| 1901 | Graham Energy LTD | Houston, TX 77024 | Oil & Gas Operator | Mar 1994 |
| 1902 | Graham Expl LTD-DRLG PRNRSHP | | Oil & Gas Operator | Aug 1984 |
| 1903 | Graham Exploration, LTD. | | Oil & Gas Operator | Oct 1993 |
| 1904 | Graham Oil And Gas LTD | Covington, LA 70434-3134 | Oil & Gas Operator | Aug 2013 |
| 1905 | Graham Royalty LTD | Covington, LA 70434 | Oil & Gas Operator | Jul 2007 |
| 1906 | Graham-McCormick Oper. PRTSHP. | | Oil & Gas Operator | Aug 1989 |
| 1907 | Grand Energy, Inc. | Dallas, TX 75248 | Oil & Gas Operator | Oct 2002 |
| 1908 | Grand Gulf Production, L.L.C. | Houston, TX 77002 | Oil & Gas Operator | Dec 1997 |
| 1909 | Grand Operating, Inc. | Addison, TX 75001 | Oil & Gas Operator | Nov 2025 |
| 1910 | Grand Resources Inc | Tulsa, OK 74137 | Oil & Gas Operator | Feb 2026 |
| 1911 | Granja Corporation | | Oil & Gas Operator | Dec 2003 |
| 1912 | Gravel & Troegel-Petrofunds | | Oil & Gas Operator | Mar 1984 |
| 1913 | Gravtro, Inc. | | Oil Operator | Apr 1986 |
| 1914 | Gray Energy Corporation | | Oil & Gas Operator | May 1987 |
| 1915 | Grayrock Corp., The | Dallas, TX 75243 | Oil & Gas Operator | Dec 1999 |
| 1916 | Grease Exploration Incorporated | | Oil & Gas Operator | Dec 2024 |
| 1917 | Great River Oil & Gas Corp. | | Oil & Gas Operator | Sep 1998 |
| 1918 | Great Scott, Inc. | | Oil & Gas Operator | Oct 1993 |
| 1919 | Great Southern - Joe Scates | | Oil Operator | Dec 1979 |
| 1920 | Great Southern Oil &Gas Co Inc | | Oil & Gas Operator | Dec 2004 |
| 1921 | Great Southern-Caddo-Lyons | | Oil & Gas Operator | Sep 1982 |
| 1922 | Great Valley Resources, Inc. | | Oil & Gas Operator | Aug 1992 |
| 1923 | Great West Energy & Expl., Inc. | Addison, TX 75001 | Oil & Gas Operator | Mar 2008 |
| 1924 | Great Yellowstone Corporation | | Oil & Gas Operator | Apr 1993 |
| 1925 | Grecian Gas Company | | Gas Operator | Dec 2002 |
| 1926 | Green Operating | | Oil Operator | Jun 2010 |
| 1927 | Green Production, LLC | | Oil & Gas Operator | Dec 2016 |
| 1928 | Greenbrier Oper. Co. | Dallas, TX 75229 | Oil & Gas Operator | Feb 2001 |
| 1929 | Greenhill Petroleum Corporation | Houston, TX 77077 | Oil & Gas Operator | Jan 1998 |
| 1930 | Greer Energy, Inc. | | Oil Operator | Dec 1996 |
| 1931 | Greka Am Inc | Santa Maria, CA 93454 | Oil & Gas Operator | May 2013 |
| 1932 | Grenadier Energy Partners II,LLC | The Woodlands, TX 77380 | Oil & Gas Operator | Dec 2020 |
| 1933 | Grey Oil Co | Pratt, KS 67124 | Oil & Gas Operator | Sep 2007 |
| 1934 | Greystone Oil & Gas, LLP | Houston, TX 77057 | Oil & Gas Operator | Dec 2015 |
| 1935 | Greystone Operating, Inc. | | Oil & Gas Operator | Nov 2009 |
| 1936 | Greystone Petroleum, LLC | Tulsa, OK 74136 | Oil & Gas Operator | Feb 2026 |
| 1937 | Gribble Oil Company | | Oil & Gas Operator | Jun 1996 |
| 1938 | Griffin & Griffin Expl, LLC | | Oil & Gas Operator | Dec 2025 |
| 1939 | Griffin & Griffin Oil Co Inc | | Oil & Gas Operator | Jun 2001 |
| 1940 | Griffin Energy | | Oil & Gas Operator | May 1991 |
| 1941 | Griffin Operating | | Oil & Gas Operator | Mar 1995 |
| 1942 | Griffin Petroleum Company | Midland, TX 79705 | Oil & Gas Operator | Feb 2026 |
| 1943 | Griffin Southern Corp. | | Oil & Gas Operator | Jun 1983 |
| 1944 | Grigsby Petroleum Inc. | Shreveport, LA 71101 | Oil & Gas Operator | Feb 2026 |
| 1945 | Grigsby-McCord Joint Account | | Oil Operator | Apr 1984 |
| 1946 | Grigsby-McCord Joint Acct Etal | | Oil Operator | Apr 1984 |
| 1947 | Grit Operating, L.L.C. | Shreveport, LA 71101 | Oil & Gas Operator | Nov 2023 |
| 1948 | Grizzly Operating, LLC | Houston, TX 77057 | Oil & Gas Operator | Nov 2025 |
| 1949 | Grogan Field Production, L.L.C. | | Oil Operator | Jan 2025 |
| 1950 | Gruy Management Service Co. | | Oil & Gas Operator | Apr 1982 |
| 1951 | Gruy Petroleum Management Co. | Irving, TX 75014 | Oil & Gas Operator | Nov 2014 |
| 1952 | Grynberg Petroleum Company | Greenwood Vge, CO 80111-3326 | Oil & Gas Operator | Oct 2019 |
| 1953 | Gryphon Exploration Company | Mandeville, LA 70471 | Oil & Gas Operator | Aug 2009 |
| 1954 | GT Energy | | Oil & Gas Operator | Mar 1993 |
| 1955 | Guaranty Energy Corp. | | Oil & Gas Operator | Aug 1990 |
| 1956 | Guardian Oil Company | | Oil & Gas Operator | Aug 1985 |
| 1957 | Guernsey Petroleum Corporation | Atlanta, GA 30318 | Oil & Gas Operator | Nov 1997 |
| 1958 | Guernsey/Rosbottom | | Oil Operator | Apr 1989 |
| 1959 | Guido & Arnold | | Oil & Gas Operator | Feb 1982 |
| 1960 | Guido Energy Co & Guernsey Pet | | Oil Operator | Aug 1991 |
| 1961 | Gulf Coast Crude O&G Co., Inc. | | Oil & Gas Operator | May 1982 |
| 1962 | Gulf Coast Drill. & Expl. Inc. | | Oil & Gas Operator | Nov 1988 |
| 1963 | Gulf Exploration Company, Inc. | | Oil & Gas Operator | Dec 2024 |
| 1964 | Gulf Exploration Corporation | Irving, TX 75062 | Oil & Gas Operator | Feb 2026 |
| 1965 | Gulf Oil Corp. | Denver, CO 80201-0599 | Oil & Gas Operator | Dec 2014 |
| 1966 | Gulf Outlet Resources, L.L.C. | | Oil & Gas Operator | Apr 2008 |
| 1967 | Gulf Production Company, Inc. | | Oil & Gas Operator | Dec 2024 |
| 1968 | Gulf South Minerals, Inc. | | Oil Operator | Nov 1993 |
| 1969 | Gulf South Oil & Gas, Inc. | | Oil & Gas Operator | Feb 1990 |
| 1970 | Gulf South Operators, Inc. | New Orleans, LA 70130 | Oil & Gas Operator | Oct 2015 |
| 1971 | Gulf South Pipeline Company, LLC | | Oil & Gas Operator | Jan 2025 |
| 1972 | Gulf South Pipeline Company, LP | Houston, TX 77001 | Oil & Gas Operator | Dec 2020 |
| 1973 | Gulf States Exploration Co. | | Oil & Gas Operator | Dec 1983 |
| 1974 | Gulf States Pipeline Corp. | | Oil & Gas Operator | May 2003 |
| 1975 | Gulf States Production Company | Houston, TX 77027 | Oil & Gas Operator | Aug 1997 |
| 1976 | Gulf Tech Energy LLC | | Oil & Gas Operator | Dec 2002 |
| 1977 | Gulfland Resources, Inc. | | Oil & Gas Operator | Aug 1996 |
| 1978 | Gulfport Energy Corporation | Oklahoma City, OK 73114-5003 | Oil & Gas Operator | Aug 2025 |
| 1979 | Gulfstream Of Louisiana, Inc. | | Oil & Gas Operator | Jan 1996 |
| 1980 | Gulfstream Petroleum Corp | | Oil & Gas Operator | Feb 2002 |
| 1981 | Gulfstream Resources, Inc. | | Oil & Gas Operator | May 1996 |
| 1982 | Guynes And Backus | | Oil Operator | Nov 1999 |
| 1983 | Gyb-Britlind Oil, LLC | | Oil & Gas Operator | Jun 2016 |
| 1984 | H & B Production | | Oil Operator | Mar 1995 |
| 1985 | H & B Well Service, Inc. | | Oil & Gas Operator | Aug 1993 |
| 1986 | H & H & S Oil Producers | | Oil Operator | Jan 2025 |
| 1987 | H & H Compressors, Inc. | | Oil & Gas Operator | Oct 1997 |
| 1988 | H & H Oil Co. #1 | | Oil Operator | Jan 2025 |
| 1989 | H & H Oil Company | | Oil & Gas Operator | Sep 2025 |
| 1990 | H & H Oil Producers | | Oil & Gas Operator | Jan 2025 |
| 1991 | H & H Production Company | Muenster, TX 76252 | Oil & Gas Operator | Oct 2005 |
| 1992 | H & N Operating Co., Inc. | | Oil & Gas Operator | Oct 1997 |
| 1993 | H & S Operating Company Inc | Winesburg, OH 44690 | Oil & Gas Operator | Dec 2024 |
| 1994 | H E C I Exploration Company | | Oil & Gas Operator | Dec 1990 |
| 1995 | H H H Oil Company | | Oil Operator | Jan 2025 |
| 1996 | H L Brown Jr | Midland, TX 79702 | Oil & Gas Operator | May 2001 |
| 1997 | H M Jarred & Walsh-Watts | | Oil & Gas Operator | Sep 1992 |
| 1998 | H&S Production, LLC | | Oil Operator | Nov 2024 |
| 1999 | H. & H. Development Co. | | Gas Operator | Aug 2019 |
| 2000 | H. A. Harper | | Oil Operator | Dec 1982 |