How do they build oil rigs, in the water ?

Question

What are the process
How do they dig through the ocean
Just a little bit of everything

In: Engineering

Answer 1

Oil rigs have legs that look like bell-bottom pants. The rig is built close to shore or even up a river. The bell shape legs are later pressurized with air to raise the rig higher in order to be towed out to sea.

Once in deep water and near its destination the bells are filled with water and lowered to it’s desired height from sea level. The legs never touch the bottom but are anchored to the seabed preventing the oil rig from floating away.

There are some really big rigs that have sections shipped out on barges and assembled onto the oil rig platform.