| 4101 | Northeast Shelf Energy, L.L.C. | | Oil & Gas Operator | Jun 2017 |
| 4102 | Northern Pump Company | Denver, CO 80202-3130 | Oil & Gas Operator | Feb 2006 |
| 4103 | Northport Production Company | Oklahoma City, OK 73113 | Oil & Gas Operator | Mar 2025 |
| 4104 | Northwest Disposal Corporation | Laverne, OK 73848-0504 | Oil & Gas Operator | Jul 2014 |
| 4105 | Northwest Exploration Co | Salt Lake City, UT 84108-0900 | Oil & Gas Operator | Sep 1991 |
| 4106 | Northwest Oil Company | Dallas, TX 75204 | Oil & Gas Operator | Jun 2014 |
| 4107 | Northwind Development Company | | Oil Operator | Oct 1995 |
| 4108 | Northwind Oil Company | Tulsa, OK 74137 | Oil & Gas Operator | May 1998 |
| 4109 | Nossaman E Oil Inc | Del City, OK 73155-5449 | Oil Operator | Oct 2002 |
| 4110 | Notting Hill Energy LLC | Fort Worth, TX 76101 | Oil & Gas Operator | May 2025 |
| 4111 | Nova Energy Corporation | Denver, CO 80201 | Oil & Gas Operator | Jun 2003 |
| 4112 | Novy Oil & Gas, Inc. | Goddard, KS 67052 | Oil & Gas Operator | Mar 2025 |
| 4113 | Nowata Gas Company | Tulsa, OK 74136 | Oil & Gas Operator | Sep 1997 |
| 4114 | Nowata Petroleum Operating Co | Nowata, OK 74048-9617 | Oil Operator | Aug 2014 |
| 4115 | NRG Oil LLC | Stratford, OK 74872-9732 | Oil Operator | Feb 2012 |
| 4116 | NS Oil LLC | Minneapolis, MN 55410 | Oil Operator | Feb 2025 |
| 4117 | NTR Energy LLC (Osage Cty Only) | | Oil & Gas Operator | Apr 2020 |
| 4118 | Nub'S Well Servicing Inc | Ratliff City, OK 73481 | Oil & Gas Operator | Mar 2025 |
| 4119 | Nutt Jerrie | Duncan, OK 73534-0698 | Oil & Gas Operator | Nov 2016 |
| 4120 | NV O&G Investments LLC /Osage Only | | Oil Operator | Sep 2022 |
| 4121 | NWM Operating Inc | Okeene, OK 73763 | Oil & Gas Operator | Mar 2025 |
| 4122 | NWM Properties LLC | Tulsa, OK 74131-4426 | Oil Operator | Feb 2025 |
| 4123 | Nyc Resources LTD | Tulsa, OK 74133-5700 | Oil & Gas Operator | Sep 2014 |
| 4124 | Nye Oil Company | Oklahoma City, OK 73118-1245 | Oil & Gas Operator | Jun 2004 |
| 4125 | Nytex Energy LLC | Edmond, OK 73083-5946 | Oil & Gas Operator | Sep 2015 |
| 4126 | Nytex, L.L.C. | Edmond, OK 73083 | Oil & Gas Operator | Feb 2006 |
| 4127 | O G & E | Oklahoma City, OK 73124 | Oil & Gas Operator | Feb 2014 |
| 4128 | O K Swabbing Inc | Hennessey, OK 73742 | Oil & Gas Operator | Feb 2025 |
| 4129 | O'Blue Corp. | Kerrville, TX 78028 | Oil & Gas Operator | Mar 1998 |
| 4130 | O'Brien Energy Resources Corp | Portsmouth, NH 03801 | Oil & Gas Operator | May 2025 |
| 4131 | O'Brien Oil Corporation | Guthrie, OK 73044-3154 | Oil & Gas Operator | Feb 2025 |
| 4132 | O'Brien Oil LLC | Guthrie, OK 73044-3154 | Oil & Gas Operator | Apr 2020 |
| 4133 | O'Brien Resources LLC | Shreveport, LA 71136 | Oil Operator | Nov 2017 |
| 4134 | O'Donnell Bill C | Tulsa, OK 74135-4241 | Oil & Gas Operator | Oct 2014 |
| 4135 | O'Hern Morris D | Mounds, OK 74047-5163 | Oil & Gas Operator | Sep 2016 |
| 4136 | O'Neal Oil & Gas Co | Fort Worth, TX 76107-1479 | Oil & Gas Operator | Mar 2025 |
| 4137 | O'Neal Oil Company | Nocona, TX 76255 | Oil & Gas Operator | May 2025 |
| 4138 | O'Neal, Lindell | Nocona, TX 76255 | Oil & Gas Operator | Mar 2025 |
| 4139 | O'Neill Properties, LTD. | Midland, TX 79702 | Oil & Gas Operator | May 2025 |
| 4140 | O.G.P. Operating, Inc. | Dallas, TX 75231 | Oil & Gas Operator | May 2025 |
| 4141 | Oak Hill Petroleum Corporation | Oklahoma City, OK 73116-5627 | Oil & Gas Operator | Feb 2025 |
| 4142 | Oak Hills Drilling & Oper., LLC | Holdenville, OK 74848 | Oil & Gas Operator | May 2013 |
| 4143 | Oak Hills Energy Inc | Holdenville, OK 74848-0470 | Oil & Gas Operator | Sep 2014 |
| 4144 | Oak Resources Inc | Tulsa, OK 74153 | Oil & Gas Operator | Aug 2013 |
| 4145 | Oak Tree Natural Res LLC | Oklahoma City, OK 73120-5065 | Oil & Gas Operator | Mar 2015 |
| 4146 | Oak Valley SWD LLC | Enid, OK 73703-4637 | Oil Operator | Aug 2022 |
| 4147 | Oakland Petroleum Oper Co., Inc. | Kilgore, TX 75663 | Oil & Gas Operator | May 2025 |
| 4148 | Oakwood Resources, Inc. | Dallas, TX 75374 | Oil & Gas Operator | May 1998 |
| 4149 | Oasis Energy Resources LLC | Norman, OK 73072-9668 | Oil & Gas Operator | Feb 2025 |
| 4150 | Obele Oil Corporation | Sedona, AZ 86336-5745 | Oil & Gas Operator | May 2017 |
| 4151 | Obele Operating Company LLC | Sedona, AZ 86336-5745 | Oil & Gas Operator | Feb 2025 |
| 4152 | Oberlander Leslie A Jake | Covington, OK 73730 | Oil Operator | Jun 2007 |
| 4153 | Ochiltree Oil Company | Edmond, OK 73034 | Oil & Gas Operator | Apr 2020 |
| 4154 | Octagon Resources LLC | Norman, OK 73071-1295 | Oil & Gas Operator | May 2015 |
| 4155 | Odell Larry | Oologah, OK 74053 | Oil Operator | Apr 2011 |
| 4156 | Odessa Oil Investment Co., Inc. | Odessa, TX 79762 | Oil & Gas Operator | Nov 2016 |
| 4157 | Odum Ronald L | Garfield, AR 72732 | Oil Operator | Feb 2025 |
| 4158 | Oex-1 LLC | Tulsa, OK 74105-5153 | Oil & Gas Operator | Mar 2024 |
| 4159 | Oexco, Inc. | Tulsa, OK 74136 | Oil & Gas Operator | Mar 2015 |
| 4160 | Offield Lease Operations LLC | Wilson, OK 73463 | Oil & Gas Operator | May 2023 |
| 4161 | Ofs-Tulsa Corporation | Fort Worth, TX 76102 | Oil & Gas Operator | Feb 1997 |
| 4162 | Oil & Gas Exploration Inc | Cleveland, OK 74020 | Oil & Gas Operator | Aug 2013 |
| 4163 | Oil & Gas Unlimited Inc | | Oil & Gas Operator | May 2013 |
| 4164 | Oil Center Operating Inc | Fort Worth, TX 76102-5108 | Oil & Gas Operator | Apr 2014 |
| 4165 | Oil Creek Production Company | Prague, OK 74864-0667 | Oil & Gas Operator | Feb 2025 |
| 4166 | Oil Exploration Of America Inc | Sisseton, SD 57262-9503 | Oil & Gas Operator | Jun 2001 |
| 4167 | Oil Field Production Inc | Tulsa, OK 74133 | Oil Operator | Feb 2025 |
| 4168 | Oil Investors Inc | Crescent, OK 73028 | Oil & Gas Operator | Mar 2025 |
| 4169 | Oil Lift, Incorporated | Metairie, LA 70002 | Oil & Gas Operator | Apr 2020 |
| 4170 | Oil Operations Inc | | Oil & Gas Operator | Apr 2011 |
| 4171 | Oil Patch Energy LLC | Broken Arrow, OK 74014 | Oil & Gas Operator | Jan 2025 |
| 4172 | Oil Pool Inc | Tulsa, OK 74132-2659 | Oil & Gas Operator | Jan 2025 |
| 4173 | Oil Producers, Inc. Of Kansas | Wichita, KS 67206 | Oil & Gas Operator | May 2025 |
| 4174 | Oil Production Management Inc | Squaw Valley, CA 93675-9725 | Oil & Gas Operator | Dec 2002 |
| 4175 | Oil Production Systems Inc | Cushing, OK 74023 | Oil & Gas Operator | Jan 2013 |
| 4176 | Oil Property Management, Inc. | Attica, KS 67009 | Oil & Gas Operator | Feb 2021 |
| 4177 | Oil Recovery Systems Inc | Tulsa, OK 74145-4619 | Oil & Gas Operator | Feb 2025 |
| 4178 | Oil State Petroleum Inc | Jennings, OK 74038 | Oil & Gas Operator | Jan 2025 |
| 4179 | Oil Ventures LTD | | Oil & Gas Operator | Jan 2013 |
| 4180 | Oilbank Production LLC | Norman, OK 73072 | Oil Operator | Feb 2025 |
| 4181 | Oilco Energy Inc | Duncan, OK 73533 | Oil & Gas Operator | Mar 2015 |
| 4182 | Oilfield Leasing Inc | Cushing, OK 74023-0967 | Oil & Gas Operator | Aug 2018 |
| 4183 | Oilfield Operating Company | Cushing, OK 74023-1347 | Oil & Gas Operator | Jan 2018 |
| 4184 | Oilrox Resources LLC | San Antonio, TX 78258 | Oil & Gas Operator | Mar 2025 |
| 4185 | Oilsearch Corporation | Albuquerque, NM 87109 | Oil & Gas Operator | Feb 1994 |
| 4186 | Oilton Petroleum Inc | Oilton, OK 74052-0459 | Oil & Gas Operator | Oct 2001 |
| 4187 | Oilwell Operators, Inc. | Pampa, TX 79066 | Oil & Gas Operator | May 2025 |
| 4188 | Ok Production Services Inc | Broken Arrow, OK 74014 | Oil & Gas Operator | Feb 2025 |
| 4189 | Okc Energy Corporation | Oklahoma City, OK 73120-3119 | Oil & Gas Operator | Nov 2014 |
| 4190 | Okie Crude Company | Tulsa, OK 74103 | Oil & Gas Operator | Feb 2025 |
| 4191 | Okie Oil Inc | Sapulpa, OK 74067-0290 | Oil & Gas Operator | Mar 2011 |
| 4192 | Okla Sub-Surface Pump & Supply Co | Seminole, OK 74804 | Oil & Gas Operator | Sep 2024 |
| 4193 | Oklahoma Basic Economy Corp | Houston, TX 77002-6003 | Oil & Gas Operator | Apr 2020 |
| 4194 | Oklahoma Cellulose Inc | Cleveland, OK 74020 | Oil Operator | Feb 2025 |
| 4195 | Oklahoma Crude Inc | Broken Arrow, OK 74012 | Oil & Gas Operator | Apr 2024 |
| 4196 | Oklahoma Crude Reclaimers, LLC | | Oil Operator | Mar 2025 |
| 4197 | Oklahoma Energy Acquisitions LP | Houston, TX 77094-1900 | Oil & Gas Operator | Jan 2025 |
| 4198 | Oklahoma Energy Exchange LLC | Duncan, OK 73534-1105 | Oil & Gas Operator | Sep 2012 |
| 4199 | Oklahoma Energy LLC | Skiatook, OK 74070-3998 | Oil Operator | Nov 2024 |
| 4200 | Oklahoma Equipment & Salvage | Oklahoma City, OK 73120-5903 | Oil & Gas Operator | Mar 2015 |