| 1001 | Annulus Energy LLC | | Gas Operator | Dec 2021 |
| 1002 | Anr Limited Inc/Coastal | Houston, TX 770460995 | Oil & Gas Operator | Dec 1987 |
| 1003 | Anr Production C | | Gas Operator | Apr 1994 |
| 1004 | Anr Production Company | Houston, TX 77046 | Oil & Gas Operator | Aug 2017 |
| 1005 | Ansbro Petroleum Company, LLC | Denver, CO 80202 | Oil & Gas Operator | Feb 2008 |
| 1006 | Anschutz Corporation | Denver, CO 80202 | Oil & Gas Operator | Sep 2016 |
| 1007 | Anschutz Drilling Co. | | Oil Operator | Jul 1961 |
| 1008 | Anschutz Exploration Corporation | Denver, CO 80202 | Oil & Gas Operator | Feb 2026 |
| 1009 | Anschutz Oil Co. | | Oil & Gas Operator | Jul 1984 |
| 1010 | Anschutz Oil Company LLC | Denver, CO 80202 | Oil & Gas Operator | Sep 2020 |
| 1011 | Anschutz Pinedale Corporation | Denver, CO 80202 | Oil & Gas Operator | Dec 2015 |
| 1012 | Anshutz Oil | | Oil Operator | Dec 2009 |
| 1013 | Anson Charles Dba Anson Oil | Seminole, OK 74868 | Oil Operator | Nov 2025 |
| 1014 | Anson Company | Oklahoma City, OK 73124 | Oil & Gas Operator | Apr 2018 |
| 1015 | Anson Gas Corporation | Oklahoma City, OK 73116 | Oil & Gas Operator | May 1997 |
| 1016 | Anson J W | Seminole, OK 74818-1280 | Oil & Gas Operator | Oct 2020 |
| 1017 | Anson Robert L & Teresa M | Seminole, OK 74868 | Oil & Gas Operator | Dec 2025 |
| 1018 | Anstine & Musgrove Inc | Ponca City, OK 74602 | Oil & Gas Operator | Nov 2025 |
| 1019 | Anstine Oil Company | | Oil Operator | Sep 2025 |
| 1020 | Anstine-Musgrove | Ponca City, OK 74602 | Oil & Gas Operator | Feb 2017 |
| 1021 | Anstine-Musgrove Oil Company | Ponca City, OK 74602-0391 | Oil & Gas Operator | Jan 2013 |
| 1022 | Ansythe Exploration Co., Inc. | | Oil & Gas Operator | Oct 1982 |
| 1023 | Ant Hills Production | Lusk, WY 82225 | Oil & Gas Operator | Dec 2025 |
| 1024 | Antara Resources, Inc. | Houston, TX 77002 | Oil & Gas Operator | Apr 2004 |
| 1025 | Antares Energy Company | Houston, TX 77010 | Oil & Gas Operator | Feb 2026 |
| 1026 | Antares Oil Corp | Denver, CO 80202 | Oil & Gas Operator | Oct 2015 |
| 1027 | Antares Ventures, L.L.C. | | Oil Operator | Oct 2016 |
| 1028 | Antelope Energy Company LLC | Denver, CO 80202 | Oil & Gas Operator | Dec 2024 |
| 1029 | Antelope Energy Partners, LLC | Houston, TX 77027 | Oil & Gas Operator | Feb 2026 |
| 1030 | Antelope Production Co. | Midland, TX 79701 | Oil & Gas Operator | Oct 1995 |
| 1031 | Antelope Resources Inc | Billings, MT 59101 | Oil & Gas Operator | May 2017 |
| 1032 | Antero Energy LLC | Denver, CO 80202 | Gas Operator | Nov 2003 |
| 1033 | Antero Resources Bluestone LLC | | Gas Operator | Dec 2013 |
| 1034 | Antero Resources Corporation | Denver, CO 80202 | Oil & Gas Operator | Sep 2025 |
| 1035 | Antero Resources I, LP | Denver, CO 80202 | Oil & Gas Operator | Jun 2005 |
| 1036 | Antero Resources II, LP | Denver, CO 80202 | Oil & Gas Operator | May 2006 |
| 1037 | Anterra Energy Services Inc. | | Oil & Gas Operator | Nov 2025 |
| 1038 | Anterra Services Inc. | | Oil & Gas Operator | Dec 2025 |
| 1039 | Anthem Energy Operating (Oklahoma) LLC | Tulsa, OK 74119 | Oil & Gas Operator | Nov 2025 |
| 1040 | Anthony Oil & Gas Co. | Shreveport, LA 71135 | Oil Operator | May 1993 |
| 1041 | Anthony Oil Company | | Oil & Gas Operator | Oct 1987 |
| 1042 | Anthony, Bob G. Inc. | Brookhaven, MS 39601 | Oil & Gas Operator | Feb 2026 |
| 1043 | Anticline Energy, LLC | Three Rivers, MI 49093 | Oil & Gas Operator | Jul 2023 |
| 1044 | Antilley, Joe | Abilene, TX 79602 | Oil & Gas Operator | Jan 2024 |
| 1045 | Antioch Disposal Well Inc | Duncan, OK 73533 | Oil Operator | Jan 1994 |
| 1046 | Antioch Operating LLC | Dallas, TX 75206 | Oil & Gas Operator | Dec 2025 |
| 1047 | Antle Operating, Inc. | Graham, TX 76450 | Oil & Gas Operator | Feb 2026 |
| 1048 | Antle, E. | Graham, TX 76450 | Oil & Gas Operator | Oct 1994 |
| 1049 | Antler Energy LLC | Baggs, WY 82321 | Oil & Gas Operator | Aug 2025 |
| 1050 | Antlers Energy LLC | Tulsa, OK 74136 | Oil & Gas Operator | Dec 2025 |
| 1051 | Antrim Development Corp | | Oil & Gas Operator | Oct 2018 |
| 1052 | Anvil Oil Co., Inc. | Bartlesville, OK 74003-5030 | Oil & Gas Operator | Dec 2008 |
| 1053 | Anzalone, James A. | Leesburg, FL 34748 | Gas Operator | Dec 2024 |
| 1054 | Aoco Operating Company, L.L.C. | Houston, TX 77008 | Oil & Gas Operator | Feb 2005 |
| 1055 | Aoco Operating, L.P. | Houston, TX 77008 | Oil & Gas Operator | Mar 2008 |
| 1056 | Aocswd LLC | Marietta, OH 45750 | Oil & Gas Operator | Dec 2024 |
| 1057 | Aog Operating LLC | Oklahoma City, OK 73120 | Oil & Gas Operator | Nov 2025 |
| 1058 | Aog, Inc. | Norman, OK 73070 | Oil & Gas Operator | Nov 2014 |
| 1059 | Aogp, LLC | Turtle Lake, WI 54889 | Oil & Gas Operator | Sep 2019 |
| 1060 | Aop Operating Corporation | Dallas, TX 75313 | Oil & Gas Operator | Aug 2003 |
| 1061 | Ap Operating LLC | Claflin, KS 67525 | Oil Operator | Jul 2025 |
| 1062 | Ap Operating, Inc. | Richardson, TX 75080 | Oil & Gas Operator | Feb 2026 |
| 1063 | Ap Production LLC | Utica, OH 43080 | Oil & Gas Operator | Dec 2023 |
| 1064 | Apache Corporation | Houston, TX 77042 | Oil & Gas Operator | Feb 2026 |
| 1065 | Apache Drilling | | Oil Operator | Sep 1994 |
| 1066 | Apache Drilling Co | Kingman, KS 67068 | Oil Operator | Feb 2006 |
| 1067 | Apache Energy Resources Corp. | Houston, TX 77056 | Oil & Gas Operator | Mar 2015 |
| 1068 | Apache Natural Gas Co., Inc. | | Oil Operator | Nov 1992 |
| 1069 | Apache Oil Company | San Antonio, TX 78227 | Oil & Gas Operator | Jun 2023 |
| 1070 | Apache PHN North America, Inc. | | Oil & Gas Operator | Mar 2005 |
| 1071 | Apache Production Company | Holliday, TX 76366 | Oil & Gas Operator | Feb 2026 |
| 1072 | Apache Shelf, Inc. | Houston, TX 77056 | Oil & Gas Operator | Jan 2014 |
| 1073 | Apb Oil Corporation | Houston, TX 77052 | Oil & Gas Operator | Apr 1996 |
| 1074 | Apc Operating Partnership | Tulsa, OK 74136 | Oil & Gas Operator | Oct 1996 |
| 1075 | Apc Operating Partnership LP | Tulsa, OK 74136-4224 | Oil & Gas Operator | Jun 2015 |
| 1076 | Apco Oil Corp | Oklahoma City, OK 73116 | Oil & Gas Operator | Jun 1993 |
| 1077 | Apd Company | | Oil & Gas Operator | Apr 1987 |
| 1078 | Apex Crude Oil Co | Logan, OH 43138 | Oil & Gas Operator | Dec 1996 |
| 1079 | Apex DRLG | Bermuda Dunes, CA 92203 | Oil & Gas Operator | Dec 2019 |
| 1080 | Apex Energy (Pa) LLC | Canonsburg, PA 15317-6523 | Gas Operator | May 2025 |
| 1081 | Apex Energy, Inc. | Corpus Chrsti, TX 78413 | Oil & Gas Operator | Feb 2026 |
| 1082 | Apex Energy, L.L.C. | Tulsa, OK 74114 | Oil & Gas Operator | Oct 2025 |
| 1083 | Apex Minerals Inc | Oklahoma City, OK 73102 | Oil & Gas Operator | Mar 1994 |
| 1084 | Apex Natural Gas Co Inc | Canton, OH 44718 | Oil & Gas Operator | Dec 1991 |
| 1085 | Apex Natural Gas, LLC | Houston, TX 77002 | Gas Operator | Feb 2026 |
| 1086 | Apex Oil & Gas, Inc. | Houston, TX 77067 | Oil & Gas Operator | Oct 2009 |
| 1087 | Apex Oil Ventures Inc | | Oil & Gas Operator | Oct 2025 |
| 1088 | Apex Operating & Equip. Co. | Bowie, TX 76230 | Oil & Gas Operator | Nov 2003 |
| 1089 | Apex Operating Company, Inc. | Denver, CO 80202 | Gas Operator | Mar 2003 |
| 1090 | Apex Operating Partners, LLC | San Angelo, TX 76902 | Oil & Gas Operator | Feb 2026 |
| 1091 | Apex Production LTD. | Albany, TX 76430 | Oil Operator | Feb 2026 |
| 1092 | Apex Resources Inc | Allison Park, PA 15101-3838 | Oil & Gas Operator | Dec 1993 |
| 1093 | Apex Resources LLC | Kilgore, TX 75663 | Oil & Gas Operator | Feb 2026 |
| 1094 | Apex Royalties, Inc. | Midland, TX 79702 | Oil & Gas Operator | May 1997 |
| 1095 | Apexco Explor. & Prod., Inc. | | Oil & Gas Operator | May 1988 |
| 1096 | Apexco, Inc. | Sand Springs, OK 74063 | Oil & Gas Operator | Oct 2025 |
| 1097 | Apexco-McCormick-Coastal | | Oil & Gas Operator | Dec 1977 |
| 1098 | Apexway Corp. | | Oil Operator | Dec 2024 |
| 1099 | API Operating Co. | Houston, TX 77036 | Oil & Gas Operator | Feb 2026 |
| 1100 | Apogee Oil & Gas LLC | Edmond, OK 73034 | Oil Operator | Oct 2025 |