| 1101 | Andover Oil Comp | | Oil & Gas Operator | Oct 1989 |
| 1102 | Andover Oil Company | | Oil Operator | Sep 1982 |
| 1103 | Andrea Operating Company | Edmond, OK 73013-6627 | Oil & Gas Operator | Jan 2025 |
| 1104 | Andress Bill O | Tulsa, OK 74135-3553 | Oil & Gas Operator | Sep 2003 |
| 1105 | Andrew Alan Exploration, Inc. | Kilgore, TX 75663 | Oil & Gas Operator | Mar 2017 |
| 1106 | Andrew L. Newkirk | | Oil Operator | Feb 2025 |
| 1107 | Andrew, Robert Oneal | Olney, TX 76374 | Oil & Gas Operator | Sep 1998 |
| 1108 | Andrews & Corkran, L.L.C. | Austin, TX 78746 | Oil & Gas Operator | Feb 2000 |
| 1109 | Andrews Cable Tool Co | | Gas Operator | Nov 2000 |
| 1110 | Andrews, B. C. | Graham, TX 76450 | Oil & Gas Operator | May 2025 |
| 1111 | Andries Oil Company | | Oil Operator | Jan 2025 |
| 1112 | Andrikopoulos A G | Cheyenne, WY 82009 | Oil & Gas Operator | Dec 1994 |
| 1113 | Andrikopoulos Resources* A G | | Oil & Gas Operator | Jul 2015 |
| 1114 | Andrus Resources Corporation | Houston, TX 77046 | Oil & Gas Operator | Oct 2002 |
| 1115 | Anegada Energy LLC | Canonsburg, PA 15317-0400 | Gas Operator | Feb 2025 |
| 1116 | Anegada Resources | Kerrville, TX 78029 | Oil & Gas Operator | Jan 2002 |
| 1117 | Anejo Production, LLC | Electra, TX 76360 | Oil & Gas Operator | May 2025 |
| 1118 | Angel Exploration Company | Oklahoma City, OK 73102-8868 | Oil & Gas Operator | Jan 2019 |
| 1119 | Angel Exploration LLC | Oklahoma City, OK 73116-3603 | Oil & Gas Operator | Feb 2025 |
| 1120 | Angel Operating LLC | Metairie, LA 70033 | Oil Operator | May 2025 |
| 1121 | Angel Rose Energy, LLC | Olney, IL 62450 | Oil Operator | Dec 2023 |
| 1122 | Angelo, Ernest, Jr. | Midland, TX 79701 | Oil & Gas Operator | Mar 2008 |
| 1123 | Angerman Assoc Inc | Pittsburgh, PA 15238-1359 | Oil & Gas Operator | Dec 1998 |
| 1124 | Angerman Associates Inc | | Oil & Gas Operator | Mar 1998 |
| 1125 | Angle Exploratio | | Oil Operator | Jan 1987 |
| 1126 | Angle George A | | Gas Operator | Dec 1986 |
| 1127 | Angle Oil Compan | | Oil Operator | Jun 1994 |
| 1128 | Angle Oil Company | Hays, KS 67601 | Oil Operator | Sep 2002 |
| 1129 | Anglo Production Company | | Oil & Gas Operator | Nov 1983 |
| 1130 | Anglo-Dutch Energy, LLC | | Oil & Gas Operator | Sep 2022 |
| 1131 | Angus Petroleum Corporation | Chicago, IL 60660 | Oil & Gas Operator | Dec 2022 |
| 1132 | Anja Resources | Bridgeport, WV 26330 | Oil & Gas Operator | Dec 2021 |
| 1133 | Anjet Petroleum Company Inc | Gulfport, MS 39507-1301 | Oil & Gas Operator | Aug 2017 |
| 1134 | Ankor E&P Holdings Corporation | | Oil & Gas Operator | Jan 2021 |
| 1135 | Anloc, LLC | Houston, TX 77024 | Oil & Gas Operator | Apr 2019 |
| 1136 | Ann Brindle | | Oil Operator | Feb 2025 |
| 1137 | Ann Marie Tiers | | Oil Operator | Dec 1996 |
| 1138 | Annarock Petroleum LLC | Winter Garden, FL 34787 | Oil & Gas Operator | Dec 2024 |
| 1139 | Annco Pet. Co & Equipment, Inc | | Oil & Gas Operator | Sep 1982 |
| 1140 | Annex Oil Corp | | Oil & Gas Operator | Jun 2000 |
| 1141 | Annona Productions, Inc. | | Gas Operator | May 2019 |
| 1142 | Annulus Energy LLC | | Gas Operator | Dec 2021 |
| 1143 | Anr Limited Inc/Coastal | Houston, TX 770460995 | Oil & Gas Operator | Dec 1987 |
| 1144 | Anr Pipeline Company | Houston, TX 77002 | Oil & Gas Operator | Jan 2025 |
| 1145 | Anr Production Company | Houston, TX 77046 | Oil & Gas Operator | Aug 2017 |
| 1146 | Ansbro Petroleum Company, LLC | Denver, CO 80202 | Oil & Gas Operator | Feb 2008 |
| 1147 | Anschutz Corporation | Denver, CO 80202 | Oil & Gas Operator | Sep 2016 |
| 1148 | Anschutz Drilling Co. | | Oil Operator | Jul 1961 |
| 1149 | Anschutz Exploration Corporation | Denver, CO 80202 | Oil & Gas Operator | May 2025 |
| 1150 | Anschutz Oil Co. | | Oil & Gas Operator | Jul 1984 |
| 1151 | Anschutz Oil Company LLC | Denver, CO 80202 | Oil & Gas Operator | Sep 2020 |
| 1152 | Anschutz Pinedale Corporation | Denver, CO 80202 | Oil & Gas Operator | Dec 2015 |
| 1153 | Anshutz Oil | | Oil Operator | Dec 2009 |
| 1154 | Anson Charles Dba Anson Oil | Seminole, OK 74868 | Oil Operator | Jan 2025 |
| 1155 | Anson Company | Oklahoma City, OK 73124 | Oil & Gas Operator | Apr 2018 |
| 1156 | Anson Gas Corporation | Oklahoma City, OK 73116 | Oil & Gas Operator | May 1997 |
| 1157 | Anson J W | Seminole, OK 74818-1280 | Oil & Gas Operator | Oct 2020 |
| 1158 | Anson Robert L & Teresa M | Seminole, OK 74868 | Oil & Gas Operator | Feb 2025 |
| 1159 | Anstine & Musgrove Inc | Ponca City, OK 74602 | Oil & Gas Operator | Jan 2025 |
| 1160 | Anstine Oil Company | | Oil Operator | Jan 2025 |
| 1161 | Anstine-Musgrove | Ponca City, OK 74602 | Oil & Gas Operator | Feb 2017 |
| 1162 | Anstine-Musgrove Oil Company | Ponca City, OK 74602-0391 | Oil & Gas Operator | Jan 2013 |
| 1163 | Ansythe Exploration Co., Inc. | | Oil & Gas Operator | Oct 1982 |
| 1164 | Ant Hills Production | Lusk, WY 82225 | Oil & Gas Operator | Feb 2025 |
| 1165 | Antara Resources Inc | Houston, TX 77002 | Oil & Gas Operator | Apr 2004 |
| 1166 | Antares Energy Company | Houston, TX 77010 | Oil & Gas Operator | May 2025 |
| 1167 | Antares Oil Corp | Denver, CO 80202 | Oil & Gas Operator | Oct 2015 |
| 1168 | Antares Ventures, L.L.C. | | Oil Operator | Oct 2016 |
| 1169 | Antelope Energy Company LLC | Denver, CO 80202 | Oil & Gas Operator | Dec 2024 |
| 1170 | Antelope Energy Partners, LLC | Houston, TX 77027 | Oil & Gas Operator | May 2025 |
| 1171 | Antelope Production Co. | Midland, TX 79701 | Oil & Gas Operator | Oct 1995 |
| 1172 | Antelope Resources Inc | Billings, MT 59101 | Oil & Gas Operator | May 2017 |
| 1173 | Antero Energy LLC | Denver, CO 80202 | Gas Operator | Nov 2003 |
| 1174 | Antero Resources Bluestone LLC | | Gas Operator | Dec 2013 |
| 1175 | Antero Resources Corporation | Denver, CO 80202 | Oil & Gas Operator | Dec 2024 |
| 1176 | Antero Resources I, LP | Denver, CO 80202 | Oil & Gas Operator | Jun 2005 |
| 1177 | Antero Resources II, LP | Denver, CO 80202 | Oil & Gas Operator | May 2006 |
| 1178 | Antero Resources Piceance LLC | | Oil & Gas Operator | Dec 2012 |
| 1179 | Anterra Energy Services Inc. | | Oil & Gas Operator | Feb 2025 |
| 1180 | Anterra Services Inc. | | Oil & Gas Operator | Feb 2025 |
| 1181 | Anthony Oil & Gas Co. | Shreveport, LA 71135 | Oil Operator | May 1993 |
| 1182 | Anthony Oil Company | | Oil & Gas Operator | Oct 1987 |
| 1183 | Anthony, Bob G. Inc. | Brookhaven, MS 39601 | Oil & Gas Operator | May 2025 |
| 1184 | Antilley, Joe | Abilene, TX 79602 | Oil & Gas Operator | Jan 2024 |
| 1185 | Antioch Disposal Well Inc | Duncan, OK 73533 | Oil Operator | Jan 1994 |
| 1186 | Antioch Operating LLC | Dallas, TX 75206 | Oil & Gas Operator | Feb 2025 |
| 1187 | Antle Operating, Inc. | Graham, TX 76450 | Oil & Gas Operator | May 2025 |
| 1188 | Antle, E. | Graham, TX 76450 | Oil & Gas Operator | Oct 1994 |
| 1189 | Antler Energy LLC | Baggs, WY 82321 | Oil & Gas Operator | Feb 2025 |
| 1190 | Antlers Energy LLC | Tulsa, OK 74137 | Oil & Gas Operator | Jan 2025 |
| 1191 | Antrim Development Corp | | Oil & Gas Operator | Oct 2018 |
| 1192 | Anvil Oil Co., Inc. | Bartlesville, OK 74003-5030 | Oil & Gas Operator | Dec 2008 |
| 1193 | Anzalone, James A. | Leesburg, FL 34748 | Gas Operator | Dec 2023 |
| 1194 | Aoco Operating Company, L.L.C. | Houston, TX 77008 | Oil & Gas Operator | Feb 2005 |
| 1195 | Aoco Operating, L.P. | Houston, TX 77008 | Oil & Gas Operator | Mar 2008 |
| 1196 | Aocswd LLC | Marietta, OH 45750 | Oil & Gas Operator | Dec 2024 |
| 1197 | Aog Operating LLC | Oklahoma City, OK 73120 | Oil & Gas Operator | Jan 2025 |
| 1198 | Aog, Inc. | Norman, OK 73070 | Oil & Gas Operator | Nov 2014 |
| 1199 | Aogp, LLC | Turtle Lake, WI 54889 | Oil & Gas Operator | Sep 2019 |
| 1200 | Aop Operating Corporation | Dallas, TX 75313 | Oil & Gas Operator | Aug 2003 |