| 201 | Anstine-Musgrove Oil Company | Ponca City, OK 74602-0391 | Oil & Gas Operator | Jan 2013 |
| 202 | Antara Resources Inc | Houston, TX 77002 | Oil & Gas Operator | Apr 2004 |
| 203 | Antares Energy Company | Houston, TX 77010 | Oil & Gas Operator | Jul 2025 |
| 204 | Antero Resources Corporation | Denver, CO 80202 | Oil & Gas Operator | Mar 2025 |
| 205 | Antioch Disposal Well Inc | Duncan, OK 73533 | Oil Operator | Jan 1994 |
| 206 | Antioch Operating LLC | Dallas, TX 75206 | Oil & Gas Operator | May 2025 |
| 207 | Antlers Energy LLC | Tulsa, OK 74137 | Oil & Gas Operator | Apr 2025 |
| 208 | Anvil Oil Co., Inc. | Bartlesville, OK 74003-5030 | Oil & Gas Operator | Dec 2008 |
| 209 | Aog Operating LLC | Oklahoma City, OK 73120 | Oil & Gas Operator | Apr 2025 |
| 210 | Apache Corporation | Houston, TX 77042 | Oil & Gas Operator | Jul 2025 |
| 211 | Apache Energy Resources Corp | Houston, TX 77056 | Oil & Gas Operator | Mar 2015 |
| 212 | Apache PHN North America, Inc. | | Oil & Gas Operator | Mar 2005 |
| 213 | Apc Operating Partnership LP | Tulsa, OK 74136-4224 | Oil & Gas Operator | Jun 2015 |
| 214 | Apco Oil Corporation | Oklahoma City, OK 73116 | Oil & Gas Operator | Jun 1993 |
| 215 | Apex Energy, Inc. | Corpus Chrsti, TX 78413 | Oil & Gas Operator | Jul 2025 |
| 216 | Apex Minerals Inc | Oklahoma City, OK 73102 | Oil & Gas Operator | Mar 1994 |
| 217 | Apexco, Inc. | Sand Springs, OK 74063 | Oil & Gas Operator | Mar 2025 |
| 218 | Apogee Oil & Gas LLC | Edmond, OK 73034 | Oil Operator | Apr 2025 |
| 219 | Apollo Energies Inc | Pratt, KS 67124 | Oil & Gas Operator | May 2025 |
| 220 | Apple Petroleum Corp | Mountainside, NJ 7092 | Oil Operator | Mar 2013 |
| 221 | Appleton Oil Company | Chicago, IL 60657-4097 | Oil & Gas Operator | May 1993 |
| 222 | Apx Corporation | Houston, TX 77251 | Oil & Gas Operator | Dec 2009 |
| 223 | Aqua-Oil Inc | Enid, OK 73703-6511 | Oil & Gas Operator | May 2019 |
| 224 | Aquanyx Midstream LLC | Oklahoma City, OK 73131 | Oil Operator | Apr 2025 |
| 225 | Aquila Energy Resources Corp. | Houston, TX 77042 | Oil & Gas Operator | Nov 2013 |
| 226 | Arapaho Petroleum Inc | Englewood, CO 80155 | Oil & Gas Operator | Nov 1998 |
| 227 | Arapahoe Resources LLC | Oklahoma City, OK 73118 | Oil & Gas Operator | Apr 2025 |
| 228 | Araxas Exploration, Inc. | The Woodlands, TX 77380 | Oil & Gas Operator | Apr 1998 |
| 229 | Arbor Petroleum Corporation | Oklahoma City, OK 73102-4003 | Oil & Gas Operator | Mar 2011 |
| 230 | Arbuckle Enterprises, Inc. | Edmond, OK 73083 | Oil & Gas Operator | Apr 2025 |
| 231 | Arcadia Oil Company | Edmond, OK 73013-9009 | Oil & Gas Operator | Oct 2015 |
| 232 | Arcadia Refining Company | Tyler, TX 75701 | Oil & Gas Operator | Jan 1994 |
| 233 | Arcana Energy Corp Inc | Bartlesville, OK 74006 | Oil Operator | May 2017 |
| 234 | Arch Oil & Gas, LLC | Dallas, TX 75254 | Oil & Gas Operator | Jul 2025 |
| 235 | Archibald Oil & Gas Operating Inc | Ada, OK 74820 | Oil & Gas Operator | May 2025 |
| 236 | Arcotex Oil & Gas Inc | Gainesville, TX 76241-1357 | Oil & Gas Operator | May 2025 |
| 237 | Ardent Energy LLC | Edmond, OK 73083 | Oil & Gas Operator | Jul 2025 |
| 238 | Ardmore Production & Exploration Co | Ardmore, OK 73401 | Oil & Gas Operator | May 2025 |
| 239 | Arena Resources Inc | Tulsa, OK 74136 | Oil & Gas Operator | Mar 2015 |
| 240 | Argali Resources | Dallas, TX 75206 | Oil & Gas Operator | Apr 2003 |
| 241 | Argent Energy (Us) Holdings Inc | Sugar Land, TX 77479 | Oil & Gas Operator | Sep 2021 |
| 242 | Arica Energy Company | Beggs, OK 74421 | Oil Operator | Jun 1994 |
| 243 | Aries Exploration Co Inc | Maud, OK 74854-0160 | Oil & Gas Operator | May 2013 |
| 244 | Aries Operating LP | Houston, TX 77042 | Oil & Gas Operator | Jul 2025 |
| 245 | Arkana Operating Company, Inc | Fort Worth, TX 76116-5707 | Oil & Gas Operator | Jul 2008 |
| 246 | Arkla Energy Resources | Shreveport, LA 71151 | Oil & Gas Operator | Mar 2015 |
| 247 | Arkoma Gas Company | Edmond, OK 73003-5672 | Gas Operator | Apr 2010 |
| 248 | Arkoma Holding Corporation | Oklahoma City, OK 73102-5684 | Gas Operator | Jul 2007 |
| 249 | Arkoma Operations LLC | Tulsa, OK 74114-3502 | Oil & Gas Operator | Apr 2025 |
| 250 | Arkoma Production Company | Shreveport, LA 71101 | Gas Operator | Apr 2020 |
| 251 | Arkoma Resources LLC | Henryetta, OK 74437 | Oil & Gas Operator | Apr 2025 |
| 252 | Armitage Jerald Dba Jem Oilfield Services LLC | Bartlesville, OK 74003 | Oil Operator | May 2025 |
| 253 | Armor Energy II LLC | Tulsa, OK 74145 | Oil & Gas Operator | May 2025 |
| 254 | Armor Energy LLC | Tulsa, OK 74146 | Oil & Gas Operator | Jun 2022 |
| 255 | Armor Petroleum, Inc. | Wichita Falls, TX 76308 | Oil & Gas Operator | Jul 2025 |
| 256 | Armor SWD Inc | Oklahoma City, OK 73112 | Oil Operator | May 2020 |
| 257 | Armstrong & McLeod Company | Okmulgee, OK 74447-0819 | Oil & Gas Operator | Dec 1993 |
| 258 | Armstrong Energy Corporation | Roswell, NM 88202 | Oil & Gas Operator | May 2025 |
| 259 | Arnett Saltwater Disposal LLC | Shattuck, OK 73858-0848 | Oil Operator | Dec 2021 |
| 260 | Arnold N Krebbs | | Oil Operator | Apr 2025 |
| 261 | Arnold Oil Properties, Inc. | Oklahoma City, OK 73112 | Oil & Gas Operator | May 2019 |
| 262 | Arnold Oil Properties, L.L.C. | Nichols Hill, OK 73116 | Oil & Gas Operator | Jul 2025 |
| 263 | Aroc (Texas) Inc | Houston, TX 77090 | Oil & Gas Operator | Dec 2014 |
| 264 | Arp Oklahoma LLC | Fort Worth, TX 76102-7426 | Oil & Gas Operator | Feb 2020 |
| 265 | Arpel, Inc. | Oklahoma City, OK 73102 | Oil & Gas Operator | Apr 2014 |
| 266 | Arrington CJM, Inc. | Canadian, TX 79014 | Oil & Gas Operator | Nov 2021 |
| 267 | Arrington David Oil & Gas Inc | Midland, TX 79702-2071 | Oil & Gas Operator | Dec 2014 |
| 268 | Arrington Properties Inc | Edmond, OK 73034-3724 | Oil & Gas Operator | May 1996 |
| 269 | Arrow Energy, Incorporated | Houston, TX 77008 | Oil & Gas Operator | Apr 2025 |
| 270 | Arrow Oil & Gas, LLC | Norman, OK 73070 | Oil & Gas Operator | Jul 2025 |
| 271 | Arrow Operating Company | Dallas, TX 75231 | Oil & Gas Operator | Dec 2024 |
| 272 | Arrow Production Co. | Tulsa, OK 74108 | Oil & Gas Operator | Dec 2009 |
| 273 | Arrowhead Energy Inc | Edmond, OK 73013 | Oil & Gas Operator | May 2025 |
| 274 | Arrowhead Operating Inc. | Argyle, TX 76226 | Oil & Gas Operator | Jul 2025 |
| 275 | Aruba Petroleum, Inc. | Dallas, TX 75379 | Oil & Gas Operator | Apr 2025 |
| 276 | Arvine Pipe & Supply Co Inc | Norman, OK 73069-8224 | Oil & Gas Operator | Jul 2015 |
| 277 | Asher Resources | Boerne, TX 78006 | Oil & Gas Operator | May 2015 |
| 278 | Asher Tip Corporation | Fairfax, OK 74637-0308 | Oil & Gas Operator | Nov 2003 |
| 279 | Ashland Exploration Inc | Houston, TX 77218 | Oil & Gas Operator | Nov 2000 |
| 280 | Ashley, Jim Company | Broken Arrow, OK 74012 | Oil Operator | Feb 2025 |
| 281 | Ashlock Thomas J | Skiatook, OK 74070 | Oil & Gas Operator | Aug 2015 |
| 282 | Aspen Energy Group, Inc. | Santa Ynez, CA 93460 | Oil & Gas Operator | Mar 2015 |
| 283 | Aspen Land & Exploration Co | Tulsa, OK 74159-0335 | Oil & Gas Operator | Jul 2001 |
| 284 | Aspen Operating Company LLC | Fort Worth, TX 76116 | Oil & Gas Operator | Jul 2025 |
| 285 | Aspire Exploration LLC | Cleveland, OK 74020-0727 | Oil & Gas Operator | Feb 2015 |
| 286 | Assiduous Energy LLC | Edmond, OK 73034 | Oil & Gas Operator | May 2025 |
| 287 | Associated Oil Properties | Agoura Hills, CA 91376 | Oil Operator | Nov 2020 |
| 288 | Associated Petro Invest Inc | Stillwater, OK 74076-2346 | Oil & Gas Operator | May 2013 |
| 289 | Astro Corporation | Tulsa, OK 74145 | Oil & Gas Operator | Apr 2007 |
| 290 | Astro Energy Corporation | Edmond, OK 73083-3607 | Oil & Gas Operator | Sep 2014 |
| 291 | Atalaya Resources LLC | Tulsa, OK 74103-4361 | Oil & Gas Operator | Dec 2022 |
| 292 | Atchley Resources, Inc. | Oklahoma City, OK 73134 | Oil & Gas Operator | May 2025 |
| 293 | Athabasca Energy Corporation | Simonton, TX 77476 | Oil & Gas Operator | Dec 2017 |
| 294 | Athan Inc | Edmond, OK 73013-6628 | Oil & Gas Operator | Apr 2025 |
| 295 | Athena Energy, Inc. | Gallatin, TN 37066 | Oil & Gas Operator | Jul 2025 |
| 296 | Atkinson J V | Midland, TX 79702 | Oil & Gas Operator | Nov 2005 |
| 297 | Atkinson WM H Estate | Oklahoma City, OK 73156 | Oil & Gas Operator | Nov 2001 |
| 298 | Atlanko Oil & Gas Inc | Tulsa, OK 74135-7846 | Oil & Gas Operator | Apr 2025 |
| 299 | Atlantic Richfield Company | Plano, TX 75074 | Oil & Gas Operator | Dec 2016 |
| 300 | Atlas Oil Inc | Oklahoma City, OK 73154-0467 | Oil & Gas Operator | Aug 2008 |