| 1 | Gary-Williams Production Company | Denver, CO 80202 | Oil & Gas Operator | May 2000 |
| 2 | General American Oil Co Of TX | | Oil & Gas Operator | Jun 1983 |
| 3 | General Producing Company | Houston, TX 77002 | Oil & Gas Operator | Jun 1993 |
| 4 | Geodyne Operating Company | Tulsa, OK 74103 | Oil & Gas Operator | Jun 2015 |
| 5 | Geodyne Resources Inc. | Tulsa, OK 74103 | Oil & Gas Operator | Jul 2010 |
| 6 | George D. Hartfield Oil & Gas, Inc. | | Oil & Gas Operator | Dec 2024 |
| 7 | Getty Oil Company | Hays, KS 67601 | Oil & Gas Operator | Mar 2015 |
| 8 | Getty Reserve Oil, Inc. | White Plains, NY 10650 | Oil & Gas Operator | Mar 2005 |
| 9 | Goldking Operating Company, Inc. | Houston, TX 77002 | Oil & Gas Operator | Jun 2007 |
| 10 | Goldking Prod. Co. | Houston, TX 77002 | Oil & Gas Operator | Apr 1998 |
| 11 | Goodrich Petroleum Company | Houston, TX 77002 | Oil & Gas Operator | Feb 2022 |
| 12 | Grace Petroleum Corp. | Tulsa, OK 74103 | Oil & Gas Operator | Oct 1997 |
| 13 | Graham Energy LTD | Houston, TX 77024 | Oil & Gas Operator | Mar 1994 |
| 14 | Graham Exploration, LTD. | | Oil & Gas Operator | Oct 1993 |
| 15 | Graham Royalty LTD | Covington, LA 70434 | Oil & Gas Operator | Jul 2007 |
| 16 | Graham-McCormick Oper. PRTSHP. | | Oil & Gas Operator | Aug 1989 |
| 17 | Grease Exploration Incorporated | | Oil & Gas Operator | Dec 2024 |
| 18 | Grigsby Petroleum Inc. | Shreveport, LA 71101 | Oil & Gas Operator | Oct 2025 |
| 19 | Gruy Petroleum Management Co. | Irving, TX 75014 | Oil & Gas Operator | Nov 2014 |
| 20 | Gulf Exploration Company, Inc. | | Oil & Gas Operator | Dec 2024 |
| 21 | Gulf Oil Corp. | Denver, CO 80201-0599 | Oil & Gas Operator | Dec 2014 |
| 22 | Gulf Production Company, Inc. | | Oil & Gas Operator | Dec 2024 |
| 23 | Gulf South Operators, Inc. | New Orleans, LA 70130 | Oil & Gas Operator | Oct 2015 |
| 24 | Gulf South Pipeline Company, LLC | | Oil & Gas Operator | Jan 2025 |
| 25 | Gulf South Pipeline Company, LP | Houston, TX 77001 | Oil & Gas Operator | Dec 2020 |
| 26 | Gulfport Energy Corporation | Oklahoma City, OK 73114-5003 | Oil & Gas Operator | Feb 2025 |