| 12401 | Halgas Inc | Tulsa, OK 74101-3012 | Oil & Gas Operator | May 2013 |
| 12402 | Hall & Horning Serv Inc | Atwater, OH 44201-9375 | Oil & Gas Operator | Dec 2009 |
| 12403 | Hall And Kelley Oil & Gas | | Oil Operator | Dec 1995 |
| 12404 | Hall Drilling LLC (Oil & Gas) | Ellenboro, WV 26346 | Gas Operator | Sep 2014 |
| 12405 | Hall Drilling, LLC | Ellenboro, WV 26346 | Oil & Gas Operator | Dec 2021 |
| 12406 | Hall Edward L | Ada, OK 74820-3321 | Oil & Gas Operator | Apr 2025 |
| 12407 | Hall Energy Co. | Oklahoma City, OK 73102 | Oil & Gas Operator | Sep 2016 |
| 12408 | Hall Energy Company LLC | Oklahoma City, OK 73120-5020 | Oil & Gas Operator | Jul 2022 |
| 12409 | Hall Energy Inc | Magnetic Spring, OH 43036 | Oil & Gas Operator | Dec 2017 |
| 12410 | Hall Engineering, Inc. | | Oil & Gas Operator | Jan 2007 |
| 12411 | Hall Exploration, Inc. | Fort Worth, TX 76102 | Oil & Gas Operator | Apr 2025 |
| 12412 | Hall Farm Leasing, LLC | | Oil Operator | Dec 2012 |
| 12413 | Hall IVan & Assoc Inc | Berea, OH 44017 | Oil & Gas Operator | Dec 1997 |
| 12414 | Hall Oil & Gas | Coahoma, TX 79511 | Oil & Gas Operator | Jul 2025 |
| 12415 | Hall Oil And Gas LLC | Midland, TX 79707 | Oil & Gas Operator | Jul 2025 |
| 12416 | Hall Oil Company | Humboldt, KS 66748 | Oil Operator | Nov 2009 |
| 12417 | Hall Resources Corporation | Independence, MO 64057-2158 | Oil & Gas Operator | Jun 2016 |
| 12418 | Hall Richard A | | Oil Operator | Sep 1993 |
| 12419 | Hall Thomas E | Marietta, OH 45750 | Oil & Gas Operator | Dec 2021 |
| 12420 | Hall, D. Corporation | La Grange, TX 78945 | Oil & Gas Operator | Mar 2013 |
| 12421 | Hall, E. G., Oil Co. | Mexia, TX 76667 | Oil & Gas Operator | Jul 2025 |
| 12422 | Hall, J.J. Operating Co., Inc. | Lakewood, CO 80215 | Oil Operator | Jan 2005 |
| 12423 | Hall, James H ( Trust) | | Gas Operator | Dec 2007 |
| 12424 | Hall, Michael Wayne | Toronto, KS 66777 | Oil Operator | Dec 2009 |
| 12425 | Hall-Hargraves, L.L.C. | | Oil & Gas Operator | Dec 2024 |
| 12426 | Hall-Houston Expl. II, L.P. | Houston, TX 77027 | Oil & Gas Operator | Jul 2025 |
| 12427 | Hall-Houston Expl. III, L.P. | Houston, TX 77027 | Oil & Gas Operator | Jul 2013 |
| 12428 | Hall-Houston Oil Company | Houston, TX 77002 | Oil & Gas Operator | Oct 2002 |
| 12429 | Hallador Petroleum Company | | Oil & Gas Operator | Feb 1992 |
| 12430 | Hallador Petroleum LLP | Denver, CO 80264 | Oil & Gas Operator | Feb 2019 |
| 12431 | Hallar Enterprises, Inc. | | Oil Operator | Oct 2007 |
| 12432 | Hallco Petroleum Inc | Oklahoma City, OK 73106-5224 | Oil Operator | Aug 2018 |
| 12433 | Halliburton Oil | | Oil & Gas Operator | Sep 2008 |
| 12434 | Halliburton Oil Producing Co. | Duncan, OK 73534 | Oil & Gas Operator | Apr 2016 |
| 12435 | Halliburton Operating Company | Plano, TX 75093 | Oil & Gas Operator | Jul 2025 |
| 12436 | Hallmark Oil And Gas Co., Inc. | | Oil & Gas Operator | Dec 2024 |
| 12437 | Hallmark Resources, Inc | Stilwell, OK 74960-0312 | Oil & Gas Operator | Sep 2020 |
| 12438 | Hallum Construction Inc | Seminole, OK 74868-2427 | Oil & Gas Operator | Sep 2014 |
| 12439 | Hallwell Gas & Oil Co. | | Oil & Gas Operator | Sep 1985 |
| 12440 | Hallwood Energy Corporation | Oklahoma City, OK 73154 | Oil & Gas Operator | Feb 2005 |
| 12441 | Hallwood Petrole | | Oil & Gas Operator | Apr 1999 |
| 12442 | Hallwood Petroleum | Denver, CO 80237 | Oil & Gas Operator | Dec 1997 |
| 12443 | Hallwood Petroleum, Inc. | Midland, TX 79701 | Oil & Gas Operator | Jan 2025 |
| 12444 | Hallwood Petroleum, LLC | Dallas, TX 75219 | Oil & Gas Operator | Jan 2010 |
| 12445 | Halo Energy L.L.C. | Kilgore, TX 75662 | Oil Operator | Jul 2025 |
| 12446 | Halter Ralph P | Robertsville, OH 44670 | Oil Operator | Dec 1999 |
| 12447 | Halvey Energy Co. | Midland, TX 79702 | Oil & Gas Operator | Oct 2004 |
| 12448 | Halvey Energy, LLC | Midland, TX 79702 | Oil & Gas Operator | Jul 2025 |
| 12449 | Ham Oil & Gas, Inc. | Big Lake, TX 76932 | Oil & Gas Operator | Feb 2000 |
| 12450 | Ham Oil Company, LLC | | Oil Operator | Sep 2022 |
| 12451 | Hamblin Ralph Inc | MT Vernon, OH 43050 | Oil & Gas Operator | Dec 1991 |
| 12452 | Hamby Oil LLC | Ellinwood, KS 67526 | Oil Operator | May 2013 |
| 12453 | Hamil Oil & Gas LLC | Kingfisher, OK 73750-6500 | Oil & Gas Operator | Apr 2025 |
| 12454 | Hamill Resources, Inc. | Houston, TX 77002 | Oil & Gas Operator | Apr 1999 |
| 12455 | Hamill, Claud B. Estate Of | Houston, TX 77002 | Oil & Gas Operator | Nov 1995 |
| 12456 | Hamill, Flora Oil Co. | Levelland, TX 79336 | Oil & Gas Operator | Jul 2025 |
| 12457 | Hamilton B J | Ada, OK 74820-9404 | Oil & Gas Operator | Sep 1999 |
| 12458 | Hamilton Brother | | Gas Operator | May 1993 |
| 12459 | Hamilton Brothers | Plainview, TX 79073 | Oil & Gas Operator | Mar 2008 |
| 12460 | Hamilton Brothers Oil Co. | Houston, TX 77057 | Oil & Gas Operator | Mar 2015 |
| 12461 | Hamilton K M Oil & Gas Co | Ada, OK 74820 | Oil Operator | Jan 2013 |
| 12462 | Hamilton Leonard O | Marietta, OH 45750 | Oil & Gas Operator | Dec 2024 |
| 12463 | Hamilton, Clay | Carrizo SPGS, TX 78834 | Oil & Gas Operator | Jul 2025 |
| 12464 | Hamilton, J. R. | Carrizo SPGS, TX 78834 | Oil & Gas Operator | Jul 2025 |
| 12465 | Hamilton, John M. | Wichita Falls, TX 76301 | Oil & Gas Operator | May 2001 |
| 12466 | Hamilton, W. B., Estate | Wichita Falls, TX 76301 | Oil & Gas Operator | Mar 2004 |
| 12467 | Hamilton-Tedford Oper. Co., LLC | Wichita Falls, TX 76301 | Oil Operator | May 2007 |
| 12468 | Hamlin Oil Opera | | Oil Operator | May 1988 |
| 12469 | Hamm N R Contrac | | Oil & Gas Operator | Jun 1989 |
| 12470 | Hamm, Richard | Monahans, TX 79756 | Oil & Gas Operator | Mar 1994 |
| 12471 | Hamm, Richard Inc. | Monahans, TX 79756 | Oil & Gas Operator | Jul 2025 |
| 12472 | Hamman Oil & Refining Company | Houston, TX 77098 | Oil & Gas Operator | Jul 2025 |
| 12473 | Hamman, Blake | Graham, TX 76450 | Oil & Gas Operator | Jul 2020 |
| 12474 | Hammer Maclean Etal | Leon, KS 67074 | Oil Operator | Dec 2019 |
| 12475 | Hammer Oil Compa | | Oil Operator | Oct 1985 |
| 12476 | Hammer Oil Company | Post, TX 79356 | Oil & Gas Operator | Jun 2002 |
| 12477 | Hammer Oil Properties Inc | Enid, OK 73706-0144 | Oil & Gas Operator | Oct 2017 |
| 12478 | Hammer Ranch | Elmore City, OK 73433 | Oil & Gas Operator | Jan 2023 |
| 12479 | Hammerschmidt Wi | | Oil Operator | Sep 1991 |
| 12480 | Hammerschmidt, Leo | Plainville, KS 67663 | Oil Operator | Aug 2000 |
| 12481 | Hammerschmidt, William E | Plainville, KS 67663 | Oil Operator | Feb 2025 |
| 12482 | Hammersmith, Beverly | West Falls, NY 14170 | Gas Operator | Dec 2024 |
| 12483 | Hammon Properties | Wichita Falls, TX 76307 | Oil & Gas Operator | Apr 1996 |
| 12484 | Hammond Valley Colony, Inc. | Harlowton, MT 59036 | Gas Operator | Apr 2025 |
| 12485 | Hamon Jake L | Dallas, TX 75201-3902 | Oil & Gas Operator | Nov 1997 |
| 12486 | Hamon Oil Company | | Oil & Gas Operator | Aug 1985 |
| 12487 | Hamon Operating Company | Dallas, TX 75201 | Oil & Gas Operator | Dec 2011 |
| 12488 | Hamp Oil | Ponca City, OK 74604 | Oil & Gas Operator | Sep 2002 |
| 12489 | Hamp Oil - Pace | | Oil & Gas Operator | Apr 1994 |
| 12490 | Hampton Corporation (The) | Norman, OK 73069-5910 | Oil Operator | Jun 2016 |
| 12491 | Hampton Oil & Gas | Early, TX 76802 | Gas Operator | Feb 2012 |
| 12492 | Hampton Resources Corporation | Houston, TX 77010 | Oil & Gas Operator | Mar 1996 |
| 12493 | Hampton, Jno. W. & Son | Wichita Falls, TX 76302 | Oil & Gas Operator | Nov 1998 |
| 12494 | Hanaco Operating | Holliday, TX 76366 | Oil Operator | Mar 2008 |
| 12495 | Hanaco, LLC | Holliday, TX 76366 | Oil Operator | Dec 2017 |
| 12496 | Hanagan Petroleum Corp | Roswell, NM 88201 | Oil & Gas Operator | Sep 1999 |
| 12497 | Hancock Leon | Kingston, OK 73439-9618 | Oil Operator | Dec 2014 |
| 12498 | Hancock, Burton W | Morrison, CO 80465 | Oil & Gas Operator | Dec 2017 |
| 12499 | Hand Oil Co. | Chanute, KS 66720 | Oil Operator | Nov 2000 |
| 12500 | Handy, Daniel G. | East Aurora, NY 14052 | Gas Operator | Dec 2024 |