architecture

big

built

derrick

device

dig

digger

drill

drilling

energy

engineering

equipment

exploration

factory

fossil

hang

hanging

headgear

heavy

industrial

industry

iron

ladder

large

machine

machinery

metal

oil

rig

oilfield

outdoors

petrochemical

petroleum

power

production

railing

sky

spiral

staircase

steel

steps

storage

structure

sunlight

suspended

tank

technology

tool

tower

field

used

construction

equipped

drills

wells

natural

gas

extraction