機器
abstract
background
barrel
black
black gold
black oil
business
chemical
close up
crisis
crude
dark
design
diesel
dirty
droplet
energy
engineer
environment
environmental
exploration
factory
flow
fossil
fuel
gasoline
generation
industrial
industry
liquid
man
natural
nature
oil
oilfield
petroleum
pipeline
pollution
pouring
power
resource
technology
wave
well
worker