| 20701 | Olmos Partners, Inc. | Boerne, TX 78006 | Oil & Gas Operator | Jun 2026 |
| 20702 | Olney Oil LLC | Boerne, TX 78006 | Oil Operator | Jun 2026 |
| 20703 | Olney Properties, Inc. | Wichita Falls, TX 76307 | Oil & Gas Operator | Sep 2003 |
| 20704 | Olsan Brothers, Inc. | Dallas, TX 75251 | Oil & Gas Operator | Apr 1994 |
| 20705 | Olsen Energy Inc. | Boerne, TX 78006 | Oil & Gas Operator | Jun 2026 |
| 20706 | Olson D Producti | | Oil Operator | Jul 1994 |
| 20707 | Olson, S. A. | Kenedy, TX 78119 | Oil & Gas Operator | Aug 1994 |
| 20708 | Olson-Anderson Lease | | Oil Operator | Mar 2018 |
| 20709 | Oltex Production | Idalou, TX 79329 | Oil & Gas Operator | Jun 2026 |
| 20710 | Olympia Oil Inc | Edmond, OK 73083-7088 | Oil & Gas Operator | Jul 2020 |
| 20711 | Olympic Exploration & Production Co | Norman, OK 73072 | Oil Operator | May 2003 |
| 20712 | Olympic Exploration Inc | Denver, CO 80202 | Oil & Gas Operator | Jul 2004 |
| 20713 | Olympic Natural Gas Company | | Oil & Gas Operator | Oct 1990 |
| 20714 | Olympic Oil & Gas Co., Inc. | | Oil Operator | Apr 1991 |
| 20715 | Olympic Oil, Inc. | Hutchinson, KS 67502 | Oil & Gas Operator | Feb 2026 |
| 20716 | Olympic Petroleu | | Oil & Gas Operator | Jul 1993 |
| 20717 | Olympic Petroleum Co | Tulsa, OK 74114 | Oil & Gas Operator | Jun 1998 |
| 20718 | Olympic Production Company | | Oil & Gas Operator | Jul 1994 |
| 20719 | Olympic Resources Co | Wooster, OH 44691 | Oil & Gas Operator | Dec 2000 |
| 20720 | Olympus Energy, LLC | Canonsburg, PA 15317-7536 | Gas Operator | Jun 2025 |
| 20721 | Olympus Prop Inc | Franklin Park, IL 60131-1418 | Oil & Gas Operator | Dec 1997 |
| 20722 | Omac Oil & Gas Co | Newark, OH 43055 | Oil & Gas Operator | Dec 1990 |
| 20723 | Omar Operating Company | Midland, TX 79702 | Oil & Gas Operator | Sep 2013 |
| 20724 | Omber Petroleum & Energy Corp. | New Braunfels, TX 78131 | Oil & Gas Operator | Jun 2026 |
| 20725 | Omeara Bros. | | Oil & Gas Operator | Oct 1982 |
| 20726 | Omega Alpha Resources, LLC | Dallas, TX 75219 | Oil Operator | Jun 2026 |
| 20727 | Omega Energy Corp. | Graham, TX 76450 | Oil & Gas Operator | Jun 2026 |
| 20728 | Omega Energy Incorporated | | Oil & Gas Operator | May 1998 |
| 20729 | Omega Energy, LLC | Corpus Christ, TX 78418 | Oil & Gas Operator | Jun 2026 |
| 20730 | Omega Enterprise | | Oil Operator | Sep 1990 |
| 20731 | Omega Oil Corp | Lafayette, IN 47903 | Oil & Gas Operator | Dec 1987 |
| 20732 | Omega Operating, Inc. | Odessa, TX 79769 | Oil & Gas Operator | Mar 2001 |
| 20733 | Omega Resources Inc | | Oil & Gas Operator | Nov 1998 |
| 20734 | Omimex Canada, LTD. | Fort Worth, TX 76120-3608 | Oil & Gas Operator | Mar 2026 |
| 20735 | Omimex Energy, Inc. | Fort Worth, TX 76120 | Oil & Gas Operator | Mar 2026 |
| 20736 | Omimex International Corp | Fort Worth, TX 76103-2300 | Oil & Gas Operator | Feb 2026 |
| 20737 | Omimex Petroleum Inc | Fort Worth, TX 76120 | Oil & Gas Operator | Aug 2022 |
| 20738 | Omimex Petroleum Inc (Co) | Newcastle, WY 82701 | Oil & Gas Operator | May 2001 |
| 20739 | Omimex Petroleum Inc (De) | Fort Worth, TX 76120 | Oil & Gas Operator | Aug 2020 |
| 20740 | Omni E & P, Inc. | San Antonio, TX 78229 | Oil Operator | Apr 2010 |
| 20741 | Omni Oil & Gas, Inc. | San Antonio, TX 78229 | Oil & Gas Operator | Oct 2017 |
| 20742 | Omni Operating Company | Osage, WY 82723 | Oil & Gas Operator | Sep 2001 |
| 20743 | Omni Operating Company(A) | Dallas, TX 75370 | Oil & Gas Operator | Jun 2026 |
| 20744 | Omni Petroleum Corporation | Austin, TX 78738 | Oil & Gas Operator | Jun 2026 |
| 20745 | Omr Drilling & Acquisition LLC | Albany, KY 42602 | Oil Operator | Dec 2015 |
| 20746 | Omta Operating LLC | Corpus Christ, TX 78418 | Oil & Gas Operator | Jun 2026 |
| 20747 | On Pointe Operating LLC | Jones, OK 73049 | Oil & Gas Operator | Jun 2026 |
| 20748 | On-Line Oil Inc | Oklahoma City, OK 73105-5208 | Oil & Gas Operator | Mar 2015 |
| 20749 | Onapa Gas Company LLC | Tulsa, OK 74136-7253 | Gas Operator | Nov 2019 |
| 20750 | Onaroll Operating LLC | Lubbock, TX 79423 | Oil Operator | Jun 2026 |
| 20751 | Onco Petroleum USA Inc | | Oil Operator | Dec 2009 |
| 20752 | One Epoch Energy, Inc. | Abilene, TX 79604 | Oil & Gas Operator | Mar 2008 |
| 20753 | One Nickel Operating LLC | Ashland, MA 01721 | Oil Operator | Jun 2026 |
| 20754 | One Source Financial Services Inc. | McAllen, TX 78501 | Gas Operator | Dec 2019 |
| 20755 | One Tec Operating, LLC | Houston, TX 77002 | Oil & Gas Operator | Nov 2007 |
| 20756 | One World Operating, LLC | Tampa, FL 33602 | Oil & Gas Operator | Jun 2026 |
| 20757 | Oneenergy Partners Operating, LLC | Houston, TX 77019 | Oil & Gas Operator | Nov 2018 |
| 20758 | Oneida Energy Corporation | Tulsa, OK 74137 | Oil & Gas Operator | Jul 2003 |
| 20759 | Oneok Bushton Proces | | Gas Operator | Mar 2007 |
| 20760 | Oneok Energy Service | | Gas Operator | Dec 2008 |
| 20761 | Oneok Exploratio | | Oil & Gas Operator | Mar 1995 |
| 20762 | Oneok Exploration Company | Tulsa, OK 74102 | Oil & Gas Operator | Feb 2017 |
| 20763 | Oneok Field Services Company | Tulsa, OK 74103 | Oil & Gas Operator | Jan 2026 |
| 20764 | Oneok Gas Processing LLC | Tulsa, OK 74103 | Oil & Gas Operator | May 2018 |
| 20765 | Oneok Gas Transportation Co | Tulsa, OK 74121-2089 | Oil & Gas Operator | Oct 2014 |
| 20766 | Oneok Resources Company | Tulsa, OK 74102 | Oil & Gas Operator | Feb 2017 |
| 20767 | Onexxx Prod & Exploration Corp | Jeannette, PA 15644-9691 | Gas Operator | Dec 2025 |
| 20768 | Onnen, Gerhard E. | Yates Center, KS 66783 | Oil Operator | Feb 2002 |
| 20769 | Onpoint Oil & Gas, LLC | Oklahoma City, OK 73170 | Oil & Gas Operator | Mar 2026 |
| 20770 | Onshore Exp Cor-La Nat Res Inc | | Oil & Gas Operator | Oct 1978 |
| 20771 | Onshore Pipeline Const Co Inc | | Oil & Gas Operator | Aug 1998 |
| 20772 | Onshore Royalties LLC | Houston, TX 77269 | Oil & Gas Operator | Mar 2026 |
| 20773 | Onshore, L.L.C. | Wichita, KS 67205 | Oil & Gas Operator | Dec 2009 |
| 20774 | Onyx Energy Corporation | Oklahoma City, OK 73157 | Oil & Gas Operator | May 1994 |
| 20775 | Onyx Energy Dev Of Texas Inc. | | Oil Operator | Dec 1996 |
| 20776 | Onyx Energy Of Texas Inc. | | Oil Operator | Dec 1996 |
| 20777 | Onyx Industries LTD, Inc. | Wichita Falls, TX 76308 | Oil & Gas Operator | Aug 2003 |
| 20778 | Onyx Int'L Exploration LLC | | Oil & Gas Operator | Dec 2015 |
| 20779 | Onyx Producing Company, Inc. | Pampa, TX 79066 | Oil & Gas Operator | Mar 2008 |
| 20780 | Onyx Properties Corp | Oklahoma City, OK 73114 | Oil & Gas Operator | May 2006 |
| 20781 | Onyxx Energy LLC | | Oil & Gas Operator | Mar 2017 |
| 20782 | Onyxx Oil Corpor | | Oil Operator | Jul 1992 |
| 20783 | Oolite Energy Corp | Amarillo, TX 79105 | Oil & Gas Operator | Apr 2022 |
| 20784 | Oonk, Harvey D. | Clymer, NY 14724 | Gas Operator | Dec 2024 |
| 20785 | Opal Oil Inc. | | Oil Operator | Sep 2021 |
| 20786 | Opal Operating Company LLC | Edmond, OK 73013 | Oil & Gas Operator | Jun 2026 |
| 20787 | Opal Resources Operating Co.,LLC | Cypress, TX 77429 | Oil & Gas Operator | Jan 2019 |
| 20788 | Opco LLC | Chase, KS 67524 | Oil Operator | Dec 2019 |
| 20789 | Opco Oil & Gas Co. | Dallas, TX 75231 | Oil & Gas Operator | Aug 2003 |
| 20790 | Opdycke Lease Partners, A General Partnership | Russell, KS 67665 | Oil Operator | Feb 2026 |
| 20791 | Opef Partnership, A General Partnership | Overland Park, KS 66221 | Oil Operator | Dec 2011 |
| 20792 | Open Door Holdings Inc | Surprise, AZ 85387-2015 | Oil & Gas Operator | Feb 2024 |
| 20793 | Open Door Productions Inc | Muskogee, OK 74401-1032 | Oil & Gas Operator | Apr 2020 |
| 20794 | Open Flow Gas Supply Corp | Du Bois, PA 15801-2442 | Oil & Gas Operator | Dec 2025 |
| 20795 | Open Range Energy LLC | Jones, OK 73049-8744 | Oil & Gas Operator | Dec 2024 |
| 20796 | Operating Engineers Local 17 Training Fund | Lake VIew, NY 14085 | Gas Operator | Dec 2024 |
| 20797 | Operator Unknown | Charleston, WV 25304-0000 | Oil & Gas Operator | Dec 2021 |
| 20798 | Opes Production Inc | Buffalo, WY 82834 | Gas Operator | Mar 2015 |
| 20799 | Opex Energy, LLC | Houston, TX 77042 | Oil & Gas Operator | Mar 2008 |
| 20800 | Opmi Operating Company | Houston, TX 77057 | Oil & Gas Operator | Jun 2008 |