| 3001 | Metro Energy Group, Inc. | Bossier City, LA 71112 | Oil & Gas Operator | May 2013 |
| 3002 | Mettz,Carmody & Foster Oil Co | | Oil Operator | May 1990 |
| 3003 | Meyers-Lasher, Inc. | | Oil & Gas Operator | Mar 1999 |
| 3004 | MFP Petroleum LTD. Partnership | Oklahoma City, OK 73142 | Oil & Gas Operator | Nov 2017 |
| 3005 | MGF Oil Corporation | Tulsa, OK 74121 | Oil & Gas Operator | Jun 1998 |
| 3006 | Mich-La Oil & Gas Exploration | | Oil & Gas Operator | Jan 1992 |
| 3007 | Michael D Brown | | Oil Operator | Jul 1993 |
| 3008 | Michael W Mills | | Oil Operator | Jul 2007 |
| 3009 | Michel T. Halbouty | | Oil & Gas Operator | Dec 1996 |
| 3010 | Michel T. Halbouty Energy Co. | | Oil & Gas Operator | Nov 1986 |
| 3011 | Michigan-Wisconsin Pipe Line Co | | Oil & Gas Operator | Dec 1983 |
| 3012 | Micron Minerals Company | | Oil & Gas Operator | Sep 1988 |
| 3013 | Mid Field Oil Co. | | Oil & Gas Operator | Mar 1989 |
| 3014 | Mid Louisiana Gas Company | | Oil & Gas Operator | Oct 2002 |
| 3015 | Mid South Oil & Gas Expl Inc | | Oil & Gas Operator | Jan 1992 |
| 3016 | Mid-America Resources Corporation | | Oil Operator | Jan 2019 |
| 3017 | Mid-America Resources, Inc. | | Oil & Gas Operator | Feb 2008 |
| 3018 | Mid-America/Hughes & Hughes | | Oil Operator | Jul 1984 |
| 3019 | Mid-Con Energy Operating, Inc. | Tulsa, OK 74136 | Oil & Gas Operator | May 2020 |
| 3020 | Mid-Con Energy Operating, LLC | Tulsa, OK 74136 | Oil & Gas Operator | Feb 2025 |
| 3021 | Mid-Continent Energy Operating | | Gas Operator | Aug 2007 |
| 3022 | Mid-Continent Energy, Inc. | Tulsa, OK 74103 | Oil & Gas Operator | Apr 2020 |
| 3023 | Mid-National Resources Inc. | | Oil Operator | Feb 1999 |
| 3024 | Mid-South Trading, Inc. | | Oil & Gas Operator | Jan 2025 |
| 3025 | Middle Bay Oil Company, Inc. | Houston, TX 77002 | Oil & Gas Operator | Apr 1998 |
| 3026 | Middle Bay Production Co. Inc. | Houston, TX 77010 | Oil & Gas Operator | Sep 2014 |
| 3027 | Mideast Gas Systems, Inc. | Midland, TX 79702 | Oil & Gas Operator | Dec 2005 |
| 3028 | Midla, LTD. | | Oil & Gas Operator | Jun 1990 |
| 3029 | Midland Workover, Inc. | | Oil & Gas Operator | Dec 2024 |
| 3030 | Midnight Drilling LLC | | Oil & Gas Operator | Jan 2016 |
| 3031 | Midroc Operating Company | | Oil & Gas Operator | Apr 2013 |
| 3032 | Midstates Oil Company | Oklahoma City, OK 73112 | Oil & Gas Operator | Nov 2000 |
| 3033 | Midstates Petroleum Company LLC | Tulsa, OK 74103 | Oil & Gas Operator | May 2018 |
| 3034 | Midstates Petroleum Corp. | | Oil & Gas Operator | Dec 2008 |
| 3035 | Midway Production Co. | | Gas Operator | May 1990 |
| 3036 | Midway Testing Company Inc | | Gas Operator | Mar 1984 |
| 3037 | Midwest Energy Companies, Inc. | | Oil & Gas Operator | Feb 1998 |
| 3038 | Midwest Enterprises, Inc. | Cashion, OK 73016-9626 | Oil & Gas Operator | Oct 2024 |
| 3039 | Mike Bonner | | Oil Operator | Aug 1999 |
| 3040 | Mil-Cro Inc. | | Oil Operator | Jan 1994 |
| 3041 | Milagro Exploration, LLC | Houston, TX 77010 | Oil & Gas Operator | Aug 2018 |
| 3042 | Miles Oil & Gas Co. | | Oil & Gas Operator | Feb 1988 |
| 3043 | Millennium Offshore Group, Inc. | Houston, TX 77007 | Oil & Gas Operator | Sep 2005 |
| 3044 | Miller Exploration Company | Tulsa, OK 74136-1020 | Oil & Gas Operator | Mar 2015 |
| 3045 | Miller Oil Field Services, Inc | | Oil Operator | Feb 1990 |
| 3046 | Miller S.W.D., Inc. | | Oil Operator | Oct 2002 |
| 3047 | Milton Crow,Inc.&RP Evans Etal | | Oil & Gas Operator | Aug 1988 |
| 3048 | Milton Galoob | | Oil Operator | Dec 1988 |
| 3049 | Minatome Corpora | | Oil & Gas Operator | Sep 1987 |
| 3050 | Minden Oil & Gas, Inc. | | Oil & Gas Operator | May 1985 |
| 3051 | Mineral Development, Inc. | Dallas, TX 75231 | Oil & Gas Operator | Aug 1996 |
| 3052 | Mineral Ventures, Inc. | | Oil & Gas Operator | Dec 2024 |
| 3053 | Minerex Engineering Corp. | | Oil & Gas Operator | Mar 2004 |
| 3054 | Miocene Oil & Gas, LTD. | Englewood, CO 80110 | Oil & Gas Operator | Mar 2025 |
| 3055 | Miss Chub LLC | | Gas Operator | Dec 2024 |
| 3056 | Miss Lou Oil Producers, Inc. | | Oil & Gas Operator | Dec 1998 |
| 3057 | Miss-Lou Operating, LLC | | Oil & Gas Operator | Dec 2024 |
| 3058 | Miss-Lou Petroleum LLC | | Oil & Gas Operator | Jun 2011 |
| 3059 | Mission Energy Inc. | Midland, TX 79702 | Oil & Gas Operator | Mar 2025 |
| 3060 | Mission Exploration, Inc. | Tolar, TX 76476 | Oil & Gas Operator | Dec 1987 |
| 3061 | Mission Resources Corporation | Houston, TX 77002 | Oil & Gas Operator | Mar 2008 |
| 3062 | Mission River Systems, Inc. | Corpus Chrsti, TX 78473 | Oil & Gas Operator | Mar 2025 |
| 3063 | Mississippi River Transm. Corp | | Oil & Gas Operator | Sep 2002 |
| 3064 | Mississippi Ventures | | Gas Operator | Feb 1992 |
| 3065 | Mitchell Energy & Goodrich Oil | | Oil & Gas Operator | Feb 1985 |
| 3066 | Mitchell Energy Company L.P. | Spring, TX 77387 | Oil & Gas Operator | Mar 2008 |
| 3067 | Mitchell Energy Corp | Houston, TX 77002 | Oil & Gas Operator | Aug 2013 |
| 3068 | MJ Energy, LLC | Denver, CO 80206 | Oil Operator | Jan 2025 |
| 3069 | MJ Energy, LLC Of Arkansas | | Oil Operator | Jan 2025 |
| 3070 | MJB Production Company, Inc. | Brownfield, TX 79316 | Oil & Gas Operator | Mar 2025 |
| 3071 | ML Resources, Inc. | Dallas, TX 75240 | Oil & Gas Operator | Mar 2008 |
| 3072 | MLGW | | Gas Operator | Sep 1984 |
| 3073 | Mobil E&P N.A.-Pel-Tex | | Oil & Gas Operator | Dec 1993 |
| 3074 | Mobil E&P N.A.-WM Scully Et Al | | Oil & Gas Operator | Dec 1993 |
| 3075 | Mobil E&P North America Inc. | | Oil & Gas Operator | Jan 1994 |
| 3076 | Mobil Oil E & P Southeast Inc | | Oil & Gas Operator | Sep 2013 |
| 3077 | Mobil Oil E&P Se Inc - Pel-Tex | | Oil & Gas Operator | Dec 2005 |
| 3078 | Mobley & Davis | | Oil & Gas Operator | Oct 1986 |
| 3079 | Mobley & McCain | | Oil & Gas Operator | Nov 1979 |
| 3080 | Mobley & McCain, Et Al | | Oil & Gas Operator | Jul 1986 |
| 3081 | Mobley Oil Company, Inc. | | Oil & Gas Operator | Feb 1990 |
| 3082 | Mobley Valve Service, Inc. | | Oil & Gas Operator | Nov 2006 |
| 3083 | Moco Operating Company | | Oil & Gas Operator | Mar 2002 |
| 3084 | Mole Operating Co., Inc. | | Oil & Gas Operator | Oct 1983 |
| 3085 | Monarch Petroleum Corporation | FT Worth, TX 76102 | Oil & Gas Operator | Dec 2019 |
| 3086 | Monex | | Oil Operator | Apr 1988 |
| 3087 | Monexco, Inc. | | Oil Operator | Dec 2003 |
| 3088 | Mongrue Oil Company, Inc. | | Oil & Gas Operator | Oct 1999 |
| 3089 | Mongrue, Roland, Inc | | Oil & Gas Operator | Mar 1979 |
| 3090 | Monroe Gas Associates-1 | | Gas Operator | Mar 2000 |
| 3091 | Monroe Gas Associates-2 | | Gas Operator | Mar 2000 |
| 3092 | Monroe Gas Joint Venture | | Gas Operator | Sep 2011 |
| 3093 | Monroe Well Ser-Amsterdam | | Oil Operator | Dec 1988 |
| 3094 | Monroe Well Ser-La Petr Assoc | | Oil Operator | Dec 1988 |
| 3095 | Monroe Well Ser-La Petro II | | Oil Operator | Dec 1988 |
| 3096 | Monroe Well Ser-New American85 | | Oil Operator | Dec 1988 |
| 3097 | Monroe Well Ser-Ocean Petr '84 | | Oil & Gas Operator | Dec 1988 |
| 3098 | Monroe Well Ser-Ocean Yacht II | | Oil Operator | May 1989 |
| 3099 | Monroe Well Ser-Oceanyacht1985 | | Oil Operator | Dec 1988 |
| 3100 | Monroe Well Ser-Riverside 1985 | | Oil Operator | Dec 1988 |