| 1 | D & B Operating, Inc. | Midland, TX 79701 | Oil & Gas Operator | Dec 2003 |
| 2 | D & V Oil Co., LP | San Angelo, TX 76909 | Oil & Gas Operator | Jan 2019 |
| 3 | D G D Oil Co. | Imperial, TX 79743 | Oil & Gas Operator | Dec 2024 |
| 4 | Dabb Energy Company | Fort Worth, TX 76132 | Oil & Gas Operator | Aug 2020 |
| 5 | Dakota Resources, Inc. (I) | Midland, TX 79707 | Oil & Gas Operator | Dec 2024 |
| 6 | Dallas Production, Inc. | Dallas, TX 75206 | Oil & Gas Operator | Mar 2021 |
| 7 | DCP Operating Co LP | Houston, TX 77042 | Oil & Gas Operator | Sep 2024 |
| 8 | Desert States Energy, Inc. | Hobbs, NM 88240 | Oil & Gas Operator | Aug 1995 |
| 9 | Devon Energy Corp (Nevada) | Oklahoma City, OK 73102 | Oil & Gas Operator | Feb 2017 |
| 10 | Devon Energy Production Company LP | Oklahoma City, OK 73102 | Oil & Gas Operator | Dec 2024 |
| 11 | Devon Gas Services, L.P. | Oklahoma City, OK 73102 | Oil & Gas Operator | Aug 2023 |
| 12 | Devon Louisiana Corporation | Houston, TX 77002 | Oil & Gas Operator | Oct 2019 |
| 13 | Devon SFS Operating Inc | Oklahoma City, OK 73102 | Oil & Gas Operator | Mar 2008 |
| 14 | Diamond G Production | FT Stockton, TX 79735 | Oil & Gas Operator | Dec 2024 |
| 15 | Diamond S Energy Company | Fort Worth, TX 76132 | Oil & Gas Operator | Dec 2024 |
| 16 | Diamondback E&P LLC | Midland, TX 79701 | Oil & Gas Operator | Dec 2024 |
| 17 | Dinero Operating Co | Midland, TX 79702 | Oil & Gas Operator | Dec 2024 |
| 18 | Dominion Oklahoma Texas E&P, Inc | Richmond, VA 23219 | Oil & Gas Operator | Sep 2018 |
| 19 | Dorado Oil Company | Corpus Chrsti, TX 78403 | Oil & Gas Operator | Dec 2014 |
| 20 | Dorr, John R. | Pecos, TX 79772 | Oil & Gas Operator | Dec 2024 |
| 21 | Double Eagle Operating, LLC | Fort Worth, TX 76113 | Oil & Gas Operator | Dec 2024 |
| 22 | Double Eagle Petroleum Corp | Evansville, IN 47725 | Oil & Gas Operator | Dec 2024 |
| 23 | Draco Energy, Inc. | Midland, TX 79701 | Oil & Gas Operator | Dec 2024 |
| 24 | Dreyfus, Louis Natural Gas Corp | Oklahoma City, OK 73134 | Oil & Gas Operator | Nov 2001 |
| 25 | Drilmor, Inc. | Midland, TX 79701 | Oil & Gas Operator | Feb 1998 |
| 26 | DSR Oil & Gas, Inc. | Monahans, TX 79756 | Oil & Gas Operator | Dec 2024 |
| 27 | Dudley Oil Co. | Crane, TX 79731 | Oil & Gas Operator | Jan 2006 |
| 28 | Dugan Production Corp | Farmington, NM 87499 | Oil & Gas Operator | Oct 2024 |
| 29 | Dune Oil And Gas, Inc. | Odessa, TX 79768 | Oil & Gas Operator | Aug 2006 |
| 30 | Dune Petroleum Corporation | Midland, TX 79702 | Oil & Gas Operator | Apr 1997 |
| 31 | Durham, Inc. | Midland, TX 79701 | Oil & Gas Operator | Jul 2016 |