| 401 | Nicor Exploration Company | Houston, TX 77002 | Oil & Gas Operator | Jun 1993 |
| 402 | NMR Energy LLC | Houston, TX 77063 | Oil & Gas Operator | Jul 2026 |
| 403 | Noble Energy Inc | Midland, TX 79706 | Oil & Gas Operator | Jul 2026 |
| 404 | Noble Operating, LLC | Flower Mound, TX 75028 | Oil & Gas Operator | Sep 2013 |
| 405 | North American Royalties, Inc. | Chattanooga, TN 37408 | Oil & Gas Operator | Oct 2001 |
| 406 | O'Neill Properties, LTD. | Midland, TX 79702 | Oil & Gas Operator | Jul 2026 |
| 407 | O. H. B. Inc. | San Angelo, TX 76902 | Oil & Gas Operator | Sep 2019 |
| 408 | Oak Prairie Operations, LLC | The Woodlands, TX 77381 | Oil & Gas Operator | Jul 2026 |
| 409 | Oakland Petroleum Oper Co., Inc. | Kilgore, TX 75663 | Oil & Gas Operator | Jul 2026 |
| 410 | Oasis Petroleum Permian LLC | Houston, TX 77002 | Oil & Gas Operator | Jul 2026 |
| 411 | Occidental Energy Marketing, Inc. | Houston, TX 77227 | Gas Operator | Sep 2015 |
| 412 | Occidental Permian LTD. | Houston, TX 77046 | Oil & Gas Operator | Jul 2026 |
| 413 | Ocean Energy Inc | Houston, TX 77002 | Oil & Gas Operator | Aug 2003 |
| 414 | Ogog Operating, LLC | Dallas, TX 75367 | Oil & Gas Operator | Jul 2026 |
| 415 | Ogris Operating, LLC | Midland, TX 79710 | Oil & Gas Operator | Jul 2026 |
| 416 | Ogx Operating, LLC | Midland, TX 79702 | Oil & Gas Operator | Jul 2026 |
| 417 | Ogx Resources LLC | Midland, TX 79702 | Oil & Gas Operator | Oct 2011 |
| 418 | Oklahoma RB Operating Company | Midland, TX 79701 | Oil & Gas Operator | Jan 1998 |
| 419 | Older Than Dirt LLC | Weatherford, TX 76086 | Oil & Gas Operator | Jul 2026 |
| 420 | Olsen Energy Inc. | Boerne, TX 78006 | Oil & Gas Operator | Jul 2026 |
| 421 | On Pointe Operating LLC | Jones, OK 73049 | Oil & Gas Operator | Jul 2026 |
| 422 | Oryx Energy Company | Dallas, TX 75221 | Oil & Gas Operator | May 2002 |
| 423 | Osceola Oil & Gas Corporation | Somerset, TX 78069 | Oil & Gas Operator | Aug 1994 |
| 424 | Osr Oil & Gas Company | Victoria, TX 77902 | Oil & Gas Operator | Jul 2000 |
| 425 | Oxbow Petroleum, LLC | Midland, TX 79703 | Oil & Gas Operator | May 2025 |
| 426 | Oxy USA Inc | Houston, TX 77046 | Oil & Gas Operator | Jul 2026 |
| 427 | Oxy USA WTP LP | Houston, TX 77046 | Oil & Gas Operator | Jul 2026 |
| 428 | Page Exploration | Midland, TX 79701 | Oil & Gas Operator | Apr 2007 |
| 429 | Paladin Petroleum III, L.L.C. | Austin, TX 78746 | Oil & Gas Operator | Jul 2026 |
| 430 | Panhandle Oil & Gas Inc | Oklahoma City, OK 73112-5688 | Oil & Gas Operator | May 2007 |
| 431 | Panther Exploration, LLC | Tulsa, OK 74136 | Oil & Gas Operator | Feb 2017 |
| 432 | Parker & Parsley Development Co. | Midland, TX 79702 | Oil & Gas Operator | May 1995 |
| 433 | Parker & Parsley Development L.P | Midland, TX 79702 | Oil & Gas Operator | Oct 2007 |
| 434 | Parker & Parsley Producing LP | Midland, TX 79702 | Oil & Gas Operator | Oct 1997 |
| 435 | Parsley Energy Operations, LLC | Irving, TX 75038 | Oil & Gas Operator | Jan 2021 |
| 436 | Passmore, Mike F. | Monahans, TX 79756 | Oil & Gas Operator | Jul 2026 |
| 437 | Patoil Corp. | San Antonio, TX 78205 | Oil & Gas Operator | Aug 2003 |
| 438 | Patriot Production LLC | Southlake, TX 76092 | Oil & Gas Operator | Apr 2023 |
| 439 | PDC Energy | Denver, CO 80203 | Oil & Gas Operator | Nov 2012 |
| 440 | PDC-WV-Co Corporation | Denver, CO 80203 | Oil & Gas Operator | Aug 2010 |
| 441 | Pdeh LLC | Midland, TX 79701 | Oil & Gas Operator | Jul 2026 |
| 442 | Pearce Trust And Blair | Midland, TX 79702 | Oil & Gas Operator | Mar 2008 |
| 443 | Pearl, Bill H. Productions, Inc. | Corpus Chrsti, TX 78460 | Oil & Gas Operator | Jul 2026 |
| 444 | Pecos Operating Company, LLC | Midland, TX 79701 | Oil & Gas Operator | Jun 2021 |
| 445 | Pecos Operators, Inc. | Midland, TX 79702 | Oil & Gas Operator | Dec 1993 |
| 446 | Pecos Production Company | Oklahoma City, OK 73154 | Oil & Gas Operator | Apr 2005 |
| 447 | Penergy | Midland, TX 79710 | Oil & Gas Operator | Jul 2026 |
| 448 | Pennzenergy Exp. & Prod., L.L.C. | Houston, TX 77210 | Oil & Gas Operator | Mar 2000 |
| 449 | Pennzoil Exploration & Production Co. | Carthage, TX 75633 | Oil & Gas Operator | Mar 2008 |
| 450 | Pennzoil Petroleum Company | Houston, TX 77252 | Oil & Gas Operator | Nov 1999 |
| 451 | Penwell Energy, Inc. | Houston, TX 77057 | Oil & Gas Operator | Jul 2026 |
| 452 | Penwell South Operating LLC | Austin, TX 78746 | Oil & Gas Operator | Jul 2026 |
| 453 | Percussion Petroleum Oper II,LLC | Houston, TX 77042 | Oil & Gas Operator | Jul 2023 |
| 454 | Perimeter Resource Company | Midland, TX 79702 | Oil & Gas Operator | Jul 2026 |
| 455 | Perkins-Prothro Company | Wichita Falls, TX 76308 | Oil & Gas Operator | May 2002 |
| 456 | Permex Petroleum Corporation | Graham, TX 76450 | Oil & Gas Operator | Jul 2026 |
| 457 | Permian Natural Resources | Tyler, TX 75701 | Oil & Gas Operator | Jul 2026 |
| 458 | Permian Resources Operating, LLC | Midland, TX 79701 | Oil & Gas Operator | Jul 2026 |
| 459 | Permian Resources, Inc. | Midland, TX 79702 | Oil & Gas Operator | Mar 2008 |
| 460 | Petex | Breckenridge, TX 76424 | Oil & Gas Operator | Jul 2026 |
| 461 | Petro-Hunt, L.L.C. | Dallas, TX 75201 | Oil & Gas Operator | Jul 2026 |
| 462 | Petroleum Capital, L.C. | Dallas, TX 75367 | Oil & Gas Operator | Jul 2026 |
| 463 | Petroleum Technical Services Co. | Midland, TX 79707 | Oil & Gas Operator | Dec 2004 |
| 464 | Petroplex Energy Inc. | Midland, TX 79702 | Oil & Gas Operator | Jul 2026 |
| 465 | Petx Operating LLC | Midland, TX 79702 | Oil & Gas Operator | Jul 2026 |
| 466 | Pharaoh Oil & Gas, Inc. | MC Camey, TX 79752 | Oil & Gas Operator | Jul 2026 |
| 467 | Phillips Petroleum Company | Houston, TX 77251 | Oil & Gas Operator | Mar 2013 |
| 468 | Phoenix Hydrocarbons Operating | Midland, TX 79702 | Oil & Gas Operator | Jun 2024 |
| 469 | Pillar Energy, LLC | Charleston, WV 25312-5987 | Oil & Gas Operator | Dec 2025 |
| 470 | Pioneer Natural Res. USA, Inc. | Spring, TX 77389 | Oil & Gas Operator | Jul 2026 |
| 471 | Pioneer Resources Producing, L.P | Irving, TX 75039 | Oil & Gas Operator | Feb 2001 |
| 472 | Pitco Investments, LTD. | Scottsdale, AZ 85261 | Oil & Gas Operator | Jan 2013 |
| 473 | Plains Exploration & Prod. Co. | Houston, TX 77002 | Oil & Gas Operator | Jul 2013 |
| 474 | Plains Marketing, LP | Cushing, OK 74023 | Oil Operator | Jan 2012 |
| 475 | Plains Production Inc | Wichita Falls, TX 76308 | Oil & Gas Operator | Dec 1995 |
| 476 | Plantation Operating, LLC | Houston, TX 77041 | Oil & Gas Operator | Nov 2011 |
| 477 | Platinum Exploration Inc. | Midland, TX 79701 | Oil & Gas Operator | Jul 2026 |
| 478 | Pogo Producing Company | Houston, TX 77002 | Oil & Gas Operator | Jan 2008 |
| 479 | Pogo Producing Company LLC | Houston, TX 77002 | Oil & Gas Operator | May 2026 |
| 480 | Pogue, Randall R. | Ada, OK 74820 | Oil & Gas Operator | May 2003 |
| 481 | Point Energy Partners Petro, LLC | Fort Worth, TX 76102 | Oil & Gas Operator | Jul 2026 |
| 482 | Pride Energy Company | Tulsa, OK 74170 | Oil & Gas Operator | Jul 2026 |
| 483 | Prize Operating Company | Grapevine, TX 76051 | Oil & Gas Operator | Aug 2016 |
| 484 | Production Service Co. | Lubbock, TX 79490 | Oil & Gas Operator | Oct 2015 |
| 485 | Propel Energy, LLC | Houston, TX 77024 | Oil & Gas Operator | Sep 2013 |
| 486 | Pure Resources, L.P. | Midland, TX 79701 | Oil & Gas Operator | Mar 2006 |
| 487 | Q Natural Resources, LLC | Jones, OK 73049 | Oil & Gas Operator | Jul 2026 |
| 488 | Qep Energy Company | Midland, TX 79701 | Oil & Gas Operator | Apr 2026 |
| 489 | QP, Inc. | Midland, TX 79702 | Oil & Gas Operator | Jul 2026 |
| 490 | Quantum Resources Management LLC | Houston, TX 77010 | Oil & Gas Operator | Apr 2026 |
| 491 | Questa Oil & Gas Co. | Tulsa, OK 74170 | Oil & Gas Operator | Mar 2015 |
| 492 | Questar Expl. And Prod. Co. | Salt Lake Cty, UT 84145 | Oil & Gas Operator | Jul 2011 |
| 493 | Quicksilver Resources Inc | Fort Worth, TX 76102 | Oil & Gas Operator | Mar 2018 |
| 494 | R K Petroleum Corp. | Midland, TX 79708 | Oil & Gas Operator | May 2024 |
| 495 | R. B. Oil Company | Monahans, TX 79756 | Oil & Gas Operator | Nov 1996 |
| 496 | Rad Oil Company | Snyder, TX 79549 | Oil & Gas Operator | Jul 2026 |
| 497 | Raider Oil & Gas Company | MC Camey, TX 79752 | Oil & Gas Operator | Jul 2026 |
| 498 | Ram Energy LLC | Tulsa, OK 74152 | Oil & Gas Operator | Apr 2026 |
| 499 | Ram Operating Company, Inc. | Houston, TX 77002 | Oil & Gas Operator | Sep 2012 |
| 500 | Ram Operating Inc. | Browns, IL 62818 | Oil & Gas Operator | Aug 2008 |