| 1 | D & B Operating, Inc. | Midland, TX 79701 | Oil & Gas Operator | Dec 2003 |
| 2 | Dakota Resources, Inc | Midland, TX 79707 | Oil & Gas Operator | Jun 2025 |
| 3 | Dallas Operating Corp. | Dallas, TX 75205 | Oil & Gas Operator | Nov 2006 |
| 4 | Dallas Production, Inc. | Dallas, TX 75206 | Oil & Gas Operator | Mar 2021 |
| 5 | DCP Operating Co LP | Houston, TX 77042 | Oil & Gas Operator | May 2025 |
| 6 | De Compiegne Prop. Co. 20, The | Midland, TX 79702 | Oil Operator | Oct 2019 |
| 7 | De IV Operating, LLC | Midland, TX 79701 | Oil & Gas Operator | Apr 2025 |
| 8 | De Operating LLC | Austin, TX 78701 | Oil & Gas Operator | Apr 2017 |
| 9 | De V Operating, LLC | Fort Worth, TX 76107 | Oil & Gas Operator | Oct 2025 |
| 10 | De3 Operating LLC | Irving, TX 75038 | Oil & Gas Operator | Jun 2021 |
| 11 | Desert Production, Inc. | Midland, TX 79702 | Oil & Gas Operator | Oct 2025 |
| 12 | Devon Energy Corp (Nevada) | Oklahoma City, OK 73102 | Oil & Gas Operator | Feb 2017 |
| 13 | Devon Energy Production Company LP | Oklahoma City, OK 73102 | Oil & Gas Operator | Oct 2025 |
| 14 | Devon SFS Operating Inc | Oklahoma City, OK 73102 | Oil & Gas Operator | Mar 2008 |
| 15 | Diamondback E&P LLC | Midland, TX 79701 | Oil & Gas Operator | Oct 2025 |
| 16 | Dickson Petroleum, Inc. | Midland, TX 79710 | Oil & Gas Operator | May 2000 |
| 17 | Dinero Operating Co | Midland, TX 79702 | Oil & Gas Operator | Oct 2025 |
| 18 | Discovery Natural Resources LLC | Denver, CO 80202 | Oil & Gas Operator | Oct 2025 |
| 19 | Discovery Operating Inc | Midland, TX 79705 | Oil & Gas Operator | Oct 2025 |
| 20 | Dominion Oklahoma Texas E&P, Inc | Richmond, VA 23219 | Oil & Gas Operator | Sep 2018 |
| 21 | Dorado Oil Company | Corpus Chrsti, TX 78403 | Oil & Gas Operator | Oct 2013 |
| 22 | Dorland, D. L. | Midland, TX 79701 | Oil & Gas Operator | Aug 2003 |
| 23 | Dorland, D. L. Estate Of | Midland, TX 79702 | Oil & Gas Operator | Nov 1994 |
| 24 | Dorland, D. L. Inc. | Midland, TX 79701 | Oil & Gas Operator | Jul 1994 |
| 25 | Double Eagle Operating, LLC | Fort Worth, TX 76113 | Oil & Gas Operator | Oct 2025 |
| 26 | Double Eagle Petroleum Corp | Evansville, IN 47725 | Oil & Gas Operator | Oct 2025 |
| 27 | Draco Energy, Inc. | Midland, TX 79701 | Oil & Gas Operator | Oct 2025 |
| 28 | Dreyfus, Louis Natural Gas Corp | Oklahoma City, OK 73134 | Oil & Gas Operator | Nov 2001 |
| 29 | Dyad Petroleum Company | Midland, TX 79710 | Oil & Gas Operator | Sep 2021 |