| 1 | D-S-B Properties, Inc. | Kilgore, TX 75663 | Oil & Gas Operator | Sep 2014 |
| 2 | D-S-B Properties, LLC | Kilgore, TX 75663 | Oil & Gas Operator | Oct 2025 |
| 3 | Daco Oil | Joinerville, TX 75658 | Oil & Gas Operator | Aug 2019 |
| 4 | Dallas Production Company LLC | Dallas, TX 75206 | Oil & Gas Operator | Oct 2025 |
| 5 | Dallas Production, Inc. | Dallas, TX 75206 | Oil & Gas Operator | Mar 2021 |
| 6 | Danmark Energy Services, Inc. | White Oak, TX 75693 | Oil & Gas Operator | Apr 2021 |
| 7 | Desana Development Corporation | Midland, TX 79701 | Oil & Gas Operator | Oct 2025 |
| 8 | Devon Energy Production Company LP | Oklahoma City, OK 73102 | Oil & Gas Operator | Oct 2025 |
| 9 | Devon Louisiana Corporation | Houston, TX 77002 | Oil & Gas Operator | Oct 2019 |
| 10 | Diversified Production LLC | Keithville, LA 71047 | Oil & Gas Operator | Oct 2025 |
| 11 | Dominion Minerals Corporation | Houston, TX 77014 | Oil & Gas Operator | Nov 2009 |
| 12 | Dorfman Production Company | Beloit, OH 44609 | Oil & Gas Operator | Oct 2025 |
| 13 | Douglas Investments Inc | Fort Worth, TX 76137 | Oil Operator | Jan 2020 |
| 14 | DPMP Energy LLC | Prosper, TX 75078 | Oil & Gas Operator | Dec 2023 |
| 15 | Dyersdale Energy, L.P. | Kilgore, TX 75663 | Oil & Gas Operator | Oct 2025 |
| 16 | Dyersdale Production Co, Inc. | Houston, TX 77019 | Oil & Gas Operator | Oct 2025 |