| 1 | H & B Production | | Oil Operator | Mar 1995 |
| 2 | H & B Well Service, Inc. | | Oil & Gas Operator | Aug 1993 |
| 3 | H & H & S Oil Producers | | Oil Operator | Jan 2025 |
| 4 | H & H Compressors, Inc. | | Oil & Gas Operator | Oct 1997 |
| 5 | H & H Oil Co. #1 | | Oil Operator | Jan 2025 |
| 6 | H & H Oil Company | | Oil & Gas Operator | Sep 2025 |
| 7 | H & H Oil Producers | | Oil & Gas Operator | Jan 2025 |
| 8 | H & H Production Company | Muenster, TX 76252 | Oil & Gas Operator | Oct 2005 |
| 9 | H & N Operating Co., Inc. | | Oil & Gas Operator | Oct 1997 |
| 10 | H & S Operating Company Inc | Winesburg, OH 44690 | Oil & Gas Operator | Dec 2024 |
| 11 | H E C I Exploration Company | | Oil & Gas Operator | Dec 1990 |
| 12 | H H H Oil Company | | Oil Operator | Jan 2025 |
| 13 | H L Brown Jr | Midland, TX 79702 | Oil & Gas Operator | May 2001 |
| 14 | H M Jarred & Walsh-Watts | | Oil & Gas Operator | Sep 1992 |
| 15 | H&S Production, LLC | | Oil Operator | Nov 2024 |
| 16 | H. & H. Development Co. | | Gas Operator | Aug 2019 |
| 17 | H. A. Harper | | Oil Operator | Dec 1982 |
| 18 | H. B. McCullough | | Oil Operator | Oct 2004 |
| 19 | H. D. McCormick | | Oil & Gas Operator | Jun 2016 |
| 20 | H. E. Sutton | | Oil & Gas Operator | Jan 1990 |
| 21 | H. G. Oil Operator | | Oil Operator | Mar 2001 |
| 22 | H. J. Bonner | | Oil & Gas Operator | Aug 1991 |
| 23 | H. K. Beebe | | Oil Operator | Jan 1990 |
| 24 | H. L. McKee & J. P. McKee Jr. | | Gas Operator | Mar 2023 |
| 25 | H. L. Richey | | Oil & Gas Operator | Sep 1995 |
| 26 | H. Proler-Luffey Gas Corp. | | Gas Operator | Apr 1979 |
| 27 | H.E. Sutton, Et Al | | Oil & Gas Operator | Jan 1990 |
| 28 | H.L.Hawkins &H.L.Hawkins, Jr. | | Oil & Gas Operator | Feb 1989 |
| 29 | Habetz Oilfield Saltwater Ser, Inc | | Oil Operator | Dec 2024 |
| 30 | Hackberry Production, Inc. | | Oil Operator | Mar 1988 |
| 31 | Haddox Petroleum Corp | | Gas Operator | Dec 2010 |
| 32 | Hadson Energy Resources Corp. | Houston, TX 77056 | Oil & Gas Operator | Dec 1994 |
| 33 | Hadson Petroleum (USA), Inc. | | Oil & Gas Operator | Dec 1992 |
| 34 | Haffaday Oil LLC | | Oil Operator | Jan 2025 |
| 35 | Hal Oil & Gas Co., Inc. | | Oil & Gas Operator | Apr 1993 |
| 36 | Haland Operating Company, LLC | | Oil & Gas Operator | Jul 2018 |
| 37 | Halbouty-Reserve | | Oil & Gas Operator | Sep 1987 |
| 38 | Halbouty-Reserve-Pel-Tex | | Oil & Gas Operator | May 1985 |
| 39 | Halcon Louisiana Operating, LP | | Oil & Gas Operator | Sep 2017 |
| 40 | Halcon Resources Operating, Inc. | Tulsa, OK 74135 | Oil & Gas Operator | Dec 2013 |
| 41 | Hale Oil | | Oil & Gas Operator | Dec 2024 |
| 42 | Hale Oil Co. | | Oil & Gas Operator | Jan 2025 |
| 43 | Hall Engineering, Inc. | | Oil & Gas Operator | Jan 2007 |
| 44 | Hall-Hargraves, L.L.C. | | Oil & Gas Operator | Dec 2024 |
| 45 | Hall-Houston Oil Company | Houston, TX 77002 | Oil & Gas Operator | Oct 2002 |
| 46 | Hallador Petroleum Company | | Oil & Gas Operator | Feb 1992 |
| 47 | Hallar Enterprises, Inc. | | Oil Operator | Oct 2007 |
| 48 | Halliburton Operating Company | Plano, TX 75093 | Oil & Gas Operator | Feb 2026 |
| 49 | Hallmark Oil And Gas Co., Inc. | | Oil & Gas Operator | Dec 2024 |
| 50 | Hallwell Gas & Oil Co. | | Oil & Gas Operator | Sep 1985 |
| 51 | Hallwood Petroleum, Inc. | Midland, TX 79701 | Oil & Gas Operator | Jun 2025 |
| 52 | Hallwood Petroleum, LLC | Dallas, TX 75219 | Oil & Gas Operator | Jan 2010 |
| 53 | Hamilton Brothers Oil Co. | Houston, TX 77057 | Oil & Gas Operator | Mar 2015 |
| 54 | Hamilton Gas Co., Inc. | | Gas Operator | Mar 1999 |
| 55 | Hamlin'S Production, Inc. | | Oil & Gas Operator | May 1981 |
| 56 | Hamman Oil & Refining Company | Houston, TX 77098 | Oil & Gas Operator | Feb 2026 |
| 57 | Hamon Oil Company | | Oil & Gas Operator | Aug 1985 |
| 58 | Hamon Operating Company | Dallas, TX 75201 | Oil & Gas Operator | Dec 2011 |
| 59 | Hampton Resources Corporation | Houston, TX 77010 | Oil & Gas Operator | Mar 1996 |
| 60 | Hanover Management Company | | Oil Operator | Aug 1979 |
| 61 | Hansen Oil Corporation | Shreveport, LA 71106 | Oil Operator | Apr 2003 |
| 62 | Hanson Natural Resources Co. | | Oil & Gas Operator | Nov 1991 |
| 63 | Hanvey Production Co., Inc. | Roanoke, TX 76262 | Oil & Gas Operator | Nov 2012 |
| 64 | Harbert Energy Corp | Irving, TX 75015-2510 | Oil & Gas Operator | Feb 1993 |
| 65 | Harbert Energy Corp/Gulf Coast | | Oil & Gas Operator | Dec 1991 |
| 66 | Harbor Operating, LLC | | Oil & Gas Operator | Dec 1999 |
| 67 | Harbor Petroleum, LLC | Granbury, TX 76049 | Oil & Gas Operator | Feb 2026 |
| 68 | Harcor Exploration Inc. | | Oil Operator | Aug 1989 |
| 69 | Hardco Inc | Cleveland, OH 44115 | Oil & Gas Operator | Dec 1992 |
| 70 | Hardey Co., The | Shreveport, LA 71107 | Oil & Gas Operator | Feb 2026 |
| 71 | Hardey Production Company | | Oil Operator | Dec 1998 |
| 72 | Hardy Oil & Gas USA Inc. | Houston, TX 77079 | Oil & Gas Operator | Jun 1996 |
| 73 | Hargraves Daughters | | Oil Operator | Mar 1992 |
| 74 | Hargraves Production, LLC | | Oil Operator | Jan 2025 |
| 75 | Harleton Oil & Gas Inc. | Tyler, TX 75710 | Oil & Gas Operator | Feb 2026 |
| 76 | Harold H. Hollenshead | | Oil & Gas Operator | May 2002 |
| 77 | Harrison & Lee | | Oil Operator | Sep 1996 |
| 78 | Harry L. Neeb | | Oil Operator | May 1985 |
| 79 | Hart & McFarland | Vivian, LA 71082 | Oil & Gas Operator | Feb 2026 |
| 80 | Hartco Oil Co. | | Oil Operator | Jan 2025 |
| 81 | Harter Oil Company | | Oil & Gas Operator | Apr 2011 |
| 82 | Harvard Investments, Inc. | | Oil & Gas Operator | Oct 2002 |
| 83 | Harvest Oil & Gas, LLC | | Oil & Gas Operator | Feb 2012 |
| 84 | Harvest Petroleum Inc. | Frisco, TX 75033 | Oil & Gas Operator | Feb 2026 |
| 85 | Harvey Broyles | | Oil & Gas Operator | May 2012 |
| 86 | Harvey Broyles & Munoco Co. | | Oil & Gas Operator | Jan 2002 |
| 87 | Harvey Broyles, Et Al | | Gas Operator | Nov 1985 |
| 88 | Hassie Hunt Expl. Co. | | Oil & Gas Operator | Aug 2008 |
| 89 | Haw Corporation | | Oil Operator | Dec 1979 |
| 90 | Hawk Oil Co. | Luling, TX 78648 | Oil & Gas Operator | Aug 2003 |
| 91 | Hawkeye Drilling Co. | Waskom, TX 75692 | Oil & Gas Operator | Feb 2023 |
| 92 | Hawkins Oil & Gas Inc | Tulsa, OK 74103 | Oil & Gas Operator | Dec 2016 |
| 93 | Hawthorne Oil And Gas Corp. | Houston, TX 77227 | Oil & Gas Operator | Sep 1993 |
| 94 | Hawthorne-Tipco | | Oil & Gas Operator | Oct 1978 |
| 95 | Hayden Energy Corp. | | Oil & Gas Operator | Apr 1994 |
| 96 | HC Resources, Inc. | | Oil & Gas Operator | Jul 2011 |
| 97 | HCW Exploration, Inc. | | Oil & Gas Operator | Jun 1986 |
| 98 | HDS Production | | Oil Operator | Mar 1998 |
| 99 | Headington Energy Corporation | | Oil & Gas Operator | Aug 1992 |
| 100 | Headington Oil Company | Dallas, TX 75231 | Oil & Gas Operator | Dec 2016 |