| 901 | Diamond Shamrock Chem Co | Irving, TX 75061 | Oil & Gas Operator | Dec 1990 |
| 902 | Diamond Shamrock Corp | Amarillo, TX 79105 | Oil & Gas Operator | Jan 1987 |
| 903 | Diamond Shamrock Expl | Dallas, TX 75201 | Oil & Gas Operator | May 1987 |
| 904 | Diamond Shamrock Expl. Co. | | Oil & Gas Operator | Jun 1987 |
| 905 | Diamond Star Oil, Inc. | Lacygne, KS 66040 | Oil Operator | Dec 2019 |
| 906 | Diamond T F Enterprises, Inc. | Sonora, TX 76950 | Gas Operator | Dec 2025 |
| 907 | Diamondback E&P LLC | Midland, TX 79701 | Oil & Gas Operator | Dec 2025 |
| 908 | Diamondback Oil Partners LLP | Arvada, CO 80004 | Oil & Gas Operator | Sep 2016 |
| 909 | Diamondback Operating, LP | Tulsa, OK 74132 | Gas Operator | Dec 2025 |
| 910 | Diamondback Resources LLC | Midland, TX 79705 | Oil & Gas Operator | May 2018 |
| 911 | Diamondback-Disposal LLC | Oklahoma City, OK 73134-1016 | Oil Operator | Dec 2008 |
| 912 | Diamondhead Oil Co., LLC | | Oil & Gas Operator | Nov 2025 |
| 913 | Diana Pease & Steve Pease Revocable Trust | Wellsville, NY 14895 | Gas Operator | Dec 2024 |
| 914 | Diane Oil Company | Oklahoma City, OK 73146 | Oil & Gas Operator | Oct 2025 |
| 915 | Diasu Oil & Gas Co., Inc. | Houston, TX 77002 | Oil & Gas Operator | Mar 2016 |
| 916 | Dibiaggio, Deirdre And Katherine Carmichael | Atlantis, FL 33463 | Gas Operator | Dec 2024 |
| 917 | Dick Lindsay Oil Company, Inc. | Graham, TX 76450 | Oil Operator | Dec 2025 |
| 918 | Dickerson Dennis | Velma, OK 73491 | Oil Operator | Nov 2025 |
| 919 | Dickerson Oil | Ada, OK 74820 | Oil Operator | Jan 2025 |
| 920 | Dickey Energy Company | Grafton, WV 26354 | Gas Operator | Dec 2015 |
| 921 | Dickman Farms, LLC | Auburn, NY 13021 | Gas Operator | Dec 2024 |
| 922 | Dickson Petroleum | Midland, TX 79710 | Oil & Gas Operator | Nov 1998 |
| 923 | Dickson Petroleum, Inc. | Midland, TX 79710 | Oil & Gas Operator | May 2000 |
| 924 | Didomenico, Thomas J | Jamestown, NY 14701 | Gas Operator | Dec 2024 |
| 925 | Diehl Glenn D Oi | | Oil Operator | Jul 1993 |
| 926 | Diehl Mark | | Oil Operator | Nov 1998 |
| 927 | Diehl Oil Inc | Hays, KS 67601 | Oil Operator | Sep 2025 |
| 928 | Dieter Prod Comp | | Oil & Gas Operator | Feb 1991 |
| 929 | Dieter Production Company | Durham, KS 67438 | Gas Operator | Mar 2013 |
| 930 | Dietrich Foundation | Pittsburgh, PA 15219 | Gas Operator | Dec 2024 |
| 931 | Dietrich Oil Co., A General Partnership | Humboldt, KS 66748 | Oil Operator | Jul 2000 |
| 932 | Dietrich Philip H | Jefferson, OH 44047 | Oil & Gas Operator | Dec 2024 |
| 933 | Dietrich Resources Corporation | | Oil & Gas Operator | Jun 2007 |
| 934 | Dietz Oil Field Supply | Dover, OH 44622 | Oil & Gas Operator | Dec 1997 |
| 935 | Digger Oil & Gas Inc | Prague, OK 74864 | Oil & Gas Operator | Nov 2025 |
| 936 | Digital Operating Company LLC | Boerne, TX 78006 | Oil & Gas Operator | Dec 2025 |
| 937 | Dildine Oil Well Service | | Oil Operator | Apr 2011 |
| 938 | Diler Development Inc. | Garland, TX 75043 | Oil & Gas Operator | Dec 2025 |
| 939 | Dillard & Dillard Inc. | Holliday, TX 76366 | Oil & Gas Operator | Dec 2025 |
| 940 | Dillard, A. W., Jr. | Midland, TX 79701 | Oil & Gas Operator | Jan 1995 |
| 941 | Diller Oil Company | Baird, TX 79504 | Oil Operator | Dec 2025 |
| 942 | Dilley Corp | Yale, OK 74085 | Oil & Gas Operator | May 2013 |
| 943 | Dilley, W.R. & A'Meta I. | Sedan, KS 67361 | Oil Operator | Nov 2015 |
| 944 | Dilligas, Inc. | | Oil Operator | May 1990 |
| 945 | Dillingham Ranch LC | Tulsa, OK 74152 | Oil & Gas Operator | May 2013 |
| 946 | Dillon, H. L., Jr. | Houston, TX 77027 | Oil & Gas Operator | Mar 1996 |
| 947 | Dils Oil & Gas | Parkersburg, WV 26101 | Oil & Gas Operator | Dec 2024 |
| 948 | Dils, Sherman III Dba Dils Oil & Gas | | Oil & Gas Operator | Dec 2020 |
| 949 | Dime Box Oil Company | Austin, TX 78759 | Oil & Gas Operator | Mar 2008 |
| 950 | Dimension Energy Co., L.L.C. | | Oil & Gas Operator | Dec 2024 |
| 951 | Dimes Energy GP Inc. | Olean, NY 14760 | Oil & Gas Operator | Dec 2024 |
| 952 | Dimick Production, LLC | Hamilton, KS 66853 | Oil Operator | Sep 2025 |
| 953 | Dimmit County SWD, LLC | Carrizo SPGS, TX 78834 | Oil Operator | Dec 2025 |
| 954 | Dimock Operating Company | Frisco, TX 75034 | Oil & Gas Operator | Dec 2025 |
| 955 | Dimock Petroleum | Dallas, TX 75205 | Oil Operator | Apr 2014 |
| 956 | Dinero Oil Corporation | Corpus Chrsti, TX 78460 | Oil & Gas Operator | Nov 1999 |
| 957 | Dinero Operating Co | Midland, TX 79702 | Oil & Gas Operator | Dec 2025 |
| 958 | Dino Operating LLC | Throckmorton, TX 76483 | Oil Operator | Dec 2025 |
| 959 | Dinsmore C E | Enid, OK 73702 | Oil & Gas Operator | May 2009 |
| 960 | Directional Drilling Systems, LLC | Greenwood VIllage, CO 80111 | Oil Operator | Dec 2019 |
| 961 | Dirks Petroleum Company | Beeville, TX 78104 | Oil & Gas Operator | Dec 2025 |
| 962 | Dirks, R. W. | Tuleta, TX 78162 | Oil & Gas Operator | May 1999 |
| 963 | Dirks, R.W. Pet. Eng. Inc. | Tuleta, TX 78162 | Oil & Gas Operator | Jul 1999 |
| 964 | Dirnett, Inc. | Tuleta, TX 78162 | Oil & Gas Operator | Dec 2025 |
| 965 | Dirty Devil LP | Eenglewood, CO 80111 | Oil & Gas Operator | Apr 1989 |
| 966 | Discorbis Oil Company | San Antonio, TX 78217 | Oil & Gas Operator | Jul 2019 |
| 967 | Discover Resources | Norman, OK 73070 | Oil & Gas Operator | Jan 2011 |
| 968 | Discover Resources LLC | Norman, OK 73072-2310 | Oil & Gas Operator | Oct 2025 |
| 969 | Discovery Energy Corp. CC | Corpus Chrsti, TX 78403 | Oil & Gas Operator | Dec 2025 |
| 970 | Discovery Energy Inc | Tulsa, OK 74136 | Oil & Gas Operator | Nov 2025 |
| 971 | Discovery Energy, LLC | | Oil Operator | Jan 2007 |
| 972 | Discovery Natural Resources LLC | Denver, CO 80202 | Oil & Gas Operator | Dec 2025 |
| 973 | Discovery Oil & Gas LLC | Canonsburg, PA 15317-9557 | Gas Operator | Dec 2024 |
| 974 | Discovery Oil And Gas | Canonburg, PA 15317 | Oil & Gas Operator | Dec 2024 |
| 975 | Discovery Oil LTD | Los Angeles, CA 90067 | Oil & Gas Operator | Jan 1993 |
| 976 | Discovery Operat | | Gas Operator | Jul 1988 |
| 977 | Discovery Operating Inc | Midland, TX 79705 | Oil & Gas Operator | Dec 2025 |
| 978 | Discovery Operating, LLC | | Oil & Gas Operator | Oct 2023 |
| 979 | Discovery Petroleum, L.L.C. | Alice, TX 78333 | Oil & Gas Operator | Dec 2025 |
| 980 | Discus Oil Corporation | | Oil & Gas Operator | Dec 2002 |
| 981 | Ditta Exploration Co., Inc. | | Oil & Gas Operator | Feb 1990 |
| 982 | Dittman, D. W. | Big Lake, TX 76932 | Oil & Gas Operator | Mar 2007 |
| 983 | Diversified Energy Investments | | Oil & Gas Operator | May 2009 |
| 984 | Diversified Energy LLC | Parker, CO 80138 | Oil & Gas Operator | Aug 2025 |
| 985 | Diversified Natural Res., Inc. | | Oil Operator | May 2000 |
| 986 | Diversified Oil & Gas LLC | Jackson Center, PA 16133 | Oil & Gas Operator | Nov 2025 |
| 987 | Diversified Operating Corp. | Golden, CO 80401 | Oil & Gas Operator | Oct 2012 |
| 988 | Diversified Production LLC | Keithville, LA 71047 | Oil & Gas Operator | Dec 2025 |
| 989 | Diversified Resources LLC | | Gas Operator | Oct 2025 |
| 990 | Diversified Resources, Inc. | Jackson Center, PA 16133 | Oil & Gas Operator | Dec 2020 |
| 991 | Diversified Southern Production LLC | | Oil & Gas Operator | Dec 2018 |
| 992 | Diversity Petroleum, LP | Rockwall, TX 75087 | Oil & Gas Operator | Aug 2010 |
| 993 | Divide Petroleum Co | | Oil & Gas Operator | May 2000 |
| 994 | Divine'S Service & Repairs Inc | | Oil & Gas Operator | Mar 1997 |
| 995 | Dixie Drilling Company, Inc. | Sherman, TX 75090 | Oil & Gas Operator | Nov 2011 |
| 996 | Dixie Lake Operating, LLC | Longview, TX 75606 | Gas Operator | Dec 2025 |
| 997 | Dixie Natural Gas Co. | | Oil & Gas Operator | Dec 2002 |
| 998 | Dixie Oil Company Inc | Moore, OK 73153 | Oil & Gas Operator | Nov 1994 |
| 999 | Dixie Oil Incorp | | Oil Operator | Jul 1992 |
| 1000 | Dixie Oil, LLC | Hamilton, KS 66853 | Oil Operator | Aug 2025 |