| 401 | Petrogen, Incorporated | Katy, TX 77450 | Oil & Gas Operator | Jan 2012 |
| 402 | Petroglyph Operating Co | Boise, ID 83709 | Oil & Gas Operator | Jul 2017 |
| 403 | Petrogulf Corporation | Denver, CO 80202 | Oil & Gas Operator | Apr 2025 |
| 404 | Petrohawk Energy Corporation | Houston, TX 77002 | Oil & Gas Operator | Jun 2005 |
| 405 | Petrohawk Operating Company | Houston, TX 77056 | Oil & Gas Operator | Oct 2021 |
| 406 | Petrol Industries, Inc. | Shreveport, LA 71137 | Oil & Gas Operator | Jun 2012 |
| 407 | Petrolegacy Energy II, LLC | Denver, CO 80202 | Oil & Gas Operator | Jun 2023 |
| 408 | Petrolero Corp. | San Antonio, TX 78205 | Oil & Gas Operator | Feb 1998 |
| 409 | Petrolero, LLC | Plano, TX 75026 | Oil & Gas Operator | Apr 2025 |
| 410 | Petroleum Advisors Int'L., Inc. | Houston, TX 77224 | Gas Operator | Jun 2005 |
| 411 | Petroleum Capital, L.C. | Dallas, TX 75367 | Oil & Gas Operator | Apr 2025 |
| 412 | Petroleum Inc | Wichita, KS 67202 | Oil & Gas Operator | Oct 2021 |
| 413 | Petroleum International, Inc. | Tulsa, OK 74103 | Oil & Gas Operator | Feb 2000 |
| 414 | Petroleum Investments, Inc | Shreveport, LA 71101 | Oil & Gas Operator | Dec 1977 |
| 415 | Petroleum Land Company | Abilene, TX 79606 | Oil & Gas Operator | May 2000 |
| 416 | Petroleum Management Int'L, Inc. | Sugar Land, TX 77487 | Oil & Gas Operator | Oct 1993 |
| 417 | Petroleum Management, Inc. | Corpus Chrsti, TX 78471 | Oil & Gas Operator | Apr 2025 |
| 418 | Petroleum Production Engineering | Fulton, TX 78358 | Oil Operator | Feb 2019 |
| 419 | Petroleum Production MGMT., Inc. | Kansas City, MO 64112 | Oil & Gas Operator | Apr 2025 |
| 420 | Petroleum Properties MGMT Co LLC | Oklahoma City, OK 73118 | Oil & Gas Operator | Aug 2005 |
| 421 | Petroleum Properties MGMT. Co. | Oklahoma City, OK 73118 | Oil & Gas Operator | Dec 2014 |
| 422 | Petroleum Property MGMT, Inc (A) | Fort Worth, TX 76101 | Oil & Gas Operator | May 1994 |
| 423 | Petroleum Recovery Systems, L.C. | Houston, TX 77024 | Oil Operator | Apr 2025 |
| 424 | Petroleum Reserve Corporation | Plymouth MTNG, PA 19462 | Oil & Gas Operator | May 2008 |
| 425 | Petroleum Resource Management Co | Fort Worth, TX 76107 | Oil & Gas Operator | Jan 2024 |
| 426 | Petroleum Technical Services Co. | Midland, TX 79707 | Oil & Gas Operator | Dec 2004 |
| 427 | Petrolia Energy Corporation | Pearland, TX 77581 | Oil Operator | Jan 2024 |
| 428 | Petrolia Group, L.L.C. | Katy, TX 77449 | Oil & Gas Operator | Apr 2025 |
| 429 | Petromac, Inc. | Onalaska, TX 77360 | Oil & Gas Operator | Apr 2025 |
| 430 | Petromark Energy LLC | Oklahoma City, OK 73116-7634 | Oil & Gas Operator | Jun 2000 |
| 431 | Petromining, Inc. | Plano, TX 75026 | Oil & Gas Operator | Apr 2025 |
| 432 | Petron Energy Inc | Dallas, TX 75252 | Oil & Gas Operator | Apr 2025 |
| 433 | Petron Oil Company | Missouri City, TX 77489 | Oil & Gas Operator | Apr 2025 |
| 434 | Petroneal Corporation | San Angelo, TX 76902 | Oil & Gas Operator | Nov 1995 |
| 435 | Petronomics Petroleum, Inc. | Austin, TX 78734 | Oil & Gas Operator | Jan 1995 |
| 436 | Petronomics, Inc. | Houston, TX 77074 | Oil & Gas Operator | Aug 2003 |
| 437 | Petroplex Energy Inc. | Midland, TX 79702 | Oil & Gas Operator | Apr 2025 |
| 438 | Petroplex Equipment, Inc. | Midland, TX 79701 | Oil & Gas Operator | May 2019 |
| 439 | Petropoint Energy Operating, LLC | Houston, TX 77098 | Oil & Gas Operator | Apr 2025 |
| 440 | Petropro Energy Partners, L.P. | Houston, TX 77024 | Oil & Gas Operator | Jan 2013 |
| 441 | Petroquest Energy, Inc. | Lafayette, LA 70505 | Oil & Gas Operator | Feb 2001 |
| 442 | Petroquest Energy, L.L.C. | Lafayette, LA 70505 | Oil & Gas Operator | Apr 2025 |
| 443 | Petroquest Exploration, Inc. | Dallas, TX 75251 | Oil & Gas Operator | Mar 2008 |
| 444 | Petroreal Inc. | Temple, TX 76503 | Oil & Gas Operator | Apr 2025 |
| 445 | Petrosaurus, Inc. | Somerset, TX 78069 | Oil Operator | Apr 2025 |
| 446 | Petrosearch Operating Co, LLC | Denver, CO 80202 | Oil & Gas Operator | Apr 2025 |
| 447 | Petrosource Energy Corporation | Fort Worth, TX 76112 | Oil & Gas Operator | Apr 2025 |
| 448 | Petrosource Production Co. L.P. | Midland, TX 79701 | Oil & Gas Operator | Nov 2007 |
| 449 | Petrosource Production Co., LLC | Midland, TX 79705 | Oil & Gas Operator | Apr 2025 |
| 450 | Petrotex Engineering Company | Cypress, TX 77429 | Oil & Gas Operator | Apr 2025 |
| 451 | Petrotex, Inc. | Abilene, TX 79604 | Oil & Gas Operator | Aug 2003 |
| 452 | Petrotx Operating, LLC | Kingwood, TX 77339 | Oil & Gas Operator | Apr 2025 |
| 453 | Petrox Resources Inc | Meeker, CO 81641 | Oil & Gas Operator | Mar 2025 |
| 454 | Petx Operating LLC | Sheridan, WY 82801 | Oil Operator | Apr 2025 |
| 455 | PF Operating Company | Wichita Falls, TX 76302 | Oil & Gas Operator | Aug 2003 |
| 456 | Pfed Operating | Keller, TX 76248 | Oil Operator | Apr 2025 |
| 457 | Pfog Operations, LLC | Midland, TX 79710 | Oil Operator | Apr 2025 |
| 458 | PG&E Resources Company | Houston, TX 77042 | Oil & Gas Operator | May 1995 |
| 459 | PG&E Resources Offshore Company | Dallas, TX 75206 | Oil & Gas Operator | Oct 1994 |
| 460 | PG-M International Operating,LLC | Borger, TX 79008 | Oil & Gas Operator | Apr 2025 |
| 461 | Pgi Operating, LLC | Sweetwater, TX 79556 | Oil Operator | Apr 2025 |
| 462 | Pgo, Inc. | Houston, TX 77042 | Oil & Gas Operator | Jun 1999 |
| 463 | PH Exploration, Inc. | Houston, TX 77008 | Oil & Gas Operator | Nov 2001 |
| 464 | Pharaoh & Associates, Inc. | Houston, TX 77252 | Oil & Gas Operator | Aug 2002 |
| 465 | Pharaoh Oil & Gas, Inc. | MC Camey, TX 79752 | Oil & Gas Operator | Apr 2025 |
| 466 | Pheffer Oil, L.L.C. | Laredo, TX 78041 | Oil Operator | Jul 2021 |
| 467 | Phere Operating Inc | Spring Branch, TX 78070 | Oil & Gas Operator | Apr 2025 |
| 468 | Philcon Development Co. | Amarillo, TX 79101 | Oil & Gas Operator | Sep 2014 |
| 469 | Phillips & Pierson | Olney, TX 76374 | Oil & Gas Operator | Nov 1995 |
| 470 | Phillips 66 Company | Bartlesville, OK 74004 | Oil & Gas Operator | Aug 1997 |
| 471 | Phillips Energy, Inc. | Shreveport, LA 71101 | Oil & Gas Operator | Dec 2018 |
| 472 | Phillips Operating Co. | Mineral Wells, TX 76067 | Oil & Gas Operator | Jan 2013 |
| 473 | Phillips Petroleum Company | Houston, TX 77251 | Oil & Gas Operator | Mar 2013 |
| 474 | Phillips, B. F. Jr., Estate Of | Dallas, TX 75201 | Oil & Gas Operator | Mar 2011 |
| 475 | Phillips, Bob | Weatherford, TX 76086 | Oil & Gas Operator | Nov 2019 |
| 476 | Phillips, Jack L. | Gladewater, TX 75647 | Oil & Gas Operator | Dec 1997 |
| 477 | Phillips, Jack L. Co. | Gladewater, TX 75647 | Oil & Gas Operator | Apr 2025 |
| 478 | Phillips, Ken | San Angelo, TX 76904 | Oil & Gas Operator | Jun 2021 |
| 479 | Philmar | Houston, TX 77269 | Oil Operator | Apr 2025 |
| 480 | Philpott Oil & Gas Co Inc | Atwood, KS 67730 | Oil Operator | Aug 2010 |
| 481 | Phoenix Crude Oil Company | Westbrook, TX 79565 | Oil Operator | Oct 2004 |
| 482 | Phoenix Fund, Inc. | San Antonio, TX 78217 | Oil & Gas Operator | Jun 2000 |
| 483 | Phoenix Hydrocarbons Operating | Midland, TX 79702 | Oil & Gas Operator | Jun 2024 |
| 484 | Phoenix Oil & Gas | Kyle, TX 78640 | Oil & Gas Operator | Apr 2025 |
| 485 | Phoenix Oil & Gas LTD., L.L.P. | Houston, TX 77010 | Oil & Gas Operator | Jun 2004 |
| 486 | Phoenix Oil & Gas, Inc. (A) | Canada, 00100 | Oil & Gas Operator | Oct 2005 |
| 487 | Phoenix Operating Company Of TX. | Dallas, TX 75206 | Oil & Gas Operator | Jun 1995 |
| 488 | Phoenix Operating Company, Inc. | Shreveport, LA 71161 | Oil & Gas Operator | Mar 2015 |
| 489 | Phoenix Petrocorp, Inc. | McKinney, TX 75070 | Oil & Gas Operator | Feb 2025 |
| 490 | Phoenix Resources LLC | Longview, TX 75604 | Oil & Gas Operator | Jul 2022 |
| 491 | Phylko Energy Corporation | Houston, TX 77056 | Oil & Gas Operator | Aug 2003 |
| 492 | Pi Energy, Inc. | Wichita Falls, TX 76301 | Oil & Gas Operator | Apr 2025 |
| 493 | Pickens Company, Inc., The | Dallas, TX 75225 | Oil & Gas Operator | Jul 2024 |
| 494 | Pickett Oil Co. | Gonzales, TX 78629 | Oil & Gas Operator | Oct 2019 |
| 495 | Pickett, D. W. | Corpus Chrsti, TX 78403 | Oil & Gas Operator | Sep 2004 |
| 496 | Picosa, L.L.C. | Carrizo SPGS, TX 78834 | Oil & Gas Operator | Apr 2025 |
| 497 | Pie Operating, LLC | The Woodlands, TX 77380 | Oil & Gas Operator | Apr 2025 |
| 498 | Piedra Operating, LLC | Denver, CO 80202 | Oil & Gas Operator | May 2023 |
| 499 | Pierce Junction Petroleum Inc. | Houston, TX 77002 | Oil & Gas Operator | May 2010 |
| 500 | Pierce Operating Company, L.L.C. | Bryan, TX 77808 | Oil & Gas Operator | Dec 2018 |