| 21301 | Osage Partners LLC | | Oil & Gas Operator | Jun 2025 |
| 21302 | Osage Petroleum Corporation | Saint Louis, MO 63131-4691 | Oil & Gas Operator | Mar 2009 |
| 21303 | Osage Resources, LLC | Wichita, KS 67202 | Oil & Gas Operator | Jan 2025 |
| 21304 | Osair Inc | Mentor, OH 44061 | Oil & Gas Operator | Dec 2021 |
| 21305 | Osborn Energy, L.L.C. | Bucyrus, KS 66013 | Oil & Gas Operator | Jul 2017 |
| 21306 | Osborn Heirs Co | San Antonio, TX 78217 | Oil & Gas Operator | Jun 2025 |
| 21307 | Osborn Heirs Com | | Oil & Gas Operator | May 1995 |
| 21308 | Osborn Heirs Company LTD | San Antonio, TX 78217 | Oil & Gas Operator | Mar 2025 |
| 21309 | Osborn Oil & Gas | | Oil & Gas Operator | Jun 1991 |
| 21310 | Osborn,W.B. Oil & Gas Operations | San Antonio, TX 78217 | Oil & Gas Operator | Jul 2025 |
| 21311 | Osborne Oil Co. | Dallas, TX 75244 | Oil & Gas Operator | Aug 2003 |
| 21312 | Osburn Gerald Dba Ozzy & Son Oil & Gas | Drumright, OK 74030-5467 | Oil Operator | Oct 2020 |
| 21313 | Oscar Oil Company | Iowa Park, TX 76367 | Oil & Gas Operator | Sep 2004 |
| 21314 | Oscar'S Well Service Inc | Okemah, OK 74859 | Oil & Gas Operator | Apr 1998 |
| 21315 | Osceola Oil & Gas Corporation | Somerset, TX 78069 | Oil & Gas Operator | Aug 1994 |
| 21316 | Osci Oil And Gas, Inc. | Parker, KS 66072 | Oil Operator | Jun 1998 |
| 21317 | Oshtah Oil Company LLC | Stratford, OK 74872 | Oil & Gas Operator | Sep 2018 |
| 21318 | Osman Global Services LLC | | Oil & Gas Operator | Jan 2025 |
| 21319 | Oso Exploration & Production, LLC | Houston, TX 77269 | Oil Operator | Jul 2025 |
| 21320 | Oso Exploration Co. | San Antonio, TX 78217 | Oil & Gas Operator | Jul 2011 |
| 21321 | Oso Oil & Gas Properties LLC | Price, UT 84501 | Gas Operator | Jun 2016 |
| 21322 | Oso Perdido Services LLC | Flatonia, TX 78941 | Oil Operator | May 2025 |
| 21323 | Oso Resources LLC | Oklahoma City, OK 73118-5022 | Oil & Gas Operator | Apr 2025 |
| 21324 | Ososki Edward D Dba Federal Oil Company | | Oil & Gas Operator | Jun 2025 |
| 21325 | Osprey Petroleum Company, Inc. | Manvel, TX 77578 | Oil & Gas Operator | May 2020 |
| 21326 | Osr Oil & Gas Company | Victoria, TX 77902 | Oil & Gas Operator | Jul 2000 |
| 21327 | Osr Oil & Gas Corp | Midland, TX 79710 | Oil & Gas Operator | Dec 2024 |
| 21328 | Osterhout Phillip L | Drumright, OK 74030-0693 | Oil & Gas Operator | Jan 2014 |
| 21329 | Ostrich Oil & Gas, LLC | Midland, TX 79701 | Oil & Gas Operator | Jul 2025 |
| 21330 | Oswego Arbuckle Enterprise Inc | S Coffeyville, OK 74072-9702 | Oil & Gas Operator | Mar 2015 |
| 21331 | Oswego Oil & Gas | | Oil & Gas Operator | Jun 1984 |
| 21332 | Oswego, Inc. | Amarillo, TX 79109 | Oil & Gas Operator | Jun 2004 |
| 21333 | Osyka Oil & Gas, Inc. | Metairie, LA 70004 | Oil & Gas Operator | Jul 2025 |
| 21334 | Osyka Permian, LLC | Houston, TX 77079 | Oil & Gas Operator | Jul 2025 |
| 21335 | Osyka Producing Company, Inc. | Houston, TX 77242 | Oil & Gas Operator | Jul 2025 |
| 21336 | Otb Operating, LLC | Stanton, TX 79782 | Oil & Gas Operator | Jul 2025 |
| 21337 | Otc Investors Inc | | Oil Operator | Jan 2025 |
| 21338 | Otc Petroleum Corporation | Nichols Hill, OK 73116 | Oil & Gas Operator | Mar 2015 |
| 21339 | Otc/Occ Not Assigned | | Oil & Gas Operator | Dec 2024 |
| 21340 | Otex Inc | N Canton, OH 44720 | Oil & Gas Operator | Dec 1988 |
| 21341 | Otex LLC | Santa Anna, TX 76878 | Oil & Gas Operator | Jul 2025 |
| 21342 | Otex Resources LLC | Baytown, TX 77520 | Oil & Gas Operator | Jul 2025 |
| 21343 | Otis C. Coles, Jr. | | Oil & Gas Operator | Jan 1998 |
| 21344 | Oto, Co. | Woodward, OK 73802 | Oil & Gas Operator | Jun 1998 |
| 21345 | Ott Inc | Casper, WY 82602 | Oil Operator | Apr 2025 |
| 21346 | Otter Exploration Inc | Warren, PA 16365-9689 | Oil & Gas Operator | Dec 2021 |
| 21347 | Ouachita Development Corp. | | Gas Operator | Mar 2014 |
| 21348 | Ouachita Exploration Inc | Chickasha, OK 73018 | Oil & Gas Operator | May 2025 |
| 21349 | Ouida Oil | Rowlett, TX 75030 | Oil & Gas Operator | Mar 2008 |
| 21350 | Ouida Oil Co. | | Oil & Gas Operator | Apr 1999 |
| 21351 | Outback Petroleum Inc | Moore, OK 73160-9998 | Oil & Gas Operator | Mar 2015 |
| 21352 | Outlaw Oil LLC | Caldwell, TX 77836 | Oil & Gas Operator | Jul 2025 |
| 21353 | Outlaw Well Service LLC | Hays, KS 67601 | Oil Operator | Mar 2025 |
| 21354 | Outline Oil Company LLC | Beeville, TX 78104 | Oil Operator | Jul 2025 |
| 21355 | Outline Oil Corp. | San Antonio, TX 78217 | Oil & Gas Operator | Jul 2025 |
| 21356 | Outlook Petroleum Corp. | Midland, TX 79702 | Oil & Gas Operator | Jan 2001 |
| 21357 | Outman, Joshua J. | Andover, NY 14806 | Oil & Gas Operator | Dec 2024 |
| 21358 | Output Acquisition Corp. | | Oil & Gas Operator | Jul 2010 |
| 21359 | Output Exploration LLC | | Oil & Gas Operator | Dec 2006 |
| 21360 | Ouut Investing LLC | Mineral Wells, TX 76068 | Oil Operator | Mar 2020 |
| 21361 | Ovaco Energy Inc. | | Oil & Gas Operator | Nov 2009 |
| 21362 | Ovation Energy II, LP | Houston, TX 77279 | Oil & Gas Operator | Jun 2011 |
| 21363 | Ovation Energy, LP | N Richlnd HLS, TX 76180 | Oil & Gas Operator | Sep 2004 |
| 21364 | Overfield, Lee R | Waverly, KY 42462 | Oil Operator | Dec 2016 |
| 21365 | Overflow Energy Stack LLC | Booker, TX 79005 | Oil Operator | Sep 2022 |
| 21366 | Overflow Energy, LLC | Perryton, TX 79070 | Oil & Gas Operator | Jul 2025 |
| 21367 | Overland Exploration Company | | Oil Operator | Jan 2025 |
| 21368 | Overland Investments Inc | Coweta, OK 74429 | Oil & Gas Operator | Apr 2025 |
| 21369 | Overland Operating Company, LLC | Abilene, TX 79601 | Oil Operator | Jul 2025 |
| 21370 | Overland Resources LLC | Greenwood VIllage, CO 80111 | Oil & Gas Operator | Jul 2019 |
| 21371 | Overly Operating Co. | San Antonio, TX 78209 | Oil & Gas Operator | Jul 2013 |
| 21372 | Overstreet, Jamie L | Hondo, TX 78861 | Oil & Gas Operator | Jul 2025 |
| 21373 | Overton Park Oil & Gas LP | Fort Worth, TX 76109 | Oil & Gas Operator | Jul 2025 |
| 21374 | Ovintiv Mid-Continent Inc. | The Woodlands, TX 77380-2764 | Oil & Gas Operator | May 2025 |
| 21375 | Ovintiv USA Inc. | Denver, CO 80202 | Oil & Gas Operator | Jul 2025 |
| 21376 | Owco Production Co., Inc. | | Oil Operator | Aug 1997 |
| 21377 | Owen Production Co | | Oil Operator | May 2001 |
| 21378 | Owen'S Pumping Service | | Oil Operator | Mar 2025 |
| 21379 | Owen, Matthew | Hamilton, KS 66853 | Oil Operator | Sep 2016 |
| 21380 | Owens James W | Tulsa, OK 74114-1425 | Oil & Gas Operator | Oct 2022 |
| 21381 | Owens Oil | | Oil Operator | Dec 2000 |
| 21382 | Owens Oil Company | Iowa Park, TX 76367 | Oil & Gas Operator | Sep 2008 |
| 21383 | Owens Oil Company, LLC | Yates Center, KS 66783 | Oil Operator | Mar 2025 |
| 21384 | Owens Pet Inc | Midland, TX 79702 | Oil & Gas Operator | Aug 1995 |
| 21385 | Owens Petroleum | | Oil Operator | May 2006 |
| 21386 | Owens Petroleum LLC | Yates Center, KS 66783 | Oil & Gas Operator | Mar 2025 |
| 21387 | Owens Petroleum, Inc. | Midland, TX 79702 | Oil & Gas Operator | Aug 1995 |
| 21388 | Owi Operating Co. LC | Ottawa, KS 66067 | Oil & Gas Operator | Dec 2009 |
| 21389 | Owl Creek Operating Co., Inc. | Denver, CO 80206 | Oil & Gas Operator | Jul 2025 |
| 21390 | Owl Creek Production Co., Inc. | Houston, TX 77027 | Oil & Gas Operator | Apr 2006 |
| 21391 | Owl Creek Production Co., LLC | Denver, CO 80265 | Oil & Gas Operator | Jan 2006 |
| 21392 | Owl Operating Ventures L.L.C. | Midland, TX 79708 | Oil & Gas Operator | Dec 2022 |
| 21393 | Owl Ops II LLC | Midland, TX 79701 | Oil & Gas Operator | Jul 2025 |
| 21394 | Owl Ops LLC | Midland, TX 79701 | Oil & Gas Operator | Jul 2025 |
| 21395 | Own Resources Operating LLC | The Woodlands, TX 77381 | Oil & Gas Operator | May 2025 |
| 21396 | Ows Acquisition Co LLC | Louisville, OH 44641 | Oil & Gas Operator | Dec 2024 |
| 21397 | Ows Energy LLC | Carlton, PA 16311-1605 | Oil & Gas Operator | May 2025 |
| 21398 | Ows Energy, Inc. | Montgomery, TX 77356 | Oil & Gas Operator | Jul 2025 |
| 21399 | Oxbow EP LLC | Mathis, TX 78368 | Oil Operator | Jul 2025 |
| 21400 | Oxbow Oil Company,A Kansas General Partnership | Grenola, KS 67346 | Oil Operator | Apr 2015 |