This means that you'll be able to search for NAICS codes directly (if that's your jam). We'll do the math; let's make better data on public procurement together.
Possible NAICS Codes
541330 – Engineering Services
541310 – Architectural Services
324191 – Petroleum Lubricating Oil and Grease Manufacturing
237120 – Oil and Gas Pipeline and Related Structures Construction
221112 – Fossil Fuel Electric Power Generation