| 401 | Ohlhausen Oil Company | Abilene, TX 79608 | Oil & Gas Operator | Feb 2026 |
| 402 | Oil & Gas Operations | Midland, TX 79706 | Oil & Gas Operator | Feb 2026 |
| 403 | Oil Management Corporation | Dallas, TX 75206 | Oil & Gas Operator | Apr 2022 |
| 404 | Oil, Gas, Etc. LLC | Katy, TX 77449 | Oil & Gas Operator | Feb 2026 |
| 405 | Ojb, Inc. | Buda, TX 78610 | Oil & Gas Operator | Mar 2013 |
| 406 | Oklahoma Oil Company | Dallas, TX 75206 | Oil & Gas Operator | Aug 2013 |
| 407 | Olenox Corp. | Katy, TX 77449 | Oil Operator | Feb 2026 |
| 408 | Omni Petroleum Corporation | Austin, TX 78738 | Oil & Gas Operator | Feb 2026 |
| 409 | Orth Oil Company, Inc. | Cisco, TX 76437 | Oil & Gas Operator | Feb 2026 |
| 410 | Otex LLC | Santa Anna, TX 76878 | Oil & Gas Operator | Feb 2026 |
| 411 | Oxy USA Inc | Houston, TX 77046 | Oil & Gas Operator | Feb 2026 |
| 412 | P & W Well Service Inc. | Abilene, TX 79604 | Oil & Gas Operator | Feb 2026 |
| 413 | P. L. O. | Boerne, TX 78006 | Oil & Gas Operator | Jun 2016 |
| 414 | P.B. Blue Dot Properties | Wexford, PA 15090 | Oil & Gas Operator | Feb 2026 |
| 415 | Pace Operating | Abilene, TX 79608 | Oil & Gas Operator | Feb 2026 |
| 416 | Paint Rock Operating, LLC | San Angelo, TX 76904 | Oil & Gas Operator | Feb 2026 |
| 417 | Panamerican Operating Inc | Dallas, TX 75219 | Oil & Gas Operator | Feb 2026 |
| 418 | Panther Creek Resources, LLC | Denver, CO 80202 | Oil & Gas Operator | May 2012 |
| 419 | Paragon Oil & Gas, LLC | Aledo, TX 76008 | Oil & Gas Operator | Feb 2026 |
| 420 | Pardue Oil | Breckenridge, TX 76424 | Oil & Gas Operator | Sep 2006 |
| 421 | Parker Operating Co., Inc. | Aledo, TX 76008 | Oil & Gas Operator | Sep 2000 |
| 422 | Patton, E. N. Oil Company, Inc. | Abilene, TX 79604 | Oil & Gas Operator | Feb 2026 |
| 423 | Patton, Lloyd | Fort Worth, TX 76113 | Oil & Gas Operator | Aug 2003 |
| 424 | Payne Petroleum | Abilene, TX 79604 | Oil & Gas Operator | Feb 2026 |
| 425 | PDH Enterprises | Pittsburg, TX 75686 | Oil & Gas Operator | Apr 2019 |
| 426 | Penn VIrginia Oil & Gas Corp | Houston, TX 77024 | Oil & Gas Operator | Dec 2023 |
| 427 | Perimeter Resource Company | Midland, TX 79702 | Oil & Gas Operator | Feb 2026 |
| 428 | Permian Legend LLC | San Marcos, TX 78666 | Oil Operator | Feb 2026 |
| 429 | Permian Resources, Inc. | Midland, TX 79702 | Oil & Gas Operator | Mar 2008 |
| 430 | Petra Oleum Corp. | Midland, TX 79702 | Oil & Gas Operator | Feb 2026 |
| 431 | Petro 2000 Exploration Co. | Katy, TX 77450 | Oil & Gas Operator | Nov 2011 |
| 432 | Petro-West Corporation | Lubbock, TX 79404 | Oil & Gas Operator | Oct 2001 |
| 433 | Petrosource Energy Corporation | Fort Worth, TX 76112 | Oil & Gas Operator | Feb 2026 |
| 434 | Pinon Petroleum, Inc. | San Angelo, TX 76903 | Oil & Gas Operator | Apr 2004 |
| 435 | Pioneer Energy Corporation | Dallas, TX 75204 | Oil & Gas Operator | Feb 2026 |
| 436 | Pioneer Exploration Company | Houston, TX 77090 | Oil & Gas Operator | Dec 2025 |
| 437 | Pioneer Exploration, LLC | Houston, TX 77090 | Oil & Gas Operator | Dec 2025 |
| 438 | Pioneer Exploration, LTD. | Houston, TX 77090 | Oil & Gas Operator | Sep 2008 |
| 439 | Pittencrieff America Inc | Abilene, TX 79608 | Oil & Gas Operator | Feb 2003 |
| 440 | Place Oil And Gas Co. | Eastland, TX 76448 | Oil & Gas Operator | Feb 2026 |
| 441 | Plover Production Company | Fort Worth, TX 76109 | Oil & Gas Operator | Jul 2006 |
| 442 | PNG Operating Company | Oklahoma City, OK 73172 | Oil & Gas Operator | Feb 2026 |
| 443 | Pony Express Corporate Trust | Aledo, TX 76008 | Oil & Gas Operator | Feb 2026 |
| 444 | Powell, A. Brandt | Coleman, TX 76834 | Oil & Gas Operator | Mar 1999 |
| 445 | Powell, A. Brandt Co. | Hawley, TX 79525 | Oil & Gas Operator | Feb 2026 |
| 446 | Powerflex Services Inc. | Winters, TX 79567 | Oil & Gas Operator | Feb 2026 |
| 447 | Precision Drilling Company, Inc. | Santa Anna, TX 76878 | Oil & Gas Operator | Nov 1995 |
| 448 | Prensorus Energy, LLC | Abilene, TX 79604 | Oil & Gas Operator | Feb 2026 |
| 449 | Pruitt Engineering & Petro. Co. | Kerrville, TX 78028 | Oil & Gas Operator | Jul 2007 |
| 450 | Purvis Operating Co. | Midland, TX 79710 | Oil & Gas Operator | Feb 2026 |
| 451 | PWR Operating, LLC | Dallas, TX 75219 | Oil & Gas Operator | Feb 2026 |
| 452 | Pyramid Production Co. | Abilene, TX 79608 | Oil & Gas Operator | Jun 1994 |
| 453 | Qri Industries, Inc. | Katy, TX 77449 | Oil Operator | Feb 2026 |
| 454 | Quail Well Service, Inc. | Abilene, TX 79604 | Oil & Gas Operator | Feb 2026 |
| 455 | Quicksilver Resources Inc | Fort Worth, TX 76102 | Oil & Gas Operator | Mar 2018 |
| 456 | R & P Operating | Tuscola, TX 79562 | Oil & Gas Operator | Jun 1997 |
| 457 | R & R Well Service | Fort Worth, TX 76120 | Oil & Gas Operator | Jan 2005 |
| 458 | R & R Well Service, Inc. | Arlington, TX 76012 | Oil & Gas Operator | Feb 2026 |
| 459 | Ram Operating Inc. | Browns, IL 62818 | Oil & Gas Operator | Aug 2008 |
| 460 | Ranger Operating Co. | Graham, TX 76450 | Oil & Gas Operator | Feb 2026 |
| 461 | Ratex Energy Inc. | Manchaca, TX 78652 | Oil & Gas Operator | Sep 2002 |
| 462 | Ratts, Robert V. Inc. | Bedford, TX 76021 | Oil & Gas Operator | Aug 2003 |
| 463 | Rayco Operating, Inc. | Abilene, TX 79604 | Oil & Gas Operator | Feb 2026 |
| 464 | RBD-Shelby Agency | Dallas, TX 75283 | Oil & Gas Operator | Dec 1993 |
| 465 | Red Willow Production, LLC | Ignacio, CO 81137 | Oil & Gas Operator | Oct 2015 |
| 466 | Red-Tex Petroleum, Inc. | Abilene, TX 79608 | Oil & Gas Operator | Aug 2003 |
| 467 | Remuda Operating Company | Midland, TX 79711 | Oil & Gas Operator | Feb 2026 |
| 468 | Reo Operating LLC | Austin, TX 78747 | Oil & Gas Operator | Feb 2026 |
| 469 | Resource Expl & Prod, Inc. | Salado, TX 76571 | Oil & Gas Operator | Feb 2026 |
| 470 | Retriever Operating LLC | Midland, TX 79704 | Oil & Gas Operator | Feb 2026 |
| 471 | Revard Petroleum, L.L.C. | Tulsa, OK 74170 | Oil & Gas Operator | Feb 2026 |
| 472 | Rhyne, J.V. | Cisco, TX 76437 | Oil & Gas Operator | Feb 2026 |
| 473 | Riata Energy, Inc. | Oklahoma City, OK 73101 | Oil & Gas Operator | Nov 2006 |
| 474 | Rice Drilling Company | Santa Anna, TX 76878 | Oil & Gas Operator | Feb 2026 |
| 475 | Richardson, Bud II | Graham, TX 76450 | Oil & Gas Operator | Feb 2026 |
| 476 | Richey, Ray Management Co., Inc. | Fort Worth, TX 76108 | Oil & Gas Operator | Feb 2026 |
| 477 | Ridglea Energy I, LLC | Spring, TX 77379 | Oil & Gas Operator | Feb 2026 |
| 478 | Rife Oil Properties Inc | Fort Worth, TX 76107 | Oil & Gas Operator | Feb 2026 |
| 479 | Ring Energy, Inc. | Midland, TX 79702 | Oil & Gas Operator | Feb 2026 |
| 480 | Rio Exploration Company | San Antonio, TX 78209 | Gas Operator | Dec 2005 |
| 481 | Rise Petroleum Investments LLC | Tomball, TX 77377 | Oil & Gas Operator | Feb 2026 |
| 482 | Rivercity Operating, Inc. | Austin, TX 78766 | Oil & Gas Operator | Feb 2026 |
| 483 | Ro-Jo, Inc. | Highland VLG, TX 75077 | Oil & Gas Operator | Aug 2003 |
| 484 | Robertson Resources, Inc. | Horseshoe Bay, TX 78657 | Oil & Gas Operator | Feb 2026 |
| 485 | Robertson, French M. Oil Co. | Abilene, TX 79608 | Oil & Gas Operator | Mar 1995 |
| 486 | Rockwood Resources Inc | Coleman, TX 76834 | Oil & Gas Operator | Feb 2026 |
| 487 | Roco Petroleum, Incorporated | Abilene, TX 79605 | Oil & Gas Operator | Feb 2026 |
| 488 | Rosson, Robert K. | Novice, TX 79538 | Oil & Gas Operator | Aug 2003 |
| 489 | Rough Creek Exploration, Inc. | Santa Anna, TX 76878 | Oil & Gas Operator | Jan 1996 |
| 490 | Royal Texan Resources Co. | Breckenridge, TX 76424 | Oil & Gas Operator | Feb 2026 |
| 491 | Rust Oil Corp. | Fort Worth, TX 76121 | Oil & Gas Operator | Feb 2026 |
| 492 | Ruthson Energy, Inc. | Judson, TX 75660 | Oil Operator | Feb 2026 |
| 493 | RWJ Operating LLC | Dallas, TX 75201 | Oil & Gas Operator | Feb 2026 |
| 494 | Ryholland Fielder, Inc | Delray Beach, FL 33446 | Oil & Gas Operator | Feb 2026 |
| 495 | S & H Resources | Abilene, TX 79605 | Oil & Gas Operator | Feb 2026 |
| 496 | S & J Operating Company | Wichita Falls, TX 76301 | Oil & Gas Operator | Mar 2015 |
| 497 | S & V Operating | Zephyr, TX 76890 | Oil & Gas Operator | Feb 2026 |
| 498 | S.B. Street Operating, Inc. | Graham, TX 76450 | Oil & Gas Operator | Feb 2026 |
| 499 | Sabre Oil And Gas Corp. | Houston, TX 77063 | Oil & Gas Operator | Feb 2026 |
| 500 | Saga Petroleum Corp. | Midland, TX 79701 | Oil & Gas Operator | Mar 2008 |