| 801 | O.B. Whatley Oil Company, Inc. | | Oil Operator | Feb 2013 |
| 802 | O.B., Keith & Owen B. Whatley | | Oil Operator | Jul 1989 |
| 803 | Oak Valley Operating, LLC | The Woodlands, TX 77380 | Oil & Gas Operator | Jun 2015 |
| 804 | Ocean Energy Inc | Houston, TX 77002 | Oil & Gas Operator | Aug 2003 |
| 805 | Oil & Gas Producers, Inc | Topeka, KS 66604 | Oil Operator | Jun 2004 |
| 806 | Oil Country Management, Inc. | | Oil & Gas Operator | Jan 2005 |
| 807 | Oil Lift Inc | Metairie, LA 70002 | Oil & Gas Operator | Apr 2020 |
| 808 | Oil Reserves Corp Of America | | Oil & Gas Operator | May 2002 |
| 809 | Oil,Gas & Other Minerals, Inc. | | Oil & Gas Operator | Apr 1996 |
| 810 | Ok Oil Company, Inc. | Bivins, TX 75555 | Oil & Gas Operator | Feb 2013 |
| 811 | Ok-La-Tex Production, Inc. | | Oil & Gas Operator | Jan 1982 |
| 812 | Okie Crude Company | Tulsa, OK 74103 | Oil & Gas Operator | Nov 2025 |
| 813 | Olympic Oil & Gas Expl. Co. | | Oil & Gas Operator | Nov 1987 |
| 814 | Omega Energy Incorporated | | Oil & Gas Operator | May 1998 |
| 815 | Ora Oil Company | | Oil & Gas Operator | May 2017 |
| 816 | Orx Resources, L.L.C. | Houston, TX 77067 | Oil & Gas Operator | Feb 2026 |
| 817 | Oryx Energy Company | Dallas, TX 75221 | Oil & Gas Operator | May 2002 |
| 818 | Owen Production Co | | Oil Operator | May 2001 |
| 819 | Oxy USA Inc | Houston, TX 77046 | Oil & Gas Operator | Feb 2026 |
| 820 | Ozark Production Company, Inc. | | Oil & Gas Operator | Jan 2025 |
| 821 | P.C.S.I. | | Oil & Gas Operator | Jun 1987 |
| 822 | P.T.L. Operating Co. | | Oil Operator | Jun 2003 |
| 823 | Pace Royalty Trust Fund, Inc. | Shreveport, LA 71135 | Oil & Gas Operator | Nov 2001 |
| 824 | Pacific Atlantic Oil Co. | | Oil & Gas Operator | Dec 2003 |
| 825 | Palmer Petroleum, Inc. | Shreveport, LA 71105 | Oil & Gas Operator | Jun 2025 |
| 826 | Paloma Natural Gas, LLC | Houston, TX 77002 | Oil & Gas Operator | Dec 2024 |
| 827 | Pan-Ok Production Company | | Oil & Gas Operator | Nov 2024 |
| 828 | Par Minerals Corporation | Shreveport, LA 71101 | Oil & Gas Operator | Feb 2026 |
| 829 | Parker Enterprises, Inc. | | Oil & Gas Operator | Jun 1999 |
| 830 | Parker Oil Company | Abilene, TX 79601 | Oil & Gas Operator | Feb 2024 |
| 831 | Partners Oil Company | Tulsa, OK 74135 | Oil & Gas Operator | Aug 1995 |
| 832 | Patkim Production Inc. | | Oil Operator | Jan 2025 |
| 833 | Pearl Resources Inc. | | Oil & Gas Operator | Jul 1990 |
| 834 | Pelican Gas Prod. Assoc. | | Oil & Gas Operator | Oct 1987 |
| 835 | Pennzenergy Explor & Prod LLC | | Oil & Gas Operator | Dec 1999 |
| 836 | Pennzoil Exploration & Production Co. | Carthage, TX 75633 | Oil & Gas Operator | Mar 2008 |
| 837 | Peoples Energy Prod.-TX, L.P. | Houston, TX 77002 | Oil & Gas Operator | Sep 2007 |
| 838 | Perdido Energy Louisiana, LLC | | Oil & Gas Operator | Dec 2024 |
| 839 | Perkins Oil Properties | | Oil & Gas Operator | Nov 2024 |
| 840 | Pesco | | Oil & Gas Operator | Oct 1984 |
| 841 | Petro Energy Inc | Farmington, NM 87499 | Oil & Gas Operator | Sep 2025 |
| 842 | Petro-Chem Operating Company, Inc. | Shreveport, LA 71101 | Oil & Gas Operator | Feb 2026 |
| 843 | Petro-Hunt, L.L.C. | Dallas, TX 75201 | Oil & Gas Operator | Feb 2026 |
| 844 | Petro-Search, Inc. | | Oil Operator | Jul 1992 |
| 845 | Petrohawk Operating Company | Houston, TX 77056 | Oil & Gas Operator | Oct 2021 |
| 846 | Petrol Industries, Inc. | Shreveport, LA 71137 | Oil & Gas Operator | Jun 2012 |
| 847 | Petroleum Corporation Of Texas | Breckenridge, TX 76024 | Oil & Gas Operator | May 2002 |
| 848 | Petroleum Investments, Inc | Shreveport, LA 71101 | Oil & Gas Operator | Dec 1977 |
| 849 | Petroleum Production MGMT., Inc. | Kansas City, MO 64112 | Oil & Gas Operator | Feb 2026 |
| 850 | Petroleum Venture Capitol Corp | | Oil Operator | Jun 1980 |
| 851 | PG&E Resources Company | Houston, TX 77042 | Oil & Gas Operator | May 1995 |
| 852 | Pharaoh Oil, LLC | | Oil Operator | Jan 2025 |
| 853 | Phillips Petroleum Company | Houston, TX 77251 | Oil & Gas Operator | Mar 2013 |
| 854 | Phoenic Opr Co Inc-SPD | | Oil Operator | Feb 1993 |
| 855 | Phoenix - Comco, Inc. | | Oil Operator | Aug 2004 |
| 856 | Phoenix Oper Co Inc-New Amer | | Oil Operator | Jul 1994 |
| 857 | Phoenix Operating Company, Inc. | Shreveport, LA 71161 | Oil & Gas Operator | Mar 2015 |
| 858 | Phoenix Opr Co Inc - West End | | Oil Operator | Dec 1992 |
| 859 | Phoenix Opr Co Inc-Acc | | Oil Operator | Dec 1992 |
| 860 | Phoenix Opr Co Inc-Amsterdam | | Oil Operator | Nov 1994 |
| 861 | Phoenix Opr Co Inc-Broadway | | Oil Operator | Dec 1992 |
| 862 | Phoenix Opr Co Inc-Caddo | | Oil Operator | Dec 1992 |
| 863 | Phoenix Opr Co Inc-HGC 1985 | | Oil Operator | Dec 1992 |
| 864 | Phoenix Opr Co Inc-New Amer 85 | | Oil Operator | Dec 1992 |
| 865 | Phoenix Opr Co Inc-Northern La | | Oil Operator | Dec 1992 |
| 866 | Phoenix Opr Co Inc-Oc Yacht 85 | | Oil Operator | Dec 1992 |
| 867 | Phoenix Opr Co Inc-Oc Yacht II | | Oil Operator | Dec 1992 |
| 868 | Phoenix Opr Co Inc-Ocean Yacht | | Oil Operator | Dec 1992 |
| 869 | Phoenix Opr Co Inc-Petrovest | | Oil Operator | Dec 1992 |
| 870 | Phoenix Opr Co Inc-PML | | Oil Operator | Dec 1992 |
| 871 | Phoenix Opr Co Inc-Rvside '85 | | Oil Operator | Dec 1992 |
| 872 | Phoenix Opr Co Inc-Salem 1985 | | Oil Operator | Dec 1992 |
| 873 | Phoenix Opr Co Inc-TG I | | Oil Operator | Dec 1992 |
| 874 | Phoenix Opr Co Inc-TG II | | Oil Operator | Dec 1992 |
| 875 | Phoenix Opr Co Inc-Vista | | Oil Operator | Dec 1992 |
| 876 | Pine Island Operating, L.L.C. | Graham, TX 76450 | Oil & Gas Operator | Feb 2026 |
| 877 | Pine Island Production LLC | | Oil Operator | Jan 2025 |
| 878 | Pine Top Energy Inc. | | Oil & Gas Operator | May 1997 |
| 879 | Pine Wave Energy Partners Operating, LLC | | Gas Operator | Apr 2022 |
| 880 | Pinnacle Operating Company, Inc. | Shreveport, LA 71135 | Oil & Gas Operator | Feb 2026 |
| 881 | Platt Oil Production | | Oil & Gas Operator | Jan 2007 |
| 882 | Poston'S Oil Co. | | Gas Operator | Jan 1993 |
| 883 | Pride Exploration, Inc. | Shreveport, LA 71101 | Oil & Gas Operator | Jul 2015 |
| 884 | Pritchard Engineering | | Oil & Gas Operator | Mar 1989 |
| 885 | Prostar Energy, LLC | | Oil Operator | Sep 2011 |
| 886 | Proven Oil Production | | Oil Operator | Mar 2002 |
| 887 | PSM Oil Production LLC | | Oil Operator | Jan 2025 |
| 888 | Pullco Services LLC | Jefferson, TX 75657 | Oil Operator | Feb 2026 |
| 889 | PXP Gulf Coast Inc. | Houston, TX 77002 | Oil & Gas Operator | Mar 2015 |
| 890 | PXP Louisiana L.L.C. | | Oil & Gas Operator | Nov 2010 |
| 891 | Qep Energy Company | Midland, TX 79701 | Oil & Gas Operator | Nov 2025 |
| 892 | Quad L Oil Company | | Oil & Gas Operator | Dec 2024 |
| 893 | Quality Petroleum, Inc. | Dallas, TX 75240 | Oil & Gas Operator | Jan 2022 |
| 894 | Quasha Oil Co. | | Oil & Gas Operator | Feb 1998 |
| 895 | Quest Energies | | Oil & Gas Operator | Mar 1997 |
| 896 | Questar Expl. And Prod. Co. | Salt Lake Cty, UT 84145 | Oil & Gas Operator | Jul 2011 |
| 897 | R & P Oil Co. | | Oil & Gas Operator | Jul 2014 |
| 898 | R & R Oil Company | Pampa, TX 79065 | Oil & Gas Operator | Jul 2002 |
| 899 | R & R Production Company | | Oil Operator | Feb 2000 |
| 900 | R & R Production, Inc. | | Oil & Gas Operator | Feb 1990 |