| 201 | A J S Oil Corporation | Oklahoma City, OK 73112-4799 | Oil & Gas Operator | Jul 2004 |
| 202 | A K Holdings Inc | Scottsdale, AZ 85254 | Oil & Gas Operator | Mar 2011 |
| 203 | A L Jones Revocable Trust | Wilson, OK 73463-7316 | Oil Operator | Jul 2013 |
| 204 | A Miller Oil Company | Millersburg, OH 44654 | Oil & Gas Operator | Dec 2024 |
| 205 | A N R Pipeline Co | | Oil & Gas Operator | Jan 2025 |
| 206 | A N R Storage Company | | Oil & Gas Operator | Oct 2016 |
| 207 | A P S, Inc. | Hays, KS 67601 | Oil Operator | Mar 2024 |
| 208 | A P X Corporatio | | Oil & Gas Operator | Nov 1992 |
| 209 | A Producing Co | Wooster, OH 44691 | Oil & Gas Operator | Dec 1992 |
| 210 | A R & R Limited | | Oil & Gas Operator | Jul 1993 |
| 211 | A R W Exploration Corp | Stillwater, OK 74076 | Oil & Gas Operator | May 2013 |
| 212 | A S B Oil & Gas Exploration LLC | Sand Springs, OK 74063-1508 | Oil & Gas Operator | Nov 2021 |
| 213 | A S Energy | Tiffin, OH 44883 | Oil & Gas Operator | Dec 2001 |
| 214 | A S N F Producing Inc | N. Canton, OH 44720 | Oil & Gas Operator | Dec 2013 |
| 215 | A T M Corporation | Mathis, TX 78368 | Oil & Gas Operator | Oct 2002 |
| 216 | A T Oil | Bartlesville, OK 74003 | Oil Operator | Mar 1996 |
| 217 | A V Company | Burton, WV 26562-0000 | Gas Operator | Dec 2021 |
| 218 | A W Yenne Trust No 2 | Wooster, OH 44691 | Oil & Gas Operator | Dec 2018 |
| 219 | A X & P Incorpor | | Oil Operator | Sep 1996 |
| 220 | A X & P, Inc. | Independence, KS 67301 | Oil & Gas Operator | Jul 2015 |
| 221 | A&K Production LLC Of Texas | | Oil & Gas Operator | Nov 2024 |
| 222 | A&M Oil & Gas LLC | Kermit, TX 79745 | Oil & Gas Operator | May 2026 |
| 223 | A&S Mineral Development Company, LLC | Poplar, MT 59255 | Oil & Gas Operator | Mar 2026 |
| 224 | A-1 Oil Operators | Beggs, OK 74421-0329 | Oil & Gas Operator | Jan 2013 |
| 225 | A-1 Well Service | Coffeyville, KS 67337-9578 | Oil & Gas Operator | Mar 2021 |
| 226 | A-E Operating Committee | Wichita Falls, TX 76307 | Oil & Gas Operator | Dec 1996 |
| 227 | A-G-B, Inc. | Houston, TX 77084 | Oil & Gas Operator | Aug 2003 |
| 228 | A-W Wellman Limited | East Sparta, OH 44626 | Oil & Gas Operator | Dec 2001 |
| 229 | A. B. Energy LLC | Chester, MT 59522 | Oil & Gas Operator | Feb 2026 |
| 230 | A. Bauer, LLC | Red Rock, TX 78662 | Oil Operator | May 2026 |
| 231 | A. Francis Vonfeldt Co. | | Oil Operator | Nov 2019 |
| 232 | A. J. Hayes | | Oil & Gas Operator | Dec 1998 |
| 233 | A. J. Hodges, Ind. Inc Et Al | | Oil & Gas Operator | Jan 1979 |
| 234 | A. L. & V. I. Grayson | | Oil Operator | Dec 1993 |
| 235 | A. L. Coon | | Oil Operator | May 1979 |
| 236 | A. M. A. Chiles | | Oil & Gas Operator | Jan 2025 |
| 237 | A. Michael Hyde Oil & Gas Co. | | Oil & Gas Operator | Jan 1989 |
| 238 | A. P. B. Petro | Winters, TX 79567 | Oil & Gas Operator | Oct 2005 |
| 239 | A. R. & R., LTD. | Bartlesville, OK 74006 | Oil & Gas Operator | Dec 2025 |
| 240 | A. R. Wherrett Trustees | | Oil Operator | Jan 1987 |
| 241 | A. S. Johnston Drilling Corp. | | Oil & Gas Operator | Dec 1987 |
| 242 | A. Scott Ritchie | | Oil Operator | Mar 1985 |
| 243 | A. T. Teague, Jr. | | Oil Operator | Aug 1993 |
| 244 | A. W. Sour, Jr. | | Oil Operator | Mar 2003 |
| 245 | A.A.F. Production Co., Inc. | Abilene, TX 79606 | Oil & Gas Operator | Dec 1997 |
| 246 | A.C.T. Operating Company | Lubbock, TX 79401 | Oil & Gas Operator | May 2026 |
| 247 | A.D. Operating | Graham, TX 76450 | Oil & Gas Operator | May 2026 |
| 248 | A.D.A. Oil Co | Iowa Park, TX 76367 | Oil Operator | Aug 2003 |
| 249 | A.D.C.O. Well Services Inc. | Waterloo, NY 13165 | Gas Operator | Dec 2024 |
| 250 | A.D.I.D. Corporation | Emlyn, KY 40730 | Oil & Gas Operator | Dec 2019 |
| 251 | A.D.S. Resources, Inc. | Lubbock, TX 79413 | Oil & Gas Operator | Jul 2008 |
| 252 | A.E.N. Energy | Abilene, TX 79608 | Oil & Gas Operator | Feb 2005 |
| 253 | A.E.N. Energy, Inc. | Abilene, TX 79608 | Oil & Gas Operator | Jan 1996 |
| 254 | A.J. Hodges Industries, Inc. | | Oil & Gas Operator | Sep 1987 |
| 255 | A.L.S. Resources Inc. | | Oil Operator | Dec 2004 |
| 256 | A.O.E. Operators, Inc. | Fulshear, TX 77441 | Oil & Gas Operator | May 2026 |
| 257 | A2c Energy LLC | Lockhart, TX 78644 | Oil Operator | May 2026 |
| 258 | A2k LLC | Lancaster, NY 14086 | Gas Operator | Dec 2024 |
| 259 | A5 Oil And Gas LLC | | Oil Operator | Dec 2024 |
| 260 | Aa Production Services Inc. | | Gas Operator | Dec 2025 |
| 261 | Aaa Oil & Gas Inc | Pauls Valley, OK 73075-0863 | Oil Operator | Mar 2000 |
| 262 | Aaa Oil Company | Castroville, TX 78009 | Oil & Gas Operator | May 2026 |
| 263 | Aalpha Energy Inc. | | Oil & Gas Operator | Mar 2026 |
| 264 | Aardolie Oil Company | Dallas, TX 75370 | Oil & Gas Operator | Jul 2003 |
| 265 | Aaron & Jeter | Seminole, TX 79360 | Oil & Gas Operator | Jan 2003 |
| 266 | Aaron Arnold B | Sulphur, OK 73086-6853 | Oil & Gas Operator | May 2004 |
| 267 | Aaron Oil Company Inc | Shawnee, OK 74801-2321 | Oil Operator | Oct 2022 |
| 268 | Aaron Oil Operations LLC | Hays, KS 67601 | Oil Operator | Dec 2025 |
| 269 | Aaron Well Service Inc | Enid, OK 73703 | Gas Operator | Feb 2026 |
| 270 | Aaronmark Services, LLC | New Braunfels, TX 78130 | Oil Operator | May 2026 |
| 271 | Aas Oil Co., Inc. | Arkansas City, KS 67005 | Oil & Gas Operator | Dec 2025 |
| 272 | Ab Reserve, LLC | Rockdale, TX 76567 | Oil Operator | May 2026 |
| 273 | Ab Resources Oh LLC | Brecksville, OH 44141 | Oil & Gas Operator | Dec 2010 |
| 274 | Ab Resources Pa LLC | Brecksville, OH 44141-3296 | Oil & Gas Operator | Dec 2011 |
| 275 | Aba Energy Corporation | | Oil & Gas Operator | Mar 2026 |
| 276 | Aba Oil LLC | Burkburnett, TX 76354 | Oil Operator | May 2026 |
| 277 | Abaco Operating, LLC | San Antonio, TX 78209 | Oil & Gas Operator | May 2026 |
| 278 | Abarr Trust (The) | Oklahoma City, OK 73179 | Oil & Gas Operator | Feb 2026 |
| 279 | Abarta Oil & Gas Co., Inc. | Pittsburgh, PA 15238 | Oil & Gas Operator | Dec 2020 |
| 280 | Abarta Oil & Gas Co., LLC | | Oil & Gas Operator | Dec 2021 |
| 281 | Abb Oil Co., Inc. | Wichita Falls, TX 76310 | Oil & Gas Operator | May 2026 |
| 282 | Abbey, Kevin R. | South Dayton, NY 14138 | Gas Operator | Dec 2024 |
| 283 | Abbott Donald Jay | Edinboro, PA 16412-4129 | Gas Operator | Dec 2018 |
| 284 | Abbott, John Operating | Abilene, TX 79605 | Oil & Gas Operator | May 2026 |
| 285 | ABC NRG | Vernon, TX 76384 | Oil Operator | May 2026 |
| 286 | ABC Oil & Gas | Morris, OK 74445-0273 | Oil & Gas Operator | May 2025 |
| 287 | ABC Oil Company Inc | Wichita Falls, TX 76301 | Oil & Gas Operator | Oct 2023 |
| 288 | Abco Petroleum Corp. | | Oil & Gas Operator | Feb 1999 |
| 289 | Abderhalden, R. R. | Wichita, KS 67202 | Oil & Gas Operator | Dec 2019 |
| 290 | Abe Giesbrecht | | Gas Operator | Dec 1983 |
| 291 | Abel Production Company | San Angelo, TX 76904 | Oil & Gas Operator | Sep 2000 |
| 292 | Abel, M.D. Co. | Lampasas, TX 76550 | Oil & Gas Operator | Jun 2017 |
| 293 | Aber Oil & Gas Co. | Tyler, TX 75702 | Oil & Gas Operator | Nov 2013 |
| 294 | Abercrombie A L | | Oil & Gas Operator | Nov 1995 |
| 295 | Abercrombie A L Inc | Wichita, KS 67202 | Oil & Gas Operator | Dec 2025 |
| 296 | Abercrombie Dril | | Oil Operator | Jan 1990 |
| 297 | Abercrombie Drilling, Inc. | Wichita, KS 67202 | Oil Operator | May 1997 |
| 298 | Abercrombie Energy, LLC | Wichita, KS 67212 | Oil & Gas Operator | Dec 2025 |
| 299 | Aberdeen American Petr Co Inc | | Oil & Gas Operator | Dec 1989 |
| 300 | Aberdeen Petroleum (USA) Inc. | Abilene, TX 79608 | Oil & Gas Operator | Sep 1994 |