Offshore oil rigs are some of the largest structures found on the water, but are they just floating out there? How do they stay in place? Here's what we know.

Once a deposit of oil has been found deep under ... the petroleum comes up from the sea floor. Offshore rigs usually also have helipads, living quarters and lifeboats for the crew that work ...

The deepest offshore oil well was over 35,000 feet by the Deepwater Horizon, and the Maersk Voyager operated in the deepest ...