| 7901 | One Nickel Operating LLC | Westbrook, TX 79565 | Oil Operator | Oct 2025 |
| 7902 | One Tec Operating, LLC | Houston, TX 77002 | Oil & Gas Operator | Nov 2007 |
| 7903 | One World Operating, LLC | Tampa, FL 33602 | Oil & Gas Operator | Oct 2025 |
| 7904 | Oneok Exploration Company | Tulsa, OK 74102 | Oil & Gas Operator | Feb 2017 |
| 7905 | Oneok Resources Company | Tulsa, OK 74102 | Oil & Gas Operator | Feb 2017 |
| 7906 | Onshore Royalties LLC | Houston, TX 77269 | Oil & Gas Operator | Jul 2025 |
| 7907 | Onyx Industries LTD, Inc. | Wichita Falls, TX 76308 | Oil & Gas Operator | Aug 2003 |
| 7908 | Onyx Producing Company, Inc. | Pampa, TX 79066 | Oil & Gas Operator | Mar 2008 |
| 7909 | Opal Energy, Inc. | Katy, TX 77494 | Oil & Gas Operator | Jun 2009 |
| 7910 | Opal Operating Company LLC | Edmond, OK 73013 | Oil & Gas Operator | Oct 2025 |
| 7911 | Opal Resources Operating Co.,LLC | Cypress, TX 77429 | Oil & Gas Operator | Jan 2019 |
| 7912 | Opco Oil & Gas Co. | Dallas, TX 75231 | Oil & Gas Operator | Aug 2003 |
| 7913 | Opex Energy, LLC | Houston, TX 77042 | Oil & Gas Operator | Mar 2008 |
| 7914 | Opmi Operating Company | Houston, TX 77057 | Oil & Gas Operator | Jun 2008 |
| 7915 | Ops Group Limited | Houston, TX 77060 | Oil & Gas Operator | Jun 2014 |
| 7916 | Optimum Exploration LLC | Dallas, TX 75254 | Oil & Gas Operator | Oct 2025 |
| 7917 | Orange Petroleum Co. | Orangefield, TX 77639 | Oil & Gas Operator | May 1995 |
| 7918 | Orangefield Operating Corporation | Dallas, TX 75382 | Oil Operator | Oct 2025 |
| 7919 | Orbis Energy, L.L.C. | Austin, TX 78746 | Oil & Gas Operator | Oct 2001 |
| 7920 | Orbit Crude, Inc. | Midland, TX 79710 | Oil & Gas Operator | Oct 2025 |
| 7921 | Orbit Enterprises, Inc. | Lovington, NM 88260 | Oil & Gas Operator | Mar 2015 |
| 7922 | Orbitron Operating Corp. | Fort Worth, TX 76102 | Oil & Gas Operator | Dec 1995 |
| 7923 | Orca Operating Company LLC | Houston, TX 77056 | Oil & Gas Operator | Jul 2025 |
| 7924 | Oretta Holdings LLC | Houston, TX 77010 | Oil & Gas Operator | Oct 2025 |
| 7925 | Origin Prod Co Gonzales Prop LLC | New Braunfels, TX 78132 | Oil & Gas Operator | Oct 2025 |
| 7926 | Origin Production Company, Inc. | New Braunfels, TX 78132 | Oil & Gas Operator | Oct 2025 |
| 7927 | Origin Production Group LLC | Luling, TX 78648 | Oil Operator | Oct 2025 |
| 7928 | Oringderff, Alma Oil Properties | Dallas, TX 75225 | Oil & Gas Operator | Mar 2012 |
| 7929 | Oriole Operating LLC | Wichita Falls, TX 76308 | Oil Operator | Oct 2025 |
| 7930 | Orion Energen Inc. | Austin, TX 78731 | Oil & Gas Operator | Jul 2023 |
| 7931 | Orion Oil & Gas Properties | Amarillo, TX 79109 | Gas Operator | Oct 2000 |
| 7932 | Orion Oil & Gas, LLC | Houston, TX 77042 | Oil & Gas Operator | Oct 2007 |
| 7933 | Orion Oil And Gas Corporation | Houston, TX 77082 | Oil & Gas Operator | Oct 2025 |
| 7934 | Orisol Oil Co. | Houston, TX 77206 | Oil Operator | Jun 2000 |
| 7935 | Orla Petco, Inc. | Midland, TX 79708 | Oil & Gas Operator | Oct 2025 |
| 7936 | Orland Oil & Gas LLC | FT Lauderdale, FL 33305 | Oil Operator | Aug 2024 |
| 7937 | Ormand, Don R. | Midland, TX 79705 | Oil & Gas Operator | Jan 2016 |
| 7938 | Oro Resources, LLC | Houston, TX 77024 | Oil & Gas Operator | Oct 2025 |
| 7939 | Orr Production Company | Austin, TX 78746 | Oil & Gas Operator | Dec 2000 |
| 7940 | Orr, Robert M. | Monahans, TX 79756 | Oil & Gas Operator | Oct 1998 |
| 7941 | Orsburn, Wade Inc. | Gainesville, TX 76240 | Oil & Gas Operator | Nov 2002 |
| 7942 | Orson Leasing & Supply | Rockdale, TX 76567 | Oil & Gas Operator | Dec 2006 |
| 7943 | Orth Oil Company, Inc. | Cisco, TX 76437 | Oil & Gas Operator | Oct 2025 |
| 7944 | Orx Resources, L.L.C. | Houston, TX 77067 | Oil & Gas Operator | Oct 2025 |
| 7945 | Oryx Energy Company | Dallas, TX 75221 | Oil & Gas Operator | May 2002 |
| 7946 | Os&S Operating Inc. | Electra, TX 76360 | Oil & Gas Operator | Oct 2025 |
| 7947 | Osborn Heirs Co | San Antonio, TX 78217 | Oil & Gas Operator | Aug 2025 |
| 7948 | Osborn,W.B. Oil & Gas Operations | San Antonio, TX 78217 | Oil & Gas Operator | Oct 2025 |
| 7949 | Osborne Oil Co. | Dallas, TX 75244 | Oil & Gas Operator | Aug 2003 |
| 7950 | Oscar Oil Company | Iowa Park, TX 76367 | Oil & Gas Operator | Sep 2004 |
| 7951 | Osceola Oil & Gas Corporation | Somerset, TX 78069 | Oil & Gas Operator | Aug 1994 |
| 7952 | Oso Exploration & Production, LLC | Houston, TX 77269 | Oil Operator | Oct 2025 |
| 7953 | Oso Exploration Co. | San Antonio, TX 78217 | Oil & Gas Operator | Jul 2011 |
| 7954 | Osprey Petroleum Company, Inc. | Manvel, TX 77578 | Oil & Gas Operator | May 2020 |
| 7955 | Osr Oil & Gas Company | Victoria, TX 77902 | Oil & Gas Operator | Jul 2000 |
| 7956 | Osr Oil & Gas Corp | Midland, TX 79710 | Oil & Gas Operator | Dec 2024 |
| 7957 | Ostrich Oil & Gas, LLC | Midland, TX 79701 | Oil & Gas Operator | Oct 2025 |
| 7958 | Oswego, Inc. | Amarillo, TX 79109 | Oil & Gas Operator | Jun 2004 |
| 7959 | Osyka Oil & Gas, Inc. | Metairie, LA 70004 | Oil & Gas Operator | Oct 2025 |
| 7960 | Osyka Permian, LLC | Houston, TX 77079 | Oil & Gas Operator | Oct 2025 |
| 7961 | Osyka Producing Company, Inc. | Houston, TX 77242 | Oil & Gas Operator | Oct 2025 |
| 7962 | Otb Operating, LLC | Stanton, TX 79782 | Oil & Gas Operator | Oct 2025 |
| 7963 | Otc Petroleum Corporation | Nichols Hill, OK 73116 | Oil & Gas Operator | Mar 2015 |
| 7964 | Otex LLC | Santa Anna, TX 76878 | Oil & Gas Operator | Oct 2025 |
| 7965 | Otex Resources LLC | Baytown, TX 77520 | Oil & Gas Operator | Oct 2025 |
| 7966 | Oto, Co. | Woodward, OK 73802 | Oil & Gas Operator | Jun 1998 |
| 7967 | Ouachita Exploration Inc | Chickasha, OK 73018 | Oil & Gas Operator | Jun 2025 |
| 7968 | Ouida Oil | Rowlett, TX 75030 | Oil & Gas Operator | Mar 2008 |
| 7969 | Outlaw Oil LLC | Caldwell, TX 77836 | Oil & Gas Operator | Oct 2025 |
| 7970 | Outline Oil Company LLC | Beeville, TX 78104 | Oil Operator | Oct 2025 |
| 7971 | Outline Oil Corp. | San Antonio, TX 78217 | Oil & Gas Operator | Oct 2025 |
| 7972 | Ouut Investing LLC | Mineral Wells, TX 76068 | Oil Operator | Mar 2020 |
| 7973 | Ovation Energy II, LP | Houston, TX 77279 | Oil & Gas Operator | Jun 2011 |
| 7974 | Ovation Energy, LP | N Richlnd HLS, TX 76180 | Oil & Gas Operator | Sep 2004 |
| 7975 | Overflow Energy, LLC | Perryton, TX 79070 | Oil & Gas Operator | Oct 2025 |
| 7976 | Overland Operating Company, LLC | Abilene, TX 79601 | Oil Operator | Oct 2025 |
| 7977 | Overly Operating Co. | San Antonio, TX 78209 | Oil & Gas Operator | Jul 2013 |
| 7978 | Overstreet, Jamie L | Hondo, TX 78861 | Oil & Gas Operator | Oct 2025 |
| 7979 | Overton Park Oil & Gas LP | Fort Worth, TX 76109 | Oil & Gas Operator | Oct 2025 |
| 7980 | Ovintiv USA Inc. | Denver, CO 80202 | Oil & Gas Operator | Oct 2025 |
| 7981 | Owens Oil Company | Iowa Park, TX 76367 | Oil & Gas Operator | Sep 2008 |
| 7982 | Owens Petroleum, Inc. | Midland, TX 79702 | Oil & Gas Operator | Aug 1995 |
| 7983 | Owl Creek Operating Co., Inc. | Denver, CO 80206 | Oil & Gas Operator | Oct 2025 |
| 7984 | Owl Creek Production Co., Inc. | Houston, TX 77027 | Oil & Gas Operator | Apr 2006 |
| 7985 | Owl Creek Production Co., LLC | Denver, CO 80265 | Oil & Gas Operator | Jan 2006 |
| 7986 | Owl Operating Ventures L.L.C. | Midland, TX 79708 | Oil & Gas Operator | Dec 2022 |
| 7987 | Owl Ops II LLC | Midland, TX 79701 | Oil & Gas Operator | Oct 2025 |
| 7988 | Owl Ops LLC | Midland, TX 79701 | Oil & Gas Operator | Oct 2025 |
| 7989 | Own Resources Operating LLC | The Woodlands, TX 77381 | Oil & Gas Operator | Jul 2025 |
| 7990 | Ows Energy, Inc. | Montgomery, TX 77356 | Oil & Gas Operator | Oct 2025 |
| 7991 | Oxbow EP LLC | Mathis, TX 78368 | Oil Operator | Oct 2025 |
| 7992 | Oxbow Petroleum, LLC | Midland, TX 79703 | Oil & Gas Operator | May 2025 |
| 7993 | Oxenergy Incorporated | Flower Mound, TX 75022 | Oil & Gas Operator | Oct 2025 |
| 7994 | Oxford Exploration Company | Denver, CO 80237 | Oil & Gas Operator | Aug 1995 |
| 7995 | Oxford Oil Co. | Rockdale, TX 76567 | Oil & Gas Operator | Aug 2004 |
| 7996 | Oxson Co. | Uvalde, TX 78802 | Gas Operator | Oct 2025 |
| 7997 | Oxxn | Weatherford, TX 76086 | Oil & Gas Operator | Oct 2023 |
| 7998 | Oxy USA Inc | Houston, TX 77046 | Oil & Gas Operator | Oct 2025 |
| 7999 | Oxy USA WTP LP | Houston, TX 77046 | Oil & Gas Operator | Oct 2025 |
| 8000 | Oxyrock Operating, LLC | Houston, TX 77046 | Oil & Gas Operator | Oct 2025 |