The popular image of offshore work often centers on a muddy drill floor, where wells are drilled to target the reservoirs of oil and gas below the surface - but this is only the beginning of the story.
The top end of each production well sprouts a branching series of pipes, gauges and valves called the 'Christmas tree'. At this point, crude oil is a hot, frothy, corrosive, high-pressure fluid containing gas, water and sand.
After separation, the crude oil is metered and pumped into the pipeline, or stored until sent ashore by tanker.
The gas separated from the oil may be used for fuel, or compressed and piped to shore or re-injected into the reservoir. Any gas that cannot be used is burnt in the platform's flare, very little gas is now flared.
Processing systems for the gas fields of the southern North Sea are relatively simple. The gas liquids are removed and then the gas is compressed, cooled, dehydrated and metered before being piped to shore.
All production and drilling systems have to be monitored constantly for leaks, since oil and gas are hazardous and extremely flammable.
There is no mains electricity offshore! Power has to be generated on the installation to drive production and drilling equipment, and to support life.
In other words, offshore installations are packed with complex equipment and systems that need to be operated and maintained safely by highly skilled people who understand the technology and the processes involved, and who can work together in integrated teams.