| 1 | D. B. McClinton | | Oil & Gas Operator | Jun 1992 |
| 2 | D. C. Bintliff Et Al | | Oil & Gas Operator | Feb 1987 |
| 3 | D90 Energy, LLC | Houston, TX 77024 | Oil & Gas Operator | Oct 2025 |
| 4 | Damian Oil, Inc. | | Oil & Gas Operator | Dec 2024 |
| 5 | Damson Oil Corporation | Houston, TX 77210 | Oil & Gas Operator | Mar 2005 |
| 6 | Damson-Franks-McCord-Goodrich | | Oil & Gas Operator | Aug 1984 |
| 7 | Daniel Oil Company | | Oil & Gas Operator | Jan 1983 |
| 8 | Dant Operating Company Inc. | | Oil & Gas Operator | Jan 1989 |
| 9 | Dardan Expl Inc-H Edison Ellis | | Oil & Gas Operator | Apr 1990 |
| 10 | Darsey Operating Corporation | | Oil & Gas Operator | Sep 1990 |
| 11 | Davis Petroleum Corp. | Houston, TX 77027 | Oil & Gas Operator | Oct 2025 |
| 12 | Daylight Petroleum LLC | Houston, TX 77052 | Oil & Gas Operator | Oct 2025 |
| 13 | DBL DRLG.&Prod. Services, Inc. | | Oil & Gas Operator | Jul 1997 |
| 14 | Delta Energy Resources, Inc. | | Oil & Gas Operator | Jun 1990 |
| 15 | Delta Petroleum Corp Of Co | | Oil & Gas Operator | Oct 2010 |
| 16 | Delta Petroleum Inc | Houston, TX 77269-1007 | Oil & Gas Operator | May 2009 |
| 17 | Denovo Oil & Gas, Inc. | Houston, TX 77210 | Oil & Gas Operator | May 1995 |
| 18 | Devon Louisiana Corporation | Houston, TX 77002 | Oil & Gas Operator | Oct 2019 |
| 19 | Dew Oil And Gas Co.,Inc. | | Oil & Gas Operator | Dec 1989 |
| 20 | Drew Cornell, Inc. | | Oil & Gas Operator | Jun 1992 |
| 21 | Duer Wagner & Company | Fort Worth, TX 76102 | Oil & Gas Operator | Dec 1998 |
| 22 | Duncan Energy Company | Denver, CO 80202 | Oil & Gas Operator | Mar 2008 |
| 23 | Duncan Oil Inc | Denver, CO 80210 | Oil & Gas Operator | Jun 2016 |
| 24 | Dynamic Exploration, Inc. | | Oil & Gas Operator | Oct 2003 |