| 8001 | Dexco, Inc. | | Oil & Gas Operator | May 1990 |
| 8002 | Dexxon, Inc. | Kiefer, OK 74041 | Oil & Gas Operator | Mar 2025 |
| 8003 | DFG Energy Company LLC | Eastland, TX 76448 | Oil & Gas Operator | Jun 2025 |
| 8004 | DFP Oil Company | Tulsa, OK 74114-1345 | Oil & Gas Operator | Dec 2004 |
| 8005 | DG&E/Slocum, Limited Partnership | Dallas, TX 75206 | Oil & Gas Operator | Jun 2025 |
| 8006 | DGH Oil, LLC | Logan, KS 67646 | Oil Operator | Feb 2025 |
| 8007 | DGH Petroleum, Inc. | | Oil & Gas Operator | Aug 2011 |
| 8008 | DGP Energy, LLC | Wilmington, DE 19801 | Oil & Gas Operator | Apr 2025 |
| 8009 | DH Operating, Inc. | Gordon, TX 76453 | Oil & Gas Operator | Jun 2025 |
| 8010 | DH Production | Albany, TX 76430 | Oil Operator | Dec 2005 |
| 8011 | DHC, Inc. | Midland, TX 79710 | Oil & Gas Operator | Dec 1997 |
| 8012 | DHP Investments, LTD. | Tyler, TX 75703 | Oil Operator | Feb 2025 |
| 8013 | DHW Energy LLC | | Oil Operator | Dec 2024 |
| 8014 | Di Energy Inc. | Houston, TX 77067 | Oil & Gas Operator | Jan 2004 |
| 8015 | Diablo Oil Corp. | | Oil & Gas Operator | Apr 1989 |
| 8016 | Diamar Oil Company, Inc. | | Oil Operator | Nov 1983 |
| 8017 | Diamex Company | | Oil & Gas Operator | Oct 1982 |
| 8018 | Diamond "S" Oil, Inc. | Houston, TX 77065 | Oil & Gas Operator | Apr 1994 |
| 8019 | Diamond A Inc. | Tulsa, OK 74137 | Oil & Gas Operator | Jun 2001 |
| 8020 | Diamond B Company Inc | Tulsa, OK 74170 | Oil & Gas Operator | Dec 2010 |
| 8021 | Diamond B Indust | | Oil Operator | Nov 1996 |
| 8022 | Diamond B Industries Inc | Belle Fourche, SD 57717 | Oil & Gas Operator | Apr 2010 |
| 8023 | Diamond B Miami Flood, LTD. | Paola, KS 66071 | Oil Operator | Feb 2025 |
| 8024 | Diamond Chemical | | Oil & Gas Operator | Jan 1995 |
| 8025 | Diamond Cross Oil Co LLC | Ponca City, OK 74601-1104 | Oil & Gas Operator | Mar 2025 |
| 8026 | Diamond D Operating | | Oil & Gas Operator | Apr 1995 |
| 8027 | Diamond Dixie Ex | | Oil Operator | Jul 1985 |
| 8028 | Diamond Drilling Co. | | Oil Operator | Apr 1983 |
| 8029 | Diamond E Oil Company LLC | | Oil Operator | Mar 2025 |
| 8030 | Diamond Endeavors Inc | | Oil Operator | Dec 2020 |
| 8031 | Diamond Energy Operating Company | Tulsa, OK 74137 | Oil & Gas Operator | Mar 2005 |
| 8032 | Diamond Energy Partners LLC | Collinsville, OK 74021 | Oil & Gas Operator | Mar 2025 |
| 8033 | Diamond Energy Services LLC | Tulsa, OK 74103-3862 | Oil & Gas Operator | Jan 2016 |
| 8034 | Diamond Energy Services, LP | Tulsa, OK 74103 | Oil Operator | Jun 2025 |
| 8035 | Diamond Energy, Inc. | Sherman, TX 75091 | Oil & Gas Operator | Jun 2025 |
| 8036 | Diamond G Production | FT Stockton, TX 79735 | Oil & Gas Operator | Jun 2025 |
| 8037 | Diamond Halo Group LLC | Grandview, TX 76050 | Oil Operator | Mar 2025 |
| 8038 | Diamond Harry H Inc | Shawnee, OK 74801 | Oil & Gas Operator | Feb 2025 |
| 8039 | Diamond M DRLG & Expl Co. | San Antonio, TX 78217 | Oil & Gas Operator | Jun 2025 |
| 8040 | Diamond M Oil Co., Inc. | Monahans, TX 79756 | Oil & Gas Operator | Jun 2025 |
| 8041 | Diamond Mineral Investments Inc. | Bangs, TX 76823 | Gas Operator | Feb 2008 |
| 8042 | Diamond Oil & Gas LLC | Casper, WY 82604 | Oil & Gas Operator | Apr 2025 |
| 8043 | Diamond Oil And Gas, Inc. | Kalamazoo, MI 49001 | Oil & Gas Operator | Jun 2025 |
| 8044 | Diamond Oil Co | Lancaster, OH 43130 | Oil & Gas Operator | Dec 1992 |
| 8045 | Diamond Onshore Production, L. L. C. | | Oil & Gas Operator | Sep 2005 |
| 8046 | Diamond Operating, Inc. | | Oil & Gas Operator | Feb 2022 |
| 8047 | Diamond Operating, LLC | Wichita Falls, TX 76308 | Oil & Gas Operator | Aug 2010 |
| 8048 | Diamond Petroleum LLC | | Oil & Gas Operator | Dec 2005 |
| 8049 | Diamond Production Company LLC | Irving, TX 75016-7853 | Oil & Gas Operator | Mar 2025 |
| 8050 | Diamond S Energy Company | Fort Worth, TX 76132 | Oil & Gas Operator | Jun 2025 |
| 8051 | Diamond S Masada LLC | Magnolia, TX 77354 | Oil & Gas Operator | Jun 2025 |
| 8052 | Diamond S Operating Co. | | Oil & Gas Operator | Oct 1992 |
| 8053 | Diamond Shamrock Chem Co | Irving, TX 75061 | Oil & Gas Operator | Dec 1990 |
| 8054 | Diamond Shamrock Corp | Amarillo, TX 79105 | Oil & Gas Operator | Jan 1987 |
| 8055 | Diamond Shamrock Expl | Dallas, TX 75201 | Oil & Gas Operator | May 1987 |
| 8056 | Diamond Shamrock Expl. Co. | | Oil & Gas Operator | Jun 1987 |
| 8057 | Diamond Star Oil, Inc. | Lacygne, KS 66040 | Oil Operator | Dec 2019 |
| 8058 | Diamond T F Enterprises, Inc. | Sonora, TX 76950 | Gas Operator | Jun 2025 |
| 8059 | Diamondback E&P LLC | Midland, TX 79701 | Oil & Gas Operator | Jun 2025 |
| 8060 | Diamondback Oil Partners LLP | Arvada, CO 80004 | Oil & Gas Operator | Dec 2016 |
| 8061 | Diamondback Operating, LP | Tulsa, OK 74132 | Gas Operator | Jun 2025 |
| 8062 | Diamondback Resources LLC | Midland, TX 79705 | Oil & Gas Operator | May 2018 |
| 8063 | Diamondback-Disposal LLC | Oklahoma City, OK 73134-1016 | Oil Operator | Dec 2008 |
| 8064 | Diamondhead Oil Co., LLC | | Oil & Gas Operator | Apr 2025 |
| 8065 | Diana Pease & Steve Pease Revocable Trust | Wellsville, NY 14895 | Gas Operator | Dec 2023 |
| 8066 | Diane Oil Company | Oklahoma City, OK 73146 | Oil & Gas Operator | Feb 2025 |
| 8067 | Diasu Oil & Gas Co., Inc. | Houston, TX 77002 | Oil & Gas Operator | Mar 2016 |
| 8068 | Dibiaggio, Deirdre And Katherine Carmichael | Atlantis, FL 33463 | Gas Operator | Dec 2023 |
| 8069 | Dick Lindsay Oil Company, Inc. | Graham, TX 76450 | Oil Operator | Jun 2025 |
| 8070 | Dickerson Dennis | Velma, OK 73491 | Oil Operator | Apr 2025 |
| 8071 | Dickerson Oil | Ada, OK 74820 | Oil Operator | Jan 2025 |
| 8072 | Dickey Energy Company | Grafton, WV 26354 | Gas Operator | Dec 2015 |
| 8073 | Dickson Petroleum | Midland, TX 79710 | Oil & Gas Operator | Nov 1998 |
| 8074 | Dickson Petroleum, Inc. | Midland, TX 79710 | Oil & Gas Operator | May 2000 |
| 8075 | Didomenico, Thomas J | Jamestown, NY 14701 | Gas Operator | Dec 2023 |
| 8076 | Diehl Glenn D Oi | | Oil Operator | Jul 1993 |
| 8077 | Diehl Mark | | Oil Operator | Nov 1998 |
| 8078 | Diehl Oil Inc | Hays, KS 67601 | Oil Operator | Feb 2025 |
| 8079 | Dieter Prod Comp | | Oil & Gas Operator | Feb 1991 |
| 8080 | Dieter Production Company | Durham, KS 67438 | Gas Operator | Mar 2013 |
| 8081 | Dietrich Foundation | Pittsburgh, PA 15219 | Gas Operator | Dec 2024 |
| 8082 | Dietrich Oil Co., A General Partnership | Humboldt, KS 66748 | Oil Operator | Jul 2000 |
| 8083 | Dietrich Philip H | Jefferson, OH 44047 | Oil & Gas Operator | Dec 2023 |
| 8084 | Dietrich Resources Corporation | | Oil & Gas Operator | Jun 2007 |
| 8085 | Dietz Oil Field Supply | Dover, OH 44622 | Oil & Gas Operator | Dec 1997 |
| 8086 | Digger Oil & Gas Inc | Prague, OK 74864 | Oil & Gas Operator | Mar 2025 |
| 8087 | Digital Operating Company LLC | Boerne, TX 78006 | Oil & Gas Operator | Jun 2025 |
| 8088 | Dildine Oil Well Service | | Oil Operator | Apr 2011 |
| 8089 | Diler Development Inc. | Garland, TX 75043 | Oil & Gas Operator | Jun 2025 |
| 8090 | Dillard & Dillard Inc. | Holliday, TX 76366 | Oil & Gas Operator | Jun 2025 |
| 8091 | Dillard, A. W., Jr. | Midland, TX 79701 | Oil & Gas Operator | Jan 1995 |
| 8092 | Diller Oil Company | Baird, TX 79504 | Oil Operator | Jun 2025 |
| 8093 | Dilley Corp | Yale, OK 74085 | Oil & Gas Operator | May 2013 |
| 8094 | Dilley, W.R. & A'Meta I. | Sedan, KS 67361 | Oil Operator | Nov 2015 |
| 8095 | Dilligas, Inc. | | Oil Operator | May 1990 |
| 8096 | Dillingham Ranch LC | Tulsa, OK 74152 | Oil & Gas Operator | May 2013 |
| 8097 | Dillon, H. L., Jr. | Houston, TX 77027 | Oil & Gas Operator | Mar 1996 |
| 8098 | Dils Oil & Gas | Parkersburg, WV 26101 | Oil & Gas Operator | Dec 2023 |
| 8099 | Dils, Sherman III Dba Dils Oil & Gas | | Oil & Gas Operator | Dec 2020 |
| 8100 | Dime Box Oil Company | Austin, TX 78759 | Oil & Gas Operator | Mar 2008 |