| 901 | Petro Nova | | Oil Operator | Dec 2000 |
| 902 | Petro Oil Produc | | Oil Operator | Aug 1989 |
| 903 | Petro Oilfield Equipment Inc | Drumright, OK 74030-1233 | Oil & Gas Operator | Dec 2010 |
| 904 | Petro Operating Company | | Oil & Gas Operator | Dec 2024 |
| 905 | Petro Operating Company LLC | | Oil & Gas Operator | Jun 2025 |
| 906 | Petro Pak Corpor | | Oil Operator | Aug 1988 |
| 907 | Petro Plex Oil Co Inc. | Homosassa, FL 34448 | Oil & Gas Operator | Jul 2020 |
| 908 | Petro Producers Corporation | | Oil & Gas Operator | Mar 1993 |
| 909 | Petro Productions,Petrotec Production,Inc Dba | Wichita, KS 67202 | Oil Operator | Aug 1993 |
| 910 | Petro Quest Inc | Guysville, OH 45735 | Oil & Gas Operator | Dec 2024 |
| 911 | Petro Resources, Inc. | Fulton, TX 78358 | Oil & Gas Operator | Sep 2025 |
| 912 | Petro River Operating, LLC | New York City, NY 10017 | Oil & Gas Operator | Jul 2011 |
| 913 | Petro Speed Inc | Norman, OK 73069-8116 | Oil & Gas Operator | Mar 2015 |
| 914 | Petro SVC Partners Inc | Indiana, PA 15701-8556 | Oil & Gas Operator | Dec 2024 |
| 915 | Petro Valley Ser | | Gas Operator | Dec 1986 |
| 916 | Petro Ventures Inc | Oklahoma City, OK 73118 | Oil & Gas Operator | Dec 2019 |
| 917 | Petro Vest Operating LLC | | Oil Operator | Aug 2013 |
| 918 | Petro Vest, Inc. | Houston, TX 77046 | Oil & Gas Operator | Sep 2014 |
| 919 | Petro Warrior LLC | Wichita, KS 67206 | Oil & Gas Operator | Jun 2025 |
| 920 | Petro-Assets Corporation | | Oil & Gas Operator | Feb 2000 |
| 921 | Petro-Beth Oil & Gas, Inc. | Abilene, TX 79604 | Oil & Gas Operator | Mar 2006 |
| 922 | Petro-Canada Resources (USA) | | Oil & Gas Operator | Dec 2009 |
| 923 | Petro-Canada Resources (USA) Inc | Denver, CO 80202-472 | Oil & Gas Operator | Feb 2010 |
| 924 | Petro-Chem Operating Company, Inc. | Shreveport, LA 71101 | Oil & Gas Operator | Sep 2025 |
| 925 | Petro-Flow, Inc | | Gas Operator | Dec 2023 |
| 926 | Petro-Go, Inc. | | Oil & Gas Operator | Mar 1996 |
| 927 | Petro-Guard Company, Inc. | Houston, TX 77057 | Oil & Gas Operator | Nov 2014 |
| 928 | Petro-Guard Production,L.L.C. | Houston, TX 77063 | Oil & Gas Operator | Dec 2024 |
| 929 | Petro-Haley | Borger, TX 79008 | Oil & Gas Operator | Sep 2025 |
| 930 | Petro-Hunt Corporation | Dallas, TX 75201 | Oil & Gas Operator | Jun 2003 |
| 931 | Petro-Hunt Dakota, LLC | | Oil & Gas Operator | Jul 2025 |
| 932 | Petro-Hunt Permian, LLC | Dallas, TX 75201 | Oil & Gas Operator | Sep 2025 |
| 933 | Petro-Hunt, L.L.C. | Dallas, TX 75201 | Oil & Gas Operator | Sep 2025 |
| 934 | Petro-Lewis Corp. | | Oil & Gas Operator | Feb 1994 |
| 935 | Petro-Lud Inc. | | Oil & Gas Operator | Jul 2025 |
| 936 | Petro-Mac Corporation | Tulsa, OK 74103 | Oil & Gas Operator | Apr 2025 |
| 937 | Petro-Management Assoc., Inc. | Edmond, OK 73083-2346 | Oil & Gas Operator | Jun 2007 |
| 938 | Petro-Management Inc | | Oil Operator | Dec 1998 |
| 939 | Petro-Mark, Inc. | St Petersburg, FL 33701 | Oil & Gas Operator | Dec 2021 |
| 940 | Petro-Met Energy LLC | Edmond, OK 73034-1237 | Oil Operator | May 2025 |
| 941 | Petro-Raider LLC | Midland, TX 79702 | Oil & Gas Operator | Sep 2025 |
| 942 | Petro-Smith Operating LLC | Houston, TX 77010 | Oil & Gas Operator | Sep 2025 |
| 943 | Petro-Technology | | Oil & Gas Operator | Aug 1991 |
| 944 | Petro-Technology, Inc. | Topeka, KS 66604 | Gas Operator | Dec 1997 |
| 945 | Petro-Tex Energy & Expl.Co.,Inc. | Llano, TX 78643 | Oil & Gas Operator | Sep 2025 |
| 946 | Petro-Ventures, Inc. - Miss. | | Oil & Gas Operator | Apr 2009 |
| 947 | Petro-West Corporation | Lubbock, TX 79404 | Oil & Gas Operator | Oct 2001 |
| 948 | Petro-X Corporation | Houston, TX 77092 | Oil & Gas Operator | Jul 2002 |
| 949 | Petrobal Omega 1, LLC | Little Elm, TX 75068 | Oil & Gas Operator | Sep 2025 |
| 950 | Petrobank Opr Co | Denver, CO 80202-4675 | Gas Operator | Dec 1992 |
| 951 | Petrocan, Inc. | | Oil & Gas Operator | Apr 1998 |
| 952 | Petrocana,Inc. | | Oil & Gas Operator | Aug 1993 |
| 953 | Petrocat Innovations, LLC | Forney, TX 75126 | Oil Operator | Sep 2025 |
| 954 | Petrocoastal, Inc. | Frisco, TX 75036 | Oil & Gas Operator | Sep 2025 |
| 955 | Petrocon Inc | Delaware, OH 43015-7147 | Oil & Gas Operator | Dec 2010 |
| 956 | Petrocorp | | Oil & Gas Operator | Nov 1992 |
| 957 | Petrocorp Acquisition Company | Tulsa, OK 74121 | Oil & Gas Operator | Dec 2002 |
| 958 | Petrocorp Incorporated | Tulsa, OK 74170 | Oil & Gas Operator | Nov 2021 |
| 959 | Petrocorp Incorporated,A TX.Corp | Tulsa, OK 74170 | Oil & Gas Operator | Apr 2005 |
| 960 | Petroda Oil & Gas LLC | Edmond, OK 73054 | Oil & Gas Operator | Feb 2023 |
| 961 | Petrodata Resources, Inc. | Midland, TX 79702 | Oil & Gas Operator | Sep 2025 |
| 962 | Petrodome Operating, LLC | Houston, TX 77265 | Oil & Gas Operator | Apr 2025 |
| 963 | Petrodril Inc | Farmington, NM 87401 | Oil & Gas Operator | Jan 1987 |
| 964 | Petroel | Marietta, OH 45750 | Oil & Gas Operator | Dec 2000 |
| 965 | Petroflow Energy Corporation | Tulsa, OK 74119-5405 | Oil & Gas Operator | Oct 2016 |
| 966 | Petrofunds, Inc & Sunny South | | Oil & Gas Operator | Feb 1984 |
| 967 | Petrofunds, Inc. | Shreveport, LA 71101 | Oil & Gas Operator | Jun 1996 |
| 968 | Petrofunds, Inc. & Herd | | Oil & Gas Operator | Mar 1984 |
| 969 | Petrogas Energy Services, LLC | Dallas, TX 75214 | Oil Operator | Sep 2025 |
| 970 | Petrogas Exploration Inc | | Oil Operator | Feb 2025 |
| 971 | Petrogas Operating Corporation | Garland, TX 75043 | Oil Operator | Feb 2010 |
| 972 | Petrogen, Incorporated | Katy, TX 77450 | Oil & Gas Operator | Jan 2012 |
| 973 | Petroglen Company, Inc. | | Oil & Gas Operator | Jul 1990 |
| 974 | Petroglyph Operating Co | Boise, ID 83709 | Oil & Gas Operator | Jul 2017 |
| 975 | Petrogulf Corporation | Denver, CO 80202 | Oil & Gas Operator | Sep 2025 |
| 976 | Petrohawk Energy Corporation | Houston, TX 77002 | Oil & Gas Operator | Jun 2005 |
| 977 | Petrohawk Operating Company | Houston, TX 77056 | Oil & Gas Operator | Oct 2021 |
| 978 | Petrojen Production Company Inc | Bakersfield, CA 93311 | Oil Operator | Jul 2025 |
| 979 | Petrol Industries, Inc. | Shreveport, LA 71137 | Oil & Gas Operator | Jun 2012 |
| 980 | Petrol Oil & Gas, Inc. | Overland Park, KS 66210 | Oil & Gas Operator | Dec 2008 |
| 981 | Petrolanic Inc | Tulsa, OK 74105 | Oil Operator | Oct 1991 |
| 982 | Petrolegacy Energy II, LLC | Denver, CO 80202 | Oil & Gas Operator | Jun 2023 |
| 983 | Petrolero Corp. | San Antonio, TX 78205 | Oil & Gas Operator | Sep 1994 |
| 984 | Petrolero, LLC | Plano, TX 75026 | Oil & Gas Operator | Sep 2025 |
| 985 | Petroleum Advisors Int'L., Inc. | Houston, TX 77224 | Gas Operator | Jun 2005 |
| 986 | Petroleum Capital, L.C. | Dallas, TX 75367 | Oil & Gas Operator | Sep 2025 |
| 987 | Petroleum Corpor | | Oil Operator | Jan 1983 |
| 988 | Petroleum Corporation Of Texas | Breckenridge, TX 76024 | Oil & Gas Operator | May 2002 |
| 989 | Petroleum Develo | | Oil Operator | Sep 1986 |
| 990 | Petroleum Development Company | Tulsa, OK 74103 | Oil & Gas Operator | May 2025 |
| 991 | Petroleum Development Cor | Bridgeport, WV 26330 | Oil & Gas Operator | Dec 2004 |
| 992 | Petroleum Development Corporation | Denver, CO 80202 | Oil & Gas Operator | Dec 2017 |
| 993 | Petroleum Development LLC | | Oil Operator | Jul 2018 |
| 994 | Petroleum Energy | | Oil & Gas Operator | Mar 1991 |
| 995 | Petroleum Energy Corp | | Oil & Gas Operator | Aug 2012 |
| 996 | Petroleum Energy, Inc. | Wichita, KS 67202 | Oil Operator | May 1999 |
| 997 | Petroleum Engineering & Management Corp. | Casper, WY 82609 | Oil & Gas Operator | Jul 2018 |
| 998 | Petroleum Engineers, Inc. | | Oil & Gas Operator | Jun 1983 |
| 999 | Petroleum Enterp | | Oil & Gas Operator | Sep 1995 |
| 1000 | Petroleum Enterprises, Inc. | Hutchinson, KS 67504 | Oil & Gas Operator | May 2001 |