| 1 | Kaiser-Francis Oil Company | Tulsa, OK 74121 | Oil & Gas Operator | Oct 2025 |
| 2 | Kaneb Energy Company | | Oil & Gas Operator | Jan 1986 |
| 3 | Kaneb Oil & Gas Company | | Oil & Gas Operator | Nov 1985 |
| 4 | Kaneb Operg Co. LTD. PTN. | | Oil & Gas Operator | Aug 1988 |
| 5 | Kash Oil And Gas, Inc | | Oil & Gas Operator | Oct 2020 |
| 6 | Kelly H. Baxter | Austin, TX 78767 | Oil & Gas Operator | Nov 2006 |
| 7 | Kerr-McGee Corporation | Dallas, TX 75380 | Oil & Gas Operator | May 2025 |
| 8 | Kerr-McGee Oil & Gas Onshore LP | Houston, TX 77046 | Oil & Gas Operator | Oct 2025 |
| 9 | Kerr-McGee Oil & Gas Onshr LLC | | Oil & Gas Operator | Dec 2005 |
| 10 | Kerr-McGee Rocky Mountain Corp | Denver, CO 80202 | Oil & Gas Operator | Jan 2007 |
| 11 | Key Operating Co., Inc. | Duncan, OK 73534-1284 | Oil & Gas Operator | Jan 2025 |
| 12 | Kilmarnock Oil Company, Inc. | Corsicana, TX 75110 | Oil & Gas Operator | Oct 2025 |
| 13 | Kimball Production Co. | Houston, TX 77042 | Oil & Gas Operator | Jul 2002 |
| 14 | King Ranch Oil & Gas, Inc. | Houston, TX 77002 | Oil & Gas Operator | Dec 1997 |
| 15 | King Resources Co. | | Oil & Gas Operator | Dec 1977 |
| 16 | Koch Gateway Pipeline Company | | Oil & Gas Operator | Feb 2001 |