The North Sea is a continental shelf body of water lying between the east coast of the UK and Europe, namely Norway, Denmark, Germany, The Netherlands and Belgium. It is a shallow sea, averaging around 30 metres deep in the south to around 100 metres deep in the north, up to Shetland. The vast reserves of oil below its surface and its relative accessability has meant that the oil industry has been present in the region in ernest since the early 1970s.

I worked in the oil industry on a summer placement in 2004, which involved a couple of trips to offshore installations. I spent nine days aboard the jack-up drilling rig Maersk "Innovator" in the central North Sea, 161 miles ESE of Aberdeen, by the border with the Norwegian sector, and three days on board the Transocean "JW McLean", approximately 120 miles NE of Aberdeen.

Here I am aboard the Innovator with my sparkly clean new overalls - instantly identifying me as a rookie. The green hard hat also shows that I am an infrequent visitor to this particular rig. I am carrying a gas detector over my shoulder, required during photography as the batteries and flash on a camera can be an ignition source.

This is a view of the Innovator deck from the top of the derrick, 250 feet above the deck and 400 feet above the sea. The cranes were nicely placed for this picture. Surrounding the forward leg is the accommodation block, and behind it is the helipad.

The derrick stands on top of the cantilever section, which skids out over the top of the wellhead platform to drill through it. Consequently, I am standing on a 6000 tonne lump of the rig which isn't supported from underneath, there is just fresh air. When the rig is not drilling, the cantilever is skidded back in over the deck and does not overhang the water.

Innovator stands on three triangular profile legs, at each corner of which is a continuous rack from top to bottom. Each tooth here is about 6 inches wide at the base. The rig hull "climbs" up the racks to lift itself out of the water. The legs are 205 metres high, about same as a 50 storey office building, allowing the rig to operate safely in water 150 metres deep. At this central North Sea field the water is 80 metres deep, so there is a lot of spare leg sticking up.

Here we can see the six jacking motors which operate on one of the nine racks, giving a total of 54 motors used to lift the 28,000 tonne rig out of the water. The motors are geared down 1:5000 and run electrically, lifting the rig up at just a few inches per minute. Once in place, the racks are clamped and the load is removed from the motors.

Looking down through the hollow of the forward leg from the deck to the seabed, you can see a ladder going all the way down - about the last resort for escape short of jumping.

There is a standby boat continually circling the rig, in case assistance is required or to rescue anyone who might be unfortunate enough to fall off. Here you can also see the underside of the helipad and one of the four lifeboats, each of which can carry 60 people.

Accommodation on board the Innovator is some of the best in the offshore oil and gas industry today. Bunks were not used to eliminate the number of annual injuries due to falling out of bed, and there is an ensuite toilet and shower in each cabin. At the bottom of the mirror is written: "This is the person who is responsible for your safety today".

The galley was my favourite place on board, there are four buffet meals served each day, with lots of chips and a selection of desserts. A cooked breakfast was the order of each morning, and who would know what delights would be in store for lunch, dinner and the midnight meal? If I work offshore full time, I will have to exercise some more self-control.

After all that lovely nosebag you can visit the gym to alleviate some guilt and possibly even some weight, it is one of the best equipped gyms to be found on an oil rig anywhere.

Other sources of entertainment were available, such as TV rooms, a cinema, internet cafe and pool. I was told that somebody once put a pool room on a floating facility, not realising their folly.

I was on board the Innovator to witness the well flow test, which looked like this. Unfortunately I could not stay long enough for it; this picture was taken just a couple of days after I left. The well is flowed to clear out impurities and to test it, the gas is not suitable for production at this stage so it is flared. There is a water deluge curtain in place to protect the rig.

Maersk Innovator as seen from a helicopter, during the well flow. The accommodation block and helipad are in the foreground. The starboard flare boom is in use due to the wind direction, but if necessary the gas can be flared out of the other side.