| 1 | Genesis Producing Company | Houston, TX 77024 | Oil & Gas Operator | Oct 2007 |
| 2 | Geodominion Petroleum | Corpus Chrsti, TX 78403 | Oil & Gas Operator | May 2012 |
| 3 | Geodyne Operating Company | Tulsa, OK 74103 | Oil & Gas Operator | Jun 2015 |
| 4 | Glenn, Wayne E. & Assoc., Inc. | Dickinson, TX 77539 | Oil & Gas Operator | Jun 2005 |
| 5 | GMT Inc. | Houston, TX 77042 | Oil & Gas Operator | Jan 2003 |
| 6 | Goldking Prod. Co. | Houston, TX 77002 | Oil & Gas Operator | Apr 1998 |
| 7 | Graham Royalty LTD | Covington, LA 70434 | Oil & Gas Operator | Jul 2007 |
| 8 | Graward Operating, Inc. | Tyler, TX 75702 | Oil & Gas Operator | Oct 2025 |
| 9 | Great Bay Operations, LLC | Portsmouth, NH 03801 | Oil & Gas Operator | Nov 2016 |
| 10 | Great Western Onshore Inc | Houston, TX 77002 | Oil & Gas Operator | Mar 2008 |
| 11 | Greehey & Company, LTD. | San Antonio, TX 78216 | Oil & Gas Operator | May 2020 |
| 12 | Green Exploration Company | Austin, TX 78711 | Oil & Gas Operator | Oct 2025 |
| 13 | Greenbrier Oper. Co. | Dallas, TX 75229 | Oil & Gas Operator | Feb 2001 |
| 14 | GWM Operating Company, LLC | Sugar Land, TX 77479 | Oil & Gas Operator | Oct 2025 |