| 401 | Oil & Gas Property MGMT., Inc. | Dallas, TX 75201 | Oil & Gas Operator | Jul 1996 |
| 402 | Oil Management Corporation | Dallas, TX 75206 | Oil & Gas Operator | Apr 2022 |
| 403 | Oilfield Management, Inc. (A) | Midland, TX 79702 | Oil & Gas Operator | Feb 2026 |
| 404 | Ojai Oil Company | Camarillo, CA 93012 | Oil & Gas Operator | Nov 2025 |
| 405 | Okla. Magic Circle Energy Corp. | Shawnee, OK 74801 | Oil & Gas Operator | Jul 2004 |
| 406 | Oklahoma RB Operating Company | Midland, TX 79701 | Oil & Gas Operator | Jan 1998 |
| 407 | Olsen Energy Inc. | Boerne, TX 78006 | Oil & Gas Operator | Feb 2026 |
| 408 | Omimex Petroleum Inc | Fort Worth, TX 76120 | Oil & Gas Operator | Aug 2022 |
| 409 | On Pointe Operating LLC | Jones, OK 73049 | Oil & Gas Operator | Feb 2026 |
| 410 | Opal Resources Operating Co.,LLC | Cypress, TX 77429 | Oil & Gas Operator | Jan 2019 |
| 411 | Oryx Energy Company | Dallas, TX 75221 | Oil & Gas Operator | May 2002 |
| 412 | Osborn Heirs Co | San Antonio, TX 78217 | Oil & Gas Operator | Dec 2025 |
| 413 | Ovintiv USA Inc. | Denver, CO 80202 | Oil & Gas Operator | Feb 2026 |
| 414 | Owens Petroleum, Inc. | Midland, TX 79702 | Oil & Gas Operator | Aug 1995 |
| 415 | Oxbow Petroleum, LLC | Midland, TX 79703 | Oil & Gas Operator | May 2025 |
| 416 | Oxy USA Inc | Houston, TX 77046 | Oil & Gas Operator | Feb 2026 |
| 417 | Oxy USA WTP LP | Houston, TX 77046 | Oil & Gas Operator | Feb 2026 |
| 418 | Oxyrock Operating, LLC | Houston, TX 77046 | Oil & Gas Operator | Feb 2026 |
| 419 | Palo Petroleum, Inc. | Dallas, TX 75360 | Oil & Gas Operator | Feb 2026 |
| 420 | Panola Corporation, The | Dallas, TX 75252 | Oil & Gas Operator | Sep 2002 |
| 421 | Parker & Parsley Acq. Group LLC | Midland, TX 79702 | Oil & Gas Operator | Aug 2002 |
| 422 | Parker & Parsley Development Co. | Midland, TX 79702 | Oil & Gas Operator | May 1995 |
| 423 | Parker & Parsley Development L.P | Midland, TX 79702 | Oil & Gas Operator | Oct 2007 |
| 424 | Parker & Parsley Operating LLC | Midland, TX 79702 | Oil & Gas Operator | Nov 2000 |
| 425 | Parsley Energy Operations, LLC | Irving, TX 75038 | Oil & Gas Operator | Jan 2021 |
| 426 | Pathfinder Exploration LLC | Norman, OK 73069-8516 | Gas Operator | Aug 2003 |
| 427 | Patriot Production LLC | Southlake, TX 76092 | Oil & Gas Operator | Apr 2023 |
| 428 | Pbex Operating, LTD. | Midland, TX 79702 | Oil & Gas Operator | Apr 2017 |
| 429 | Pbex Operations, LLC | Midland, TX 79702 | Oil & Gas Operator | Feb 2026 |
| 430 | Pech Oil Co., No. 2 | Midland, TX 79702 | Oil & Gas Operator | Apr 2013 |
| 431 | Pech Oil Company | Midland, TX 79702 | Oil & Gas Operator | Apr 2013 |
| 432 | Pecos Operating Company, LLC | Midland, TX 79701 | Oil & Gas Operator | Jun 2021 |
| 433 | Pecos Valley Management Co. | Dallas, TX 75206 | Oil & Gas Operator | Aug 2008 |
| 434 | Ped Oil Corporation | Midland, TX 79702 | Oil & Gas Operator | Feb 2026 |
| 435 | Peery, J. W. | Midland, TX 79701 | Oil & Gas Operator | Aug 2007 |
| 436 | Penn VIrginia Oil & Gas, L.P. | Houston, TX 77084 | Oil & Gas Operator | Nov 2022 |
| 437 | Pennzoil Exploration & Production Co. | Carthage, TX 75633 | Oil & Gas Operator | Mar 2008 |
| 438 | Pennzoil Petroleum Company | Houston, TX 77252 | Oil & Gas Operator | Nov 1999 |
| 439 | Penwell Energy, Inc. | Houston, TX 77057 | Oil & Gas Operator | Feb 2026 |
| 440 | Perenco LLC | Houston, TX 77002 | Oil & Gas Operator | Apr 2005 |
| 441 | Permian Resources Operating, LLC | Midland, TX 79701 | Oil & Gas Operator | Feb 2026 |
| 442 | Permian Resources, Inc. | Midland, TX 79702 | Oil & Gas Operator | Mar 2008 |
| 443 | Permian Resources, LLC | Houston, TX 77002 | Oil & Gas Operator | Mar 2018 |
| 444 | Permian Solutions LLC | Midland, TX 79702 | Oil & Gas Operator | Feb 2026 |
| 445 | Permian West Corp. | Odessa, TX 79762 | Oil & Gas Operator | Feb 2026 |
| 446 | Peterson Oil And Gas LLC | Wichita Falls, TX 76310 | Oil & Gas Operator | Feb 2026 |
| 447 | Petex | Breckenridge, TX 76424 | Oil & Gas Operator | Feb 2026 |
| 448 | Petro-Hunt, L.L.C. | Dallas, TX 75201 | Oil & Gas Operator | Feb 2026 |
| 449 | Petromark Energy LLC | Oklahoma City, OK 73116-7634 | Oil & Gas Operator | Jun 2000 |
| 450 | Petroplex Energy Inc. | Midland, TX 79702 | Oil & Gas Operator | Feb 2026 |
| 451 | Petroplex Equipment, Inc. | Midland, TX 79701 | Oil & Gas Operator | May 2019 |
| 452 | Petx Operating LLC | Midland, TX 79702 | Oil & Gas Operator | Feb 2026 |
| 453 | PG&E Resources Company | Houston, TX 77042 | Oil & Gas Operator | May 1995 |
| 454 | Pharaoh Oil & Gas, Inc. | MC Camey, TX 79752 | Oil & Gas Operator | Feb 2026 |
| 455 | Phillips Petroleum Company | Houston, TX 77251 | Oil & Gas Operator | Mar 2013 |
| 456 | Phoenix Hydrocarbons Operating | Midland, TX 79702 | Oil & Gas Operator | Jun 2024 |
| 457 | Pioneer Exploration Company | Houston, TX 77090 | Oil & Gas Operator | Dec 2025 |
| 458 | Pioneer Exploration, LLC | Houston, TX 77090 | Oil & Gas Operator | Dec 2025 |
| 459 | Pioneer Exploration, LTD. | Houston, TX 77090 | Oil & Gas Operator | Sep 2008 |
| 460 | Pioneer Natural Res. USA, Inc. | Spring, TX 77389 | Oil & Gas Operator | Feb 2026 |
| 461 | Pitts Energy Co. | Midland, TX 79707 | Oil & Gas Operator | Feb 2026 |
| 462 | Plains Marketing, LP | Cushing, OK 74023 | Oil Operator | Jan 2012 |
| 463 | Plains Petroleum Operating Co | Denver, CO 80202 | Oil & Gas Operator | Dec 2014 |
| 464 | Platform Operating, LLC | Midland, TX 79702 | Oil & Gas Operator | Feb 2026 |
| 465 | Platinum Exploration Inc. | Midland, TX 79701 | Oil & Gas Operator | Feb 2026 |
| 466 | Pogo Producing Company | Houston, TX 77002 | Oil & Gas Operator | Jan 2008 |
| 467 | Polaris Production Corp. | Midland, TX 79702 | Oil & Gas Operator | Jan 2024 |
| 468 | Powerline Energy Corporation | Arlington, TX 76015 | Oil & Gas Operator | Feb 2026 |
| 469 | Primal Energy Corporation | The Woodlands, TX 77380 | Oil & Gas Operator | Feb 2026 |
| 470 | Prime Operating Company | Midland, TX 79705 | Oil & Gas Operator | Feb 2026 |
| 471 | Prospctv Invstmnt & TRDG Co, LTD | Tulsa, OK 74170 | Oil & Gas Operator | May 2001 |
| 472 | PT Petroleum, LLC | Argyle, TX 76226 | Oil & Gas Operator | Oct 2019 |
| 473 | Pure Resources, L.P. | Midland, TX 79701 | Oil & Gas Operator | Mar 2006 |
| 474 | Purvis Oil Corp | Midland, TX 79702 | Oil & Gas Operator | Jul 1994 |
| 475 | Purvis Operating Co. | Midland, TX 79710 | Oil & Gas Operator | Feb 2026 |
| 476 | Purvis, J. H. | Midland, TX 79702 | Oil & Gas Operator | Dec 1994 |
| 477 | Q Natural Resources, LLC | Jones, OK 73049 | Oil & Gas Operator | Feb 2026 |
| 478 | QP, Inc. | Midland, TX 79702 | Oil & Gas Operator | Feb 2026 |
| 479 | Quantum Resources Management LLC | Houston, TX 77010 | Oil & Gas Operator | Nov 2025 |
| 480 | Quatro Oil And Gas, Inc. | Joshua, TX 76058 | Oil & Gas Operator | Feb 2026 |
| 481 | Quay Valley, Inc. | Midland, TX 79710 | Oil & Gas Operator | Oct 2007 |
| 482 | Quicksilver Resources Inc | Fort Worth, TX 76102 | Oil & Gas Operator | Mar 2018 |
| 483 | R K Petroleum Corp. | Midland, TX 79708 | Oil & Gas Operator | May 2024 |
| 484 | R. K. G. Engineering, Inc. | Odessa, TX 79760 | Oil & Gas Operator | Feb 2026 |
| 485 | R.K.G. Operations, Inc. | Odessa, TX 79760 | Oil & Gas Operator | Jun 2004 |
| 486 | R3 Operating Corporation | Denver, CO 80222 | Oil & Gas Operator | Feb 2026 |
| 487 | Raider Oil & Gas Company | MC Camey, TX 79752 | Oil & Gas Operator | Feb 2026 |
| 488 | Ram Operating Inc. | Browns, IL 62818 | Oil & Gas Operator | Aug 2008 |
| 489 | Ranger 40 Petroleum, LLC | Fairfield, CT 06824 | Oil & Gas Operator | Feb 2026 |
| 490 | Rattler Midstream Operating LLC | Midland, TX 79701 | Oil Operator | Feb 2026 |
| 491 | Rayden | Midland, TX 79711 | Oil & Gas Operator | Feb 2026 |
| 492 | RBJ & Associates, LP | Midland, TX 79707 | Oil Operator | Jan 2020 |
| 493 | Regions Energy LLC | Midland, TX 79702 | Oil & Gas Operator | Sep 2016 |
| 494 | Regions Operating, LLC | Midland, TX 79702 | Oil & Gas Operator | May 2024 |
| 495 | Rein Pusher Operating LLC | Brenham, TX 77834 | Oil & Gas Operator | Feb 2026 |
| 496 | Remnant Oil Operating, LLC | Midland, TX 79704 | Oil & Gas Operator | Jul 2024 |
| 497 | Remuda Operating Company | Midland, TX 79711 | Oil & Gas Operator | Feb 2026 |
| 498 | Rendova Oil Company, Inc. | Midland, TX 79702 | Oil & Gas Operator | Oct 2002 |
| 499 | Reverence Operating LLC | Odessa, TX 79768 | Oil & Gas Operator | Feb 2026 |
| 500 | Rex Energy Operating Corp. | State College, PA 16801 | Oil & Gas Operator | Jun 2012 |