| 4201 | Omimex Petroleum Inc | Fort Worth, TX 76120 | Oil & Gas Operator | Aug 2022 |
| 4202 | Omni Oil & Gas, Inc. | San Antonio, TX 78229 | Oil & Gas Operator | Oct 2017 |
| 4203 | On-Line Oil Inc | Oklahoma City, OK 73105-5208 | Oil & Gas Operator | Mar 2015 |
| 4204 | Onapa Gas Company LLC | Tulsa, OK 74136-7253 | Gas Operator | Nov 2019 |
| 4205 | Oneok Exploration Company | Tulsa, OK 74102 | Oil & Gas Operator | Feb 2017 |
| 4206 | Oneok Field Services Company | Tulsa, OK 74103 | Oil & Gas Operator | Jul 2022 |
| 4207 | Oneok Gas Processing LLC | Tulsa, OK 74103 | Oil & Gas Operator | May 2018 |
| 4208 | Oneok Gas Transportation Co | Tulsa, OK 74121-2089 | Oil & Gas Operator | Oct 2014 |
| 4209 | Oneok Resources Company | Tulsa, OK 74102 | Oil & Gas Operator | Feb 2017 |
| 4210 | Onpoint Oil & Gas LLC | Oklahoma City, OK 73170-4848 | Oil & Gas Operator | Apr 2025 |
| 4211 | Onshore Royalties LLC | Houston, TX 77269 | Oil & Gas Operator | May 2025 |
| 4212 | Onyx Energy Corporation | Oklahoma City, OK 73157 | Oil & Gas Operator | May 1994 |
| 4213 | Onyx Properties Corp | Oklahoma City, OK 73114 | Oil & Gas Operator | May 2006 |
| 4214 | Opal Operating Company LLC | Edmond, OK 73013 | Oil & Gas Operator | Jul 2025 |
| 4215 | Open Door Holdings Inc | Surprise, AZ 85387-2015 | Oil & Gas Operator | Feb 2024 |
| 4216 | Open Door Productions Inc | Muskogee, OK 74401-1032 | Oil & Gas Operator | Apr 2020 |
| 4217 | Open Range Energy LLC | Jones, OK 73049-8744 | Oil & Gas Operator | Mar 2025 |
| 4218 | Optima Exploration LLC | Tulsa, OK 74116-5664 | Oil & Gas Operator | Mar 2015 |
| 4219 | Opubco Resources Of TX Inc | Dallas, TX 75231 | Oil & Gas Operator | Sep 2005 |
| 4220 | Oracle Resources Oklahoma LP | Dallas, TX 75240-5751 | Oil & Gas Operator | Feb 2008 |
| 4221 | Orason Resources Inc | Tulsa, OK 74169-1225 | Oil & Gas Operator | Nov 2006 |
| 4222 | Orca Operating Company LLC | Houston, TX 77056 | Oil & Gas Operator | May 2025 |
| 4223 | Oren Stone | Erick, OK 73645-4542 | Gas Operator | Jun 2022 |
| 4224 | Orion Exploration LLC | Tulsa, OK 74105-5153 | Oil & Gas Operator | Apr 2015 |
| 4225 | Orion Exploration Partners LLC | Tulsa, OK 74105-5153 | Oil & Gas Operator | Apr 2025 |
| 4226 | Orloski John C | Bartlesville, OK 74006 | Oil & Gas Operator | Apr 2025 |
| 4227 | Osa Oil & Gas LLC | Tulsa, OK 74131 | Oil & Gas Operator | Aug 2023 |
| 4228 | Osage Energy Resources LLC | Bartlesville, OK 74005-2527 | Oil & Gas Operator | Apr 2025 |
| 4229 | Osage Exploration & Development Inc | San Diego, CA 92131-3807 | Oil & Gas Operator | Oct 2016 |
| 4230 | Osage Oil & Transportation Inc | Cleveland, OK 74020 | Oil & Gas Operator | Nov 2000 |
| 4231 | Osage Petroleum Corporation | Saint Louis, MO 63131-4691 | Oil & Gas Operator | Mar 2009 |
| 4232 | Osborn Heirs Co | San Antonio, TX 78217 | Oil & Gas Operator | Jun 2025 |
| 4233 | Osburn Gerald Dba Ozzy & Son Oil & Gas | Drumright, OK 74030-5467 | Oil Operator | Oct 2020 |
| 4234 | Oscar'S Well Service Inc | Okemah, OK 74859 | Oil & Gas Operator | Apr 1998 |
| 4235 | Oshtah Oil Company LLC | Stratford, OK 74872 | Oil & Gas Operator | Sep 2018 |
| 4236 | Oso Resources LLC | Oklahoma City, OK 73118-5022 | Oil & Gas Operator | Apr 2025 |
| 4237 | Osterhout Phillip L | Drumright, OK 74030-0693 | Oil & Gas Operator | Jan 2014 |
| 4238 | Oswego Arbuckle Enterprise Inc | S Coffeyville, OK 74072-9702 | Oil & Gas Operator | Mar 2015 |
| 4239 | Otc Investors Inc | | Oil Operator | Jan 2025 |
| 4240 | Otc Petroleum Corporation | Nichols Hill, OK 73116 | Oil & Gas Operator | Mar 2015 |
| 4241 | Otc/Occ Not Assigned | | Oil & Gas Operator | Dec 2024 |
| 4242 | Ouachita Exploration Inc | Chickasha, OK 73018 | Oil & Gas Operator | May 2025 |
| 4243 | Outback Petroleum Inc | Moore, OK 73160-9998 | Oil & Gas Operator | Mar 2015 |
| 4244 | Ovation Energy II, LP | Houston, TX 77279 | Oil & Gas Operator | Jun 2011 |
| 4245 | Ovation Energy, LP | N Richlnd HLS, TX 76180 | Oil & Gas Operator | Sep 2004 |
| 4246 | Overflow Energy Stack LLC | Booker, TX 79005 | Oil Operator | Sep 2022 |
| 4247 | Overflow Energy, LLC | Perryton, TX 79070 | Oil & Gas Operator | Jul 2025 |
| 4248 | Overland Investments Inc | Coweta, OK 74429 | Oil & Gas Operator | Apr 2025 |
| 4249 | Ovintiv Mid-Continent Inc. | The Woodlands, TX 77380-2764 | Oil & Gas Operator | May 2025 |
| 4250 | Ovintiv USA Inc. | Denver, CO 80202 | Oil & Gas Operator | Jul 2025 |
| 4251 | Owens James W | Tulsa, OK 74114-1425 | Oil & Gas Operator | Oct 2022 |
| 4252 | Owl Creek Production Co., Inc. | Houston, TX 77027 | Oil & Gas Operator | Apr 2006 |
| 4253 | Oxco, LLC | | Oil & Gas Operator | Feb 2015 |
| 4254 | Oxford Exploration Company | Denver, CO 80237 | Oil & Gas Operator | Aug 1995 |
| 4255 | Oxford Oil Inc | Cleveland, OK 74020 | Oil & Gas Operator | Feb 1997 |
| 4256 | Oxley Energy LLC | Houston, TX 77042 | Gas Operator | Apr 2025 |
| 4257 | Oxley John C | Tulsa, OK 74103 | Oil & Gas Operator | Sep 1996 |
| 4258 | Oxley Petroleum | Tulsa, OK 74119-3609 | Oil & Gas Operator | Jan 2020 |
| 4259 | Oxley Petroleum Co | Oklahoma City, OK 73118-1044 | Oil & Gas Operator | Sep 2017 |
| 4260 | Oxy USA Inc | Houston, TX 77046 | Oil & Gas Operator | Jul 2025 |
| 4261 | Ozark Oil Corporation | Springfield, MO 65804 | Oil & Gas Operator | Oct 1992 |
| 4262 | P & C Oil Company | Leona, TX 75850 | Oil & Gas Operator | May 2025 |
| 4263 | P & H Construction Inc | Wewoka, OK 74884 | Oil & Gas Operator | Jun 2024 |
| 4264 | P & H Oil & Gas Inc | Stroud, OK 74079 | Oil & Gas Operator | May 2025 |
| 4265 | P & M Drilling Company Inc | Depew, OK 74028 | Oil & Gas Operator | Dec 2004 |
| 4266 | P & M Petroleum Management | Denver, CO BAD ADDR | Oil & Gas Operator | Apr 2010 |
| 4267 | P & P Producing Inc | Midland, TX 79702 | Oil & Gas Operator | Feb 2015 |
| 4268 | P A Energy Inc | Calvin, OK 74531-0248 | Oil & Gas Operator | Apr 2020 |
| 4269 | P F Beeler LLC | Norman, OK 73072-7522 | Oil & Gas Operator | May 2025 |
| 4270 | P I C Inc | Ponca City, OK 74602 | Oil & Gas Operator | Jan 2013 |
| 4271 | P K & L Oil Properties | Shawnee, OK 74802-0931 | Oil & Gas Operator | Mar 2001 |
| 4272 | P O & G Panhandle LP | Houston, TX 77057 | Oil & Gas Operator | Apr 2025 |
| 4273 | P T Oil Co Inc | Walters, OK 73572-9505 | Oil Operator | Nov 2014 |
| 4274 | P-2 Exploraton Co Inc | Pampa, TX 79065-2920 | Oil & Gas Operator | Jun 1996 |
| 4275 | P.O.&G. Operating, LLC | Houston, TX 77057 | Oil & Gas Operator | Jul 2025 |
| 4276 | Pablo Energy II, LLC | Amarillo, TX 79105 | Oil & Gas Operator | Apr 2025 |
| 4277 | Pace Exploration LLC | Tulsa, OK 74133 | Oil & Gas Operator | Apr 2025 |
| 4278 | Pace Petroleum Company | Dallas, TX 75206 | Oil & Gas Operator | Jul 2025 |
| 4279 | Pacific Enterprise Oil Co USA | Los Angeles, CA 90071-2005 | Oil & Gas Operator | Aug 2012 |
| 4280 | Pacific Enterprises Royalty Co | Oklahoma City, OK 73101 | Oil & Gas Operator | Feb 2002 |
| 4281 | Pactola Development Co | Tulsa, OK 74159 | Oil & Gas Operator | Sep 2004 |
| 4282 | Page Petroleum Inc | Calgary, AB T2P3M-3000 | Oil & Gas Operator | Nov 1998 |
| 4283 | Painter & McPhail | Bartlesville, OK 74006 | Oil Operator | Sep 1996 |
| 4284 | Pak Energy LLC | Calgary, AB T3A-5E8 | Oil Operator | Sep 2022 |
| 4285 | Pal Energy LLC | Guymon, OK 73942-1950 | Gas Operator | Aug 2009 |
| 4286 | Pal Kids Inc | Coronado, CA 92118 | Oil & Gas Operator | Nov 2000 |
| 4287 | Palace Exploration Company | Houston, TX 77002 | Oil & Gas Operator | Mar 2007 |
| 4288 | Paleo, Inc. | Oklahoma City, OK 73112 | Oil & Gas Operator | Jul 2025 |
| 4289 | Palisades Asset Holding Co LLC | Dallas, TX 75201 | Oil & Gas Operator | Aug 2017 |
| 4290 | Palm Oil & Gas Company | Sedona, AZ 86340 | Oil & Gas Operator | May 2025 |
| 4291 | Palm Operating LLC | Oklahoma City, OK 73106-5646 | Oil & Gas Operator | Nov 2019 |
| 4292 | Paloma Operating Co Inc | Houston, TX 77002-5220 | Oil & Gas Operator | Apr 2025 |
| 4293 | Paloma Resources, LLC | Houston, TX 77002 | Oil & Gas Operator | Jun 2018 |
| 4294 | Palomino Petroleum Inc | Newton, KS 67114 | Oil & Gas Operator | Mar 2025 |
| 4295 | Paluca Petroleum Inc | Holdenville, OK 74848 | Oil & Gas Operator | Apr 2025 |
| 4296 | Pan Petroleum MLP | Kansas City, MO 64114 | Oil & Gas Operator | Aug 1997 |
| 4297 | Pan Texas Petroleum Inc | Fort Worth, TX 76102 | Oil & Gas Operator | Nov 2003 |
| 4298 | Pan Western Energy Corporation | Tulsa, OK 74114 | Oil & Gas Operator | Jul 2025 |
| 4299 | Panada Exploration, Inc. | Tulsa, OK 74135 | Oil & Gas Operator | Jun 1996 |
| 4300 | Panadero Oil Company | Dallas, TX 75206 | Oil & Gas Operator | Apr 2002 |