| 301 | Phillips Lake Corp. | | Oil Operator | Dec 1985 |
| 302 | Phillips Oil Company | Casper, WY 82602 | Oil & Gas Operator | Sep 1986 |
| 303 | Phillips Petroleum Company | Houston, TX 77251 | Oil & Gas Operator | Mar 2013 |
| 304 | Pine Island Operating, L.L.C. | Graham, TX 76450 | Oil & Gas Operator | Feb 2026 |
| 305 | Pinnacle Operating Company, Inc. | Shreveport, LA 71135 | Oil & Gas Operator | Feb 2026 |
| 306 | Pioneer Exploration, LLC | Houston, TX 77090 | Oil & Gas Operator | Dec 2025 |
| 307 | Pioneer Prod. Corp. | | Oil & Gas Operator | Jun 1986 |
| 308 | Placid Oil Company | Houston, TX 77227 | Oil & Gas Operator | Mar 2008 |
| 309 | Pool Company | | Oil Operator | Dec 2002 |
| 310 | Pool Production Services | | Oil Operator | Aug 1990 |
| 311 | Pride Exploration, Inc. | Shreveport, LA 71101 | Oil & Gas Operator | Jul 2015 |
| 312 | Pruet Production Co. | Jackson, MS 39201 | Oil & Gas Operator | Dec 2025 |
| 313 | Qep Energy Company | Midland, TX 79701 | Oil & Gas Operator | Nov 2025 |
| 314 | Quantum Resources MGMT, LLC | | Oil & Gas Operator | Nov 2014 |
| 315 | Quest Energies Group,LTD. | Shreveport, LA 71106 | Oil & Gas Operator | Mar 1997 |
| 316 | Quest Energies, L.L.C. | | Oil & Gas Operator | Jan 2025 |
| 317 | Questar Expl. And Prod. Co. | Salt Lake Cty, UT 84145 | Oil & Gas Operator | Jul 2011 |
| 318 | R & C Petroleum, Inc. | Flint, TX 75762 | Oil & Gas Operator | Feb 2026 |
| 319 | Rabwin Oil & Gas, Inc. | | Oil & Gas Operator | Nov 1991 |
| 320 | Ralph L. Leaderbrand | | Oil & Gas Operator | Dec 1996 |
| 321 | Rebel Oil Of North Louisiana, LLC | | Oil & Gas Operator | Dec 2007 |
| 322 | Red River Gas Company | | Oil & Gas Operator | May 2000 |
| 323 | Red River Oil & Gas Inc. | | Oil & Gas Operator | May 2012 |
| 324 | Reef Exploration Inc | Denver, CO 80202 | Oil & Gas Operator | Feb 2007 |
| 325 | Regency Field Services LLC | Dallas, TX 75201 | Oil Operator | Jul 2017 |
| 326 | Regency Intrastate Gas LLC | | Oil Operator | Feb 2009 |
| 327 | Reliance Well Service, Inc. | | Oil & Gas Operator | Apr 1997 |
| 328 | Reliant Energy Field SVS Inc. | | Oil Operator | Sep 2002 |
| 329 | Reynolds Oil Company | | Oil Operator | Nov 2005 |
| 330 | Richard B. Nelson,Etal | | Oil & Gas Operator | May 1979 |
| 331 | Rimfire Swabbing, Inc. | | Oil Operator | Jan 2025 |
| 332 | Rising Star 2000 Oil & Gas, Inc. | | Oil Operator | Dec 2024 |
| 333 | Robco Investments, Inc. | | Oil & Gas Operator | Jul 2016 |
| 334 | Rojo Oil Company | McLean, TX 79057 | Oil & Gas Operator | Feb 2026 |
| 335 | Rosbottom Petroleum | | Oil & Gas Operator | Aug 1988 |
| 336 | Ross & Glenn Petroleum Inc. | | Oil & Gas Operator | Aug 1984 |
| 337 | Rusk Co. Well Service Co., Inc. | Kilgore, TX 75663 | Oil & Gas Operator | Feb 2026 |
| 338 | S Enterprises | | Oil & Gas Operator | Nov 1986 |
| 339 | S. G. Myers, Jr. | | Oil & Gas Operator | May 2005 |
| 340 | S. G. Myers, Jr. Et Al | | Oil & Gas Operator | Jul 1991 |
| 341 | Sabre Operating, Inc. | Wichita Falls, TX 76308 | Oil & Gas Operator | Feb 2026 |
| 342 | Sam Aertker | | Oil Operator | Jul 1992 |
| 343 | Samson Contour Energy E&P, LLC | Tulsa, OK 74103 | Oil & Gas Operator | Sep 2017 |
| 344 | Samson Kelley Operating Co., LTD. | | Oil & Gas Operator | Feb 2004 |
| 345 | Sandefer & Andress, Inc. | | Oil & Gas Operator | Apr 1982 |
| 346 | Sandhill Production Inc | Shongaloo, LA 71072 | Oil & Gas Operator | Dec 2019 |
| 347 | Sapient Energy Corp | Oklahoma City, OK 73154 | Oil & Gas Operator | Jan 2002 |
| 348 | Seagull Operating Co., Inc. | Shreveport, LA 71101 | Oil & Gas Operator | Jan 2025 |
| 349 | Ses Production | | Oil & Gas Operator | Oct 2023 |
| 350 | Shongaloo Midstream, LLC | | Oil Operator | Mar 2019 |
| 351 | Shuler Drilling Co., Inc. | El Dorado, AR 71730 | Oil & Gas Operator | Jan 2025 |
| 352 | Silver Oak Operating, Inc. | Longview, TX 75601 | Oil & Gas Operator | Dec 2009 |
| 353 | Silver Pines Energy Corp. | Houston, TX 77005 | Oil & Gas Operator | Nov 2025 |
| 354 | Sklar & Phillips Oil Co. | Shreveport, LA 71101 | Oil & Gas Operator | Dec 2000 |
| 355 | Sklar Exploration Company LLC | Shreveport, LA 71101 | Oil & Gas Operator | Feb 2026 |
| 356 | SM Energy Company | Midland, TX 79707 | Oil & Gas Operator | Feb 2026 |
| 357 | Smackover Drilling Co. Inc. | Shreveport, LA 71105 | Oil & Gas Operator | Jan 2025 |
| 358 | Smith Operating And MGMT Co. | Shreveport, LA 71161 | Oil & Gas Operator | Jun 2023 |
| 359 | Smith Operating-Germany Oil | | Oil & Gas Operator | Dec 1995 |
| 360 | SMR Natural Gas Ventures Inc | Oklahoma City, OK 73112 | Oil & Gas Operator | Jan 1999 |
| 361 | Sonat Exploration Co. | Houston, TX 77251 | Oil & Gas Operator | Dec 2021 |
| 362 | Special Energy Corp. | Stillwater, OK 74076 | Oil & Gas Operator | Feb 2026 |
| 363 | St. Mary Land & Exploration Co | Denver, CO 80201 | Oil & Gas Operator | Jun 2010 |
| 364 | State Line Vacuum Services, LLC | | Oil Operator | Mar 2021 |
| 365 | Stephens & Johnson Operating Co. | Wichita Falls, TX 76307 | Oil & Gas Operator | Feb 2026 |
| 366 | Story Oil And Gas Inc | Magnolia, AR 71753 | Oil & Gas Operator | Jan 2025 |
| 367 | STS Petroleum LLC | Houston, TX 77289 | Oil & Gas Operator | Feb 2026 |
| 368 | Sun Exploration And Production Co | | Oil & Gas Operator | Jan 1990 |
| 369 | Sundance Energy Corporation | | Oil & Gas Operator | Jan 2025 |
| 370 | Sunland Production Company, Inc. | Shreveport, LA 71101 | Oil & Gas Operator | Dec 2025 |
| 371 | Swift Energy Company | Houston, TX 77060 | Oil & Gas Operator | Mar 2021 |
| 372 | T & L Production Company | | Oil Operator | Feb 1984 |
| 373 | T. L. James & Co., Inc. | | Oil & Gas Operator | Oct 1992 |
| 374 | T. M. Hopkins | | Oil & Gas Operator | Aug 2007 |
| 375 | T. N. T. Energy Co. | Belcher, LA 71004 | Oil Operator | May 1991 |
| 376 | T.O.I. | Midland, TX 79710 | Oil & Gas Operator | Mar 2001 |
| 377 | Taggart Oil Co., Inc. | | Oil Operator | Oct 1992 |
| 378 | Tanos Exploration II, LLC | Tyler, TX 75701 | Oil & Gas Operator | Sep 2023 |
| 379 | TDX Energy, LLC | Shreveport, LA 71101 | Oil & Gas Operator | Dec 2024 |
| 380 | Tellurian Operating LLC | | Oil & Gas Operator | Jun 2024 |
| 381 | Tensas Delta Expl Co., LLC | Shreveport, LA 71101-5323 | Oil & Gas Operator | Jul 2021 |
| 382 | Texas Eastern Transm. Corp. | | Oil & Gas Operator | Dec 2002 |
| 383 | Texas Oil & Gas Corporation | Dallas, TX 75201 | Oil & Gas Operator | Feb 2001 |
| 384 | Texex Petroleum Corporation | | Oil & Gas Operator | Dec 2024 |
| 385 | The Maurice L. Brown Company | | Oil & Gas Operator | Aug 1987 |
| 386 | Thomas E. Slack | | Oil Operator | Mar 2003 |
| 387 | Tierra Petroleum Corp. | | Oil & Gas Operator | Jun 1987 |
| 388 | Tigner Walker | | Oil & Gas Operator | Dec 2021 |
| 389 | Tipco Operating Co. | Marshall, TX 75671 | Oil & Gas Operator | Feb 2026 |
| 390 | Tma Production, LLC | | Oil Operator | Dec 2024 |
| 391 | TMR Exploration, Inc. | Bossier City, LA 71171 | Oil & Gas Operator | Feb 2026 |
| 392 | Total E&P USA, Inc. | Houston, TX 77210 | Oil & Gas Operator | May 2025 |
| 393 | Totalfinaelf E&P USA Inc | Houston, TX 77024 | Oil & Gas Operator | Jul 2007 |
| 394 | Trafalgar House Oil & Gas Inc | Houston, TX 77002-7346 | Oil & Gas Operator | Jan 1992 |
| 395 | Transcontinental Oil Corp. | | Oil & Gas Operator | Sep 1985 |
| 396 | Triple L Oil Company | Corpus Chrsti, TX 78469 | Oil & Gas Operator | Jan 1998 |
| 397 | Tristate Nla, LLC | | Oil Operator | Dec 2024 |
| 398 | Txo Production Corp. | Ganado, TX 77962 | Oil & Gas Operator | Aug 2022 |
| 399 | U. D. Man, Inc. | San Antonio, TX 78212 | Oil & Gas Operator | Feb 2026 |
| 400 | United Gas Pipe Line Co. | | Oil Operator | Aug 1993 |