| 7701 | O'Brien Operating Company | Shreveport, LA 71164 | Oil & Gas Operator | Dec 2004 |
| 7702 | O'Brien Resources LLC | Shreveport, LA 71136 | Oil Operator | Nov 2017 |
| 7703 | O'Brien, George H. Jr. | Midland, TX 79701 | Oil & Gas Operator | Jun 1994 |
| 7704 | O'Connor & Hewitt, LTD. | Victoria, TX 77901 | Oil & Gas Operator | Jun 1998 |
| 7705 | O'Connor Energy Management, LLC | Victoria, TX 77902 | Oil Operator | Jun 2026 |
| 7706 | O'Dell, Mitchell | Cross Plains, TX 76443 | Oil & Gas Operator | Jun 2026 |
| 7707 | O'Donohoe, Jack | Wichita Falls, TX 76301 | Oil & Gas Operator | May 2002 |
| 7708 | O'Leary'S Oil & Gas Inc. | Arcadia, FL 34266 | Oil & Gas Operator | May 2008 |
| 7709 | O'Neal Cattle Co. | Pampa, TX 79066 | Gas Operator | Jun 2026 |
| 7710 | O'Neal Oil & Gas Co | Fort Worth, TX 76107-1479 | Oil & Gas Operator | Mar 2026 |
| 7711 | O'Neal Oil Company | Nocona, TX 76255 | Oil & Gas Operator | Jun 2026 |
| 7712 | O'Neal Operating Company | Wichita Falls, TX 76307 | Oil & Gas Operator | Dec 1999 |
| 7713 | O'Neal, Lindell | Nocona, TX 76255 | Oil & Gas Operator | Feb 2026 |
| 7714 | O'Neil, Pat | Wichita Falls, TX 76308 | Oil & Gas Operator | Nov 2005 |
| 7715 | O'Neill Properties, LTD. | Midland, TX 79702 | Oil & Gas Operator | Jun 2026 |
| 7716 | O'Ryan Oil And Gas | Odessa, TX 79768 | Oil & Gas Operator | Jun 2026 |
| 7717 | O'Sand Production, Inc. | Tomball, TX 77377 | Oil & Gas Operator | Aug 2003 |
| 7718 | O'Sullivan Oil & Gas Co., Inc. | Houston, TX 77002 | Oil & Gas Operator | Oct 2000 |
| 7719 | O'Tool Oil & Gas, LLC | Dallas, TX 75205 | Oil & Gas Operator | Jun 2026 |
| 7720 | O. H. B. Inc. | San Angelo, TX 76902 | Oil & Gas Operator | Sep 2019 |
| 7721 | O. H. M. Operating | Pampa, TX 79065 | Oil & Gas Operator | Jun 2026 |
| 7722 | O.G.O. Refining | Luling, TX 78648 | Oil & Gas Operator | Jun 2013 |
| 7723 | O.G.P. Operating, Inc. | Dallas, TX 75231 | Oil & Gas Operator | Jun 2026 |
| 7724 | O.T. Oil | Kilgore, TX 75663 | Oil Operator | Jun 2026 |
| 7725 | Oahe Oil Company | Texline, TX 79087 | Oil & Gas Operator | May 2004 |
| 7726 | Oak Energy, LLC | Houston, TX 77027 | Oil & Gas Operator | Jun 2026 |
| 7727 | Oak Hills Drilling & Oper., LLC | Holdenville, OK 74848 | Oil & Gas Operator | May 2013 |
| 7728 | Oak Prairie Operations, LLC | The Woodlands, TX 77381 | Oil & Gas Operator | Jun 2026 |
| 7729 | Oak Resources Inc | Tulsa, OK 74153 | Oil & Gas Operator | Aug 2013 |
| 7730 | Oak Valley Operating, LLC | The Woodlands, TX 77380 | Oil & Gas Operator | Jun 2015 |
| 7731 | Oakland Petroleum Oper Co., Inc. | Kilgore, TX 75663 | Oil & Gas Operator | Jun 2026 |
| 7732 | Oakmont Oil And Gas | Graham, TX 76450 | Oil & Gas Operator | Jun 2026 |
| 7733 | Oakridge Energy, Inc. | Wichita Falls, TX 76302 | Oil & Gas Operator | Jun 2026 |
| 7734 | Oakridge Oil And Gas, LP | Jacksboro, TX 76458 | Oil & Gas Operator | Jun 2026 |
| 7735 | Oaktree Oil Company | Albany, TX 76430 | Oil & Gas Operator | Jun 2026 |
| 7736 | Oasis Operating, Inc. | Lubbock, TX 79404 | Oil & Gas Operator | Nov 2020 |
| 7737 | Oasis Petroleum Permian LLC | Houston, TX 77002 | Oil & Gas Operator | Jun 2026 |
| 7738 | Oates, John Co., Inc. | Stinnett, TX 79083 | Oil & Gas Operator | Jun 2026 |
| 7739 | Obax Oil And Gas LLC | Saint Louis, MO 63131 | Oil Operator | Jun 2026 |
| 7740 | Oblaen Resources LLC | Wallis, TX 77485 | Oil & Gas Operator | Jun 2026 |
| 7741 | Occam Petroleum E&P, LLC | Meeker, OK 74855 | Oil Operator | Jun 2026 |
| 7742 | Occidental Energy Company, Inc. | Houston, TX 77282 | Oil & Gas Operator | Jul 2021 |
| 7743 | Occidental Energy Marketing, Inc. | Houston, TX 77227 | Gas Operator | Sep 2015 |
| 7744 | Occidental Permian LTD. | Houston, TX 77046 | Oil & Gas Operator | Jun 2026 |
| 7745 | Occidental W TX Overthrust, Inc. | Houston, TX 77210 | Oil & Gas Operator | Dec 2021 |
| 7746 | Ocean Energy Inc | Houston, TX 77002 | Oil & Gas Operator | Aug 2003 |
| 7747 | Ocotillo Energy Resources, LLC | Odessa, TX 79765 | Oil Operator | Jun 2026 |
| 7748 | Octane Energy Operating, LLC | Midland, TX 79701 | Oil & Gas Operator | Jun 2026 |
| 7749 | Odegard Energy, Inc. | Houston, TX 77024 | Oil & Gas Operator | Jul 2020 |
| 7750 | Oden, Robin H., Inc. | Midland, TX 79702 | Oil & Gas Operator | Apr 1994 |
| 7751 | Odessa Exploration, Inc. | Midland, TX 79702 | Oil & Gas Operator | Jun 2026 |
| 7752 | Odessa Oil Investment Co., Inc. | Odessa, TX 79762 | Oil & Gas Operator | Nov 2016 |
| 7753 | Odom, R. H. | Snyder, TX 79550 | Oil & Gas Operator | Jun 1996 |
| 7754 | Odum Oil & Gas Co. | Harper, TX 78631 | Oil & Gas Operator | Jun 2026 |
| 7755 | Odyssey Operating Company | Shreveport, LA 71106 | Oil & Gas Operator | Sep 2020 |
| 7756 | Odyssey Petroleum Company | Houston, TX 77010 | Oil & Gas Operator | Apr 1995 |
| 7757 | Oexco, Inc. | Tulsa, OK 74136 | Oil & Gas Operator | Mar 2015 |
| 7758 | Offset Oil & Gas | Big Spring, TX 79720 | Oil & Gas Operator | Aug 2003 |
| 7759 | Offshore Group, Inc. The | Houston, TX 77024 | Oil & Gas Operator | Jun 2026 |
| 7760 | Offshore Oil & Gas Inc | Houston, TX 77063 | Oil & Gas Operator | Sep 1994 |
| 7761 | Oft Inc. | Houston, TX 77079 | Oil & Gas Operator | Jun 2026 |
| 7762 | Og Co., Inc. | Houston, TX 77057 | Oil & Gas Operator | Jun 2026 |
| 7763 | Oga Operating L.L.C. | Midland, TX 79702 | Oil & Gas Operator | Jan 2000 |
| 7764 | Ogden Resources Corporation | Bryan, TX 77805 | Oil & Gas Operator | Jun 2026 |
| 7765 | Ogden Resources, LTD. | Bryan, TX 77802 | Oil & Gas Operator | Feb 2009 |
| 7766 | Ogog Operating, LLC | Dallas, TX 75367 | Oil & Gas Operator | Jun 2026 |
| 7767 | Ogris Operating, LLC | Midland, TX 79710 | Oil & Gas Operator | Jun 2026 |
| 7768 | Ogs Operating Company, Inc. | Midland, TX 79701 | Oil & Gas Operator | Sep 2008 |
| 7769 | Ogx Operating, LLC | Midland, TX 79702 | Oil & Gas Operator | Jun 2026 |
| 7770 | Ogx Resources LLC | Midland, TX 79702 | Oil & Gas Operator | Oct 2011 |
| 7771 | Ohlhausen Oil Company | Abilene, TX 79608 | Oil & Gas Operator | Jun 2026 |
| 7772 | Oil & Gas Acquisition Group Inc | Austin, TX 78716 | Oil & Gas Operator | May 2003 |
| 7773 | Oil & Gas Operations | Midland, TX 79706 | Oil & Gas Operator | Jun 2026 |
| 7774 | Oil & Gas Properties | Midland, TX 79704 | Oil & Gas Operator | Jun 2026 |
| 7775 | Oil & Gas Property MGMT., Inc. | Dallas, TX 75201 | Oil & Gas Operator | Jul 1996 |
| 7776 | Oil Capital Operating, LLC | Tulsa, OK 74103 | Oil & Gas Operator | Jun 2026 |
| 7777 | Oil Coast Corp. | S Houston, TX 77587 | Oil & Gas Operator | Jun 2026 |
| 7778 | Oil Lease Operating Co. | Coldspring, TX 77331 | Oil & Gas Operator | Aug 2003 |
| 7779 | Oil Management Corporation | Dallas, TX 75206 | Oil & Gas Operator | Apr 2022 |
| 7780 | Oil Patch Operators Co., L.L.C. | Kilgore, TX 75663 | Oil & Gas Operator | Jun 2026 |
| 7781 | Oil Producers, Inc. Of Kansas | Wichita, KS 67206 | Oil & Gas Operator | Jun 2026 |
| 7782 | Oil Projects, LLC | Houston, TX 77027 | Oil & Gas Operator | Jun 2026 |
| 7783 | Oil Rock Resources, LLC | Weatherford, TX 76088 | Oil & Gas Operator | Jan 2024 |
| 7784 | Oil Well Buyers Corp. | Houston, TX 77056 | Oil & Gas Operator | Dec 2024 |
| 7785 | Oil, Gas, Etc. LLC | Katy, TX 77449 | Oil & Gas Operator | Jun 2026 |
| 7786 | Oil-X Corp., The | FT Stockton, TX 79735 | Oil & Gas Operator | Jun 2026 |
| 7787 | Oilex Int'L Investments, Inc. | Luling, TX 78648 | Oil & Gas Operator | Jun 2026 |
| 7788 | Oilfield Management, Inc. (A) | Midland, TX 79702 | Oil & Gas Operator | Jun 2026 |
| 7789 | Oilrox Resources LLC | San Antonio, TX 78258 | Oil & Gas Operator | Feb 2026 |
| 7790 | Oilton Resources, Inc. | Laredo, TX 78041 | Oil & Gas Operator | Jun 2026 |
| 7791 | Oilwell Operators, Inc. | Pampa, TX 79066 | Oil & Gas Operator | Jun 2026 |
| 7792 | Oily Dog Operators Texas, LLC | Allen, TX 75002 | Oil Operator | Jun 2026 |
| 7793 | Ojai Oil Company | Camarillo, CA 93012 | Oil & Gas Operator | Dec 2025 |
| 7794 | Ojb, Inc. | Buda, TX 78610 | Oil & Gas Operator | Mar 2013 |
| 7795 | Ojt, LLC | Richmond, TX 77469 | Oil Operator | Jun 2026 |
| 7796 | Ok Arena Operating Company | Oklahoma City, OK 73101 | Oil & Gas Operator | Jun 2026 |
| 7797 | Ok Oil Company, Inc. | Bivins, TX 75555 | Oil & Gas Operator | Feb 2013 |
| 7798 | Okie Crude Company | Tulsa, OK 74103 | Oil & Gas Operator | Feb 2026 |
| 7799 | Okie Operating Company, LTD. | Tulsa, OK 74103 | Oil & Gas Operator | Jun 2026 |
| 7800 | Okla. Magic Circle Energy Corp. | Shawnee, OK 74801 | Oil & Gas Operator | Jul 2004 |