| 401 | Penn VIrginia Oil & Gas, L.P. | Houston, TX 77084 | Oil & Gas Operator | Nov 2022 |
| 402 | Pennzenergy Exp. & Prod., L.L.C. | Houston, TX 77210 | Oil & Gas Operator | Mar 2000 |
| 403 | Pennzoil Exploration & Production Co. | Carthage, TX 75633 | Oil & Gas Operator | Mar 2008 |
| 404 | Penroc Oil Corp. | Hobbs, NM 88241 | Oil & Gas Operator | Jun 2026 |
| 405 | Peoples Energy Prod.-TX, L.P. | Houston, TX 77002 | Oil & Gas Operator | Sep 2007 |
| 406 | Permian Natural Resources | Tyler, TX 75701 | Oil & Gas Operator | Sep 2026 |
| 407 | Petro-Hunt, L.L.C. | Dallas, TX 75201 | Oil & Gas Operator | Sep 2026 |
| 408 | Petrogas Energy Services, LLC | Dallas, TX 75214 | Oil Operator | Sep 2026 |
| 409 | Petrohawk Operating Company | Houston, TX 77056 | Oil & Gas Operator | Oct 2021 |
| 410 | Petroleum Investments, Inc | Shreveport, LA 71101 | Oil & Gas Operator | Dec 1977 |
| 411 | Petroleum Production MGMT., Inc. | Kansas City, MO 64112 | Oil & Gas Operator | Sep 2026 |
| 412 | Petroquest Energy, L.L.C. | Lafayette, LA 70505 | Oil & Gas Operator | Sep 2026 |
| 413 | PG&E Resources Company | Houston, TX 77042 | Oil & Gas Operator | May 1995 |
| 414 | Phillips Energy, Inc. | Shreveport, LA 71101 | Oil & Gas Operator | Dec 2018 |
| 415 | Phillips Petroleum Company | Houston, TX 77251 | Oil & Gas Operator | Mar 2013 |
| 416 | Phillips, Jack L. | Gladewater, TX 75647 | Oil & Gas Operator | Dec 1997 |
| 417 | Phillips, Jack L. Co. | Gladewater, TX 75647 | Oil & Gas Operator | Sep 2026 |
| 418 | Pine Wave Energy Partners Op,LLC | Dallas, TX 75205 | Oil & Gas Operator | Mar 2026 |
| 419 | Pinewood Exploration Inc. | Arlington, TX 76096 | Oil & Gas Operator | Oct 2011 |
| 420 | Pintail Production Co., Inc. | Fort Worth, TX 76132 | Oil & Gas Operator | Sep 2026 |
| 421 | Placid Oil Company | Houston, TX 77227 | Oil & Gas Operator | Mar 2008 |
| 422 | Plains Marketing, LP | Cushing, OK 74023 | Oil Operator | Jan 2012 |
| 423 | Plains Production Inc | Wichita Falls, TX 76308 | Oil & Gas Operator | Dec 1995 |
| 424 | Powell, Gene Investments, Inc. | Longview, TX 75608 | Oil & Gas Operator | Apr 2024 |
| 425 | Premier Oil & Gas LLC | Blanchard, OK 73010-2010 | Oil Operator | Dec 2022 |
| 426 | Preston Exploration LLC | Spring, TX 77387 | Oil & Gas Operator | Dec 2014 |
| 427 | Pride Energy Company | Tulsa, OK 74170 | Oil & Gas Operator | Sep 2026 |
| 428 | Pride Exploration, Inc. | Shreveport, LA 71101 | Oil & Gas Operator | Jul 2015 |
| 429 | Princess Three Corporation | Henderson, TX 75653 | Oil & Gas Operator | Apr 2020 |
| 430 | Princess Three Operating, LLC | Henderson, TX 75653 | Oil & Gas Operator | Sep 2026 |
| 431 | Proex Energy Management, L.L.C. | Spring, TX 77386 | Oil & Gas Operator | Sep 2026 |
| 432 | Proline Energy Resources Inc | Sugar Land, TX 77479 | Oil & Gas Operator | Sep 2026 |
| 433 | Providence Oil & Gas Corp | Tulsa, OK 74135-5463 | Oil & Gas Operator | May 2005 |
| 434 | PXP Gulf Coast Inc. | Houston, TX 77002 | Oil & Gas Operator | Mar 2015 |
| 435 | PXP Texas Inc. | Houston, TX 77002 | Oil & Gas Operator | Feb 2007 |
| 436 | Quantum Resources Management LLC | Houston, TX 77010 | Oil & Gas Operator | May 2026 |
| 437 | Quatros Operating Company | Kilgore, TX 75663 | Oil Operator | Sep 2026 |
| 438 | R & C Petroleum, Inc. | Flint, TX 75762 | Oil & Gas Operator | Sep 2026 |
| 439 | R & S Investments | Tulsa, OK 74146-4743 | Oil Operator | Aug 2013 |
| 440 | R. Lacy Services, LTD. | Longview, TX 75606 | Oil & Gas Operator | Sep 2026 |
| 441 | Rabalais, F.W. Inc. | Fort Worth, TX 76101 | Oil & Gas Operator | Sep 2023 |
| 442 | Range Production Company | Fort Worth, TX 76102 | Oil & Gas Operator | Sep 2021 |
| 443 | Range Production Company, LLC | Fort Worth, TX 76102 | Oil & Gas Operator | May 2026 |
| 444 | Ratex Energy Inc. | Manchaca, TX 78652 | Oil & Gas Operator | Sep 2002 |
| 445 | RBD-Shelby Agency | Dallas, TX 75283 | Oil & Gas Operator | Dec 1993 |
| 446 | Red Hills Energy, LLC | Medicine Lodge, KS 67104 | Oil & Gas Operator | Apr 2026 |
| 447 | Redmon Oil Company, Inc., The | Plano, TX 75023 | Oil & Gas Operator | Sep 2026 |
| 448 | Redstone Oil & Gas Company | Dallas, TX 75225 | Oil & Gas Operator | Jan 2020 |
| 449 | Reef Exploration, Inc. (A-1) | Richardson, TX 75080 | Oil & Gas Operator | Oct 2006 |
| 450 | Remuda Operating Company | Midland, TX 79711 | Oil & Gas Operator | Sep 2026 |
| 451 | Resaca Resources, L.L.C. | Austin, TX 78746 | Oil & Gas Operator | Sep 2026 |
| 452 | Reserve Management, Inc. | Tyler, TX 75711 | Oil & Gas Operator | Sep 2026 |
| 453 | Resource America Inc | Uniontown, OH 44685 | Oil & Gas Operator | Dec 2011 |
| 454 | Resource Energy Inc | Uniontown, OH 44685 | Gas Operator | Dec 2007 |
| 455 | Ress Production Co. | Farmington, NM 87499 | Oil & Gas Operator | Mar 2026 |
| 456 | Revilo Exploration, Inc. | Richardson, TX 75081 | Oil & Gas Operator | Jul 2021 |
| 457 | Reynolds Drilling Co., Inc. | Shreveport, LA 71105 | Oil & Gas Operator | Sep 2026 |
| 458 | Reynolds E & P, Inc. | Shreveport, LA 71105 | Oil & Gas Operator | Sep 2026 |
| 459 | Rfe Operating, LLC | Tyler, TX 75703 | Oil & Gas Operator | Sep 2026 |
| 460 | Richey Operating, Inc. | Tyler, TX 75711 | Oil & Gas Operator | Sep 2026 |
| 461 | Richey Properties, Inc. | Tyler, TX 75711 | Oil & Gas Operator | Sep 2026 |
| 462 | Rippy Oil Company | Tyler, TX 75702 | Oil & Gas Operator | Sep 2026 |
| 463 | Riverstone Energy Operating, LLC | Houston, TX 77090 | Oil & Gas Operator | Sep 2026 |
| 464 | Rme Petroleum Company | Houston, TX 77251 | Oil & Gas Operator | Nov 2016 |
| 465 | Roberts & Murphy, Inc. | Shreveport, LA 71137 | Oil & Gas Operator | Apr 2016 |
| 466 | Rockcliff Energy Operating LLC | Houston, TX 77002 | Oil & Gas Operator | Sep 2026 |
| 467 | Rodessa Management, Inc. | Longview, TX 75606 | Oil & Gas Operator | May 1995 |
| 468 | Rojo Burro Petroleo & Gas | Kilgore, TX 75662 | Oil & Gas Operator | Aug 2007 |
| 469 | Roosth & Genecov Production Co. | Tyler, TX 75710 | Oil & Gas Operator | Aug 2003 |
| 470 | Roosth Production Co. | Tyler, TX 75711 | Oil & Gas Operator | Sep 2026 |
| 471 | Rosbottom Production Corp | Shreveport, LA 71134 | Oil & Gas Operator | Dec 2017 |
| 472 | Rusk Co. Well Service Co., Inc. | Kilgore, TX 75663 | Oil & Gas Operator | Sep 2026 |
| 473 | Rusk Energy Management, LLC | Houston, TX 77002 | Oil & Gas Operator | Feb 2008 |
| 474 | S M K Energy Corporation | Corpus Chrsti, TX 78475 | Oil & Gas Operator | Sep 2026 |
| 475 | Sabine Energy Inc. | Houston, TX 77002 | Oil & Gas Operator | Sep 2026 |
| 476 | Sabine Oil & Gas Corporation | Houston, TX 77002 | Oil & Gas Operator | Dec 2025 |
| 477 | Sabine Oil & Gas LLC | Houston, TX 77002 | Oil & Gas Operator | Dec 2017 |
| 478 | Sabine Pipe & Supply Co. | Kilgore, TX 75663 | Oil & Gas Operator | Sep 2004 |
| 479 | Salt Creek Resources, LLC | Caney, KS 67333 | Oil Operator | Oct 2019 |
| 480 | Samson Exploration LLC | Tulsa, OK 74101 | Oil & Gas Operator | Jul 2026 |
| 481 | Samson Hydrocarbons Company | Tulsa, OK 74103 | Oil & Gas Operator | Nov 2016 |
| 482 | Samson Lone Star LP | Tulsa, OK 74103 | Oil & Gas Operator | Jun 2007 |
| 483 | Samson Lone Star, LLC | Tulsa, OK 74103 | Oil & Gas Operator | Sep 2026 |
| 484 | Samson Resources Company | Tulsa, OK 74103 | Oil & Gas Operator | May 2026 |
| 485 | Scheriger Production | Graham, TX 76450 | Oil & Gas Operator | Jun 2006 |
| 486 | Scythian, LTD. | Midland, TX 79701 | Oil & Gas Operator | Dec 2020 |
| 487 | SDG Operating Company, Inc | Tyler, TX 75701 | Oil & Gas Operator | Sep 2026 |
| 488 | Se USA Operating, Inc. | Houston, TX 77002 | Oil & Gas Operator | Dec 2009 |
| 489 | Seagull Energy E & P Inc | Houston, TX 77002 | Oil & Gas Operator | Jan 2015 |
| 490 | Seagull Mid-South Inc | Houston, TX 77002 | Oil & Gas Operator | Mar 2015 |
| 491 | Sendero Energy Inc. | Dallas, TX 75205 | Oil & Gas Operator | Sep 2026 |
| 492 | Senora Resources, Inc. | Dime Box, TX 77853 | Oil & Gas Operator | Sep 2026 |
| 493 | Shappell Oil Company | Holliday, TX 76366 | Oil & Gas Operator | Sep 2012 |
| 494 | Shappell Oil Company, L.L.C. | Harrisonburg, LA 71340 | Oil & Gas Operator | Sep 2026 |
| 495 | Shelby Operating Company | Dallas, TX 75205 | Oil & Gas Operator | Sep 2026 |
| 496 | Shelby Production Co. | Kilgore, TX 75663 | Oil & Gas Operator | Mar 2009 |
| 497 | Shelby, Michael H. | Shreveport, LA 71101 | Oil & Gas Operator | Sep 2026 |
| 498 | Sheridan Energy,Inc. | Houston, TX 77002 | Oil & Gas Operator | Feb 2000 |
| 499 | Sheridan Production Co III, LLC | Houston, TX 77056 | Oil & Gas Operator | Sep 2026 |
| 500 | Sheridan Production Company, LLC | Houston, TX 77056 | Oil & Gas Operator | May 2026 |