accumulation
bank
barrel
borehole
ca
california
chain link
chamber
chemistry
chink
competition
concept
deposit
digging
economy
energetic
engineering
exploitation
extraction
fence
fuel
geological
hill
hole
industry
ledge
long beach
los angeles
mineral
oil
oil derrick
petroleum
pipe
power
production derrick
pump
pumpset
refinery
rig
rivalries
rivalry
signal
signal hill
spoil
technology
tower
treasures of the soil
usa
well
work