| 1 | D J Production | Pasadena, TX 77502 | Oil & Gas Operator | Mar 2025 |
| 2 | Daniel Explorations Inc | Georgetown, TX 78627 | Oil & Gas Operator | Apr 2009 |
| 3 | Davis, A. L. Production Co.,Inc. | Van Vleck, TX 77482 | Oil & Gas Operator | Aug 2003 |
| 4 | Decker Operating Co., L.L.C. | Houston, TX 77008 | Oil & Gas Operator | Oct 2025 |
| 5 | Delfin Operating, LLC | Dallas, TX 75243 | Oil & Gas Operator | Oct 2025 |
| 6 | Delta Exploration Company Inc | Denver, CO 80202 | Oil & Gas Operator | Oct 2025 |
| 7 | Denali Oil & Gas Management, LLC | Houston, TX 77060 | Oil & Gas Operator | Dec 2012 |
| 8 | Denbury Onshore, LLC | Plano, TX 75024 | Oil & Gas Operator | Oct 2025 |
| 9 | Denovo Oil & Gas, Inc. | Houston, TX 77210 | Oil & Gas Operator | May 1995 |
| 10 | Devon Energy Operating Co., L.P. | Oklahoma City, OK 73102 | Oil & Gas Operator | Jun 2009 |
| 11 | Devon Energy Production Company LP | Oklahoma City, OK 73102 | Oil & Gas Operator | Oct 2025 |
| 12 | Diasu Oil & Gas Co., Inc. | Houston, TX 77002 | Oil & Gas Operator | Mar 2016 |
| 13 | DJ Exploration, Inc. | San Antonio, TX 78257 | Oil & Gas Operator | Oct 2025 |
| 14 | DSTJ Corporation | Montgomery, TX 77316 | Oil & Gas Operator | Mar 2001 |
| 15 | Duncan Oil Properties, Inc. | Oklahoma City, OK 73102 | Oil & Gas Operator | Oct 2025 |
| 16 | Dynamic Production, Inc. | Fort Worth, TX 76106 | Oil & Gas Operator | Oct 2025 |