| 401 | Eureka Gas Co, Inc | Pikeville, KY 41502 | Gas Operator | Dec 2010 |
| 402 | Eureka Prospecting Company | Wimberley, TX 78676 | Oil & Gas Operator | Jun 2023 |
| 403 | European-Southwest Co. | Houston, TX 77254 | Oil & Gas Operator | Feb 2026 |
| 404 | Eurotex Royalty, Inc. | Arlington, TX 76012 | Oil & Gas Operator | Aug 2003 |
| 405 | Eurovest Oil & Gas, Inc. | Graham, TX 76450 | Oil & Gas Operator | Mar 2008 |
| 406 | Ev Fleming Enterprises, LLC | Kilgore, TX 75662 | Oil & Gas Operator | Aug 2024 |
| 407 | Evangeline Trading Company | Ballinger, TX 76821 | Oil & Gas Operator | Feb 2026 |
| 408 | Evans Production Co. | Pampa, TX 79066 | Oil & Gas Operator | Sep 2020 |
| 409 | Evans, Carl N. | Graham, TX 76450 | Oil & Gas Operator | Feb 2001 |
| 410 | Evans, Julian | Houston, TX 77024 | Oil & Gas Operator | Nov 1995 |
| 411 | Evans, Ralph | San Antonio, TX 78209 | Oil & Gas Operator | Jan 2011 |
| 412 | Evans, S. Lavon Jr. Oper. Co. | Laurel, MS 39442 | Oil & Gas Operator | Feb 2026 |
| 413 | Evantech Energy Corp. | Fort Worth, TX 76120 | Oil & Gas Operator | Apr 1995 |
| 414 | Evarado Oil Company | Strawn, TX 76475 | Oil & Gas Operator | Feb 2026 |
| 415 | Evarado Oil, LLC | Strawn, TX 76475 | Oil & Gas Operator | Feb 2026 |
| 416 | Everest Minerals Corp. | Corpus Chrsti, TX 78403 | Oil & Gas Operator | Apr 2001 |
| 417 | Everest Network LLC | Eastland, TX 76448 | Oil & Gas Operator | Feb 2026 |
| 418 | Everest Resource Company | Corpus Chrsti, TX 78403 | Oil & Gas Operator | Feb 2026 |
| 419 | Everett Oil | San Antonio, TX 78258 | Oil & Gas Operator | Apr 2015 |
| 420 | Everett Oil, Inc. | San Antonio, TX 78258 | Oil Operator | Feb 2026 |
| 421 | Everett, Joe Mack | Throckmorton, TX 76483 | Oil & Gas Operator | Feb 2026 |
| 422 | Evergreen Energy, Inc | Houston, TX 77098 | Oil & Gas Operator | Feb 2026 |
| 423 | Evergreen Operating Co., LTD. | McAllen, TX 78502 | Oil & Gas Operator | Feb 2026 |
| 424 | Evergreen Operating Corp | Denver, CO 80202 | Oil & Gas Operator | Dec 2019 |
| 425 | Everquest Energy Corporation | Fredericksbrg, TX 78624 | Oil & Gas Operator | Sep 2025 |
| 426 | Evinger, Ernest E. | Midland, TX 79705 | Oil & Gas Operator | Mar 2002 |
| 427 | Evolution Operating Co., Inc. | Houston, TX 77079 | Oil & Gas Operator | Feb 2026 |
| 428 | Evolution Resources, LLC | Houston, TX 77070 | Oil & Gas Operator | Feb 2026 |
| 429 | Ew Energy Operator LLC | Houston, TX 77079 | Oil & Gas Operator | Jul 2015 |
| 430 | Ewt Operating Company | Andrews, TX 79714 | Oil & Gas Operator | Feb 2026 |
| 431 | Ex-Cel Resources, LLC | Breckenridge, TX 76424 | Oil & Gas Operator | Feb 2026 |
| 432 | Exaro Energy II, LLC | Houston, TX 77057 | Oil & Gas Operator | Feb 2026 |
| 433 | Excalibur E & P, LLC | Johnson City, TX 78636 | Oil & Gas Operator | Feb 2026 |
| 434 | Exceed Petroleum LLC | Houston, TX 77070 | Oil & Gas Operator | Feb 2026 |
| 435 | Excel Energy Co. | Coahoma, TX 79511 | Oil & Gas Operator | Feb 2026 |
| 436 | Excel Energy, Inc. | Cisco, TX 76437 | Oil & Gas Operator | Feb 2026 |
| 437 | Excel Oil & Gas, Inc. | Waxahachie, TX 75168 | Oil & Gas Operator | Feb 2026 |
| 438 | Excelco Energy Inc. | Kingwood, TX 77339 | Oil & Gas Operator | Jul 2018 |
| 439 | Exchange Avenue Production Co. | Weatherford, TX 76086 | Oil & Gas Operator | Sep 2021 |
| 440 | Exchange Exploration & Production Co. | Dallas, TX 75219 | Oil & Gas Operator | Nov 2025 |
| 441 | Exchange Oil & Gas Corporation | Tulsa, OK 74103 | Oil & Gas Operator | Oct 1987 |
| 442 | Exco Operating Company, LP | Dallas, TX 75251 | Oil & Gas Operator | Feb 2026 |
| 443 | Exco Partners Operating PTSHP LP | Dallas, TX 75251 | Oil & Gas Operator | Jan 2009 |
| 444 | Exco Production Company, LP | Dallas, TX 75251 | Oil & Gas Operator | Dec 2009 |
| 445 | Exco Resources Inc | Dallas, TX 75251 | Oil & Gas Operator | Nov 2025 |
| 446 | Exco/Hgi JV Assets, LLC | Dallas, TX 75251 | Oil & Gas Operator | Jun 2014 |
| 447 | Executive Production, Inc. | Tyler, TX 75713 | Oil & Gas Operator | Feb 2026 |
| 448 | Exit Oil & Gas | Flower Mound, TX 75028 | Oil & Gas Operator | Feb 2026 |
| 449 | Exl Petroleum Operating Inc. | Midland, TX 79705 | Oil & Gas Operator | Feb 2020 |
| 450 | Exl Petroleum, LP | Midland, TX 79705 | Oil & Gas Operator | Jun 2017 |
| 451 | Exlco, Inc. | Wichita Falls, TX 76308 | Oil & Gas Operator | Feb 2026 |
| 452 | Exmoor Oil & Minerals Corp. | Dallas, TX 75225 | Oil & Gas Operator | May 1994 |
| 453 | Exodus Energy, Inc. | Huntington Beach, CA 92615 | Oil & Gas Operator | Jul 2018 |
| 454 | Exok Inc | Oklahoma City, OK 73116 | Oil & Gas Operator | Nov 2025 |
| 455 | Exorare Energy, Inc. | Dallas, TX 75218 | Oil & Gas Operator | Feb 2026 |
| 456 | Exotic Oil & Gas LLC | Indiana, PA 15701-3634 | Oil & Gas Operator | Dec 2025 |
| 457 | Exp, Inc. | Dallas, TX 75244 | Oil & Gas Operator | May 2003 |
| 458 | Expand Oper LLC | Morgantown, WV 26508 | Oil & Gas Operator | Dec 2025 |
| 459 | Expanding Energy Corporation | New Braunfels, TX 78132 | Oil & Gas Operator | Mar 2008 |
| 460 | Explo Oil, Inc. | Dallas, TX 75251 | Oil & Gas Operator | Feb 2026 |
| 461 | Exploration Company, The | San Antonio, TX 78258 | Oil & Gas Operator | Jun 2010 |
| 462 | Exploration Techniques Inc. | Houston, TX 77027 | Oil & Gas Operator | Feb 2026 |
| 463 | Export Petroleum Corporation | Fort Worth, TX 76147 | Oil & Gas Operator | Feb 2026 |
| 464 | Express Energy Group, LLC | Atlanta, TX 75551 | Oil & Gas Operator | Feb 2026 |
| 465 | Express Oil And Gas | La Grange, TX 78945 | Oil & Gas Operator | Feb 2026 |
| 466 | Express Oil Co. | Hallettsville, TX 77964 | Oil & Gas Operator | Feb 2026 |
| 467 | Expro Engineering, Inc. | Fort Worth, TX 76179 | Oil & Gas Operator | Feb 2026 |
| 468 | Extech Operating, LLC | Fort Worth, TX 76147 | Oil & Gas Operator | Feb 2026 |
| 469 | Extenergy, L.P. | The Woodlands, TX 77380 | Oil & Gas Operator | Dec 2014 |
| 470 | Extex Operating Company | Houston, TX 77057 | Oil & Gas Operator | Feb 2026 |
| 471 | Exxcel Production Company | Pampa, TX 79066 | Oil & Gas Operator | Feb 2026 |
| 472 | Exxon Corp. - Midland | Houston, TX 77210 | Gas Operator | Jul 1997 |
| 473 | Exxon Corporation | Houston, TX 77210 | Oil & Gas Operator | Feb 2026 |
| 474 | Exxon Mobil Corporation | Spring, TX 77389 | Oil & Gas Operator | Feb 2026 |
| 475 | Exxonmobil Oil Corp | Houston, TX 77210 | Oil & Gas Operator | Sep 2025 |
| 476 | Exzena Oil Corp. | Tyler, TX 75713 | Oil & Gas Operator | Feb 2026 |
| 477 | Eylau Oil Inc. | Atlanta, TX 75551 | Oil & Gas Operator | Oct 2021 |