| 1 | H & H Star Energy Inc | Traverse City, MI 49684 | Oil & Gas Operator | Aug 2016 |
| 2 | H2ox Operating LLC | | Oil Operator | Feb 2024 |
| 3 | Hadson Petro USA Inc | | Oil & Gas Operator | Nov 2016 |
| 4 | Halcon Holdings Inc | Ada, OK 74820 | Oil & Gas Operator | Nov 2018 |
| 5 | Halcyon Natural Gas LLC | Oklahoma City, OK 73116-9111 | Oil & Gas Operator | Feb 2024 |
| 6 | Halliburton Oil Producing Co. | Duncan, OK 73534 | Oil & Gas Operator | Apr 2016 |
| 7 | Ham Oil Company, LLC | | Oil Operator | Sep 2022 |
| 8 | Harbor Resources LLC | Oklahoma City, OK 73120 | Oil & Gas Operator | Apr 2024 |
| 9 | Harding & Shelton Inc | Oklahoma City, OK 73104-2410 | Oil & Gas Operator | Jan 2024 |
| 10 | Harrell Verlan W | Oklahoma City, OK 73102-7201 | Oil & Gas Operator | Nov 1999 |
| 11 | Harris Minerals Corp (The) | Oklahoma City, OK 73162-1045 | Oil & Gas Operator | Jan 2024 |
| 12 | Hawkins Oil & Gas Inc | Tulsa, OK 74103 | Oil & Gas Operator | Dec 2016 |
| 13 | Headington Oil Company | Dallas, TX 75231 | Oil & Gas Operator | Dec 2016 |
| 14 | Heartlands Development Co Inc | Bristow, OK 74010-3826 | Oil & Gas Operator | May 2017 |
| 15 | Helmerich & Payne, Inc. | Tulsa, OK 74114 | Oil & Gas Operator | Jan 2024 |
| 16 | Hep Oil Company LTD | Gainesville, TX 76240 | Oil & Gas Operator | Mar 2012 |
| 17 | Hep Oil GP, LLC | Gainesville, TX 76241 | Oil & Gas Operator | Mar 2015 |
| 18 | Hess Corporation | Houston, TX 77010 | Oil & Gas Operator | Aug 2017 |
| 19 | High Sierra Crude Oil& Marketing LLC | Ardmore, OK 73401 | Oil Operator | Nov 2013 |
| 20 | High Sierra Water Services Mid Continent LLC | Denver, CO 80209 | Oil Operator | Feb 2010 |
| 21 | Highland Energy Co | Dallas, TX 75201 | Oil & Gas Operator | Jun 1994 |
| 22 | Highland Oil & Gas LLC | Houston, TX 77079-7220 | Oil & Gas Operator | Feb 2015 |
| 23 | Hilliard Oil & Gas Inc | New Orleans, LA 70112 | Oil & Gas Operator | May 2001 |
| 24 | Hillin-Simon Oil Company | Houston, TX 77079 | Oil & Gas Operator | Mar 2013 |
| 25 | HK Energy Operating, LLC | Houston, TX 77002 | Oil & Gas Operator | May 2023 |
| 26 | Hodgden Operating Co., Inc. | Enid, OK 73702 | Oil & Gas Operator | Feb 2024 |
| 27 | Home Petroleum Corp | Victoria, TX 77902 | Oil & Gas Operator | Apr 2024 |
| 28 | Home-Stake Royalty Corp., The | Tulsa, OK 74103 | Oil & Gas Operator | Feb 2014 |
| 29 | Hondo Oil & Gas Company | Roswell, NM 88202 | Oil & Gas Operator | Aug 2006 |
| 30 | Horizon Natural Gas Company | Tulsa, OK 74170 | Oil & Gas Operator | Jan 2024 |
| 31 | Horizon Natural Resources, Inc. | Tulsa, OK 74136 | Oil & Gas Operator | Jan 2019 |
| 32 | Horizon Oil & Gas Co. | Dallas, TX 75221 | Oil & Gas Operator | Jan 2005 |
| 33 | Hull Oil Co. | Wichita Falls, TX 76308 | Oil & Gas Operator | Sep 2021 |
| 34 | Hulsey Larry O & Co | Graham, TX 76046 | Oil & Gas Operator | Jun 2012 |
| 35 | Hunt Oil Company | Dallas, TX 75201 | Oil & Gas Operator | Apr 2024 |
| 36 | Hunt, H L | Dallas, TX 75202-2785 | Oil & Gas Operator | Feb 2020 |
| 37 | Huntington Energy LLC | Oklahoma City, OK 73116 | Oil & Gas Operator | Apr 2024 |
| 38 | Hy-Carb Energy Inc | | Oil & Gas Operator | Feb 2009 |