| 401 | Ovintiv USA Inc. | Denver, CO 80202 | Oil & Gas Operator | Apr 2024 |
| 402 | Oxley Petroleum | Tulsa, OK 74119-3609 | Oil & Gas Operator | Jan 2020 |
| 403 | Oxley Petroleum Co | Oklahoma City, OK 73118-1044 | Oil & Gas Operator | Sep 2017 |
| 404 | Oxy USA Inc | Houston, TX 77046 | Oil & Gas Operator | Apr 2024 |
| 405 | Pacific Enterprise Oil Co USA | Los Angeles, CA 90071-2005 | Oil & Gas Operator | Aug 2012 |
| 406 | Pacific Enterprises Royalty Co | Oklahoma City, OK 73101 | Oil & Gas Operator | Feb 2002 |
| 407 | Paloma Operating Co Inc | | Oil & Gas Operator | Dec 2023 |
| 408 | Panhandle Trading Company | Houston, TX 77251-1642 | Oil & Gas Operator | Jun 2003 |
| 409 | Paramount Petroleum Corp | Dallas, TX 75374 | Oil Operator | Dec 2000 |
| 410 | Pardee Production Co. | Skiatook, OK 74070 | Oil & Gas Operator | Mar 2021 |
| 411 | Park Avenue Exploration Corp | Oklahoma City, OK 73102-5604 | Oil & Gas Operator | Sep 2011 |
| 412 | Parker & Parsley Dev LP | Irving, TX 75039-3745 | Oil & Gas Operator | Mar 2015 |
| 413 | Patina Oil & Gas Corporation | Denver, CO 80202 | Oil & Gas Operator | May 2016 |
| 414 | Payne Exploration Company | Crescent, OK 73028-0502 | Oil & Gas Operator | Dec 2023 |
| 415 | PBT Enterprises Inc | Garber, OK 73738-0262 | Oil & Gas Operator | May 2023 |
| 416 | Penn VIrginia MC Operating Co LLC | Houston, TX 77084-7213 | Oil & Gas Operator | Dec 2023 |
| 417 | Pennzoil Company | Midland, TX 79710-0090 | Oil & Gas Operator | Mar 2000 |
| 418 | Pennzoil Explor & Prod Co | Houston, TX 77002 | Oil & Gas Operator | Mar 2000 |
| 419 | Petro Speed Inc | Norman, OK 73069-8116 | Oil & Gas Operator | Mar 2015 |
| 420 | Petrocorp Incorporated | Tulsa, OK 74170 | Oil & Gas Operator | Nov 2021 |
| 421 | Petrohawk Operating Company | Houston, TX 77056 | Oil & Gas Operator | Oct 2021 |
| 422 | Petroleum Investment Inc | Oklahoma City, OK 73118 | Oil & Gas Operator | Nov 1998 |
| 423 | Petroleum Properties MGMT. Co. | Oklahoma City, OK 73118 | Oil & Gas Operator | Dec 2014 |
| 424 | Petromark Energy LLC | Oklahoma City, OK 73116-7634 | Oil & Gas Operator | Jun 2000 |
| 425 | Petroquest Energy, L.L.C. | Lafayette, LA 70505 | Oil & Gas Operator | Apr 2024 |
| 426 | Philcon Development Co. | Amarillo, TX 79101 | Oil & Gas Operator | Sep 2014 |
| 427 | Pioneer Resources Prod LP | Irving, TX 75039-3745 | Oil & Gas Operator | Feb 2005 |
| 428 | Piper Operating LLC | | Oil & Gas Operator | Jan 2024 |
| 429 | Pitco Production Company | Tulsa, OK 74170-2320 | Oil & Gas Operator | May 2013 |
| 430 | Plains Liquids Transport Inc | Houston, TX 77002 | Oil & Gas Operator | May 1996 |
| 431 | Plains Marketing & Trans Inc | Houston, TX 76002 | Oil & Gas Operator | Oct 1998 |
| 432 | Plains Marketing LP | Cushing, OK 74023 | Oil & Gas Operator | Dec 2022 |
| 433 | Plains Resources Inc. | Houston, TX 77002 | Oil & Gas Operator | Jul 2008 |
| 434 | Plymouth Exploration LLC | Tulsa, OK 74119-1031 | Oil & Gas Operator | Jan 2024 |
| 435 | Pogo Producing Company LLC | Houston, TX 77002 | Oil & Gas Operator | Jan 2024 |
| 436 | Powerline Energy Corporation | Arlington, TX 76015 | Oil & Gas Operator | Apr 2024 |
| 437 | Prentice Napier & Green Inc | Oklahoma City, OK 73172-1424 | Oil & Gas Operator | Jan 2024 |
| 438 | Presidio Petroleum LLC | Fort Worth, TX 76102 | Oil & Gas Operator | Apr 2024 |
| 439 | Pride Energy Company | Tulsa, OK 74170 | Oil & Gas Operator | Apr 2024 |
| 440 | Primary Natural Resources III LLC | Tulsa, OK 74136-6351 | Oil & Gas Operator | Jan 2024 |
| 441 | Primary Natural Resources Inc. | Tulsa, OK 74136-6351 | Oil & Gas Operator | Mar 2023 |
| 442 | Primexx Operating Corporation | Dallas, TX 75206 | Oil & Gas Operator | Dec 2023 |
| 443 | Prize Operating Company | Grapevine, TX 76051 | Oil & Gas Operator | Aug 2016 |
| 444 | Prospective Investment & Trading | Scottsdale, AZ 85261-4190 | Oil & Gas Operator | Jun 2016 |
| 445 | Proven Reserves Management, Inc. | Dallas, TX 75370 | Oil & Gas Operator | Jan 2024 |
| 446 | Pyro Energy Corp | Kingwood, TX 77339-2102 | Oil & Gas Operator | Mar 1998 |
| 447 | Qep Energy Company | Midland, TX 79701 | Oil & Gas Operator | Dec 2023 |
| 448 | Quantum Resources Management LLC | Houston, TX 77010 | Oil & Gas Operator | Dec 2023 |
| 449 | Quarles Drilling Corporation | Tulsa, OK 74136 | Oil & Gas Operator | Feb 2008 |
| 450 | Questar Energy Trading | Salt Lake City, UT 84145-0601 | Oil & Gas Operator | Mar 2020 |
| 451 | Questar Explor & Prod Co | Tulsa, OK 74136 | Oil & Gas Operator | Jan 2017 |
| 452 | R C Taylor Operating Company LLC | Oklahoma City, OK 73118 | Oil & Gas Operator | Jan 2024 |
| 453 | R L Clampitt & Associates LLC | Bartlesville, OK 74006-3313 | Oil & Gas Operator | Jan 2024 |
| 454 | Rafter H Operating LLC | El Reno, OK 73036-2714 | Oil & Gas Operator | Jan 2024 |
| 455 | Ramco Oil & Gas Inc | Midland, TX 79701 | Oil & Gas Operator | Nov 2006 |
| 456 | Range Production Company | Fort Worth, TX 76102 | Oil & Gas Operator | Sep 2021 |
| 457 | Range Production Company, LLC | Fort Worth, TX 76102 | Oil & Gas Operator | Dec 2023 |
| 458 | Ratex Resources Inc | Oklahoma City, OK 73118 | Oil & Gas Operator | May 2000 |
| 459 | RB Operating Company | Shawnee, OK 74802-1488 | Oil & Gas Operator | Apr 2015 |
| 460 | Reading & Bates Petroleum Co | Tulsa, OK 74136 | Oil & Gas Operator | Aug 2009 |
| 461 | Red Bluff Resources Operating LLC | | Oil & Gas Operator | Dec 2023 |
| 462 | Red Hawk Disposal LLC | | Oil Operator | Jun 2023 |
| 463 | Red Wolf Operating LLC | | Oil & Gas Operator | Jan 2024 |
| 464 | Redline Energy LLC | | Oil & Gas Operator | Jan 2024 |
| 465 | Republic Energy Inc. | Decatur, TX 76234 | Oil & Gas Operator | Dec 2016 |
| 466 | Reserve Acquisition Group | Tulsa, OK 74153 | Oil & Gas Operator | Dec 1993 |
| 467 | Resolute Wyoming Inc | Denver, CO 80203 | Oil & Gas Operator | May 2018 |
| 468 | Resources Operating Co Inc | Enid, OK 73703-1628 | Oil & Gas Operator | Dec 2023 |
| 469 | Revelation Resources | Cypress, TX 77410-2578 | Oil & Gas Operator | Dec 2023 |
| 470 | Reynolds J W & Associates | Sapulpa, OK 74066 | Oil & Gas Operator | Dec 2000 |
| 471 | Richland Resources Corporation | Oklahoma City, OK 73114 | Oil & Gas Operator | Apr 2024 |
| 472 | Ricks Expl Acquisition Corp | Oklahoma City, OK 73102 | Oil & Gas Operator | Jan 2004 |
| 473 | Ricks Expl Acquisition LLC | Midland, TX 79701 | Oil & Gas Operator | Aug 2013 |
| 474 | Ricks Exploration Co | Oklahoma City, OK 73112 | Oil & Gas Operator | Mar 2015 |
| 475 | Rimrock Resource Operating LLC | | Oil & Gas Operator | Jan 2024 |
| 476 | Riviera Operating, LLC | Houston, TX 77002 | Oil & Gas Operator | Jan 2024 |
| 477 | Rja Energy LLC | | Oil & Gas Operator | Feb 2024 |
| 478 | RKK Production Company | Mustang, OK 73064 | Oil & Gas Operator | Jan 2024 |
| 479 | RMS Monte Christo, LLC | Snowmass VLG., CO 81615 | Oil & Gas Operator | Mar 2023 |
| 480 | Rockwell Energy Corporation | Tulsa, OK 74105 | Oil & Gas Operator | Apr 2014 |
| 481 | Rocky Roads Operating LLC | | Oil & Gas Operator | Jan 2024 |
| 482 | Rosetta Resources Operating LP | San Antonio, TX 78216 | Oil & Gas Operator | Apr 2024 |
| 483 | Royal Oaks Petroleum Corp | Fort Worth, TX 76116 | Oil & Gas Operator | Dec 2001 |
| 484 | RTC Resources, LLP | Weatherford, OK 73096 | Oil & Gas Operator | Apr 2024 |
| 485 | Rupe Oil Company, Inc. | Wichita, KS 67278 | Oil & Gas Operator | Dec 2023 |
| 486 | Rush-Andrus Engineering | Royse City, TX 75189 | Oil & Gas Operator | Feb 2022 |
| 487 | Russell D Meloy Oil & Gas Co | Enid, OK 73703-1623 | Oil & Gas Operator | Jan 2024 |
| 488 | S & G Operating LLC | Kingfisher, OK 73750-0256 | Oil & Gas Operator | Jan 2024 |
| 489 | S & S Oil & Gas Corporation | Okemah, OK 74859-0659 | Oil & Gas Operator | Sep 2014 |
| 490 | S & S Star Operating LLC | | Oil & Gas Operator | Jun 2023 |
| 491 | Sabre Operating, Inc. | Wichita Falls, TX 76308 | Oil & Gas Operator | Apr 2024 |
| 492 | Salty Dog Disposal LLC | | Oil Operator | Feb 2024 |
| 493 | Samedan Oil Corporation | Houston, TX 77067 | Oil & Gas Operator | Dec 2019 |
| 494 | Samson Hydrocarbons Company | Tulsa, OK 74103 | Oil & Gas Operator | Nov 2016 |
| 495 | Samson Resources Company | Tulsa, OK 74103 | Oil & Gas Operator | Feb 2024 |
| 496 | Sandridge Exploration And Production LLC | Oklahoma City, OK 73102 | Oil & Gas Operator | Apr 2024 |
| 497 | Sanguine Gas Exploration, LLC | Tulsa, OK 74119 | Oil & Gas Operator | Apr 2024 |
| 498 | Santa Fe Energy Company | Midland, TX 79701 | Oil & Gas Operator | Dec 2015 |
| 499 | Santa Fe Energy Operating Partner LP | Midland, TX 79701 | Oil & Gas Operator | Sep 2004 |
| 500 | Santa Fe Minerals, Inc. | Dallas, TX 75240 | Oil & Gas Operator | Sep 2013 |