Gas Operator | Dec 2022 |
| 31509 | Zimmerman, Wayne W. And Pauline R. | Penn Yan, NY 14527 | Gas Operator | Dec 2022 |
| 31510 | Zimtex Energy LLC | | Oil & Gas Operator | Nov 2017 |
| 31511 | Zingara Grimes, LLC | Dallas, TX 75205 | Oil & Gas Operator | Jun 2024 |
| 31512 | Zink Petroleum Corp | Uniontown, OH 44685 | Oil & Gas Operator | Dec 1993 |
| 31513 | Zinke & Trumbo L | | Oil & Gas Operator | Nov 2000 |
| 31514 | Zinke & Trumbo LTD | Tulsa, OK 74105 | Oil & Gas Operator | Sep 2017 |
| 31515 | Zinke & Trumbo, Inc. | Tulsa, OK 74136 | Oil & Gas Operator | Mar 2007 |
| 31516 | Zinn Petroleum Co. | Houston, TX 77024 | Oil & Gas Operator | Nov 2021 |
| 31517 | Zinszer Oil Co., Inc. | Hays, KS 67601 | Oil Operator | Dec 2019 |
| 31518 | Zinszer Oil Comp | | Oil Operator | Aug 1985 |
| 31519 | Zion Energy Corporation | Peru, KS 67360-0082 | Oil Operator | Aug 2000 |
| 31520 | Zittel, Kenneth D. | Springville, NY 14141 | Gas Operator | Dec 2022 |
| 31521 | Zivney Energy | White Oak, TX 75693 | Oil & Gas Operator | Jun 2024 |
| 31522 | ZK Petroleum Co., L.L.C. | Houston, TX 77057 | Oil Operator | Jun 2024 |
| 31523 | Zlab, Adolph | Yates Center, KS 66783 | Oil Operator | Jul 1997 |
| 31524 | Zlomek, John | Belmont, NY 14813 | Oil & Gas Operator | Dec 2022 |
| 31525 | Zoandra Petroleu | | Oil & Gas Operator | May 1993 |
| 31526 | Zoe Oil & Energy, LP | Fort Worth, TX 76148 | Oil & Gas Operator | Jun 2024 |
| 31527 | Zoller & Danneberg Inc | Denver, CO 80203 | Oil & Gas Operator | May 1975 |
| 31528 | Zollinger Veldon | Cresent, OK 73028 | Oil & Gas Operator | Apr 2009 |
| 31529 | Zollinger Veldon Inc | Crescent, OK 73028-9280 | Oil & Gas Operator | Nov 2018 |
| 31530 | Zonal Holding Corp. | | Oil Operator | Dec 1998 |
| 31531 | Zone Energy, LLC | Houston, TX 77251 | Oil & Gas Operator | Dec 2023 |
| 31532 | Zoran Oil & Gas | Jefferson, OH 44047 | Oil & Gas Operator | Dec 2011 |
| 31533 | Zoran Oil & Gas Co | Jefferson, OH 44047 | Oil & Gas Operator | Dec 2023 |
| 31534 | Zorger, Gerald W. | Wichita, KS 67202 | Oil & Gas Operator | Apr 1985 |
| 31535 | Zorra Oil & Gas | Dilley, TX 78017 | Oil & Gas Operator | Jun 2024 |
| 31536 | ZP Disposal Systems LLC | Kingfisher, OK 73750-7084 | Oil Operator | Mar 2024 |
| 31537 | ZSX, Inc. | Corsicana, TX 75110 | Oil & Gas Operator | Jul 1997 |
| 31538 | ZTC Petro Investments LP | Houston, TX 77056 | Oil & Gas Operator | May 2020 |
| 31539 | ZTH Operating, LLC | Arp, TX 75750 | Oil & Gas Operator | Jun 2024 |
| 31540 | Zu, LLC | Hays, KS 67601 | Oil Operator | Dec 2019 |
| 31541 | Zuhone William H | Mattoon, IL 61938-4019 | Oil & Gas Operator | Jan 2015 |
| 31542 | Zukowski, Eve | Springville, NY 14141 | Gas Operator | Dec 2022 |
| 31543 | Zumyers Inc | Newalla, OK 74857-0259 | Oil Operator | Apr 2003 |
| 31544 | Zynergy LLC | | Oil Operator | Mar 2024 |
| 31545 | ZZ Energy LLC | Norman, OK 73070-4531 | Gas Operator | Feb 2024 |
| 31546 | Zzron Inc. | Midland, TX 79704 | Oil & Gas Operator | Aug 2003 |