| 12001 | H & L Operators | | Oil & Gas Operator | Dec 2002 |
| 12002 | H & L Oprerating Company LLP | Amarillo, TX 79114 | Oil & Gas Operator | Nov 2019 |
| 12003 | H & M Oil Producers | Littleton, CO 80160 | Oil & Gas Operator | Apr 2000 |
| 12004 | H & M Packers Serv. L.L.C. | | Oil Operator | Dec 2019 |
| 12005 | H & M Petroleum Corporation | Lincoln, NE 68516 | Oil & Gas Operator | Jun 2025 |
| 12006 | H & M Productions L.L.C. | Overland Park, KS 66210 | Oil Operator | May 1998 |
| 12007 | H & M Resources LLC | Dallas, TX 75225 | Oil & Gas Operator | May 2026 |
| 12008 | H & N Operating Co. Inc. | | Oil & Gas Operator | Oct 1997 |
| 12009 | H & O Oil Co. | | Oil & Gas Operator | Dec 1989 |
| 12010 | H & O Operating Co | Odessa, TX 79764 | Oil & Gas Operator | Mar 2008 |
| 12011 | H & P Exploration Co. | Alice, TX 78333 | Oil & Gas Operator | May 2019 |
| 12012 | H & P Partnership | La Vernia, TX 78121 | Oil Operator | May 2026 |
| 12013 | H & R Expl & Production Inc | Sidney, NE 69162 | Oil Operator | May 2007 |
| 12014 | H & R Exploratio | | Oil Operator | Feb 1992 |
| 12015 | H & R Oil Company | | Oil & Gas Operator | Dec 2000 |
| 12016 | H & R Well Services, Inc. | FT Morgan, CO 80701 | Oil & Gas Operator | Apr 2015 |
| 12017 | H & S Drilling Co Inc | Frazeysburg, OH 43822 | Oil & Gas Operator | Dec 2016 |
| 12018 | H & S Investments LLC | Fairview, PA 16415-1807 | Oil & Gas Operator | Dec 2025 |
| 12019 | H & S Oil Co., LLC | Cherryvale, KS 67335 | Oil Operator | Oct 2024 |
| 12020 | H & S Oil LLC | Roswell, NM 882022387 | Oil & Gas Operator | Jul 2013 |
| 12021 | H & S Operating Company Inc | Winesburg, OH 44690 | Oil & Gas Operator | Dec 2025 |
| 12022 | H & S Production | Farmington, NM 87401 | Oil Operator | Dec 2007 |
| 12023 | H & S Production, Inc. | Dallas, TX 75252 | Oil & Gas Operator | Mar 2004 |
| 12024 | H & T Brock Oil Company LLC | Comanche, OK 73529-7140 | Oil & Gas Operator | Feb 2024 |
| 12025 | H & T Disposal | Abilene, TX 79608 | Oil Operator | Apr 2003 |
| 12026 | H & T Exploration, Inc. | Longview, TX 75605 | Oil & Gas Operator | May 2026 |
| 12027 | H & T Oil & Gas Company, Inc. | Alice, TX 78333 | Oil & Gas Operator | Mar 2008 |
| 12028 | H & W Drilling Inc | Racine, OH 45769 | Oil & Gas Operator | Dec 2023 |
| 12029 | H & W Energy | Youngstown, OH 44512 | Oil & Gas Operator | Dec 2015 |
| 12030 | H & W Oil | Electra, TX 76360 | Oil & Gas Operator | Mar 2008 |
| 12031 | H & W Oil Company, Incorporated | Palm Desert, CA 92255 | Oil Operator | Nov 2017 |
| 12032 | H & W Oil Corpor | | Oil Operator | Dec 1996 |
| 12033 | H - A Energy, Inc. | Midland, TX 79704 | Oil & Gas Operator | May 2026 |
| 12034 | H A L Petroleum | | Oil Operator | Oct 1987 |
| 12035 | H And H | Gonzales, TX 78629 | Oil Operator | Feb 1999 |
| 12036 | H And H Star Energy Inc Dba Petrostar Energy | | Oil & Gas Operator | Feb 2004 |
| 12037 | H And K Resources Inc | | Oil Operator | Dec 2012 |
| 12038 | H B Oil & Gas Inc | Oklahoma City, OK 73159 | Oil & Gas Operator | Jun 2000 |
| 12039 | H C M Energy LLC | Billings, MT 59102 | Oil Operator | Jul 2003 |
| 12040 | H D Oil Company | Thermopolis, WY 82443 | Oil Operator | Feb 2026 |
| 12041 | H E C H Corporation | Ada, OK 74820-9528 | Oil Operator | Sep 2019 |
| 12042 | H E C I Exploration Company | | Oil & Gas Operator | Dec 1990 |
| 12043 | H F Production Co., LTD. | Wichita Falls, TX 76309 | Oil Operator | Feb 2020 |
| 12044 | H G & G Inc | Edmond, OK 73034 | Oil & Gas Operator | Jan 2006 |
| 12045 | H G H Oil Company | | Oil Operator | Dec 1990 |
| 12046 | H H Exploration, Inc. | Incline VLLG, NV 89451 | Gas Operator | Feb 2018 |
| 12047 | H H H Oil Company | | Oil Operator | Jan 2025 |
| 12048 | H I Smith Oil & Gas Inc | Holmesville, OH 44633 | Oil & Gas Operator | Dec 2024 |
| 12049 | H K A Enterprises Inc | Kettle, KY 42717 | Oil Operator | Dec 2021 |
| 12050 | H K Keesee And C J Keesee Trust | Aztec, NM 87410 | Gas Operator | Feb 2026 |
| 12051 | H L Altier Service Co Inc | Canton, OH 44718-3752 | Oil & Gas Operator | Dec 2013 |
| 12052 | H L Brown Jr | Midland, TX 79702 | Oil & Gas Operator | May 2001 |
| 12053 | H L Brown Operating LLC | Midland, TX 79702 | Oil & Gas Operator | Dec 2025 |
| 12054 | H L L Inc | Scottsdale, AZ 85251 | Oil & Gas Operator | Jan 2007 |
| 12055 | H M Jarred & Walsh-Watts | | Oil & Gas Operator | Sep 1992 |
| 12056 | H Oil Company, Inc. | Edna, TX 77957 | Oil & Gas Operator | Mar 2005 |
| 12057 | H P S Investments | Graham, TX 76450 | Oil & Gas Operator | Mar 2008 |
| 12058 | H R Collier Collier Oil & Gas | | Oil & Gas Operator | Feb 2026 |
| 12059 | H R E Rental Company | Premont, TX 78375 | Oil & Gas Operator | Sep 2015 |
| 12060 | H R F Antrim LP | | Gas Operator | Jan 2026 |
| 12061 | H&G Petroleum Corporation | Midland, TX 79710 | Oil & Gas Operator | May 2026 |
| 12062 | H&K Energy | Stockdale, TX 78160 | Oil & Gas Operator | Jul 2005 |
| 12063 | H&M Production, Inc. | New Braunfels, TX 78132 | Oil & Gas Operator | Aug 2012 |
| 12064 | H&P Oil & Gas LLC | Mertzon, TX 76941 | Oil & Gas Operator | May 2026 |
| 12065 | H&P Operating | Megargel, TX 76370 | Oil & Gas Operator | Jan 2015 |
| 12066 | H&S Production, LLC | | Oil Operator | Nov 2024 |
| 12067 | H-30 Incorporate | | Oil & Gas Operator | Nov 1990 |
| 12068 | H-30, Inc. | Wichita, KS 67202 | Gas Operator | Oct 2006 |
| 12069 | H-40 Drilling, Inc. | Medicine Lodge, KS 67104 | Gas Operator | Nov 2025 |
| 12070 | H-5 Service | Plainville, KS 67663 | Oil Operator | May 1989 |
| 12071 | H-D Oilfield Service, Inc. | Bazine, KS 67516 | Oil Operator | Dec 2025 |
| 12072 | H-D Operating Services L.L.C. | Pampa, TX 79065 | Oil Operator | May 2026 |
| 12073 | H-M Resource Management, Inc. | Houston, TX 77055 | Oil & Gas Operator | Feb 2023 |
| 12074 | H-Petro-R Inc | Edmond, OK 73013 | Oil & Gas Operator | Jan 2026 |
| 12075 | H-S Exploration | Gunnison, CO 81230 | Oil & Gas Operator | May 2026 |
| 12076 | H-Two-O Investments | Iowa Park, TX 76367 | Oil Operator | Sep 2019 |
| 12077 | H. & H. Development Co. | | Gas Operator | Aug 2019 |
| 12078 | H. & J. Drilling Company | River Oaks, TX 76114 | Oil & Gas Operator | Aug 2003 |
| 12079 | H. & L. Oil Company | Midland, TX 79707 | Oil & Gas Operator | Mar 2005 |
| 12080 | H. A. Harper | | Oil Operator | Dec 1982 |
| 12081 | H. B. McCullough | | Oil Operator | Oct 2004 |
| 12082 | H. Bryan Poff, LLC | Cedar Park, TX 78613 | Oil & Gas Operator | Oct 2018 |
| 12083 | H. C. Oil Co. | Weatherford, TX 76085 | Oil & Gas Operator | May 2026 |
| 12084 | H. D. Investments | Breckenridge, TX 76424 | Oil & Gas Operator | Mar 2025 |
| 12085 | H. D. McCormick | | Oil & Gas Operator | Jun 2016 |
| 12086 | H. E. Sutton | | Oil & Gas Operator | Jan 1990 |
| 12087 | H. G. Oil Operator | | Oil Operator | Mar 2001 |
| 12088 | H. H. Blair Oil Company, Inc. | Atlanta, KS 67008 | Oil Operator | Dec 2009 |
| 12089 | H. I. M. Producers | Graham, TX 76450 | Oil & Gas Operator | May 1999 |
| 12090 | H. I., Inc. | Liberal, KS 67901 | Oil & Gas Operator | Feb 2012 |
| 12091 | H. J. Bonner | | Oil & Gas Operator | Aug 1991 |
| 12092 | H. K. Beebe | | Oil Operator | Jan 1990 |
| 12093 | H. L. Hunt | | Oil & Gas Operator | Jun 1980 |
| 12094 | H. L. McKee & J. P. McKee Jr. | | Gas Operator | Mar 2023 |
| 12095 | H. L. Richey | | Oil & Gas Operator | Sep 1995 |
| 12096 | H. O. Strickler Operator | | Oil & Gas Operator | Dec 1993 |
| 12097 | H. Olsen & Sons Contractors, Inc. | Forestville, NY 14062 | Gas Operator | Dec 2024 |
| 12098 | H. Proler-Luffey Gas Corp. | | Gas Operator | Apr 1979 |
| 12099 | H. T. Hilliard & Co. | | Oil & Gas Operator | Dec 1999 |
| 12100 | H. W. Reynolds Jr. | | Gas Operator | Dec 1984 |