| 11501 | U.S. Enercorp, LLC | San Antonio, TX 78217 | Oil & Gas Operator | Jul 2004 |
| 11502 | U.S. Enercorp, LTD. | San Antonio, TX 78209 | Oil & Gas Operator | Sep 2019 |
| 11503 | U.S. Exploration Company | Houston, TX 77002 | Oil & Gas Operator | Aug 2003 |
| 11504 | U.S. Sovereign Oil And Gas, Inc. | Dallas, TX 75355 | Oil & Gas Operator | Jun 2026 |
| 11505 | U.S.A. Plugging Company | Pearsall, TX 78061 | Oil & Gas Operator | Jun 2026 |
| 11506 | U1 Ranch Oil | Houston, TX 77269 | Oil & Gas Operator | Jun 2026 |
| 11507 | Ubetco, Inc. | Rockdale, TX 76567 | Oil & Gas Operator | Jun 2026 |
| 11508 | Uhc Petroleum Corporation | Rocksprings, TX 78880 | Oil & Gas Operator | Jun 2026 |
| 11509 | Ulatex Oil & Gas Inc. | Nocona, TX 76255 | Oil & Gas Operator | Dec 1998 |
| 11510 | Ultra Oil & Gas, Inc. | Centerton, AR 72719 | Oil & Gas Operator | Jun 2026 |
| 11511 | Ultra Petroleum (U.S.A.), Inc. | Granbury, TX 76048 | Oil & Gas Operator | Sep 2003 |
| 11512 | Ultra Resources Inc | Houston, TX 77060 | Oil & Gas Operator | Sep 2018 |
| 11513 | Umc Petroleum Corporation | Houston, TX 77002 | Oil & Gas Operator | Mar 2015 |
| 11514 | Umma Resources, LLC | Portland, TX 78374 | Gas Operator | Jun 2026 |
| 11515 | Unbridled Resources, LLC | Oklahoma City, OK 73102 | Oil & Gas Operator | Jun 2026 |
| 11516 | Underwood, Jim | Graham, TX 76450 | Oil & Gas Operator | Mar 2018 |
| 11517 | Unicorn Energy, Inc. | Elgin, TX 78621 | Oil & Gas Operator | Jun 2026 |
| 11518 | Unified Oil & Gas Corp. | Snyder, TX 79550 | Oil Operator | Jun 2026 |
| 11519 | Union Crude Company | Baytown, TX 77521 | Oil & Gas Operator | Apr 2018 |
| 11520 | Union Crude Operating Co. | Baytown, TX 77521 | Oil Operator | Aug 2003 |
| 11521 | Union Gas Operating Company | Spring, TX 77391 | Oil & Gas Operator | Jun 2026 |
| 11522 | Union Oil Co Of California | Midland, TX 79706 | Oil & Gas Operator | Jan 2022 |
| 11523 | Union Pacific Austin Chalk Co. | Fort Worth, TX 76101 | Oil & Gas Operator | Jan 2001 |
| 11524 | Union Pacific Resources Co. | Fort Worth, TX 76101 | Oil & Gas Operator | Jan 2001 |
| 11525 | Union Royalty, Inc. | Midland, TX 79706 | Oil & Gas Operator | Jul 2014 |
| 11526 | Union Seaboard Corporation | Houston, TX 77024 | Oil & Gas Operator | Mar 2008 |
| 11527 | Unit Petroleum Company | Tulsa, OK 74170 | Oil & Gas Operator | Jun 2026 |
| 11528 | United Company | Lubbock, TX 79408 | Oil & Gas Operator | Jun 1995 |
| 11529 | United Energy Corporation | San Antonio, TX 78209 | Oil & Gas Operator | Jun 2026 |
| 11530 | United Energy Operating, LLC | Edmond, OK 73083 | Oil & Gas Operator | Jun 2026 |
| 11531 | United Energy Partners, Inc. | Dallas, TX 75201 | Oil & Gas Operator | Mar 2008 |
| 11532 | United Oil & Minerals L. P. | Austin, TX 78746 | Oil & Gas Operator | Jun 2003 |
| 11533 | United Oil & Minerals, Inc. | Austin, TX 78746 | Oil & Gas Operator | Jan 2001 |
| 11534 | United Oil & Shale LLC | Woodward, OK 73801 | Oil & Gas Operator | Jun 2026 |
| 11535 | United Operating Company | Olney, TX 76374 | Oil & Gas Operator | Aug 2003 |
| 11536 | United Operating, LLC *** | Midland, TX 79710 | Oil & Gas Operator | Jun 2026 |
| 11537 | United Petroleum & Gas, Inc. | Kilgore, TX 75663 | Oil & Gas Operator | Jun 2026 |
| 11538 | United Petroleum Technologies | Hondo, TX 78861 | Oil & Gas Operator | Aug 2001 |
| 11539 | United Resources LP | Austin, TX 78746 | Oil & Gas Operator | Oct 2011 |
| 11540 | United States Gypsum Company | Oakfield, NY 14125 | Oil & Gas Operator | Dec 2024 |
| 11541 | United Texas Oil LLC | Houston, TX 77027 | Oil & Gas Operator | Jun 2026 |
| 11542 | United Texas Petroleum Inc. | McKinney, TX 75070 | Oil & Gas Operator | Jun 2026 |
| 11543 | United World Energy, Inc. | Aurora, CO 80040 | Oil & Gas Operator | Jun 2026 |
| 11544 | Unitex Oil & Gas, L.L.C. | Midland, TX 79701 | Oil & Gas Operator | Jun 2026 |
| 11545 | Universal Geopower LLC | Houston, TX 77057 | Oil & Gas Operator | May 2016 |
| 11546 | Universal Petroleum Corporation | Houston, TX 77002 | Oil & Gas Operator | Sep 2002 |
| 11547 | Universal Resources Corp. | Salt Lake Cty, UT 84145 | Oil & Gas Operator | Jan 2000 |
| 11548 | Unknown | Houston, TX 77208 | Oil & Gas Operator | Dec 2024 |
| 11549 | Unocal Exploration Corporation | Houston, TX 77001 | Oil & Gas Operator | May 1992 |
| 11550 | Unoco, Inc. | Kerrville, TX 78029 | Oil & Gas Operator | Jan 1999 |
| 11551 | Unoso Operating Company L.L.C. | Georgetown, TX 78633 | Oil & Gas Operator | Jun 2026 |
| 11552 | Unswept Oil Company | Corsicana, TX 75151 | Oil & Gas Operator | Jan 2018 |
| 11553 | Untamed Resources, LLC | Spearman, TX 79081 | Gas Operator | Jun 2026 |
| 11554 | Uosi Operating, Inc. | Lovelady, TX 75851 | Oil & Gas Operator | Jun 2026 |
| 11555 | Upcurve Energy, LLC | Houston, TX 77024 | Oil & Gas Operator | Jun 2026 |
| 11556 | Upda Operators, Inc. | Jacksboro, TX 76458 | Oil & Gas Operator | Dec 2009 |
| 11557 | Upham Oil & Gas Company | Mineral Wells, TX 76068 | Oil & Gas Operator | Jun 2026 |
| 11558 | Upham, Chester R., Jr. | Mineral Wells, TX 76067 | Oil & Gas Operator | Aug 2001 |
| 11559 | Uphill Consulting LLC | Pearland, TX 77584 | Oil & Gas Operator | Jun 2026 |
| 11560 | Upland Exploration, LLC | Boerne, TX 78006 | Oil & Gas Operator | Jul 2024 |
| 11561 | Upland Operating, LLC | Dallas, TX 75226 | Oil & Gas Operator | Jun 2026 |
| 11562 | Upland Production Company | Edmond, OK 73083 | Oil & Gas Operator | Jun 2026 |
| 11563 | Upland Resources LLC | Canadian, TX 79014 | Oil & Gas Operator | Jun 2026 |
| 11564 | Upland Resources, Inc. | Canadian, TX 79014 | Oil & Gas Operator | Dec 2009 |
| 11565 | Uplands Resources Inc | Tulsa, OK 74103-4141 | Oil & Gas Operator | Mar 2026 |
| 11566 | Uplift Production Company, Inc. | Shamrock, TX 79079 | Oil & Gas Operator | Feb 1999 |
| 11567 | Upp Operating, LLC | Houston, TX 77002 | Oil & Gas Operator | Jun 2026 |
| 11568 | Upstream Exploration LLC | Metairie, LA 70002 | Oil & Gas Operator | Jan 2020 |
| 11569 | Upstream Properties, LLC | Southlake, TX 76092 | Oil & Gas Operator | Jun 2026 |
| 11570 | Upstream Resource Partners, LLC | Elkhart, TX 75839 | Oil Operator | Jun 2026 |
| 11571 | Uptex Operating Inc. | Dallas, TX 75201 | Oil & Gas Operator | May 2011 |
| 11572 | Uptex Operating, L.P. | Dallas, TX 75201 | Oil & Gas Operator | May 2010 |
| 11573 | Urban Oil & Gas Group, LLC | Plano, TX 75074 | Oil & Gas Operator | Jun 2026 |
| 11574 | Ursa Operating Company LLC | Denver, CO 80265 | Oil & Gas Operator | Feb 2014 |
| 11575 | Ursus Oil And Gas | Tyler, TX 75703 | Oil & Gas Operator | Jun 2026 |
| 11576 | Us Ecology Winnie, LLC | Winnie, TX 77665 | Oil Operator | Jun 2026 |
| 11577 | Us Energy Corp. | Houston, TX 77057 | Oil & Gas Operator | Dec 2021 |
| 11578 | Us Energy Holdings, LLC | Richardson, TX 75080 | Oil & Gas Operator | Jun 2026 |
| 11579 | Us Petro LP | Amarillo, TX 79106 | Oil & Gas Operator | Apr 2020 |
| 11580 | Us. Fuels, Inc. | Breckenridge, TX 76424 | Oil & Gas Operator | Jun 2026 |
| 11581 | USA Superior Energy LLC | Houston, TX 77077 | Oil Operator | Mar 2010 |
| 11582 | USA Tubulars, Inc. | Valley Spring, TX 76885 | Oil & Gas Operator | Dec 1995 |
| 11583 | Usfg Oil & Gas, Inc. | Dallas, TX 75231 | Oil & Gas Operator | Dec 2005 |
| 11584 | Utility Ventures Company | Pasadena, TX 77504 | Oil & Gas Operator | Jun 2026 |
| 11585 | Utoco, LTD. | Midland, TX 79704 | Oil Operator | Jun 2026 |
| 11586 | Uvalde Energy Co. | Austin, TX 78747 | Oil & Gas Operator | Nov 1994 |
| 11587 | V & H Oil, L.P. | Muenster, TX 76252 | Oil & Gas Operator | Jun 2026 |
| 11588 | V S Oil Company | Burkburnett, TX 76354 | Oil & Gas Operator | Jun 2026 |
| 11589 | V-F Petroleum Inc. | Midland, TX 79702 | Oil & Gas Operator | Jun 2026 |
| 11590 | V/J Oil Company | Yancey, TX 78886 | Oil & Gas Operator | Oct 2015 |
| 11591 | Vaalco Energy (USA), Inc. | Houston, TX 77042 | Oil & Gas Operator | Dec 2016 |
| 11592 | Vac-U-Lift Production Co.,Inc. | Lake Forest, CA 92630 | Oil & Gas Operator | Jun 2026 |
| 11593 | Vaca Operating Company LLC | Pacific PLSDS, CA 90272 | Oil & Gas Operator | Aug 2017 |
| 11594 | Vale Petroleum Corporation | Houston, TX 77042 | Gas Operator | Jan 1995 |
| 11595 | Valence Operating Company | Kingwood, TX 77339 | Oil & Gas Operator | Jun 2026 |
| 11596 | Valentine Oil & Gas, L.C. | Carmine, TX 78932 | Oil Operator | Nov 2018 |
| 11597 | Valera Oil Company | Kingsland, TX 78639 | Oil & Gas Operator | Apr 2000 |
| 11598 | Valerius, Inc. & Zine, Inc. | Corpus Chrsti, TX 78473 | Oil & Gas Operator | Jul 1994 |
| 11599 | Valerius, Robert D. Inc. | Corpus Chrsti, TX 78473 | Oil & Gas Operator | Aug 2003 |
| 11600 | Validus Energy II Midcon LLC | Denver, CO 80202 | Oil & Gas Operator | Jun 2026 |