| 901 | Weaver & Mola | | Oil Operator | Dec 1990 |
| 902 | Weaver & Weaver | | Oil & Gas Operator | Dec 1988 |
| 903 | Weir Oil Co. Inc. | | Oil & Gas Operator | Dec 2007 |
| 904 | Well Water Management | | Oil & Gas Operator | Dec 2025 |
| 905 | West American Energy Corporation | | Oil & Gas Operator | Jul 2026 |
| 906 | West Coast Oil Company | | Oil Operator | Dec 1996 |
| 907 | West Coast Operators Inc. | | Oil & Gas Operator | Jul 2026 |
| 908 | West Energy Operating LLC | | Oil & Gas Operator | Jul 2026 |
| 909 | West Newport Oil Co. | | Oil & Gas Operator | Dec 2025 |
| 910 | West Side Rentals | | Oil & Gas Operator | Dec 2025 |
| 911 | Western Avenue Properties | | Oil & Gas Operator | Dec 1993 |
| 912 | Western Continental Operating Company | | Oil & Gas Operator | Dec 2007 |
| 913 | Western Discovery USA Inc. | | Oil & Gas Operator | Jan 2018 |
| 914 | Western Metals Corporation | | Oil & Gas Operator | Jul 2026 |
| 915 | Western Oil Independent LLC | | Oil & Gas Operator | Dec 2016 |
| 916 | Western States International Inc. | | Oil & Gas Operator | Dec 2025 |
| 917 | Westside Farming Co. Inc. | | Gas Operator | Dec 1995 |
| 918 | Whisler Enterprise Company | Erie, CO 80516 | Oil & Gas Operator | Jul 2026 |
| 919 | White Knight Production LLC | Lafayette, LA 70505 | Oil & Gas Operator | Feb 2024 |
| 920 | Whiting Oil And Gas Corporation | Houston, TX 77002 | Oil & Gas Operator | Sep 2026 |
| 921 | Whiting Petroleum Corporation | Denver, CO 80290 | Oil & Gas Operator | Jan 2025 |
| 922 | Wilco-Placentia Oil Operator LLC | | Oil & Gas Operator | Jul 2026 |
| 923 | Wild Goose Storage LLC | | Gas Operator | Jul 2026 |
| 924 | William K. Barker & Associates | | Oil & Gas Operator | Dec 1986 |
| 925 | Williams Oil Company | Midland, TX 79710 | Oil & Gas Operator | Sep 2026 |
| 926 | Windrush Operating Co., L.L.C. | Longville, LA 70652 | Oil & Gas Operator | Sep 2026 |
| 927 | WM. H. Brayton Trust | | Oil & Gas Operator | Dec 2000 |
| 928 | Woodward Petroleum | | Oil & Gas Operator | Dec 2003 |
| 929 | Worldwide Energy Corporation | Freer, TX 78357 | Oil & Gas Operator | Jan 1997 |
| 930 | Yoelin Family Trust | | Oil & Gas Operator | Jun 2026 |
| 931 | Yunker Oil Co. | | Oil & Gas Operator | Dec 1986 |
| 932 | Zonal Holding Corp. | | Oil Operator | Dec 1998 |
| 933 | Zynergy LLC | | Oil Operator | Dec 2025 |