| 12401 | Harmonia Petroleum Corporation | Missouri City, TX 77459 | Oil & Gas Operator | May 2017 |
| 12402 | Harmons Well Service | Graysville, OH 45734 | Oil & Gas Operator | Dec 2019 |
| 12403 | Harmony Drilling Company, Inc. | Denver, CO 80222 | Oil & Gas Operator | Nov 2016 |
| 12404 | Harmony Exploration, Inc. | College Sta, TX 77842 | Oil & Gas Operator | Aug 2026 |
| 12405 | Harmony Oil & Gas Co Inc | Reno, NV 89509 | Oil Operator | Dec 1994 |
| 12406 | Harmony Oil LLC | Cushing, OK 74023 | Oil Operator | Apr 2026 |
| 12407 | Harmony Producing Co Inc | | Oil & Gas Operator | Dec 1995 |
| 12408 | Harms Petroleum | | Oil & Gas Operator | May 1991 |
| 12409 | Harms, H. Allan Petroleum Co., Inc. | Great Bend, KS 67530 | Oil Operator | Apr 1999 |
| 12410 | Harms, Vance N. | Talpa, TX 76882 | Oil & Gas Operator | Mar 2016 |
| 12411 | Harnetty Francis Dba Harnetty Oil & Gas | Junction City, OH 43748 | Oil & Gas Operator | Dec 2019 |
| 12412 | Harold G Raper Family Trust | Mansfield, TX 76063-1667 | Oil Operator | May 2023 |
| 12413 | Harold H. Hollenshead | | Oil & Gas Operator | May 2002 |
| 12414 | Harold M Root Foundation | | Oil Operator | Apr 2026 |
| 12415 | Harold R Elkin | Punxsutawney, PA 15767-7922 | Oil & Gas Operator | Dec 2016 |
| 12416 | Harp Peggy A | Seminole, OK 74868-2284 | Oil & Gas Operator | Mar 2024 |
| 12417 | Harp, Stephen J. | Fredonia, NY 14063 | Gas Operator | Dec 2025 |
| 12418 | Harpel John P Jr | FT. Collins, CO 80525 | Oil & Gas Operator | May 1998 |
| 12419 | Harper Crosby Holdings, LLC | Weston, WV 26452 | Oil & Gas Operator | Dec 2025 |
| 12420 | Harper Hefte, Inc. | Corpus Christ, TX 78410 | Oil & Gas Operator | Aug 2026 |
| 12421 | Harper Joe Howard Dba J H Field Service | Nowata, OK 74048-9704 | Oil & Gas Operator | Mar 2026 |
| 12422 | Harper Oil And Gas, LLC | Pratt, KS 67124 | Oil & Gas Operator | Apr 2026 |
| 12423 | Harper Oil Co. | Denver, CO 80217 | Oil & Gas Operator | Apr 2026 |
| 12424 | Harper Production, LLC | Spearman, TX 79081 | Oil & Gas Operator | Aug 2026 |
| 12425 | Harper, Clint | Woodson, TX 76491 | Oil & Gas Operator | Aug 2026 |
| 12426 | Harper, Mr. William | Clyde, NY 14433 | Gas Operator | Dec 2025 |
| 12427 | Harper, Wayne | Dallas, TX 75206 | Oil & Gas Operator | Mar 2008 |
| 12428 | Harper, William E. | Woodson, TX 76491 | Oil & Gas Operator | Jul 2016 |
| 12429 | Harrell Oil Company LLC | Ardmore, OK 73402 | Oil Operator | Jan 2025 |
| 12430 | Harrell Operating Inc | Graham, TX 76450 | Oil & Gas Operator | Sep 2005 |
| 12431 | Harrell Operating, L.L.C. | Graham, TX 76450 | Oil & Gas Operator | Jun 2008 |
| 12432 | Harrell Petroleum Inc | Oklahoma City, OK 73102-7201 | Oil & Gas Operator | Oct 2017 |
| 12433 | Harrell Verlan W | Oklahoma City, OK 73102-7201 | Oil & Gas Operator | Nov 1999 |
| 12434 | Harrell, Charles | Graham, TX 76450 | Oil & Gas Operator | Dec 2000 |
| 12435 | Harrier Holdings, LTD. | Burnet, TX 78611 | Oil Operator | Aug 2026 |
| 12436 | Harrigan Energy Partners, Inc. | Houston, TX 77058 | Oil & Gas Operator | Sep 2010 |
| 12437 | Harrigan Operating, LLC | Houston, TX 77258 | Oil & Gas Operator | Apr 2020 |
| 12438 | Harrington Billy B | Depew, OK 74028-3495 | Oil & Gas Operator | May 2006 |
| 12439 | Harrington Oil Inc. | | Oil & Gas Operator | Apr 1978 |
| 12440 | Harrington Orville | Dewey, OK 74029 | Oil Operator | Apr 2026 |
| 12441 | Harrington SR Tommy W | Drumright, OK 74030-5778 | Oil Operator | May 2015 |
| 12442 | Harris & Payne-Randel Drilling | | Oil & Gas Operator | Dec 1989 |
| 12443 | Harris & Walton | Midland, TX 79702 | Oil & Gas Operator | Feb 2004 |
| 12444 | Harris B D | Norman, OK 73071-4802 | Oil & Gas Operator | Apr 2014 |
| 12445 | Harris Energy Partners Op, LLC | Fort Worth, TX 76116 | Oil Operator | Aug 2026 |
| 12446 | Harris Energy Services, LLC | Dallas, TX 75201 | Oil & Gas Operator | Aug 2026 |
| 12447 | Harris Engineering Co | Dallas, TX 75248 | Oil & Gas Operator | Dec 1996 |
| 12448 | Harris Mildred C | Tulsa, OK 74120 | Oil & Gas Operator | Apr 2026 |
| 12449 | Harris Minerals Corp (The) | Oklahoma City, OK 73162-1045 | Oil & Gas Operator | Feb 2026 |
| 12450 | Harris Oil & Gas | | Oil & Gas Operator | Jul 1995 |
| 12451 | Harris Oil & Gas Company | Denver, CO 80202 | Oil & Gas Operator | Jun 2016 |
| 12452 | Harris Olin | Okmulgee, OK 74447-8508 | Oil Operator | Feb 2012 |
| 12453 | Harris, David | Toronto, KS 66777 | Oil Operator | Feb 2026 |
| 12454 | Harris, Jake, Trustee | Wichita Falls, TX 76301 | Oil & Gas Operator | Jun 2001 |
| 12455 | Harris, Sam E. | Albany, TX 76430 | Oil & Gas Operator | Aug 2003 |
| 12456 | Harris, William H. Jr. | Le Roy, NY 14482 | Gas Operator | Dec 2025 |
| 12457 | Harrison & Lee | | Oil Operator | Sep 1996 |
| 12458 | Harrison Drilling Co | | Oil & Gas Operator | Mar 1981 |
| 12459 | Harrison Energy | Tippecanoe, OH 44699 | Oil & Gas Operator | Dec 2000 |
| 12460 | Harrison Interests, LTD. | Houston, TX 77002 | Oil & Gas Operator | Aug 2026 |
| 12461 | Harrison Oil & Gas Inc | Houston, TX 77019 | Oil & Gas Operator | Apr 2026 |
| 12462 | Harrison, Dan J III&Bruce F Est | Houston, TX 77002 | Oil & Gas Operator | Aug 2026 |
| 12463 | Harrison, Dan J. III&Bruce F. | Houston, TX 77002 | Oil & Gas Operator | Mar 2008 |
| 12464 | Harrison, Mark V. | Madison, KS 66860 | Oil Operator | Jul 1995 |
| 12465 | Harrison, Sam G. Oil, Inc. | Houston, TX 77019 | Oil & Gas Operator | Nov 2019 |
| 12466 | Harrison, Thomas D | Park City, UT 84060-7307 | Gas Operator | Dec 1998 |
| 12467 | Harrison-Wright Oil Company LLC | Tulsa, OK 74133-7035 | Oil & Gas Operator | May 2026 |
| 12468 | Harrod Leasing | Edmond, OK 73034 | Oil & Gas Operator | Apr 2026 |
| 12469 | Harry Feder | | Oil & Gas Operator | Dec 1999 |
| 12470 | Harry L. Neeb | | Oil Operator | May 1985 |
| 12471 | Harsh International Inc | | Oil & Gas Operator | Dec 2013 |
| 12472 | Hart & McFarland | Vivian, LA 71082 | Oil & Gas Operator | Aug 2026 |
| 12473 | Hart David | Chickasha, OK 73018-7756 | Oil & Gas Operator | Mar 2015 |
| 12474 | Hart Energies, LLC | Tulsa, OK 74133 | Oil & Gas Operator | Dec 2016 |
| 12475 | Hart Energy LLC | | Oil Operator | Feb 2026 |
| 12476 | Hart Oil & Gas Inc | Houston, TX 77024 | Oil & Gas Operator | Jan 2017 |
| 12477 | Hart Oil, LLC | | Oil Operator | Dec 2014 |
| 12478 | Hart Petroleum Services, Inc | Corpus Christ, TX 78410 | Oil & Gas Operator | Jul 2025 |
| 12479 | Hart, Nick And Connie | Paola, KS 66071 | Oil Operator | Apr 2026 |
| 12480 | Hartco Oil Co. | | Oil Operator | Jan 2025 |
| 12481 | Hartel, Inc. | Abilene, TX 79601 | Oil & Gas Operator | Aug 1997 |
| 12482 | Harter Energy Inc | Tulsa, OK 74105 | Oil & Gas Operator | Dec 2025 |
| 12483 | Harter Oil Company | | Oil & Gas Operator | Apr 2011 |
| 12484 | Harter, Ron | Midland, TX 79702 | Oil & Gas Operator | Aug 2026 |
| 12485 | Hartley Natural Resource Development | | Oil & Gas Operator | Dec 2025 |
| 12486 | Hartline Tom | Drumright, OK 74030 | Oil Operator | Mar 2026 |
| 12487 | Hartman Oil And Gas Company | | Oil Operator | Dec 1998 |
| 12488 | Hartman Oil Company Inc | Wichita, KS 67206 | Oil & Gas Operator | Apr 2026 |
| 12489 | Hartman W L Trus | | Oil Operator | Jun 1992 |
| 12490 | Hartoil Corporation | Post, TX 79356 | Oil & Gas Operator | Aug 2026 |
| 12491 | Harus Inc | Indiana, PA 15701-9401 | Oil & Gas Operator | Dec 2025 |
| 12492 | Harvard Investments, Inc. | | Oil & Gas Operator | Oct 2002 |
| 12493 | Harvard Petroleum Company, LLC | Roswell, NM 88202 | Oil & Gas Operator | Aug 2026 |
| 12494 | Harvard Petroleum Corporation | Roswell, NM 88201 | Oil & Gas Operator | Dec 2004 |
| 12495 | Harvest (Us) Holdings, Inc | Houston, TX 77077 | Oil & Gas Operator | Apr 2011 |
| 12496 | Harvest Energy Company | Englewood, CO 80110 | Oil & Gas Operator | Jun 1997 |
| 12497 | Harvest Oil & Gas, LLC | | Oil & Gas Operator | Feb 2012 |
| 12498 | Harvest Operating Company, Inc. | Cisco, TX 76437 | Oil & Gas Operator | Dec 1997 |
| 12499 | Harvest Petroleum Inc. | Frisco, TX 75033 | Oil & Gas Operator | Aug 2026 |
| 12500 | Harvest Petroleum Partners LLC | Midland, TX 79705 | Oil & Gas Operator | Aug 2026 |