| 1 | Dale Operating Company | Dallas, TX 75201 | Oil & Gas Operator | Oct 2025 |
| 2 | Dallas Production, Inc. | Dallas, TX 75206 | Oil & Gas Operator | Mar 2021 |
| 3 | Dash Production Company, Inc. | Corpus Chrsti, TX 78411 | Oil & Gas Operator | Oct 2025 |
| 4 | Davis Bros. Oil Producers, Inc. | Tulsa, OK 74119 | Oil & Gas Operator | Apr 2020 |
| 5 | Decker Operating Co., L.L.C. | Houston, TX 77008 | Oil & Gas Operator | Oct 2025 |
| 6 | Devon Energy Production Company LP | Oklahoma City, OK 73102 | Oil & Gas Operator | Oct 2025 |
| 7 | Devon Louisiana Corporation | Houston, TX 77002 | Oil & Gas Operator | Oct 2019 |
| 8 | Doughtie Operating Company, LLC | MC Queeney, TX 78123 | Oil & Gas Operator | Mar 2023 |
| 9 | Draco Production Company | Tulsa, OK 74133 | Oil & Gas Operator | Jul 2012 |
| 10 | Dyersdale Production Co, Inc. | Houston, TX 77019 | Oil & Gas Operator | Oct 2025 |