| 501 | Petromark Energy LLC | Oklahoma City, OK 73116-7634 | Oil & Gas Operator | Jun 2000 |
| 502 | Petroplex Energy Inc. | Midland, TX 79702 | Oil & Gas Operator | Apr 2025 |
| 503 | Petroplex Equipment, Inc. | Midland, TX 79701 | Oil & Gas Operator | May 2019 |
| 504 | Petrosource Production Co. L.P. | Midland, TX 79701 | Oil & Gas Operator | Nov 2007 |
| 505 | Petrosource Production Co., LLC | Midland, TX 79705 | Oil & Gas Operator | Apr 2025 |
| 506 | Phillips 66 Company | Bartlesville, OK 74004 | Oil & Gas Operator | Aug 1997 |
| 507 | Phillips Petroleum Company | Houston, TX 77251 | Oil & Gas Operator | Mar 2013 |
| 508 | Piedra Operating, LLC | Denver, CO 80202 | Oil & Gas Operator | May 2023 |
| 509 | Pierce Production Company | Eunice, NM 88231 | Oil & Gas Operator | Oct 2012 |
| 510 | Pierce Production Company, LLC | Midland, TX 79702 | Oil & Gas Operator | Apr 2025 |
| 511 | Pierce, Ray A. | Eunice, NM 88231 | Oil & Gas Operator | Nov 2004 |
| 512 | Pioneer Natural Res. USA, Inc. | Irving, TX 75038 | Oil & Gas Operator | Apr 2025 |
| 513 | Pitts Energy Co. | Midland, TX 79707 | Oil & Gas Operator | Apr 2025 |
| 514 | Plains Marketing LP | Cushing, OK 74023 | Oil & Gas Operator | Dec 2022 |
| 515 | Plains Petroleum Operating Co | Denver, CO 80202 | Oil & Gas Operator | Dec 2014 |
| 516 | Plains Production Inc | Wichita Falls, TX 76308 | Oil & Gas Operator | Dec 1995 |
| 517 | Plantation Operating, LLC | Houston, TX 77041 | Oil & Gas Operator | Nov 2011 |
| 518 | Platform Operating, LLC | Midland, TX 79702 | Oil & Gas Operator | Apr 2025 |
| 519 | Platinum Exploration Inc. | Midland, TX 79701 | Oil & Gas Operator | Apr 2025 |
| 520 | Pogo Panhandle 2004, L.P. | Houston, TX 77002 | Oil & Gas Operator | Oct 2017 |
| 521 | Ponderosa Petroleum, Inc. | Brownfield, TX 79316 | Oil & Gas Operator | Apr 2025 |
| 522 | PPC Operating Company LLC | Houston, TX 77279 | Oil & Gas Operator | Jul 2019 |
| 523 | Prasad, Hari Production Co. | Midland, TX 79701 | Oil & Gas Operator | Apr 2025 |
| 524 | Pride Energy Company | Tulsa, OK 74170 | Oil & Gas Operator | Apr 2025 |
| 525 | Prime Operating Company | Houston, TX 77024 | Oil & Gas Operator | Apr 2025 |
| 526 | Primero Operating, Inc. | Roswell, NM 88202 | Oil & Gas Operator | Jun 2022 |
| 527 | Prize Operating Company | Grapevine, TX 76051 | Oil & Gas Operator | Aug 2016 |
| 528 | Probity Operating, LLC | Midland, TX 79708 | Oil & Gas Operator | Jul 2014 |
| 529 | Pronghorn Management Corporation | Hobbs, NM 88241 | Oil & Gas Operator | Apr 2025 |
| 530 | Pure Resources, L.P. | Midland, TX 79701 | Oil & Gas Operator | Mar 2006 |
| 531 | Q Natural Resources, LLC | Jones, OK 73049 | Oil & Gas Operator | Apr 2025 |
| 532 | Qep Energy Company | Midland, TX 79701 | Oil & Gas Operator | Jan 2025 |
| 533 | Qualia, C. F. Operating,Inc. | Midland, TX 79702 | Oil & Gas Operator | Aug 2013 |
| 534 | Quantum Resources Management LLC | Houston, TX 77010 | Oil & Gas Operator | Jan 2025 |
| 535 | Quay Valley, Inc. | Midland, TX 79710 | Oil & Gas Operator | Oct 2007 |
| 536 | Questa Oil & Gas Co. | Tulsa, OK 74170 | Oil & Gas Operator | Mar 2015 |
| 537 | Questar Expl. And Prod. Co. | Salt Lake Cty, UT 84145 | Oil & Gas Operator | Jul 2011 |
| 538 | R K Petroleum Corp. | Midland, TX 79708 | Oil & Gas Operator | May 2024 |
| 539 | Ram Operating Inc. | Browns, IL 62818 | Oil & Gas Operator | Aug 2008 |
| 540 | Ramtex Energy LLC | Tulsa, OK 74114 | Oil & Gas Operator | Apr 2025 |
| 541 | Rand - Paulson Oil Company, Inc. | Houston, TX 77063 | Oil & Gas Operator | Feb 1999 |
| 542 | Rand Oil & Gas Corp. | Houston, TX 77040 | Oil & Gas Operator | Apr 2025 |
| 543 | Range Production Company | Fort Worth, TX 76102 | Oil & Gas Operator | Sep 2021 |
| 544 | Ranger 40 Petroleum, LLC | Fairfield, CT 06824 | Oil & Gas Operator | Apr 2025 |
| 545 | Rasmussen, Hal J. Operating, Inc | Midland, TX 79701 | Oil & Gas Operator | Apr 2009 |
| 546 | Raven Resources LLC | Oklahoma City, OK 73172 | Oil & Gas Operator | Jan 2025 |
| 547 | Raw Oil & Gas, Inc. | Lubbock, TX 79401 | Oil & Gas Operator | Apr 2025 |
| 548 | Rayden | Midland, TX 79711 | Oil & Gas Operator | Apr 2025 |
| 549 | Read & Stevens, Inc. | Denver, CO 80202 | Oil & Gas Operator | Jul 2023 |
| 550 | Red River Oil & Gas LLC | Cherry Hills, CO 80110 | Oil & Gas Operator | Feb 2025 |
| 551 | Redmon Oil Company, Inc., The | Plano, TX 75023 | Oil & Gas Operator | Apr 2025 |
| 552 | Redstone Oil & Gas Company | Dallas, TX 75225 | Oil & Gas Operator | Jan 2020 |
| 553 | Redwood Operating, Inc. | Houston, TX 77058 | Oil & Gas Operator | Apr 2025 |
| 554 | Reef Exploration, Inc. (A-1) | Richardson, TX 75080 | Oil & Gas Operator | Oct 2006 |
| 555 | Reeves County Systems, Inc. | Odessa, TX 79760 | Oil & Gas Operator | Aug 2019 |
| 556 | Regency Petroleum Co. Of New Mex | Coppell, TX 75019 | Oil & Gas Operator | Apr 2008 |
| 557 | Regent Oil & Gas Company, L.P. | Dallas, TX 75225 | Oil & Gas Operator | Sep 2006 |
| 558 | Rein Pusher Operating LLC | Brenham, TX 77834 | Oil & Gas Operator | Apr 2025 |
| 559 | Reliance Energy, Inc. | Midland, TX 79701 | Oil & Gas Operator | Apr 2025 |
| 560 | Remnant Oil Operating, LLC | Midland, TX 79704 | Oil & Gas Operator | Jul 2024 |
| 561 | Remuda Operating Company | Midland, TX 79711 | Oil & Gas Operator | Apr 2025 |
| 562 | Rendova Oil Company, Inc. | Midland, TX 79702 | Oil & Gas Operator | Oct 2002 |
| 563 | Reo Operating LLC | Austin, TX 78747 | Oil & Gas Operator | Apr 2025 |
| 564 | Reverence Operating LLC | Odessa, TX 79768 | Oil & Gas Operator | Apr 2025 |
| 565 | RGX Energy LLC | Plano, TX 75025 | Oil & Gas Operator | Oct 2019 |
| 566 | Rhonda Operating Company | Midland, TX 79710 | Oil & Gas Operator | Aug 2017 |
| 567 | Riata Energy Inc | Oklahoma City, OK 73101 | Oil & Gas Operator | Apr 2008 |
| 568 | Richland Resources Corporation | Oklahoma City, OK 73114 | Oil & Gas Operator | Apr 2025 |
| 569 | Rim Operating, Inc. | Englewood, CO 80112 | Oil & Gas Operator | Apr 2025 |
| 570 | Ring Energy, Inc. | Midland, TX 79702 | Oil & Gas Operator | Apr 2025 |
| 571 | Rio Petroleum, Inc. | Amarillo, TX 79102 | Oil & Gas Operator | Apr 2025 |
| 572 | Robertson Resources, Inc. | Midland, TX 79708 | Oil & Gas Operator | Apr 2025 |
| 573 | Roca Operating, Inc. | Midland, TX 79702 | Oil & Gas Operator | Apr 2025 |
| 574 | Roca Resource Company, Inc. | Midland, TX 79702 | Oil & Gas Operator | Mar 2008 |
| 575 | Rock Fish Operating LLC | McKinney, TX 75070 | Oil & Gas Operator | Apr 2025 |
| 576 | Roff Operating Company LLC | Houston, TX 77002 | Oil & Gas Operator | Apr 2025 |
| 577 | Rogers, S. K. Oil, Inc. | Lubbock, TX 79424 | Oil & Gas Operator | Apr 2025 |
| 578 | Ronning Gas And Oil LLC | Mesa, AZ 85203 | Oil & Gas Operator | Apr 2025 |
| 579 | Roy Jackson Energy Operating, LLC | Midland, TX 79701 | Oil & Gas Operator | Apr 2025 |
| 580 | Rust Oil Corp. | Fort Worth, TX 76108 | Oil & Gas Operator | Apr 2025 |
| 581 | S & J Operating Company | Wichita Falls, TX 76301 | Oil & Gas Operator | Mar 2015 |
| 582 | S & M Drilling, LLC | Wichita Falls, TX 76308 | Oil Operator | Sep 2023 |
| 583 | Sabinal Energy Operating, LLC | The Woodlands, TX 77380 | Oil & Gas Operator | Apr 2025 |
| 584 | Saga Pet. LTD Liability Co Of Co | Midland, TX 79701 | Oil & Gas Operator | Apr 2004 |
| 585 | Saga Petroleum LLC Of Colorado | Norman, OK 73072 | Oil & Gas Operator | Apr 2025 |
| 586 | Sage Energy Company | San Antonio, TX 78215 | Oil & Gas Operator | Apr 2025 |
| 587 | Sahara Operating Company | Midland, TX 79704 | Oil & Gas Operator | Apr 2025 |
| 588 | Samedan Oil Corporation | Houston, TX 77067 | Oil & Gas Operator | Dec 2019 |
| 589 | Samson Lone Star, LLC | Tulsa, OK 74103 | Oil & Gas Operator | Apr 2025 |
| 590 | Samson Resources Company | Tulsa, OK 74103 | Oil & Gas Operator | Jan 2025 |
| 591 | Sanchez-O'Brien Oil & Gas Corp | Houston, TX 77057 | Oil & Gas Operator | May 1998 |
| 592 | Sandridge Exploration And Production LLC | Oklahoma City, OK 73104 | Oil & Gas Operator | Apr 2025 |
| 593 | Sandridge Tertiary, LLC | Midland, TX 79701 | Oil & Gas Operator | Jul 2012 |
| 594 | Santa Fe Energy Oper. Part., LP | Houston, TX 77057 | Oil & Gas Operator | Dec 1994 |
| 595 | Santa Fe Energy Resources, Inc. | Houston, TX 77024 | Oil & Gas Operator | Mar 2008 |
| 596 | Santa Fe Snyder Corporation | Houston, TX 77024 | Oil & Gas Operator | Oct 2000 |
| 597 | Sapient Energy Corp | Oklahoma City, OK 73154 | Oil & Gas Operator | Jan 2002 |
| 598 | Satanta Oil Company | Midland, TX 79704 | Oil & Gas Operator | Apr 2025 |
| 599 | Schlachter Operating Corporation | Dallas, TX 75225 | Oil & Gas Operator | Apr 2025 |
| 600 | Schmid Properties Inc | Hico, TX 76457 | Oil & Gas Operator | Apr 2025 |