| 401 | Pittencrieff America Inc | Abilene, TX 79608 | Oil & Gas Operator | Feb 2003 |
| 402 | Plains Marketing LP | Cushing, OK 74023 | Oil & Gas Operator | Dec 2022 |
| 403 | Plains Petroleum Operating Co | Denver, CO 80202 | Oil & Gas Operator | Dec 2014 |
| 404 | Plains Production Inc | Wichita Falls, TX 76308 | Oil & Gas Operator | Dec 1995 |
| 405 | Plantation Operating, LLC | Houston, TX 77041 | Oil & Gas Operator | Nov 2011 |
| 406 | Price, W. H. | Granbury, TX 76048 | Oil & Gas Operator | Feb 2024 |
| 407 | Pride Energy Company | Tulsa, OK 74170 | Oil & Gas Operator | Apr 2024 |
| 408 | Prize Operating Company | Grapevine, TX 76051 | Oil & Gas Operator | Aug 2016 |
| 409 | Pro- Gas, Inc. | Midland, TX 79711 | Oil & Gas Operator | Apr 2024 |
| 410 | Production Operators Of TX, LLC | Abilene, TX 79605 | Oil & Gas Operator | Apr 2024 |
| 411 | Progas Properties, Inc. | New Braunfels, TX 78132 | Oil & Gas Operator | Apr 2024 |
| 412 | Prospctv Invstmnt & TRDG Co, LTD | Tulsa, OK 74170 | Oil & Gas Operator | May 2001 |
| 413 | Purvis, J. H. | Midland, TX 79702 | Oil & Gas Operator | Dec 1994 |
| 414 | Quail Operating, Inc. | Abilene, TX 79601 | Oil & Gas Operator | Apr 2024 |
| 415 | Quail Well Service, Inc. | Abilene, TX 79604 | Oil & Gas Operator | Apr 2024 |
| 416 | Quantum Investments | Lubbock, TX 79424 | Oil Operator | Apr 2024 |
| 417 | Quantum Resources Management LLC | Houston, TX 77010 | Oil & Gas Operator | Jan 2024 |
| 418 | R & P Operating | Tuscola, TX 79562 | Oil & Gas Operator | Jun 1997 |
| 419 | Radtke, D.E. & Associates, Inc. | Midland, TX 79710 | Oil & Gas Operator | May 2004 |
| 420 | Rainey, Wayne | Sweetwater, TX 79556 | Oil & Gas Operator | Feb 2019 |
| 421 | Rampart Petroleum, Incorporated | Buffalo Gap, TX 79508 | Oil & Gas Operator | Jan 2009 |
| 422 | Rand Oil & Gas Corp. | Houston, TX 77040 | Oil & Gas Operator | Apr 2024 |
| 423 | Range Production Company | Fort Worth, TX 76102 | Oil & Gas Operator | Sep 2021 |
| 424 | Ranphil, LLC | Hiltn Head Is, SC 29928 | Oil & Gas Operator | Feb 2016 |
| 425 | Raptor Petroleum II, LLC | Houston, TX 77251 | Oil & Gas Operator | Apr 2024 |
| 426 | Raymond, WM. C. | Rockdale, TX 76567 | Oil & Gas Operator | Apr 2024 |
| 427 | Red Water Resources, Inc. | Tulsa, OK 74159 | Oil & Gas Operator | Apr 2024 |
| 428 | Red-Tex Energy Services, Inc. | Abilene, TX 79608 | Oil & Gas Operator | Nov 2000 |
| 429 | Red-Tex Petroleum, Inc. | Abilene, TX 79608 | Oil & Gas Operator | Aug 2003 |
| 430 | Redbud E & P, Inc. | Spring, TX 77379 | Oil & Gas Operator | Apr 2024 |
| 431 | Reflection Energy Search, Inc | Midland, TX 79702 | Oil Operator | Feb 2006 |
| 432 | Regent Oil & Gas Company, L.P. | Dallas, TX 75225 | Oil & Gas Operator | Sep 2006 |
| 433 | Reichmann Petroleum Corp. | Grapevine, TX 76051 | Oil & Gas Operator | Apr 2024 |
| 434 | Rendova Oil Company, Inc. | Midland, TX 79702 | Oil & Gas Operator | Oct 2002 |
| 435 | RHB Exploration & Production,LLC | Grapevine, TX 76099 | Oil & Gas Operator | Apr 2024 |
| 436 | Richardson, Bud II | Graham, TX 76450 | Oil & Gas Operator | Apr 2024 |
| 437 | Richman Petroleum Corp. | Grapevine, TX 76051 | Oil & Gas Operator | Jul 2006 |
| 438 | Riley Production | Throckmorton, TX 76483 | Oil & Gas Operator | Apr 2024 |
| 439 | Rio-Tex, Inc. | San Antonio, TX 78217 | Oil & Gas Operator | Apr 2024 |
| 440 | RMB Operating LLC | Houston, TX 77269 | Oil & Gas Operator | Apr 2024 |
| 441 | Ro-Jo, Inc. | Highland VLG, TX 75077 | Oil & Gas Operator | Aug 2003 |
| 442 | Robertson Resources, Inc. | Midland, TX 79708 | Oil & Gas Operator | Apr 2024 |
| 443 | Robertson, French M. Oil Co. | Abilene, TX 79608 | Oil & Gas Operator | Mar 1995 |
| 444 | Rodessa Operating Company | Corpus Chrsti, TX 78426 | Oil & Gas Operator | Apr 2024 |
| 445 | Roff Operating Company LLC | Houston, TX 77002 | Oil & Gas Operator | Apr 2024 |
| 446 | Rover Petroleum Operating, LLC | Plano, TX 75075 | Oil & Gas Operator | Apr 2024 |
| 447 | Rust Oil Corp. | Fort Worth, TX 76108 | Oil & Gas Operator | Apr 2024 |
| 448 | S & J Operating Company | Wichita Falls, TX 76301 | Oil & Gas Operator | Mar 2015 |
| 449 | S & R Operating | Merkel, TX 79536 | Oil & Gas Operator | Mar 2008 |
| 450 | Saber Resources, LLC | Midland, TX 79701 | Oil & Gas Operator | Aug 2008 |
| 451 | Sams Energy, Inc. | Abilene, TX 79604 | Oil & Gas Operator | May 1998 |
| 452 | Samson Hydrocarbons Company | Tulsa, OK 74103 | Oil & Gas Operator | Nov 2016 |
| 453 | Samson Lone Star LP | Tulsa, OK 74103 | Oil & Gas Operator | Jun 2007 |
| 454 | Samson Lone Star, LLC | Tulsa, OK 74103 | Oil & Gas Operator | Apr 2024 |
| 455 | Samson Resources Company | Tulsa, OK 74103 | Oil & Gas Operator | Feb 2024 |
| 456 | Santa Fe Energy Oper. Part., LP | Houston, TX 77057 | Oil & Gas Operator | Dec 1994 |
| 457 | Savannah Ross And Company, LLC | Graham, TX 76450 | Oil & Gas Operator | Apr 2024 |
| 458 | Schlagal, Inc. | Midland, TX 79702 | Oil & Gas Operator | Oct 2016 |
| 459 | Scout Energy Management LLC | Dallas, TX 75240 | Oil & Gas Operator | Apr 2024 |
| 460 | Scythian, LTD. | Midland, TX 79701 | Oil & Gas Operator | Dec 2020 |
| 461 | SD Royale Energy, Inc. | San Diego, CA 92159 | Oil & Gas Operator | Apr 2024 |
| 462 | Sensor Oil & Gas Inc | Duncan, OK 73534 | Oil & Gas Operator | May 2013 |
| 463 | Sequoia Natural Gas, Inc. | Albany, TX 76430 | Oil & Gas Operator | Apr 2024 |
| 464 | Ser E&P, Inc. | McKinney, TX 75069 | Oil & Gas Operator | Apr 2024 |
| 465 | Seven Falls Company | Dallas, TX 75201 | Oil & Gas Operator | May 2008 |
| 466 | Sha-Jam Operating Corp. | Midland, TX 79701 | Oil & Gas Operator | Apr 2024 |
| 467 | Shaida, John H. | Wichita, KS 67226 | Oil & Gas Operator | Apr 2024 |
| 468 | Sharp Image Energy, Inc. | Big Spring, TX 79721 | Oil & Gas Operator | Apr 2024 |
| 469 | Sharpe Energy Company | Conroe, TX 77305 | Oil & Gas Operator | Mar 2008 |
| 470 | Shenandoah Petroleum Corporation | Midland, TX 79705 | Oil & Gas Operator | Apr 2024 |
| 471 | Sheridan Production Company, LLC | Houston, TX 77056 | Oil & Gas Operator | Jan 2024 |
| 472 | Shifflett Operating Company | Snyder, TX 79550 | Oil & Gas Operator | Apr 2024 |
| 473 | Shiloh Oil Company LLC | Williston, FL 32696 | Oil & Gas Operator | Apr 2024 |
| 474 | Shinnery Oil Company, Inc. | Midland, TX 79701 | Oil & Gas Operator | Apr 2024 |
| 475 | Sidwell Oil & Gas, Inc. | Amarillo, TX 79105 | Oil & Gas Operator | Sep 2014 |
| 476 | Silver Pines Energy Corp. | Houston, TX 77005 | Oil & Gas Operator | Feb 2024 |
| 477 | Sinclair Exploration Company | Abilene, TX 79604 | Oil & Gas Operator | Nov 1998 |
| 478 | Sinclair Oil & Gas Company | Salt Lake Cty, UT 84130 | Oil & Gas Operator | Apr 2024 |
| 479 | Sinclair Oil Corporation | Salt Lake Cty, UT 84130 | Oil & Gas Operator | Aug 2006 |
| 480 | Smith Pipe Of Abilene | Abilene, TX 79608 | Oil & Gas Operator | Apr 2024 |
| 481 | Sojourner Drilling Corporation | Abilene, TX 79604 | Oil & Gas Operator | Apr 2024 |
| 482 | Sounion Petroleum Incorporated | Baltimore, MD 21218 | Oil & Gas Operator | Aug 1994 |
| 483 | Southern Mineral Corporation | Houston, TX 77002 | Oil & Gas Operator | Oct 2001 |
| 484 | Southern Tejas Asset Group LLC | McAllen, TX 78501 | Oil & Gas Operator | Apr 2024 |
| 485 | Southern Union Exploration Co. | Austin, TX 78701 | Oil & Gas Operator | Feb 2002 |
| 486 | Southland Royalty Company | Houston, TX 77210 | Oil & Gas Operator | Sep 2011 |
| 487 | Southwest Royalties Inc | Midland, TX 79710 | Oil & Gas Operator | Apr 2024 |
| 488 | Southwestern Energy Prod Co | Houston, TX 77032 | Oil & Gas Operator | Jun 2015 |
| 489 | Spartan Oil Corporation | Abilene, TX 79601 | Oil & Gas Operator | Aug 2003 |
| 490 | Special JHR Corp | Bridgeville, PA 15017 | Oil & Gas Operator | Apr 2024 |
| 491 | Spectrum Resources LLC | Charlotte, NC 28211-4081 | Oil Operator | Oct 2009 |
| 492 | Spence Energy Company | Dallas, TX 75206 | Oil & Gas Operator | Apr 2024 |
| 493 | Spenergy Corp. | Midland, TX 79701 | Oil & Gas Operator | Dec 1999 |
| 494 | Spheric Petroleum Inc. | Baltimore, MD 21208 | Oil & Gas Operator | Nov 2006 |
| 495 | Spiller Operating Co., Inc. | Round Rock, TX 78665 | Oil & Gas Operator | May 2015 |
| 496 | SRG Oil Corporation | Abilene, TX 79604 | Oil & Gas Operator | Apr 1994 |
| 497 | SSC, Inc. | Lubbock, TX 79408 | Oil & Gas Operator | Apr 2024 |
| 498 | St. Clair Energy Corporation | Tulsa, OK 74153 | Oil & Gas Operator | Mar 2008 |
| 499 | Staghorn Resources, LLC | Tulsa, OK 74103 | Oil & Gas Operator | Apr 2015 |
| 500 | Staley Oil Company | Wichita Falls, TX 76308 | Oil & Gas Operator | Jan 2000 |