| 801 | Ohio Production* | Newark, OH 43055 | Oil & Gas Operator | Dec 1987 |
| 802 | Ohio Valley Energy System Corp | Austintown, OH 44515 | Oil & Gas Operator | Dec 2017 |
| 803 | Oil & Gas Solutions LTD | Wooster, OH 44691 | Oil & Gas Operator | Dec 2007 |
| 804 | Oil & Realty Devlop Inc | Columbus, OH 43212 | Oil Operator | Dec 1986 |
| 805 | Oil Enterprises | Logan, OH 43138 | Oil & Gas Operator | Dec 2017 |
| 806 | Oil Search Inc | Brookfield, OH 44403 | Oil & Gas Operator | Dec 2017 |
| 807 | Oiltech Inc | Yuba City, CA 95991 | Oil & Gas Operator | Dec 1984 |
| 808 | Oiltex, Inc. | Baltimore, MD 21221 | Oil & Gas Operator | Aug 2017 |
| 809 | Okmar Oil Co | Marietta, OH 45750 | Oil & Gas Operator | Dec 1999 |
| 810 | Old South Oil LLC | Marietta, OH 45750 | Oil & Gas Operator | Dec 2017 |
| 811 | Ole Miss Oil & Gas Inc | New Bremen, OH 45689 | Oil & Gas Operator | Dec 1985 |
| 812 | Olio Resources LLC | Arroyo Seco, NM 87514 | Oil & Gas Operator | Dec 2017 |
| 813 | Olympic Resources Co | Wooster, OH 44691 | Oil & Gas Operator | Dec 2000 |
| 814 | Omac Oil & Gas Co | Newark, OH 43055 | Oil & Gas Operator | Dec 1990 |
| 815 | Omega Oil Corp | Lafayette, IN 47903 | Oil & Gas Operator | Dec 1987 |
| 816 | Orion Energy Corp | MT Vernon, IL 62864 | Oil & Gas Operator | Dec 1984 |
| 817 | Orion Petro Corp | MT Vernon, IL 62864 | Oil & Gas Operator | Dec 2016 |
| 818 | Orr Robert W Jr | Zanesville, OH 43702-2683 | Oil & Gas Operator | Dec 2017 |
| 819 | Orwig Oil Company Inc | Brandenton, FL 34212 | Oil & Gas Operator | Dec 2017 |
| 820 | Osair Inc | Mentor, OH 44061 | Oil & Gas Operator | Dec 2016 |
| 821 | Otex Inc | N Canton, OH 44720 | Oil & Gas Operator | Dec 1988 |
| 822 | Oxford Oil | Zanesville, OH 43702-0910 | Oil & Gas Operator | Dec 2012 |
| 823 | P & D Valentine Oil Co | New Matamoras, OH 45767 | Oil & Gas Operator | Dec 2017 |
| 824 | P & S Energy Inc | Mineral Ridge, OH 44440 | Oil & Gas Operator | Dec 2017 |
| 825 | P & S Production LLC | Ravenna, OH 44266 | Oil & Gas Operator | Dec 2013 |
| 826 | P P & G Oil | Pickerington, OH 43147 | Oil & Gas Operator | Dec 2017 |
| 827 | P. D. L. Services, Inc. | Paris, OH 44669 | Oil & Gas Operator | Dec 2016 |
| 828 | Pac Drilling LLC | Bolivar, OH 44612 | Oil & Gas Operator | Dec 2017 |
| 829 | Pace Co/Chas E Hall | Marietta, OH 45750 | Oil & Gas Operator | Dec 1990 |
| 830 | Paragon Energy Co | Columbus, OH 43214 | Oil & Gas Operator | Dec 1989 |
| 831 | Parker Hannifin Corp | Ravenna, OH 44266 | Oil & Gas Operator | Dec 2017 |
| 832 | Parkside Pet Of Ohio Inc | Granville, OH 43023 | Oil & Gas Operator | Dec 1987 |
| 833 | Paroco DRLG Funds Inc | Houston, TX 77002 | Oil & Gas Operator | Dec 1993 |
| 834 | Parrot Energy Company | Cortland, OH 44410 | Oil & Gas Operator | Dec 2016 |
| 835 | Partners Oil Company | ***Crooksville, OH 43731 | Oil & Gas Operator | Aug 1995 |
| 836 | Partners Petroleum Inc | Independence, OH 44131 | Oil & Gas Operator | Dec 1988 |
| 837 | Paw Oil And Gas LTD | North Canton, OH 44720 | Oil & Gas Operator | Dec 2017 |
| 838 | PDC Energy Inc | Denver, CO 80203 | Oil & Gas Operator | Jul 2018 |
| 839 | PDQ Oil & Gas LLC | The Plains, OH 45780 | Oil & Gas Operator | Dec 2017 |
| 840 | Pedgeco Inc | Cleveland, OH 44115 | Oil & Gas Operator | Dec 1984 |
| 841 | Pelican Producing Inc | Caldwell, OH 43724 | Oil & Gas Operator | Dec 1996 |
| 842 | Pemco Gas Inc | Indian Harbor B, FL 32937 | Oil & Gas Operator | Dec 1997 |
| 843 | Peninsula Group Inc | Peninsula, OH 44264 | Oil & Gas Operator | Dec 1991 |
| 844 | Peninsular Oil & Gas Co | Ada, MI 49301-96 | Oil & Gas Operator | Dec 1997 |
| 845 | Penn-Ohio Investment Corp. | New Philadelphi, OH 44663 | Oil & Gas Operator | Dec 2004 |
| 846 | Pennzenergy | Houston, TX 77252 | Oil & Gas Operator | Dec 1986 |
| 847 | Pep Drilling LLC | MT Vernon, IL 62864 | Oil & Gas Operator | Dec 2017 |
| 848 | Pepper Oil Co | Newark, OH 43055 | Oil & Gas Operator | Dec 1992 |
| 849 | Peroco Oil & Gas | Killbuck, OH 44637 | Oil & Gas Operator | Dec 1987 |
| 850 | Pet Processors L.L.C | Painesville, OH 44077 | Oil & Gas Operator | Dec 2017 |
| 851 | Petro Drilling Corp | Columbus, OH 43229 | Oil & Gas Operator | Dec 1993 |
| 852 | Petro Evaluation Serv Inc | Wooster, OH 44691 | Oil & Gas Operator | Dec 2017 |
| 853 | Petro Quest Inc | Guysville, OH 45735 | Oil & Gas Operator | Dec 2017 |
| 854 | Petro-Mark, Inc. | St Petersburg, FL 33701 | Oil & Gas Operator | Dec 2017 |
| 855 | Petrocon Inc | Delaware, OH 43015-7147 | Oil & Gas Operator | Dec 2010 |
| 856 | Petroel | Marietta, OH 45750 | Oil & Gas Operator | Dec 2000 |
| 857 | Petroleum Development Cor | Bridgeport, WV 26330 | Oil & Gas Operator | Dec 2004 |
| 858 | Petrox, Inc | Streetsboro, OH 44241 | Oil & Gas Operator | Dec 2017 |
| 859 | Pettigrew Pumping Service Inc | Ravenna, OH 44266 | Oil & Gas Operator | Dec 2017 |
| 860 | Phillips Exploration Inc | Warrendale, PA 15086 | Oil & Gas Operator | Dec 2012 |
| 861 | Phillips Margaret E | Newark, OH 43055 | Oil Operator | Dec 1993 |
| 862 | Phoenix NTL Petroleum Co | Englewood, NJ 7631 | Oil & Gas Operator | Dec 1990 |
| 863 | Piatt Enterprises LLC | Graysville, OH 45734 | Oil & Gas Operator | Dec 2017 |
| 864 | Pillar Energy, LLC | Charleston, WV 25330 | Oil & Gas Operator | Dec 2017 |
| 865 | Pilot Energy LLC | Zanesville, OH 43701 | Oil & Gas Operator | Dec 2013 |
| 866 | Pin Oak Energy Partners LLC | Akron, OH 44308-1357 | Oil & Gas Operator | Jul 2018 |
| 867 | Pin Oak Petroleum Inc | Dallas, TX 75251 | Oil & Gas Operator | Dec 1989 |
| 868 | Pine Top Inc | Akron, OH 44313 | Oil & Gas Operator | Dec 2016 |
| 869 | Pineco | Laurelville, OH 43135 | Oil & Gas Operator | Dec 2017 |
| 870 | Pinevue Farms | Chillicothe, OH 45601 | Oil & Gas Operator | Dec 1993 |
| 871 | Pioneer Drilling Co | Payne, OH 45880 | Oil & Gas Operator | Dec 1993 |
| 872 | Pioneer Resources Inc | Phillipsburg, KS 67661 | Oil & Gas Operator | Jun 2018 |
| 873 | Pipes Pursie E | MT Vernon, IL 62864 | Oil & Gas Operator | Dec 2014 |
| 874 | Pittencrieff America, Inc. | Abilene, TX 79608 | Oil & Gas Operator | Feb 2003 |
| 875 | Pleasant Hill Oil Co | Carrollton, OH 44615 | Oil Operator | Dec 2006 |
| 876 | Poling Albert | Logan, OH 43138 | Oil Operator | Dec 2017 |
| 877 | Pominex Inc | Cols, OH 43214 | Oil & Gas Operator | Dec 1988 |
| 878 | Ponderosa Consult Ser Inc | Wooster, OH 44691 | Oil & Gas Operator | Dec 2017 |
| 879 | Portage Exploration Co In | Salem, IL 62881 | Oil & Gas Operator | Dec 2004 |
| 880 | Portage Resources Inc | Warren, OH 44484 | Oil & Gas Operator | Dec 2015 |
| 881 | Porter Brothers | Zanesville, OH 43701 | Oil & Gas Operator | Dec 1995 |
| 882 | Porter Petroleum | Hopewell, OH 43746 | Oil & Gas Operator | Dec 2017 |
| 883 | Poston Operating Co Inc | Ashley, OH 43003 | Oil & Gas Operator | Dec 2003 |
| 884 | Pottmeyer David | Fleming, OH 43729 | Oil & Gas Operator | Dec 2017 |
| 885 | Power Gas Marketing & Trans | Akron, OH 44311-1057 | Oil & Gas Operator | Dec 2005 |
| 886 | Power Resour Oper Co Inc | Canton, OH 44718 | Oil & Gas Operator | Dec 2005 |
| 887 | Prime Time Energy Invest | MT Vernon, OH 43050 | Oil & Gas Operator | Dec 2017 |
| 888 | Proco | Wooster, OH 44691 | Oil Operator | Dec 1988 |
| 889 | Profit Energy Company | Jerusalem, OH 43747 | Oil & Gas Operator | Dec 2017 |
| 890 | Progressive Oil & Gas | Moxahala, OH 43761 | Oil & Gas Operator | Dec 2017 |
| 891 | Protege Energy III LLC | Tulsa, OK 74114 | Oil & Gas Operator | Oct 2018 |
| 892 | Provident Oil & Gas Co | Akron, OH 44313 | Oil & Gas Operator | Dec 1989 |
| 893 | Provident Oil & Gas Corp | Akron, OH 44333 | Oil & Gas Operator | Dec 1991 |
| 894 | Putnam, William H | Marietta, OH 45750 | Oil & Gas Operator | Dec 2017 |
| 895 | Quadrant Exploration Inc | Marietta, OH 45750 | Oil & Gas Operator | Dec 2000 |
| 896 | Quail Energy Corp | MT Gilead, OH 43338 | Oil & Gas Operator | Dec 2010 |
| 897 | Quaker State Oil Ref Corp | North Canton, OH 44720-1541 | Oil & Gas Operator | Dec 1994 |
| 898 | Quality Oil & Gas Corp | Alliance, OH 44601 | Oil & Gas Operator | Dec 2017 |
| 899 | Questa Petroleum Co | Greensburg, PA 15601 | Oil & Gas Operator | Dec 2006 |
| 900 | R & D Exploration Inc | Akron, OH 44303-1460 | Oil & Gas Operator | Dec 2017 |