| 1 | C & B Exploration Company, Inc. | | Oil & Gas Operator | Oct 2008 |
| 2 | C & B Production | Ben Bolt, TX 78342 | Oil & Gas Operator | Dec 2025 |
| 3 | C & C Oil & Gas | Ranger, TX 76470 | Oil & Gas Operator | Dec 2025 |
| 4 | C & C Operating, Inc. | | Oil Operator | Dec 2024 |
| 5 | C & D Resources, Inc. | | Oil & Gas Operator | Nov 2001 |
| 6 | C & E Oil Company | Corpus Christi, TX 78418 | Oil Operator | Jan 1989 |
| 7 | C & F Oil Company, Inc. | | Oil Operator | Jan 2025 |
| 8 | C & F Petroleum | | Oil & Gas Operator | Apr 1991 |
| 9 | C & H Oil Company | Ratliff City, OK 73481-0130 | Oil & Gas Operator | Apr 2015 |
| 10 | C & K Offshore Company | | Oil & Gas Operator | Oct 1980 |
| 11 | C & K Petroleum Inc | Denver, CO 80202 | Oil & Gas Operator | Apr 1984 |
| 12 | C & L Oil Company | Cross Plains, TX 76443 | Oil & Gas Operator | Dec 2025 |
| 13 | C & M Operating Company | Graham, TX 76450 | Oil & Gas Operator | Aug 2025 |
| 14 | C & N Royalties, L.L.C. | | Oil & Gas Operator | Oct 2015 |
| 15 | C & R Oil | | Oil Operator | Jun 2025 |
| 16 | C & S Oil Company | Odessa, TX 79763 | Oil & Gas Operator | Nov 2019 |
| 17 | C & S Petroleum, Inc. | Norman, OK 73070 | Oil & Gas Operator | Dec 2024 |
| 18 | C & S Properties | | Oil & Gas Operator | Jun 1996 |
| 19 | C & VC, Inc. | | Oil & Gas Operator | Sep 1991 |
| 20 | C C Co | Holladay, UT 84124 | Oil & Gas Operator | Jan 2020 |
| 21 | C G Davis, Et Al | | Oil & Gas Operator | Mar 1986 |
| 22 | C N Operating Co | Drumright, OK 74030 | Oil & Gas Operator | Nov 1998 |
| 23 | C&M Operating Company, LLC | | Oil & Gas Operator | Apr 2011 |
| 24 | C. A. Cardneaux, Inc. | | Oil & Gas Operator | Apr 1990 |
| 25 | C. D. Pierce | | Oil Operator | Mar 1991 |
| 26 | C. H. C. Gerard | | Oil & Gas Operator | Jan 2025 |
| 27 | C. H. Cuatro | | Gas Operator | Sep 1996 |
| 28 | C. J. Broome Oil Company | | Oil & Gas Operator | Jan 2020 |
| 29 | C. L. Brown, III | | Oil Operator | Dec 1991 |
| 30 | C. L. Brown, Inc. | | Oil Operator | Dec 1999 |
| 31 | C. L. Morris | | Oil Operator | Feb 2004 |
| 32 | C. L. Morris, Inc. | | Oil & Gas Operator | Feb 2004 |
| 33 | C. M. Frizzell | | Oil & Gas Operator | Mar 2014 |
| 34 | C. M. Roberson | | Oil Operator | Jun 1984 |
| 35 | C. Smith & Associates, Inc. | | Oil Operator | Aug 1991 |
| 36 | C. T. & Ted Paul | | Oil Operator | Mar 2019 |
| 37 | C. V. Radke | | Oil Operator | Jan 1993 |
| 38 | C. W. Brumley | | Oil & Gas Operator | Jun 2006 |
| 39 | C. W. Resources, Inc. | Longview, TX 75604 | Oil & Gas Operator | Oct 2025 |
| 40 | C. Wayland Brooks | | Oil & Gas Operator | Dec 1987 |
| 41 | C.B.C. Producing Co. | | Oil & Gas Operator | Jul 1989 |
| 42 | C.F. Braun & Company | | Oil & Gas Operator | Dec 1986 |
| 43 | C.F.D. Inc. | | Oil & Gas Operator | Nov 1988 |
| 44 | C.J. Oil Company | Iowa Park, TX 76367 | Oil Operator | Jan 2025 |
| 45 | C.P.I. | | Oil & Gas Operator | Oct 2007 |
| 46 | C.T.R. Oil, Inc. | | Oil & Gas Operator | Jan 2025 |
| 47 | C.W.F.K., Inc. | | Gas Operator | Dec 1986 |
| 48 | C6 Operating, L.L.C. | Keatchie, LA 71046 | Oil & Gas Operator | Dec 2025 |
| 49 | Caba, LLC | | Oil Operator | Jan 2025 |
| 50 | Cabot Oil & Gas Corporation | Houston, TX 77024 | Oil & Gas Operator | Aug 2025 |
| 51 | Cabot Petroleum Corporation | Englewood, CO 80111-2529 | Oil & Gas Operator | Dec 2004 |
| 52 | Caddeaux Gathering, LLC | | Oil Operator | Dec 2024 |
| 53 | Caddo Gas Processing L.L.C. | | Oil Operator | Aug 2012 |
| 54 | Caddo Management, Inc. | Shreveport, LA 71101 | Oil & Gas Operator | Jan 2025 |
| 55 | Caddo Oil & Gas Co., Inc. | | Oil Operator | Jul 1990 |
| 56 | Caddo Oil Co.,Inc. | | Oil & Gas Operator | Apr 1987 |
| 57 | Caddo Parish Holdings LLC | | Oil & Gas Operator | Jul 2020 |
| 58 | Caddo Petroleum Dev., Inc. | | Oil Operator | Aug 1986 |
| 59 | Caddo Pine Island Corp. | | Oil & Gas Operator | Sep 1997 |
| 60 | Caddo Pine Island Operating Co | | Oil & Gas Operator | Aug 1998 |
| 61 | Caddo Resources Inc | | Oil & Gas Operator | Dec 1986 |
| 62 | Caddo Western Development, Inc | | Oil & Gas Operator | Aug 1984 |
| 63 | Cadillac Operating Company, LLC | | Oil Operator | Jan 2025 |
| 64 | Cairn Energy Partners, LLC | | Oil & Gas Operator | Feb 2023 |
| 65 | Cajun Minerals, Inc. | | Oil & Gas Operator | Mar 1997 |
| 66 | Cajun Operating, Inc. | | Oil & Gas Operator | Jun 2011 |
| 67 | Cala Oil & Gas | | Oil & Gas Operator | Oct 1997 |
| 68 | Calais Oil & Gas, L.L.C. | | Oil Operator | Dec 2024 |
| 69 | Caldwell & Self | | Oil Operator | Dec 2024 |
| 70 | Caldwell & Trahan | | Oil Operator | Dec 2024 |
| 71 | Caldwell Oil Company | | Oil Operator | Jul 2012 |
| 72 | Caldwell Operating, L.L.C. | | Oil Operator | Dec 2024 |
| 73 | Caldwell Production | | Oil Operator | Dec 2024 |
| 74 | Caldwell-Bayou State | | Oil Operator | Dec 2024 |
| 75 | California Time Petroleum, Inc | | Oil Operator | Mar 1986 |
| 76 | Callon Offshore Production, Inc. | Natchez, MS 39121 | Oil & Gas Operator | Dec 2005 |
| 77 | Callon Petroleum Company | Natchez, MS 39120 | Oil & Gas Operator | Jan 2000 |
| 78 | Callon Petroleum Operating Co | Houston, TX 77042 | Oil & Gas Operator | Jul 2024 |
| 79 | Calpetco III-Teel 77 A | | Gas Operator | May 1980 |
| 80 | Calpetco-Herbst Expl. Inc. | | Gas Operator | Jan 1990 |
| 81 | Calpine Natural Gas Company | Houston, TX 77002 | Oil & Gas Operator | Apr 2002 |
| 82 | Calpine Natural Gas Company L.P. | Houston, TX 77002 | Oil & Gas Operator | Mar 2015 |
| 83 | Calpine Natural Gas L.P. | Houston, TX 77002 | Oil & Gas Operator | Dec 2005 |
| 84 | Calto Operating Company, Inc. | Dallas, TX 75225 | Oil & Gas Operator | May 2004 |
| 85 | Calumet Lubricants Company | | Oil Operator | Dec 1993 |
| 86 | Calumet Refining Co. | | Oil Operator | May 1991 |
| 87 | Calyx Exploration & Production | | Oil & Gas Operator | Jul 1991 |
| 88 | Camar Exploration | | Oil Operator | Jan 1989 |
| 89 | Cambridge Energy Corporation | | Oil & Gas Operator | Jul 2003 |
| 90 | Camco Resources, Inc. | | Oil Operator | Aug 1991 |
| 91 | Cameron Development Co., Inc. | | Oil & Gas Operator | Mar 1988 |
| 92 | Cameron LNG, LLC | | Oil Operator | Jan 2025 |
| 93 | Camex Operating Company | | Oil & Gas Operator | Dec 2024 |
| 94 | Camex, Inc. | | Oil & Gas Operator | Jun 1992 |
| 95 | Campbell & Assoc.-Ring | | Oil Operator | Nov 1980 |
| 96 | Campbell & Associates | | Oil & Gas Operator | Aug 1987 |
| 97 | Campbell Energy Corporation | | Oil & Gas Operator | May 1992 |
| 98 | Campbell Wells Corporation | | Oil Operator | Dec 1995 |
| 99 | Campground Corporation | | Oil Operator | Nov 2023 |
| 100 | Camterra Resources, Inc. | Marshall, TX 75671 | Oil & Gas Operator | Dec 2025 |