| 1 | D & J Oil Company | Kermit, TX 79745 | Oil & Gas Operator | Oct 2025 |
| 2 | D-Mil Production Inc | Argyle, TX 76226 | Oil & Gas Operator | Oct 2025 |
| 3 | Dabb Energy Company | Fort Worth, TX 76132 | Oil & Gas Operator | Aug 2020 |
| 4 | Dakota Oil Company | Hebbronville, TX 78361 | Oil & Gas Operator | Oct 2025 |
| 5 | Dallas Production, Inc. | Dallas, TX 75206 | Oil & Gas Operator | Mar 2021 |
| 6 | Daylight Petroleum LLC | Houston, TX 77052 | Oil & Gas Operator | Oct 2025 |
| 7 | DCP Operating Co LP | Houston, TX 77042 | Oil & Gas Operator | May 2025 |
| 8 | Dean'S Well Servicing Inc | Ratliff City, OK 73481 | Oil & Gas Operator | Jun 2025 |
| 9 | Dehart Company (The) | Ardmore, OK 73402 | Oil & Gas Operator | Jul 2025 |
| 10 | Deka Exploration Inc | Oklahoma City, OK 73113-0057 | Oil & Gas Operator | Nov 2019 |
| 11 | Delek Energy Systems Us Inc | Denver, CO 80202 | Oil & Gas Operator | Oct 2011 |
| 12 | Delta D Operations | Wilson, OK 73463 | Oil & Gas Operator | Jul 2014 |
| 13 | Delta D Operations Inc | Ardmore, OK 73401-8678 | Oil & Gas Operator | Apr 2014 |
| 14 | Depco Inc. | Denver, CO 80202 | Oil & Gas Operator | Apr 2014 |
| 15 | Devon Energy Corp (Nevada) | Oklahoma City, OK 73102 | Oil & Gas Operator | Feb 2017 |
| 16 | Devon Energy Production Company LP | Oklahoma City, OK 73102 | Oil & Gas Operator | Oct 2025 |
| 17 | Devon Louisiana Corporation | Houston, TX 77002 | Oil & Gas Operator | Oct 2019 |
| 18 | Devon SFS Operating Inc | Oklahoma City, OK 73102 | Oil & Gas Operator | Mar 2008 |
| 19 | Dixie Petroleum Inc | Cashion, OK 73016 | Oil & Gas Operator | May 2001 |
| 20 | Dominion Exploration & Production Inc | Houston, TX 77060 | Oil & Gas Operator | Apr 2015 |
| 21 | Dominion Ok TX E & P Inc | Oklahoma City, OK 73134 | Oil & Gas Operator | Nov 2018 |
| 22 | Duncan Oil Properties, Inc. | Oklahoma City, OK 73102 | Oil & Gas Operator | Oct 2025 |