Off shore rigs, also called oil platforms, extract oil from the earth. Off shore rigs are quite large structures, and if close to one, it probably wouldn't be too hard to see it. Off shore rigs explore, extract, store, and process petroleum (basically oil). An off shore rig extracts the oil from rocks below the seabed. It is very dangerous and difficult work to work at an oil rig, but salaries are often quite high, partially compensating for the risk.
