| 3001 | O'Connell, James P. | Vacaville, CA 95687 | Oil Operator | Nov 2009 |
| 3002 | O'Hare Energy Co | | Oil Operator | Dec 1983 |
| 3003 | Oak Ridge LLC | Wellsville, KS 66092 | Oil Operator | Dec 2019 |
| 3004 | Oaks Petroleum I | | Oil Operator | Jul 1987 |
| 3005 | Oakwood Resources, Inc. | Dallas, TX 75374 | Oil & Gas Operator | May 1998 |
| 3006 | Oast, Thomas H. | Greenville, NC 27835 | Oil Operator | Nov 1985 |
| 3007 | Occidental Energy Marketing, Inc. | Houston, TX 77227 | Gas Operator | Sep 2015 |
| 3008 | Ocean Energy Resources Inc. | Houston, TX 77002 | Oil & Gas Operator | Jan 2024 |
| 3009 | Ocfiw Oil Company, Inc. | Hartington, NE 68739 | Oil & Gas Operator | Dec 2009 |
| 3010 | Ogh Oil Company | | Oil Operator | Sep 1995 |
| 3011 | Ohio Kentucky Oil Corporation | Lexington, KY 40503 | Oil & Gas Operator | Dec 2020 |
| 3012 | Oil & Gas Producers, Inc. | Topeka, KS 66604 | Oil Operator | Jun 2004 |
| 3013 | Oil & Gas Servic | | Oil Operator | Jun 1983 |
| 3014 | Oil Company Of America, Inc. | Hays, KS 67601 | Oil Operator | Dec 2009 |
| 3015 | Oil Drillers & D | | Oil & Gas Operator | Feb 1992 |
| 3016 | Oil Field Manage | | Oil Operator | Jun 1991 |
| 3017 | Oil Gas Management, Inc. | Kansas City, MO 64106 | Oil Operator | Apr 2011 |
| 3018 | Oil Internationa | | Oil Operator | Jun 1986 |
| 3019 | Oil Lift, Incorporated | Metairie, LA 70002 | Oil & Gas Operator | Apr 2020 |
| 3020 | Oil Partners | Salina, KS 67401 | Oil Operator | Jun 2001 |
| 3021 | Oil Partners, LLC | Salina, KS 67401 | Oil Operator | Jan 2024 |
| 3022 | Oil Producers In | | Oil & Gas Operator | Dec 1996 |
| 3023 | Oil Producers, Inc. Of Kansas | Wichita, KS 67206 | Oil & Gas Operator | May 2024 |
| 3024 | Oil Production S | | Oil Operator | Sep 1993 |
| 3025 | Oil Prop Company | | Oil & Gas Operator | Sep 1995 |
| 3026 | Oil Prop Investm | | Oil Operator | Dec 1995 |
| 3027 | Oil Properties Co., Inc. | Wichita, KS 67208 | Gas Operator | Dec 2009 |
| 3028 | Oil Property Man | | Oil & Gas Operator | Jun 1995 |
| 3029 | Oil Property Management, Inc. | Attica, KS 67009 | Oil & Gas Operator | Feb 2021 |
| 3030 | Oil Tech Producers Corporation | Moundridge, KS 67107 | Gas Operator | Jan 2024 |
| 3031 | Oil-Tech Prod Co | | Oil & Gas Operator | Oct 1992 |
| 3032 | Oilfield Search | | Oil Operator | Mar 1990 |
| 3033 | Oilfield Services, LLC | Winfield, KS 67156 | Oil Operator | Nov 2017 |
| 3034 | Oilfield Truck Service | | Oil Operator | Jun 2014 |
| 3035 | Oklahoma Energy & Exploration, Inc. | Tulsa, OK 74114 | Oil Operator | Jan 1996 |
| 3036 | Oklahoma Rig & Salvage, Inc. | Oklahoma City, OK 73114 | Oil & Gas Operator | Mar 2015 |
| 3037 | Okmar Oil Compan | | Oil & Gas Operator | Feb 1995 |
| 3038 | Okmar Oil Company | Marietta, OH 45750 | Oil & Gas Operator | Jun 2005 |
| 3039 | Okt Resources, LLC | Edmond, OK 73013 | Oil & Gas Operator | May 2024 |
| 3040 | Ol' Oily LLC | | Oil Operator | Jan 2024 |
| 3041 | Olak Energy Production, LLC | Fort Gibson, OK 74434 | Oil Operator | Jan 2024 |
| 3042 | Olson D Producti | | Oil Operator | Jul 1994 |
| 3043 | Olson-Anderson Lease | | Oil Operator | Mar 2018 |
| 3044 | Olympic Oil, Inc. | Hutchinson, KS 67502 | Oil & Gas Operator | Jan 2024 |
| 3045 | Olympic Petroleu | | Oil & Gas Operator | Jul 1993 |
| 3046 | Omega Enterprise | | Oil Operator | Sep 1990 |
| 3047 | One Source Financial Services Inc. | McAllen, TX 78501 | Gas Operator | Dec 2019 |
| 3048 | Oneok Energy Service | | Gas Operator | Dec 2008 |
| 3049 | Oneok Exploratio | | Oil & Gas Operator | Mar 1995 |
| 3050 | Oneok Field Services Company | Tulsa, OK 74103 | Oil & Gas Operator | Jul 2022 |
| 3051 | Oneok Gas Processing LLC | Tulsa, OK 74103 | Oil & Gas Operator | May 2018 |
| 3052 | Oneok Resources Company | Tulsa, OK 74102 | Oil & Gas Operator | Feb 2017 |
| 3053 | Onnen, Gerhard E. | Yates Center, KS 66783 | Oil Operator | Feb 2002 |
| 3054 | Onshore, L.L.C. | Wichita, KS 67205 | Oil & Gas Operator | Dec 2009 |
| 3055 | Onyxx Oil Corpor | | Oil Operator | Jul 1992 |
| 3056 | Oolite Energy Corp | Amarillo, TX 79105 | Oil & Gas Operator | Apr 2022 |
| 3057 | Opco LLC | Chase, KS 67524 | Oil Operator | Dec 2019 |
| 3058 | Opdycke Lease Partners, A General Partnership | Russell, KS 67665 | Oil Operator | Jan 2024 |
| 3059 | Opef Partnership, A General Partnership | Overland Park, KS 66221 | Oil Operator | Dec 2011 |
| 3060 | Orca Operating Company LLC | Houston, TX 77056 | Oil & Gas Operator | Feb 2024 |
| 3061 | Oryx Energy Comp | | Oil & Gas Operator | Apr 1991 |
| 3062 | Oryx Energy Company | Dallas, TX 75221 | Oil & Gas Operator | May 2002 |
| 3063 | Osage Energy LLC | Colony, KS 66015 | Oil Operator | Nov 2023 |
| 3064 | Osage Resources, LLC | Wichita, KS 67202 | Oil & Gas Operator | Dec 2023 |
| 3065 | Osborn Energy, L.L.C. | Bucyrus, KS 66013 | Oil & Gas Operator | Jul 2017 |
| 3066 | Osborn Heirs Com | | Oil & Gas Operator | May 1995 |
| 3067 | Osborn Heirs Company LTD | San Antonio, TX 78217 | Oil & Gas Operator | Jan 2024 |
| 3068 | Osborn Oil & Gas | | Oil & Gas Operator | Jun 1991 |
| 3069 | Osci Oil And Gas, Inc. | Parker, KS 66072 | Oil Operator | Jun 1998 |
| 3070 | Oswego Oil & Gas | | Oil & Gas Operator | Jun 1984 |
| 3071 | Outlaw Well Service LLC | Hays, KS 67601 | Oil Operator | Nov 2023 |
| 3072 | Overland Exploration Company | | Oil Operator | Oct 2023 |
| 3073 | Owen'S Pumping Service | | Oil Operator | Jan 2024 |
| 3074 | Owen, Matthew | Hamilton, KS 66853 | Oil Operator | Sep 2016 |
| 3075 | Owens Oil | | Oil Operator | Dec 2000 |
| 3076 | Owens Oil Company | Iowa Park, TX 76367 | Oil & Gas Operator | Sep 2008 |
| 3077 | Owens Oil Company, LLC | Yates Center, KS 66783 | Oil Operator | Jan 2024 |
| 3078 | Owens Petroleum | | Oil Operator | May 2006 |
| 3079 | Owens Petroleum LLC | Yates Center, KS 66783 | Oil & Gas Operator | Jan 2024 |
| 3080 | Own Resources Operating LLC | The Woodlands, TX 77381 | Oil & Gas Operator | Mar 2024 |
| 3081 | Oxbow Oil Company,A Kansas General Partnership | Grenola, KS 67346 | Oil Operator | Apr 2015 |
| 3082 | Oxford Explorati | | Oil & Gas Operator | Mar 1993 |
| 3083 | Oxford Exploration | | Oil Operator | Apr 1988 |
| 3084 | Oxy USA | | Oil Operator | Apr 1992 |
| 3085 | Oxy USA Inc | Houston, TX 77046 | Oil & Gas Operator | May 2024 |
| 3086 | Ozark Enterprise | | Oil Operator | Nov 1990 |
| 3087 | P & C Petroleum, LLC | Shawnee, KS 66226 | Oil Operator | Nov 2023 |
| 3088 | P & M Oil Company | Hays, KS 67601 | Oil & Gas Operator | Feb 2024 |
| 3089 | P & M Petroleum Management LLC | Denver, CO 80202 | Oil & Gas Operator | Oct 2021 |
| 3090 | P & W Oil | Lakewood, CO 80215 | Oil Operator | Sep 1985 |
| 3091 | P I C Inc | Ponca City, OK 74602 | Oil & Gas Operator | Jan 2013 |
| 3092 | P J Oil Co. | Vernon, TX 76384 | Oil Operator | Jan 2024 |
| 3093 | P O & G Operating LLC | Houston, TX 77057 | Oil & Gas Operator | May 2024 |
| 3094 | P.M. Petroleum | | Oil Operator | Mar 1998 |
| 3095 | P3 Production | | Oil Operator | Jan 2024 |
| 3096 | Pacific Enterprises Oil Co USA | Dallas, TX 75201 | Oil & Gas Operator | Feb 2001 |
| 3097 | Packard Energy LLC | Medicine Lodge, KS 67104 | Oil & Gas Operator | Jan 2024 |
| 3098 | Packard Gas Company | Irving, TX 75063 | Oil & Gas Operator | Nov 2006 |
| 3099 | Packard, Lynn | Medicine Lodge, KS | Oil & Gas Operator | Dec 2023 |
| 3100 | Pada Petroleum, Inc. | Maple City, KS 67102 | Oil & Gas Operator | Jan 2024 |