| 2001 | CDC Operating Company | Dallas, TX 75218 | Oil & Gas Operator | Oct 2025 |
| 2002 | CDJ Oil Co. | Albany, TX 76430 | Oil & Gas Operator | Oct 2025 |
| 2003 | CDX Gas, LLC | The Woodlands, TX 77380 | Oil & Gas Operator | Oct 2009 |
| 2004 | Cedar Bend Oil Company | Colorado City, TX 79512 | Oil & Gas Operator | Oct 2025 |
| 2005 | Cedar Oil Company | Midland, TX 79707 | Oil & Gas Operator | Oct 2025 |
| 2006 | Cedar Point Oil Company | Baytown, TX 77520 | Oil & Gas Operator | Aug 2003 |
| 2007 | Cedar Ridge Energy, Inc. | Coleman, TX 76834 | Oil & Gas Operator | Oct 2025 |
| 2008 | Cedyco Corporation | Houston, TX 77227 | Oil & Gas Operator | Nov 2008 |
| 2009 | Cegx Of Texas LLC | Eastland, TX 76448 | Oil Operator | Mar 2018 |
| 2010 | Cei Operating LLC | Katy, TX 77449 | Oil & Gas Operator | Oct 2025 |
| 2011 | Cei Production Company | Dallas, TX 75225 | Oil & Gas Operator | Sep 1998 |
| 2012 | Ceja Corporation | Tulsa, OK 74172 | Oil & Gas Operator | Jul 2025 |
| 2013 | Celero Energy II, LP | Midland, TX 79701 | Oil & Gas Operator | Oct 2025 |
| 2014 | Celero Energy LP | Midland, TX 79701 | Oil & Gas Operator | May 2011 |
| 2015 | Cemco Oil | Corsicana, TX 75110 | Oil & Gas Operator | Oct 2025 |
| 2016 | Ceniza Petroleum, Inc. | Portland, TX 78374 | Oil & Gas Operator | Oct 2025 |
| 2017 | Centaur Exploration LLC | Evanston, WY 82931 | Oil & Gas Operator | Oct 2025 |
| 2018 | Centaur Petroleum Corporation | Fort Worth, TX 76101 | Oil & Gas Operator | Oct 2025 |
| 2019 | Centennial Energy Corp. | Big Lake, TX 76932 | Oil & Gas Operator | Jan 1997 |
| 2020 | Centennial Resource Prod, LLC | Denver, CO 80202 | Oil & Gas Operator | Aug 2023 |
| 2021 | Center Start, LC | Kilgore, TX 75663 | Oil & Gas Operator | May 2008 |
| 2022 | Centerfire Resources | Springerville, AZ 85938 | Oil & Gas Operator | Oct 2025 |
| 2023 | Centex Energy, LLC | Bryan, TX 77802 | Oil & Gas Operator | Oct 2025 |
| 2024 | Centex Pipe & Equipment, Inc. | Luling, TX 78648 | Oil & Gas Operator | Oct 2025 |
| 2025 | Central Basin Oil Inv. Inc. | Southlake, TX 76092 | Oil & Gas Operator | Oct 2025 |
| 2026 | Central Crude Corp. | Wichita, KS 67206 | Oil Operator | Mar 2014 |
| 2027 | Central Drilling Company, USA | Midland, TX 79710 | Oil & Gas Operator | May 2006 |
| 2028 | Central Energy Producing Company | San Antonio, TX 78217 | Oil & Gas Operator | Sep 2003 |
| 2029 | Central Gulf Petroleum Inc | The Woodlands, TX 77380 | Oil & Gas Operator | Oct 2025 |
| 2030 | Central Mineral Operating Co,Inc | San Antonio, TX 78216 | Oil & Gas Operator | Apr 1997 |
| 2031 | Central Plains Oil&Gas Corp. (A) | Bryan, TX 77802 | Oil & Gas Operator | Mar 2003 |
| 2032 | Central Resources Inc | Denver, CO 80203 | Oil & Gas Operator | Dec 2019 |
| 2033 | Central Texas Operating, Inc. | Breckenridge, TX 76424 | Oil & Gas Operator | Oct 2025 |
| 2034 | Centurion Exploration Company | Houston, TX 77042 | Oil & Gas Operator | May 2009 |
| 2035 | Centurion Gas Corporation | Midland, TX 79702 | Oil & Gas Operator | Jul 2009 |
| 2036 | Centurion Oil & Gas Op. Co. Inc. | Wichita Falls, TX 76301 | Oil & Gas Operator | Dec 1998 |
| 2037 | Centurion Operating Corporation | Rockwall, TX 75087 | Oil & Gas Operator | Oct 2025 |
| 2038 | Centurion Resources LLC | Tulsa, OK 74136 | Oil & Gas Operator | Mar 2015 |
| 2039 | Century Assets Corporation | Houston, TX 77056 | Oil Operator | Oct 2025 |
| 2040 | Century Exploration Houston, Inc | The Woodlands, TX 77380 | Oil & Gas Operator | Oct 2011 |
| 2041 | Century Exploration Houston, LLC | Austin, TX 78702 | Oil & Gas Operator | Jan 2016 |
| 2042 | Century Petroleum, Inc. | Jacksboro, TX 76458 | Oil & Gas Operator | Oct 2025 |
| 2043 | Century Resources, Inc. | Houston, TX 77056 | Oil & Gas Operator | Oct 2025 |
| 2044 | Century Royalty 2000 GP, LLC | Conroe, TX 77301 | Oil & Gas Operator | Jun 2020 |
| 2045 | Cerberus Engineering, LLC | San Antonio, TX 78209 | Oil & Gas Operator | Oct 2025 |
| 2046 | Certified Petroleum Inc. | Mineral Wells, TX 76067 | Oil & Gas Operator | May 2006 |
| 2047 | Cesinger Exploration Service, In | Dallas, TX 75208 | Oil & Gas Operator | Mar 2006 |
| 2048 | Cet Energy Corporation | Spring, TX 77391 | Oil & Gas Operator | Nov 2003 |
| 2049 | Cex Operating Company | Dallas, TX 75206 | Oil & Gas Operator | Mar 2008 |
| 2050 | Cfo Resources, Inc. | Corpus Chrsti, TX 78412 | Oil & Gas Operator | Oct 2025 |
| 2051 | CG Oil Co. | San Antonio, TX 78232 | Oil & Gas Operator | Mar 2011 |
| 2052 | CG Technical Operating Co, LLC | Stamford, TX 79553 | Oil Operator | Oct 2025 |
| 2053 | CGS Operating, LLC | Kilgore, TX 75663 | Oil & Gas Operator | May 2023 |
| 2054 | CH-Seon Inc. | Dallas, TX 75251 | Oil & Gas Operator | Oct 2025 |
| 2055 | CH4 Energy II LLC | Fort Worth, TX 76109 | Oil & Gas Operator | Apr 2018 |
| 2056 | CH4 Energy LLC | Fort Worth, TX 76102 | Oil & Gas Operator | May 2006 |
| 2057 | CH4 Energy Six, LLC | Fort Worth, TX 76107 | Oil & Gas Operator | Oct 2025 |
| 2058 | Chain Oil & Gas, Inc. | Houston, TX 77024 | Oil & Gas Operator | Oct 2025 |
| 2059 | Chalice Petroleum Corporation | Dallas, TX 75202 | Oil & Gas Operator | May 1998 |
| 2060 | Chalk, Otis, Estate | Big Spring, TX 79721 | Oil & Gas Operator | Jan 2006 |
| 2061 | Chalker Energy Management II,LLC | Houston, TX 77002 | Oil & Gas Operator | Feb 2008 |
| 2062 | Chalker Energy Management,LLC | Houston, TX 77002 | Oil & Gas Operator | Dec 2006 |
| 2063 | Chalker Operating Inc. | Richmond, TX 77406 | Oil & Gas Operator | Jul 2016 |
| 2064 | Challenge Operating Inc | Tulsa, OK 74103 | Oil & Gas Operator | Feb 2024 |
| 2065 | Challenger Energy SVCS Co., LLC | Kilgore, TX 75663 | Oil Operator | Oct 2025 |
| 2066 | Chalmers Exploration Company | Abilene, TX 79608 | Oil & Gas Operator | Apr 1997 |
| 2067 | Chama Resources | Dallas, TX 75354 | Oil & Gas Operator | Apr 2009 |
| 2068 | Chambers Operating, Inc. | Westbrook, TX 79565 | Oil & Gas Operator | Mar 2006 |
| 2069 | Chambers, R. H. | Abilene, TX 79606 | Oil & Gas Operator | Apr 2006 |
| 2070 | Chambers, R. H. LLC | Abilene, TX 79606 | Oil & Gas Operator | Oct 2025 |
| 2071 | Champ Operating Company | Dallas, TX 75208 | Oil & Gas Operator | Oct 2020 |
| 2072 | Champion Lone Star Operating,LLC | Midland, TX 79702 | Oil & Gas Operator | Mar 2020 |
| 2073 | Champlin Exploration, Inc. | Enid, OK 73702 | Oil & Gas Operator | Jul 2025 |
| 2074 | Chan West Oil Corporation | Irving, TX 75016 | Oil & Gas Operator | Oct 2025 |
| 2075 | Chanc West, Inc. | Iraan, TX 79744 | Oil & Gas Operator | Mar 1995 |
| 2076 | Chance Energy Co. Inc. | Amarillo, TX 79114 | Oil & Gas Operator | Sep 1999 |
| 2077 | Chance Oil Co., Inc. | Vernon, TX 76385 | Oil & Gas Operator | Jun 2025 |
| 2078 | Chance Properties Co. | Kermit, TX 79745 | Oil & Gas Operator | Oct 2025 |
| 2079 | Chancellor, Earl Sales Co., Inc. | Sweetwater, TX 79556 | Oil & Gas Operator | Oct 2025 |
| 2080 | Chandler & Associates, Inc. | Denver, CO 80202 | Oil & Gas Operator | May 1997 |
| 2081 | Chandler Oil & Gas, LLC | Beeville, TX 78102 | Oil & Gas Operator | Oct 2025 |
| 2082 | Chaney Oil Company | Andrews, TX 79714 | Oil & Gas Operator | Oct 2025 |
| 2083 | Channa Operating, LLC | Houston, TX 77063 | Oil & Gas Operator | Jul 2021 |
| 2084 | Channel Production Company | Marshall, TX 75670 | Oil & Gas Operator | Oct 2025 |
| 2085 | Chanze Oil Co., Inc. | Kilgore, TX 75663 | Oil & Gas Operator | Oct 2025 |
| 2086 | Chap Operating, Inc. | Knox City, TX 79529 | Oil & Gas Operator | Oct 2025 |
| 2087 | Chaparosa Production Company,Inc | Freer, TX 78357 | Oil & Gas Operator | Oct 2025 |
| 2088 | Chaparral (USA) Energy, Inc. | Oklahoma City, OK 73114 | Oil & Gas Operator | Sep 2002 |
| 2089 | Chaparral Energy, L.L.C. | Oklahoma City, OK 73142 | Oil & Gas Operator | Oct 2025 |
| 2090 | Chaparral Natural Resources,Inc. | Austin, TX 78746 | Oil & Gas Operator | Oct 2025 |
| 2091 | Chaparral Operating, Inc. | Shreveport, LA 71166 | Oil & Gas Operator | Oct 2025 |
| 2092 | Chapco, Inc. | Benavides, TX 78341 | Oil & Gas Operator | Oct 2025 |
| 2093 | Chapman Oil Company | Midland, TX 79702 | Oil & Gas Operator | Jun 2025 |
| 2094 | Chapman, Ford Operating, Inc. | Midland, TX 79702 | Oil & Gas Operator | Jan 1996 |
| 2095 | Chapparal Operating Co. | Fort Worth, TX 76121 | Oil & Gas Operator | Oct 2025 |
| 2096 | Chapter Petroleum | Borger, TX 79008 | Oil & Gas Operator | Mar 1997 |
| 2097 | Chapter Petroleum, Inc. | Borger, TX 79008 | Oil & Gas Operator | Mar 2001 |
| 2098 | Chardonnay Operating, Inc. | Olney, TX 76374 | Oil & Gas Operator | Dec 1996 |
| 2099 | Charger Oil & Gas, LLC | Houston, TX 77002 | Oil & Gas Operator | Dec 2014 |
| 2100 | Charger Shale Oil Operating, LLC | Austin, TX 78704 | Oil & Gas Operator | Sep 2021 |