| 301 | Nordstrand Engineering Inc | Houston, TX 77019 | Oil & Gas Operator | May 2025 |
| 302 | North American Royalties, Inc. | Chattanooga, TN 37408 | Oil & Gas Operator | Oct 2001 |
| 303 | Northstar Operating Company | Midland, TX 79702 | Oil & Gas Operator | Jun 2024 |
| 304 | Occidental Energy Company, Inc. | Houston, TX 77282 | Oil & Gas Operator | Jul 2021 |
| 305 | Occidental Energy Marketing, Inc. | Houston, TX 77227 | Gas Operator | Sep 2015 |
| 306 | Occidental Permian LTD. | Houston, TX 77046 | Oil & Gas Operator | May 2025 |
| 307 | Odessa Oil Investment Co., Inc. | Odessa, TX 79762 | Oil & Gas Operator | Nov 2016 |
| 308 | Ok Arena Operating Company | Oklahoma City, OK 73101 | Oil & Gas Operator | May 2025 |
| 309 | Oklahoma Oil Company | Dallas, TX 75206 | Oil & Gas Operator | Aug 2013 |
| 310 | Oklahoma RB Operating Company | Midland, TX 79701 | Oil & Gas Operator | Jan 1998 |
| 311 | Olsen Energy Inc. | Boerne, TX 78006 | Oil & Gas Operator | May 2025 |
| 312 | Orion Energen Inc. | Austin, TX 78731 | Oil & Gas Operator | Jul 2023 |
| 313 | Oryx Energy Company | Dallas, TX 75221 | Oil & Gas Operator | May 2002 |
| 314 | Osborn Heirs Co | San Antonio, TX 78217 | Oil & Gas Operator | Mar 2025 |
| 315 | Osborne Oil Co. | Dallas, TX 75244 | Oil & Gas Operator | Aug 2003 |
| 316 | Osr Oil & Gas Corp | Midland, TX 79710 | Oil & Gas Operator | Dec 2024 |
| 317 | Oxy USA WTP LP | Houston, TX 77046 | Oil & Gas Operator | May 2025 |
| 318 | Pacesetter Energy, LLC | Flower Mound, TX 75028 | Oil & Gas Operator | Jul 2020 |
| 319 | Paladin Energy Corp. | Dallas, TX 75229 | Oil & Gas Operator | Jul 2017 |
| 320 | Panada Exploration, Inc. | Tulsa, OK 74135 | Oil & Gas Operator | Jun 1996 |
| 321 | Parish, John R. | Andrews, TX 79714 | Oil & Gas Operator | May 2025 |
| 322 | Parker & Parsley Development Co. | Midland, TX 79702 | Oil & Gas Operator | May 1995 |
| 323 | Parker & Parsley Development L.P | Midland, TX 79702 | Oil & Gas Operator | Oct 2007 |
| 324 | Pate, L. T. | Austin, TX 78701 | Oil & Gas Operator | Aug 1994 |
| 325 | Ped Oil Corporation | Midland, TX 79702 | Oil & Gas Operator | May 2025 |
| 326 | Peden, Oren Inc. | Levelland, TX 79336 | Oil & Gas Operator | May 2001 |
| 327 | Pedernales Production, LP | Houston, TX 77057 | Oil & Gas Operator | Mar 2022 |
| 328 | Pennzoil Exploration & Production Co. | Carthage, TX 75633 | Oil & Gas Operator | Mar 2008 |
| 329 | Penwell Energy, Inc. | Houston, TX 77057 | Oil & Gas Operator | May 2025 |
| 330 | Perimeter Resource Company | Midland, TX 79702 | Oil & Gas Operator | May 2025 |
| 331 | Permian Resources, Inc. | Midland, TX 79702 | Oil & Gas Operator | Mar 2008 |
| 332 | Permian Solutions LLC | Midland, TX 79702 | Oil Operator | May 2025 |
| 333 | Petex | Breckenridge, TX 76424 | Oil & Gas Operator | May 2025 |
| 334 | Petro Vest, Inc. | Houston, TX 77046 | Oil & Gas Operator | Sep 2014 |
| 335 | Petrohawk Operating Company | Houston, TX 77056 | Oil & Gas Operator | Oct 2021 |
| 336 | Petrolero, LLC | Plano, TX 75026 | Oil & Gas Operator | May 2025 |
| 337 | Petroplex Equipment, Inc. | Midland, TX 79701 | Oil & Gas Operator | May 2019 |
| 338 | Philmar | Houston, TX 77269 | Oil Operator | May 2025 |
| 339 | Pitco Investments, LTD. | Scottsdale, AZ 85261 | Oil & Gas Operator | Jan 2013 |
| 340 | Pitts Energy Co. | Midland, TX 79707 | Oil & Gas Operator | May 2025 |
| 341 | Placid Oil Company | Houston, TX 77227 | Oil & Gas Operator | Mar 2008 |
| 342 | Plains Marketing, LP | Cushing, OK 74023 | Oil Operator | Jan 2012 |
| 343 | Plains Petroleum Operating Co | Denver, CO 80202 | Oil & Gas Operator | Dec 2014 |
| 344 | Platinum Exploration Inc. | Midland, TX 79701 | Oil & Gas Operator | May 2025 |
| 345 | PPC Operating Company LLC | Houston, TX 77279 | Oil & Gas Operator | Jul 2019 |
| 346 | Prasad, Hari Production Co. | Midland, TX 79701 | Oil & Gas Operator | May 2025 |
| 347 | Prasad, LTD. | Midland, TX 79701 | Oil & Gas Operator | Sep 2006 |
| 348 | Primero Operating, Inc. | Roswell, NM 88202 | Oil & Gas Operator | Jun 2022 |
| 349 | Prize Operating Company | Grapevine, TX 76051 | Oil & Gas Operator | Aug 2016 |
| 350 | Pronghorn Management Corporation | Hobbs, NM 88241 | Oil & Gas Operator | May 2025 |
| 351 | Pure Resources, L.P. | Midland, TX 79701 | Oil & Gas Operator | Mar 2006 |
| 352 | QP, Inc. | Midland, TX 79702 | Oil & Gas Operator | May 2025 |
| 353 | Quantum Resources Management LLC | Houston, TX 77010 | Oil & Gas Operator | Feb 2025 |
| 354 | Questar Expl. And Prod. Co. | Salt Lake Cty, UT 84145 | Oil & Gas Operator | Jul 2011 |
| 355 | Quien Sabe Operating, LLC | Sundown, TX 79372 | Oil & Gas Operator | Nov 2023 |
| 356 | Rainbow Energy Corporation | Midland, TX 79701 | Oil & Gas Operator | Nov 2002 |
| 357 | Ram Operating Inc. | Browns, IL 62818 | Oil & Gas Operator | Aug 2008 |
| 358 | Ramtex Energy LLC | Tulsa, OK 74114 | Oil & Gas Operator | May 2025 |
| 359 | Ranger 40 Petroleum, LLC | Fairfield, CT 06824 | Oil & Gas Operator | May 2025 |
| 360 | Rasmussen, Hal J. Operating, Inc | Midland, TX 79701 | Oil & Gas Operator | Apr 2009 |
| 361 | Raw Oil & Gas, Inc. | Lubbock, TX 79401 | Oil & Gas Operator | May 2025 |
| 362 | Read & Stevens, Inc. | Denver, CO 80202 | Oil & Gas Operator | Jul 2023 |
| 363 | Red River Oil & Gas LLC | Cherry Hills, CO 80110 | Oil & Gas Operator | Feb 2025 |
| 364 | Red Tail Exploration, LLC | Midland, TX 79702 | Oil & Gas Operator | May 2025 |
| 365 | Redstone Oil & Gas Company | Dallas, TX 75225 | Oil & Gas Operator | Jan 2020 |
| 366 | Regency Petroleum Co. | Irving, TX 75016 | Oil & Gas Operator | Aug 2002 |
| 367 | Regency Petroleum Co. Of New Mex | Coppell, TX 75019 | Oil & Gas Operator | Apr 2008 |
| 368 | Reliance Energy, Inc. | Midland, TX 79701 | Oil & Gas Operator | May 2025 |
| 369 | Reo Operating LLC | Austin, TX 78747 | Oil & Gas Operator | May 2025 |
| 370 | Reserve Management, Inc. | Tyler, TX 75711 | Oil & Gas Operator | May 2025 |
| 371 | Resolute Natural Res. Co., LLC | Midland, TX 79706 | Oil & Gas Operator | May 2025 |
| 372 | Reverence Operating LLC | Odessa, TX 79768 | Oil & Gas Operator | May 2025 |
| 373 | Rhonda Operating Company | Midland, TX 79710 | Oil & Gas Operator | Aug 2017 |
| 374 | Ricks Exploration, Inc. | Oklahoma City, OK 73154 | Oil & Gas Operator | Mar 2008 |
| 375 | Riley Exploration Opg Co, LLC | La Grange, TX 78945 | Oil & Gas Operator | May 2025 |
| 376 | Riley Permian Operating Co, LLC | Oklahoma City, OK 73104 | Oil & Gas Operator | May 2025 |
| 377 | Ring Energy, Inc. | Midland, TX 79702 | Oil & Gas Operator | May 2025 |
| 378 | Rio-Tex, Inc. | San Antonio, TX 78217 | Oil & Gas Operator | May 2025 |
| 379 | Robert C. Brower, LLC | Southlake, TX 76092 | Oil & Gas Operator | May 2025 |
| 380 | Robertson Resources, Inc. | Midland, TX 79708 | Oil & Gas Operator | May 2025 |
| 381 | Roca Operating, Inc. | Midland, TX 79702 | Oil & Gas Operator | May 2025 |
| 382 | Rogers, S. K. Oil, Inc. | Lubbock, TX 79424 | Oil & Gas Operator | May 2025 |
| 383 | Roosevelt Resources LP | Dallas, TX 75225 | Oil & Gas Operator | May 2025 |
| 384 | RSP Permian, LLC | Midland, TX 79701 | Oil & Gas Operator | Jul 2018 |
| 385 | Rusk Co. Well Service Co., Inc. | Kilgore, TX 75663 | Oil & Gas Operator | May 2025 |
| 386 | S & M Drilling, LLC | Wichita Falls, TX 76308 | Oil Operator | Sep 2023 |
| 387 | Saber Resources, LLC | Midland, TX 79701 | Oil & Gas Operator | Aug 2008 |
| 388 | Sabinal Energy Operating, LLC | The Woodlands, TX 77380 | Oil & Gas Operator | May 2025 |
| 389 | Saga Pet. LTD Liability Co Of Co | Midland, TX 79701 | Oil & Gas Operator | Apr 2004 |
| 390 | Sage Energy Company | San Antonio, TX 78215 | Oil & Gas Operator | May 2025 |
| 391 | Saguaro Petroleum, LLC | Midland, TX 79705 | Oil & Gas Operator | May 2025 |
| 392 | Samedan Oil Corporation | Houston, TX 77067 | Oil & Gas Operator | Dec 2019 |
| 393 | Samis Oil Company, Inc. | Oklahoma City, OK 73156 | Oil & Gas Operator | Sep 2000 |
| 394 | Samson Hydrocarbons Company | Tulsa, OK 74103 | Oil & Gas Operator | Nov 2016 |
| 395 | Samson Lone Star LP | Tulsa, OK 74103 | Oil & Gas Operator | Jun 2007 |
| 396 | Samson Resources Company | Tulsa, OK 74103 | Oil & Gas Operator | Feb 2025 |
| 397 | Sanchez Oil & Gas Corporation | Houston, TX 77056 | Oil & Gas Operator | May 2025 |
| 398 | Sanchez-O'Brien Oil & Gas Corp | Houston, TX 77057 | Oil & Gas Operator | May 1998 |
| 399 | Santa Fe Energy Oper. Part., LP | Houston, TX 77057 | Oil & Gas Operator | Dec 1994 |
| 400 | Santa Fe Energy Resources, Inc. | Houston, TX 77024 | Oil & Gas Operator | Mar 2008 |