| 1001 | Anthony Oil Company | | Oil & Gas Operator | Oct 1987 |
| 1002 | Anthony, Bob G. Inc. | Brookhaven, MS 39601 | Oil & Gas Operator | Jul 2025 |
| 1003 | Antilley, Joe | Abilene, TX 79602 | Oil & Gas Operator | Jan 2024 |
| 1004 | Antioch Disposal Well Inc | Duncan, OK 73533 | Oil Operator | Jan 1994 |
| 1005 | Antioch Operating LLC | Dallas, TX 75206 | Oil & Gas Operator | May 2025 |
| 1006 | Antle Operating, Inc. | Graham, TX 76450 | Oil & Gas Operator | Jul 2025 |
| 1007 | Antle, E. | Graham, TX 76450 | Oil & Gas Operator | Oct 1994 |
| 1008 | Antler Energy LLC | Baggs, WY 82321 | Oil & Gas Operator | May 2025 |
| 1009 | Antlers Energy LLC | Tulsa, OK 74137 | Oil & Gas Operator | Apr 2025 |
| 1010 | Antrim Development Corp | | Oil & Gas Operator | Oct 2018 |
| 1011 | Anvil Oil Co., Inc. | Bartlesville, OK 74003-5030 | Oil & Gas Operator | Dec 2008 |
| 1012 | Anzalone, James A. | Leesburg, FL 34748 | Gas Operator | Dec 2024 |
| 1013 | Aoco Operating Company, L.L.C. | Houston, TX 77008 | Oil & Gas Operator | Feb 2005 |
| 1014 | Aoco Operating, L.P. | Houston, TX 77008 | Oil & Gas Operator | Mar 2008 |
| 1015 | Aocswd LLC | Marietta, OH 45750 | Oil & Gas Operator | Dec 2024 |
| 1016 | Aog Operating LLC | Oklahoma City, OK 73120 | Oil & Gas Operator | Apr 2025 |
| 1017 | Aog, Inc. | Norman, OK 73070 | Oil & Gas Operator | Nov 2014 |
| 1018 | Aogp, LLC | Turtle Lake, WI 54889 | Oil & Gas Operator | Sep 2019 |
| 1019 | Aop Operating Corporation | Dallas, TX 75313 | Oil & Gas Operator | Aug 2003 |
| 1020 | Ap Operating LLC | Claflin, KS 67525 | Oil Operator | Feb 2025 |
| 1021 | Ap Operating, Inc. | Plano, TX 75074 | Oil & Gas Operator | Jul 2025 |
| 1022 | Ap Production LLC | Utica, OH 43080 | Oil & Gas Operator | Dec 2023 |
| 1023 | Apache Corporation | Houston, TX 77042 | Oil & Gas Operator | Jul 2025 |
| 1024 | Apache Drilling | | Oil Operator | Sep 1994 |
| 1025 | Apache Drilling Co | Kingman, KS 67068 | Oil Operator | Feb 2006 |
| 1026 | Apache Energy Resources Corp | Houston, TX 77056 | Oil & Gas Operator | Mar 2015 |
| 1027 | Apache Natural Gas Co., Inc. | | Oil Operator | Nov 1992 |
| 1028 | Apache Oil Company | San Antonio, TX 78227 | Oil & Gas Operator | Jun 2023 |
| 1029 | Apache PHN North America, Inc. | | Oil & Gas Operator | Mar 2005 |
| 1030 | Apache Production Company | Holliday, TX 76366 | Oil & Gas Operator | Jul 2025 |
| 1031 | Apache Shelf, Inc. | Houston, TX 77056 | Oil & Gas Operator | Jan 2014 |
| 1032 | Apb Oil Corporation | Houston, TX 77052 | Oil & Gas Operator | Apr 1996 |
| 1033 | Apc Operating Partnership | Tulsa, OK 74136 | Oil & Gas Operator | Oct 1996 |
| 1034 | Apc Operating Partnership LP | Tulsa, OK 74136-4224 | Oil & Gas Operator | Jun 2015 |
| 1035 | Apco Oil Corporation | Oklahoma City, OK 73116 | Oil & Gas Operator | Jun 1993 |
| 1036 | Apd Company | | Oil & Gas Operator | Apr 1987 |
| 1037 | Apex Crude Oil Co | Logan, OH 43138 | Oil & Gas Operator | Dec 1996 |
| 1038 | Apex DRLG | Bermuda Dunes, CA 92203 | Oil & Gas Operator | Dec 2019 |
| 1039 | Apex Energy (Pa) LLC | Canonsburg, PA 15317-6523 | Gas Operator | May 2025 |
| 1040 | Apex Energy, Inc. | Corpus Chrsti, TX 78413 | Oil & Gas Operator | Jul 2025 |
| 1041 | Apex Energy, L.L.C. | Tulsa, OK 74114 | Oil & Gas Operator | Mar 2025 |
| 1042 | Apex Minerals Inc | Oklahoma City, OK 73102 | Oil & Gas Operator | Mar 1994 |
| 1043 | Apex Oil & Gas, Inc. | Houston, TX 77067 | Oil & Gas Operator | Oct 2009 |
| 1044 | Apex Oil Ventures Inc | | Oil & Gas Operator | May 2025 |
| 1045 | Apex Operating & Equip. Co. | Bowie, TX 76230 | Oil & Gas Operator | Nov 2003 |
| 1046 | Apex Operating Partners, LLC | San Angelo, TX 76902 | Oil & Gas Operator | Jul 2025 |
| 1047 | Apex Production LTD. | Albany, TX 76430 | Oil Operator | Jul 2025 |
| 1048 | Apex Resources Inc | Allison Park, PA 15101-3838 | Oil & Gas Operator | Dec 1993 |
| 1049 | Apex Resources LLC | Kilgore, TX 75663 | Oil & Gas Operator | Jul 2025 |
| 1050 | Apex Royalties, Inc. | Midland, TX 79702 | Oil & Gas Operator | May 1997 |
| 1051 | Apexco, Inc. | Sand Springs, OK 74063 | Oil & Gas Operator | Mar 2025 |
| 1052 | Apexco-McCormick-Coastal | | Oil & Gas Operator | Dec 1977 |
| 1053 | Apexway Corp. | | Oil Operator | Dec 2024 |
| 1054 | API Operating Co. | Houston, TX 77036 | Oil & Gas Operator | Jul 2025 |
| 1055 | Apogee Oil & Gas LLC | Edmond, OK 73034 | Oil Operator | Apr 2025 |
| 1056 | Apollo 17 Oil And Gas Inc | | Oil Operator | Feb 1988 |
| 1057 | Apollo Drilling And Exploration | | Oil & Gas Operator | Oct 1980 |
| 1058 | Apollo Energies | Pratt, KS 67124 | Oil Operator | Aug 2016 |
| 1059 | Apollo Energies Inc | Pratt, KS 67124 | Oil & Gas Operator | May 2025 |
| 1060 | Apollo Energy Operating Co, LP | Lake Charles, LA 70601 | Oil & Gas Operator | Dec 2024 |
| 1061 | Apollo Energy Operating, LP | | Oil & Gas Operator | Mar 2011 |
| 1062 | Apollo Energy, L.L.C. | | Oil & Gas Operator | Jul 2018 |
| 1063 | Apollo Energy, L.P. | Lake Charles, LA 70601 | Oil Operator | May 2014 |
| 1064 | Apollo Exploration And Development Inc | | Oil & Gas Operator | Apr 2025 |
| 1065 | Apollo Gas Co | Pittsburgh, PA 15236-1435 | Gas Operator | Dec 1991 |
| 1066 | Apollo Operating LLC | | Oil & Gas Operator | Sep 2013 |
| 1067 | Apollo Petroleum Corporation | | Oil & Gas Operator | Dec 2012 |
| 1068 | Apollo Resources LLC | Vintondale, PA 15961-0222 | Oil & Gas Operator | May 2025 |
| 1069 | App Energy, LLC | Monroe, MI 48161 | Oil & Gas Operator | Dec 2021 |
| 1070 | Appalachian Ener Tech Inc | Clearwater, FL 33518 | Oil & Gas Operator | Dec 2001 |
| 1071 | Appalachian Energy Inc | Pittsburgh, PA 15220 | Gas Operator | Dec 2008 |
| 1072 | Appalachian Expl Inc | Hartville, OH 44632 | Oil & Gas Operator | Dec 1992 |
| 1073 | Appalachian Exploration Corp | McMurray, PA 15317-3452 | Gas Operator | Dec 1995 |
| 1074 | Appalachian Petrol Corp | Girard, OH 44420 | Oil & Gas Operator | Dec 1989 |
| 1075 | Appalachian Resources Of Florida, LLC | Fort Myers, FL 33902 | Oil Operator | Dec 2023 |
| 1076 | Appaloosa Operating Company LLC | The Woodlands, TX 77387 | Oil & Gas Operator | Apr 2019 |
| 1077 | Apple Petroleum Corp | Mountainside, NJ 7092 | Oil Operator | Mar 2013 |
| 1078 | Appleton Oil Company | Chicago, IL 60657-4097 | Oil & Gas Operator | May 1993 |
| 1079 | Applied Mechanics Corp. | Bridgeport, WV 26330-4609 | Oil & Gas Operator | Dec 2021 |
| 1080 | Appling, J. B. | Midland, TX 79702 | Oil & Gas Operator | Jul 1997 |
| 1081 | Approach Operating LLC | Fort Worth, TX 76116 | Oil & Gas Operator | Sep 2020 |
| 1082 | Apr Operating LLC | Midland, TX 79701 | Oil & Gas Operator | Jun 2022 |
| 1083 | April Rain Prod. Co., Inc. | | Oil & Gas Operator | Jul 1992 |
| 1084 | Apv Caddo Pine LLC | | Oil & Gas Operator | Dec 2024 |
| 1085 | Apv McCamey LLC | MC Camey, TX 79752 | Oil & Gas Operator | Jul 2025 |
| 1086 | Apx & Assoc. | FT Stockton, TX 79735 | Oil & Gas Operator | Sep 1998 |
| 1087 | Apx Corporation | Houston, TX 77251 | Oil & Gas Operator | Dec 2009 |
| 1088 | Apx Western Corporation | Denver, CO 80217 | Oil & Gas Operator | Sep 1991 |
| 1089 | Aqua-Oil Inc | Enid, OK 73703-6511 | Oil & Gas Operator | May 2019 |
| 1090 | Aquanyx Midstream LLC | Oklahoma City, OK 73131 | Oil Operator | Apr 2025 |
| 1091 | Aquarius Oil And Gas | Casper, WY 82601 | Oil & Gas Operator | Sep 2017 |
| 1092 | Aquila Energy Resources Corp. | Houston, TX 77042 | Oil & Gas Operator | Nov 2013 |
| 1093 | Aquila Resources | Burkesville, KY 42717 | Oil & Gas Operator | Dec 2022 |
| 1094 | Aquinas Oil & Gas, LLC | Muenster, TX 76252 | Oil Operator | Jul 2025 |
| 1095 | Arabella Operating, LLC | Fort Worth, TX 76102 | Oil & Gas Operator | Jul 2025 |
| 1096 | Arabella Petroleum Company, LLC | Austin, TX 78701 | Oil & Gas Operator | Jul 2025 |
| 1097 | Arabie, Inc. | Lake Charles, LA 70605 | Oil & Gas Operator | Apr 2025 |
| 1098 | Aracca Petroleum Company | | Oil Operator | May 1984 |
| 1099 | Aracca Petroleum Corporation | | Oil Operator | Dec 1987 |
| 1100 | Aralpa Corporation | | Oil & Gas Operator | May 1987 |