| 1 | Dabb Energy Company | Fort Worth, TX 76132 | Oil & Gas Operator | Aug 2020 |
| 2 | Dakota Resources, Inc. (I) | Midland, TX 79707 | Oil & Gas Operator | Oct 2025 |
| 3 | Dallas Production, Inc. | Dallas, TX 75206 | Oil & Gas Operator | Mar 2021 |
| 4 | Davcro Inc. | Lubbock, TX 79401 | Oil & Gas Operator | Dec 2003 |
| 5 | Davis Southern Operating Co LLC | Houston, TX 77004 | Oil & Gas Operator | Oct 2025 |
| 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 | De IV Operating, LLC | Midland, TX 79701 | Oil & Gas Operator | Apr 2025 |
| 9 | Dean Energy, Inc. | Midland, TX 79702 | Oil & Gas Operator | Nov 2019 |
| 10 | Dekalb Energy Company | Oklahoma City, OK 73134 | Oil & Gas Operator | Oct 1996 |
| 11 | Denbury Management, Inc. | Dallas, TX 75252 | Oil & Gas Operator | Dec 1999 |
| 12 | Desert States Energy, Inc. | Hobbs, NM 88240 | Oil & Gas Operator | Aug 1995 |
| 13 | Devon Energy Corp (Nevada) | Oklahoma City, OK 73102 | Oil & Gas Operator | Feb 2017 |
| 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 | Diamond Energy, Inc. | Sherman, TX 75091 | Oil & Gas Operator | Oct 2025 |
| 17 | Diamond S Energy Company | Fort Worth, TX 76132 | Oil & Gas Operator | Oct 2025 |
| 18 | Diamondback E&P LLC | Midland, TX 79701 | Oil & Gas Operator | Oct 2025 |
| 19 | Dickson Petroleum, Inc. | Midland, TX 79710 | Oil & Gas Operator | May 2000 |
| 20 | Dillard, A. W., Jr. | Midland, TX 79701 | Oil & Gas Operator | Jan 1995 |
| 21 | Dillon, H. L., Jr. | Houston, TX 77027 | Oil & Gas Operator | Mar 1996 |
| 22 | Dinero Operating Co | Midland, TX 79702 | Oil & Gas Operator | Oct 2025 |
| 23 | Dominion Oklahoma Texas E&P, Inc | Richmond, VA 23219 | Oil & Gas Operator | Sep 2018 |
| 24 | Dorado Oil Company | Corpus Chrsti, TX 78403 | Oil & Gas Operator | Oct 2013 |
| 25 | Double Barrel Oil LLC | Brenham, TX 77834 | Oil & Gas Operator | Oct 2025 |
| 26 | Double Eagle Petroleum Corp | Evansville, IN 47725 | Oil & Gas Operator | Oct 2025 |
| 27 | Drake Oil & Gas, LLC | Wichita Falls, TX 76308 | Oil Operator | Oct 2025 |
| 28 | Dreyfus, Louis Natural Gas Corp | Oklahoma City, OK 73134 | Oil & Gas Operator | Nov 2001 |
| 29 | DSR Oil & Gas, Inc. | Monahans, TX 79756 | Oil & Gas Operator | Oct 2025 |
| 30 | Dudley Oil Co. | Crane, TX 79731 | Oil & Gas Operator | Jan 2006 |
| 31 | Dugan Production Corp | Farmington, NM 87499 | Oil & Gas Operator | Jul 2025 |
| 32 | Duncan Oil Properties, Inc. | Oklahoma City, OK 73102 | 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 |