| 201 | Odessa Oil Investment Co., Inc. | Odessa, TX 79762 | Oil & Gas Operator | Nov 2016 |
| 202 | Oklahoma Petroleum MGMT Corp | Tulsa, OK 74119 | Oil & Gas Operator | Jun 1993 |
| 203 | Oklahoma SWD Systems Inc | Odessa, TX 79762-8132 | Oil & Gas Operator | Apr 2025 |
| 204 | Old Dominion Oil Corporation | Oklahoma City, OK 73107 | Oil & Gas Operator | Apr 2009 |
| 205 | Oneok Resources Company | Tulsa, OK 74102 | Oil & Gas Operator | Feb 2017 |
| 206 | Otc Petroleum Corporation | Nichols Hill, OK 73116 | Oil & Gas Operator | Mar 2015 |
| 207 | Oxley Petroleum | Tulsa, OK 74119-3609 | Oil & Gas Operator | Jan 2020 |
| 208 | Oxley Petroleum Co | Oklahoma City, OK 73118-1044 | Oil & Gas Operator | Sep 2017 |
| 209 | Oxy USA Inc | Houston, TX 77046 | Oil & Gas Operator | Jul 2025 |
| 210 | Pacific Enterprise Oil Co USA | Los Angeles, CA 90071-2005 | Oil & Gas Operator | Aug 2012 |
| 211 | Pantera Energy Company | Amarillo, TX 79101 | Oil & Gas Operator | Jul 2025 |
| 212 | Pardee Production Co. | Skiatook, OK 74070 | Oil & Gas Operator | Mar 2021 |
| 213 | Patina Oil & Gas Corporation | Denver, CO 80202 | Oil & Gas Operator | May 2016 |
| 214 | Penn VIrginia MC Operating Co LLC | Houston, TX 77084-7213 | Oil & Gas Operator | Jan 2025 |
| 215 | Petrocorp Incorporated | Tulsa, OK 74170 | Oil & Gas Operator | Nov 2021 |
| 216 | Petrohawk Operating Company | Houston, TX 77056 | Oil & Gas Operator | Oct 2021 |
| 217 | Petroquest Energy, L.L.C. | Lafayette, LA 70505 | Oil & Gas Operator | Jul 2025 |
| 218 | Pioneer Resources Prod LP | Irving, TX 75039-3745 | Oil & Gas Operator | Feb 2005 |
| 219 | Plains Resources Inc. | Houston, TX 77002 | Oil & Gas Operator | Jul 2008 |
| 220 | Pogo Producing Company LLC | Houston, TX 77002 | Oil & Gas Operator | May 2025 |
| 221 | Presidio Petroleum LLC | Canadian, TX 79014 | Oil & Gas Operator | Jul 2025 |
| 222 | Pride Energy Company | Tulsa, OK 74170 | Oil & Gas Operator | Jul 2025 |
| 223 | Prime Energy Corp | Charleston, WV 25301-1707 | Oil & Gas Operator | Sep 2015 |
| 224 | Prime Operating Company | Houston, TX 77024 | Oil & Gas Operator | Jul 2025 |
| 225 | Prize Operating Company | Grapevine, TX 76051 | Oil & Gas Operator | Aug 2016 |
| 226 | Qep Energy Company | Midland, TX 79701 | Oil & Gas Operator | Apr 2025 |
| 227 | R I G Producers Inc | Dewey, OK 74029 | Oil & Gas Operator | Jul 1999 |
| 228 | R L Clampitt & Associates LLC | Bartlesville, OK 74006 | Oil & Gas Operator | May 2025 |
| 229 | Ram Asset Management Co | Oklahoma City, OK 73114 | Oil & Gas Operator | Mar 2015 |
| 230 | Range Production Company | Fort Worth, TX 76102 | Oil & Gas Operator | Sep 2021 |
| 231 | Range Production Company, LLC | Fort Worth, TX 76102 | Oil & Gas Operator | Apr 2025 |
| 232 | Red Rocks Oil & Gas Operating LLC | Oklahoma City, OK 73103-4821 | Oil & Gas Operator | May 2025 |
| 233 | Ricks Expl Acquisition Corp | Oklahoma City, OK 73102 | Oil & Gas Operator | Jan 2004 |
| 234 | Ricks Exploration Co | Oklahoma City, OK 73112 | Oil & Gas Operator | Mar 2015 |
| 235 | Riviera Operating, LLC | Houston, TX 77002 | Oil & Gas Operator | May 2025 |
| 236 | RMS Monte Christo, LLC | Snowmass VLG., CO 81615 | Oil & Gas Operator | Mar 2023 |
| 237 | Roblyn Oil Inc | Allen, OK 74825-6933 | Oil & Gas Operator | Apr 2025 |
| 238 | Rupe Oil Company, Inc. | Wichita, KS 67278 | Oil & Gas Operator | Mar 2025 |
| 239 | Sabre Operating, Inc. | Wichita Falls, TX 76308 | Oil & Gas Operator | Jul 2025 |
| 240 | Samedan Oil Corporation | Houston, TX 77067 | Oil & Gas Operator | Dec 2019 |
| 241 | Samson Hydrocarbons Company | Tulsa, OK 74103 | Oil & Gas Operator | Nov 2016 |
| 242 | Samson Resources Company | Tulsa, OK 74103 | Oil & Gas Operator | Apr 2025 |
| 243 | San Francisco-Okla Pet Ex Inc | | Oil & Gas Operator | Apr 2014 |
| 244 | Sandridge Exploration And Production LLC | Oklahoma City, OK 73104 | Oil & Gas Operator | Jul 2025 |
| 245 | Sanguine Gas Exploration, LLC | Tulsa, OK 74119 | Oil & Gas Operator | Jul 2025 |
| 246 | Santa Fe Energy Company | Midland, TX 79701 | Oil & Gas Operator | Dec 2015 |
| 247 | Santa Fe Energy Operating Partner LP | Midland, TX 79701 | Oil & Gas Operator | Sep 2004 |
| 248 | Santa Fe Minerals, Inc. | Dallas, TX 75240 | Oil & Gas Operator | Sep 2013 |
| 249 | Scambler Energy Group LTD Co | Colony, OK 73021 | Oil & Gas Operator | May 2025 |
| 250 | Seagull Mid-South Inc | Houston, TX 77002 | Oil & Gas Operator | Mar 2015 |
| 251 | Seagull Midcon Inc. | Houston, TX 77002 | Oil & Gas Operator | Mar 2015 |
| 252 | Seals Oil Company | Fox, OK 73435-0222 | Oil & Gas Operator | Nov 2011 |
| 253 | Sho-Bar Energy, Inc. | Harper, KS 67058 | Oil & Gas Operator | Apr 2025 |
| 254 | Silver Pines Energy Corp. | Houston, TX 77005 | Oil & Gas Operator | Apr 2025 |
| 255 | Skycap Energy, LLC | Oklahoma City, OK 73118 | Oil & Gas Operator | May 2025 |
| 256 | Sloan Petroleum Service Inc | Guthrie, OK 73044 | Oil & Gas Operator | May 2025 |
| 257 | SM Energy Company | Midland, TX 79707 | Oil & Gas Operator | Jul 2025 |
| 258 | Sooner Oil & Gas Management Inc | Crescent, OK 73028 | Oil & Gas Operator | May 2025 |
| 259 | Sorrels J R Dba Cheyenne Oil Properties | Ponca City, OK 74601 | Oil & Gas Operator | Jul 2022 |
| 260 | Southland Royalty Company | Houston, TX 77210 | Oil & Gas Operator | Sep 2011 |
| 261 | Sparks Resources Inc | Bristow, OK 74010 | Oil & Gas Operator | May 2025 |
| 262 | St. Mary Operating Company | Denver, CO 80203 | Oil & Gas Operator | Mar 2019 |
| 263 | Staghorn Petroleum II LLC | Tulsa, OK 74103-3500 | Oil & Gas Operator | May 2025 |
| 264 | Stephens Production Company | The Woodlands, TX 77381 | Oil & Gas Operator | May 2025 |
| 265 | Stewart K Petroleum Corp | Edmond, OK 73013 | Oil & Gas Operator | Mar 2015 |
| 266 | Sundown Energy LP | Dallas, TX 75248 | Oil & Gas Operator | Jul 2025 |
| 267 | Sundown Energy, Inc. | Dallas, TX 75240 | Oil & Gas Operator | Mar 2025 |
| 268 | Sunstone Energy Company | Tulsa, OK 74153 | Oil & Gas Operator | Aug 2009 |
| 269 | Sweetwater Exploration LLC | Norman, OK 73069-5636 | Oil & Gas Operator | Apr 2025 |
| 270 | Swift Energy Company | Houston, TX 77060 | Oil & Gas Operator | Mar 2021 |
| 271 | Tapstone Energy LLC | Oklahoma City, OK 73101 | Oil & Gas Operator | May 2025 |
| 272 | Technical Energy Services, Inc. | Norman, OK 73070 | Oil & Gas Operator | Apr 2025 |
| 273 | Tecolote Energy Operating, LLC | Fort Worth, TX 76107 | Oil & Gas Operator | Jan 2024 |
| 274 | Temex Energy, Inc. | Oklahoma City, OK 73101 | Oil & Gas Operator | Feb 2002 |
| 275 | Tenneco Oil Company | Oklahoma City, OK 73125 | Oil & Gas Operator | Apr 2025 |
| 276 | Teocalli Exploration LLC | Oklahoma City, OK 73118 | Oil & Gas Operator | May 2025 |
| 277 | Texaco Expl. And Prod. Inc. | Houston, TX 77236 | Oil & Gas Operator | May 2025 |
| 278 | TGX Corporation | Houston, TX 77002 | Oil & Gas Operator | Sep 2004 |
| 279 | The Quintin Little Company Inc | Ardmore, OK 73401 | Oil & Gas Operator | May 2025 |
| 280 | Tide West Oil Company | Tulsa, OK 74136 | Oil & Gas Operator | Mar 2021 |
| 281 | TLS Oil & Gas Inc | Kingfisher, OK 73750-0901 | Oil & Gas Operator | May 2025 |
| 282 | Torch Operating Company | Houston, TX 77010 | Oil & Gas Operator | Mar 2015 |
| 283 | Total Minatome Corporation | Houston, TX 77210 | Oil & Gas Operator | Dec 1998 |
| 284 | Trail Ridge Energy Partners, LLC | Grapevine, TX 76051 | Oil & Gas Operator | May 2025 |
| 285 | Transok LLC | Oklahoma City, OK 73124-0300 | Oil & Gas Operator | Jul 2020 |
| 286 | Twisted Resources Inc | Blanchard, OK 73010-8463 | Oil & Gas Operator | Apr 2025 |
| 287 | Txo Production Corp. | Ganado, TX 77962 | Oil & Gas Operator | Aug 2022 |
| 288 | Umc Petroleum Corporation | Houston, TX 77002 | Oil & Gas Operator | Mar 2015 |
| 289 | Unbridled Resources, LLC | Houston, TX 77002 | Oil & Gas Operator | Jul 2025 |
| 290 | Union Oil Co Of California | Midland, TX 79706 | Oil & Gas Operator | Jan 2022 |
| 291 | Unit Petroleum Company | Tulsa, OK 74170 | Oil & Gas Operator | Jul 2025 |
| 292 | Vastar Resources Inc | Houston, TX 77253 | Oil & Gas Operator | Mar 2025 |
| 293 | Viersen & Cochran Drilling Company | | Oil & Gas Operator | May 2015 |
| 294 | Vitol Inc. | Houston, TX 77098 | Oil & Gas Operator | Sep 2023 |
| 295 | Walsh Jr F Howard | Fort Worth, TX 76102-4773 | Oil & Gas Operator | Apr 2025 |
| 296 | Ward Petroleum Corporation | Enid, OK 73702 | Oil & Gas Operator | Apr 2025 |
| 297 | Weatherly Oil & Gas, LLC | Dallas, TX 75206 | Oil & Gas Operator | Jul 2025 |
| 298 | Western Oil And Gas Development Corp | Oklahoma City, OK 73103-3735 | Oil & Gas Operator | Apr 2025 |
| 299 | Wil-Mar Operations | Duncan, OK 73534-1566 | Oil & Gas Operator | Oct 2016 |
| 300 | WM KS Energy Resources LLC | Shreveport, LA 71101 | Oil & Gas Operator | Nov 2019 |