| 1 | K-B Exploration Co. | Houston, TX 77057 | Oil & Gas Operator | Oct 2025 |
| 2 | Kaiser-Francis Oil Company | Tulsa, OK 74121 | Oil & Gas Operator | Oct 2025 |
| 3 | Kaneb Energy Company | | Oil & Gas Operator | Jan 1986 |
| 4 | Kaneb Operg Co. LTD. PTN. | | Oil & Gas Operator | Aug 1988 |
| 5 | Kash Oil And Gas, Inc | | Oil & Gas Operator | Oct 2020 |
| 6 | KCS Medallion Resources, Inc. | Tulsa, OK 74136 | Oil & Gas Operator | Nov 2018 |
| 7 | KCS Resources, Inc. | Houston, TX 77002 | Oil & Gas Operator | Feb 2009 |
| 8 | Kelley Oil Corp/Yuma Petroleum | | Gas Operator | Jun 1994 |
| 9 | Kelley Oil Corporation | Houston, TX 77002 | Oil & Gas Operator | Jan 2002 |
| 10 | Kelly H. Baxter | Austin, TX 78767 | Oil & Gas Operator | Nov 2006 |
| 11 | Kerr-McGee Rocky Mountain Corp | Denver, CO 80202 | Oil & Gas Operator | Jan 2007 |
| 12 | Key Operating Co., Inc. | Duncan, OK 73534-1284 | Oil & Gas Operator | Jan 2025 |
| 13 | Keystone Exploration, Inc | College Sta, TX 77845 | Oil & Gas Operator | Oct 2025 |
| 14 | Kilroy Co. Of Texas, Inc. | | Oil & Gas Operator | Jun 1991 |
| 15 | KJ Energy, LLC Of Delaware | | Oil & Gas Operator | Nov 2016 |
| 16 | Koch Gateway Pipeline Company | | Oil & Gas Operator | Feb 2001 |
| 17 | Kraker & Martin Energy, L.L.C. | Tulsa, OK 74136 | Oil & Gas Operator | Apr 2011 |
| 18 | Kriti Te Energy, Inc | Houston, TX 77079 | Oil & Gas Operator | Oct 2017 |