| 1 | D & B Oil Company | Graham, TX 76450 | Oil & Gas Operator | Oct 2025 |
| 2 | D. G. Oil Co. | Dennis, TX 76439 | Oil & Gas Operator | Oct 2025 |
| 3 | Dakota Resources, Inc | Midland, TX 79707 | Oil & Gas Operator | Jun 2025 |
| 4 | Dalen Resources Oil & Gas Co. | Dallas, TX 75206 | Oil & Gas Operator | Jun 2010 |
| 5 | Dallas Production, Inc. | Dallas, TX 75206 | Oil & Gas Operator | Mar 2021 |
| 6 | DCP Operating Co LP | Houston, TX 77042 | Oil & Gas Operator | May 2025 |
| 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 | De3 Operating LLC | Irving, TX 75038 | Oil & Gas Operator | Jun 2021 |
| 10 | Decleva, Paul | Wichita Falls, TX 76302 | Oil & Gas Operator | Dec 2020 |
| 11 | Dedica Energy Corporation | Mattoon, IL 61938 | Oil & Gas Operator | Mar 2008 |
| 12 | Delaware Davis Petroleum Corp. | Houston, TX 77056 | Oil & Gas Operator | Jan 2000 |
| 13 | Desert Production, Inc. | Midland, TX 79702 | Oil & Gas Operator | Oct 2025 |
| 14 | Devon Energy Production Company LP | Oklahoma City, OK 73102 | Oil & Gas Operator | Oct 2025 |
| 15 | Devon SFS Operating Inc | Oklahoma City, OK 73102 | Oil & Gas Operator | Mar 2008 |
| 16 | DHC, Inc. | Midland, TX 79710 | Oil & Gas Operator | Dec 1997 |
| 17 | Diamondback E&P LLC | Midland, TX 79701 | Oil & Gas Operator | Oct 2025 |
| 18 | Dickson Petroleum, Inc. | Midland, TX 79710 | Oil & Gas Operator | May 2000 |
| 19 | Dinero Operating Co | Midland, TX 79702 | Oil & Gas Operator | Oct 2025 |
| 20 | Discovery Operating Inc | Midland, TX 79705 | Oil & Gas Operator | Oct 2025 |
| 21 | Dominion Oklahoma Texas E&P, Inc | Richmond, VA 23219 | Oil & Gas Operator | Sep 2018 |
| 22 | Dorado Oil Company | Corpus Chrsti, TX 78403 | Oil & Gas Operator | Oct 2013 |
| 23 | Dorland, D. L. | Midland, TX 79701 | Oil & Gas Operator | Aug 2003 |
| 24 | Dorland, D. L. Estate Of | Midland, TX 79702 | Oil & Gas Operator | Nov 1994 |
| 25 | Dorland, D. L. Inc. | Midland, TX 79701 | Oil & Gas Operator | Jul 1994 |
| 26 | Dos Cicadas | Miles, TX 76861 | Oil & Gas Operator | Oct 2025 |
| 27 | Double Barrel Oil LLC | Brenham, TX 77834 | Oil & Gas Operator | Oct 2025 |
| 28 | Double Eagle Operating, LLC | Fort Worth, TX 76113 | Oil & Gas Operator | Oct 2025 |
| 29 | Double Eagle Petroleum Corp | Evansville, IN 47725 | Oil & Gas Operator | Oct 2025 |
| 30 | Dreher, George R. | Midland, TX 79702 | Oil & Gas Operator | Jan 2018 |
| 31 | Dreyfus, Louis Natural Gas Corp | Oklahoma City, OK 73134 | Oil & Gas Operator | Nov 2001 |
| 32 | Duncan Drilling Co. | Big Spring, TX 79721 | Oil & Gas Operator | Oct 2025 |
| 33 | Dune Oil And Gas, Inc. | Odessa, TX 79768 | Oil & Gas Operator | Aug 2006 |
| 34 | Durham, Inc. | Midland, TX 79701 | Oil & Gas Operator | Jul 2016 |