| 401 | Orca Operating Company LLC | Houston, TX 77056 | Oil & Gas Operator | Feb 2024 |
| 402 | Otc Petroleum Corporation | Oklahoma City, OK 73116 | Oil & Gas Operator | Mar 2015 |
| 403 | Ouachita Exploration Inc | Chickasha, OK 73023-0926 | Oil & Gas Operator | Jan 2024 |
| 404 | Ovintiv Mid-Continent Inc. | The Woodlands, TX 77380-2764 | Oil & Gas Operator | Jan 2024 |
| 405 | Oxley Energy LLC | Houston, TX 77042 | Gas Operator | Feb 2024 |
| 406 | Oxley Petroleum | Tulsa, OK 74119-3609 | Oil & Gas Operator | Jan 2020 |
| 407 | Oxley Petroleum Co | Oklahoma City, OK 73118-1044 | Oil & Gas Operator | Sep 2017 |
| 408 | Oxy USA Inc | Houston, TX 77046 | Oil & Gas Operator | Apr 2024 |
| 409 | P O & G Operating LLC | Houston, TX 77057 | Oil & Gas Operator | Apr 2024 |
| 410 | Pacific Enterprise Oil Co USA | Los Angeles, CA 90071-2005 | Oil & Gas Operator | Aug 2012 |
| 411 | Paleo, Inc. | Oklahoma City, OK 73112 | Oil & Gas Operator | Apr 2024 |
| 412 | Paloma Operating Co Inc | | Oil & Gas Operator | Dec 2023 |
| 413 | Paloma Resources, LLC | Houston, TX 77002 | Oil & Gas Operator | Jun 2018 |
| 414 | Palomino Petroleum Inc | Newton, KS 67114 | Oil & Gas Operator | Dec 2023 |
| 415 | Paramount Petroleum Corp | Dallas, TX 75374 | Oil Operator | Dec 2000 |
| 416 | Patina Oil & Gas Corporation | Denver, CO 80202 | Oil & Gas Operator | May 2016 |
| 417 | Patrick Exploration Company | Tulsa, OK 74136 | Oil & Gas Operator | Apr 2011 |
| 418 | Payrock Energy LLC | | Oil & Gas Operator | Feb 2023 |
| 419 | PBT Enterprises Inc | Garber, OK 73738-0262 | Oil & Gas Operator | May 2023 |
| 420 | Pelican Production Company | New Orleans, LA 70130-2477 | Oil & Gas Operator | Mar 2014 |
| 421 | Pengo Petroleum, Inc. | | Oil & Gas Operator | Dec 2013 |
| 422 | Penn VIrginia MC Operating Co LLC | Houston, TX 77084-7213 | Oil & Gas Operator | Feb 2024 |
| 423 | Petrocorp Incorporated | Tulsa, OK 74170 | Oil & Gas Operator | Nov 2021 |
| 424 | Petrohawk Operating Company | Houston, TX 77056 | Oil & Gas Operator | Oct 2021 |
| 425 | Petroleum Development Company | Tulsa, OK 74103 | Oil & Gas Operator | Jan 2024 |
| 426 | Petroleum Explo Prod Inc | Oilton, OK 74052 | Oil & Gas Operator | Jan 2017 |
| 427 | Petroquest Energy, L.L.C. | Lafayette, LA 70505 | Oil & Gas Operator | Apr 2024 |
| 428 | Pinnacle Corporation (The) | Broken Arrow, OK 74012 | Oil & Gas Operator | Nov 2014 |
| 429 | Piper Operating LLC | | Oil & Gas Operator | Feb 2024 |
| 430 | Powell Oil | Healdton, OK 73438-4463 | Oil & Gas Operator | Jan 2024 |
| 431 | Primexx Operating Corporation | Dallas, TX 75206 | Oil & Gas Operator | Jan 2024 |
| 432 | Prize Operating Company | Grapevine, TX 76051 | Oil & Gas Operator | Aug 2016 |
| 433 | Proven Reserves Management, Inc. | Dallas, TX 75370 | Oil & Gas Operator | Jan 2024 |
| 434 | Pryor, VIctor W., Jr. | Holdenville, OK 74848 | Oil & Gas Operator | Apr 2017 |
| 435 | Psec Inc | Tulsa, OK 74102-0871 | Oil & Gas Operator | Dec 2016 |
| 436 | Qep Energy Company | Midland, TX 79701 | Oil & Gas Operator | Jan 2024 |
| 437 | Quality Production Co Of Stigler Inc | Stigler, OK 74462-0635 | Gas Operator | Feb 2013 |
| 438 | Quanah Company | Tulsa, OK 74159-0469 | Oil & Gas Operator | May 2020 |
| 439 | Quantum Resources Management LLC | Houston, TX 77010 | Oil & Gas Operator | Jan 2024 |
| 440 | Quench Oil & Gas Inc | Plano, TX 75075-2902 | Oil & Gas Operator | Apr 2009 |
| 441 | Questar Energy Trading | Salt Lake City, UT 84145-0601 | Oil & Gas Operator | Mar 2020 |
| 442 | Questar Explor & Prod Co | Tulsa, OK 74136 | Oil & Gas Operator | Jan 2017 |
| 443 | Quinton Rental & Repair Serv Inc | Quinton, OK 74561-0432 | Oil & Gas Operator | Mar 2015 |
| 444 | R A Miller Energy Inc | Edmond, OK 73003 | Oil & Gas Operator | Mar 2020 |
| 445 | R C Taylor Operating Company LLC | Oklahoma City, OK 73118 | Oil & Gas Operator | Feb 2024 |
| 446 | Range Production Company | Fort Worth, TX 76102 | Oil & Gas Operator | Sep 2021 |
| 447 | Ranken Energy Corporation | Edmond, OK 73013 | Oil & Gas Operator | Jan 2024 |
| 448 | Ravil Inc | Edmond, OK 73013 | Gas Operator | Nov 1998 |
| 449 | RCK Oil And Gas LLC | | Oil & Gas Operator | Feb 2024 |
| 450 | Red Hawk Disposal LLC | | Oil Operator | Jun 2023 |
| 451 | Red Mountain Operating LLC | | Oil & Gas Operator | Jan 2024 |
| 452 | Red Rocks Oil & Gas Operating LLC | | Oil & Gas Operator | Feb 2024 |
| 453 | Redbud E & P, Inc. | Spring, TX 77379 | Oil & Gas Operator | Apr 2024 |
| 454 | Redwine Resources Inc | Dallas, TX 75225 | Oil & Gas Operator | Feb 2015 |
| 455 | Reid Williams Operating Inc | Shreveport, LA 71106-6223 | Oil & Gas Operator | Jan 2024 |
| 456 | Revere Corporation | Fort Smith, AR 72902-0908 | Oil & Gas Operator | Feb 2015 |
| 457 | Revilo Exploration, Inc. | Richardson, TX 75081 | Oil & Gas Operator | Jul 2021 |
| 458 | Riley Exploration Operating Co LLC | | Gas Operator | Jun 2017 |
| 459 | Rio VIsta Operating LLC | Eufaula, OK 74432-0789 | Gas Operator | Jan 2024 |
| 460 | River City Resources, Inc. | Tulsa, OK 74119 | Oil & Gas Operator | Nov 1997 |
| 461 | Riverfront Exploration LLC | Fort Smith, AR 72901 | Gas Operator | Feb 2024 |
| 462 | Riviera Operating, LLC | Houston, TX 77002 | Oil & Gas Operator | Feb 2024 |
| 463 | RL&B Energy LLC | | Oil & Gas Operator | Feb 2024 |
| 464 | Roberson Oil Company | Houston, TX 77046 | Oil & Gas Operator | Jan 2024 |
| 465 | Rockwell Drilling Company | New York, NY 10013 | Oil & Gas Operator | Dec 2005 |
| 466 | Rosewood Resources, Inc. | Dallas, TX 75201 | Oil & Gas Operator | Apr 2024 |
| 467 | Rover Operating, LLC | Plano, TX 75075 | Oil & Gas Operator | Feb 2024 |
| 468 | Royal Oaks Petroleum Corp | Fort Worth, TX 76116 | Oil & Gas Operator | Dec 2001 |
| 469 | Royalty Petroleum Company | Oklahoma City, OK 73120 | Gas Operator | Feb 2002 |
| 470 | Rush Creek Operating LLC | McKinney, TX 75070 | Oil & Gas Operator | Apr 2024 |
| 471 | S & J Operating Company | Wichita Falls, TX 76301 | Oil & Gas Operator | Mar 2015 |
| 472 | Sabco Operating Company, LLC | Houston, TX 77056 | Oil & Gas Operator | Jun 2018 |
| 473 | Sabre Operating, Inc. | Wichita Falls, TX 76308 | Oil & Gas Operator | Apr 2024 |
| 474 | Salt Plain Pipeline Corp | Edmond, OK 73013 | Oil & Gas Operator | Jun 2010 |
| 475 | Salty Dog Disposal LLC | | Oil Operator | Mar 2024 |
| 476 | Samson Gas Producing Company | Tulsa, OK 74103 | Oil & Gas Operator | May 2001 |
| 477 | Samson Hydrocarbons Company | Tulsa, OK 74103 | Oil & Gas Operator | Nov 2016 |
| 478 | Samson Resources Company | Tulsa, OK 74103 | Oil & Gas Operator | Feb 2024 |
| 479 | San Francisco-Okla Pet Ex Inc | | Oil & Gas Operator | Apr 2014 |
| 480 | Sandra Corporation (The) | Pampa, TX 79066-2474 | Gas Operator | Oct 1996 |
| 481 | Sanguine Gas Exploration, LLC | Tulsa, OK 74119 | Oil & Gas Operator | Apr 2024 |
| 482 | Sanguine Gathering Company | Tulsa, OK 74170 | Oil & Gas Operator | Jul 2018 |
| 483 | Santa Fe Minerals, Inc. | Dallas, TX 75240 | Oil & Gas Operator | Sep 2013 |
| 484 | Santa Fe-Andover Oil Co | Tulsa, OK 74172 | Oil & Gas Operator | Sep 2000 |
| 485 | Scana Exploration Company | Houston, TX 77002 | Oil & Gas Operator | Dec 1999 |
| 486 | Scana Petroleum Resources Inc | Houston, TX 77002 | Oil & Gas Operator | Jun 2013 |
| 487 | Schmid Properties Inc | Hico, TX 76457 | Oil & Gas Operator | Apr 2024 |
| 488 | Seagull Energy E & P Inc | Houston, TX 77002 | Oil & Gas Operator | Jan 2015 |
| 489 | Seagull Mid-South Inc | Houston, TX 77002 | Oil & Gas Operator | Mar 2015 |
| 490 | Seagull Midcon Inc. | Houston, TX 77002 | Oil & Gas Operator | Mar 2015 |
| 491 | Sebep LLC | | Gas Operator | Feb 2024 |
| 492 | Sedna Energy LLC | Blanchard, OK 73010-8043 | Gas Operator | Apr 2017 |
| 493 | Sellmeyer Frank | San Rafael, CA 94901-1339 | Oil Operator | Dec 2014 |
| 494 | Seneca Oil Company | Tulsa, OK 74121-1518 | Oil & Gas Operator | Jan 2015 |
| 495 | Shell Trading Us Company | Houston, TX 77210 | Oil & Gas Operator | Jan 2024 |
| 496 | Sheridan Production Company, LLC | Houston, TX 77056 | Oil & Gas Operator | Jan 2024 |
| 497 | Shidler, Mark L., Inc. | Houston, TX 77055 | Oil & Gas Operator | Apr 2024 |
| 498 | Shields Energy Inc | Fort Smith, AR 72901-4607 | Oil & Gas Operator | Jan 2024 |
| 499 | Shields Operating Inc | Fort Smith, AR 72901-3834 | Oil & Gas Operator | Oct 2021 |
| 500 | Short Oil Co | Luling, TX 78648 | Oil & Gas Operator | Jan 2024 |