Working in the oil and gas industry offshore can be very rewarding, but the rewards are hard-earned...

There is no doubt that the offshore oil and gas industry offers a great many career opportunities and the rewards can be significant. However, these rewards are hard-earned, and it is not everyone who can adapt to living and working offshore.

Living conditions can vary greatly between each offshore installation. Older production platforms and flotels might be less spacious than a more recently built drilling rig – but the standards are generally excellent.

There are many different types of rig including:

Production platform
Production platforms are permanent, immobile structures built on steel and/or concrete legs that are fixed directly onto the seabed. They are the largest type of structure you would work on offshore. They are built once oil or gas (hydrocarbon) has been found in commercially produce-able quantities and although further drilling will often take place on the platform, its main purpose is producing the hydrocarbon. Often, a single platform will gather hydrocarbon from a number of outlying wells through what are known as ‘tiebacks’ – a network of valves and pipes that rest on the sea bed.

Semi Submersible
Platform Semi-submersible platforms or rigs are floating (mobile) structures used for drilling for oil and natural gas in offshore environments. They have a number of pontoons and/or columns that are flooded with seawater, causing the installation to sit very low in the water, providing the stability that is required for drilling operations. The unit is fixed in position with very large mooring anchors and is moved from location to location by tugs. These types of installation can drill in very deep, rough water due to their excellent stability.

Jack-up Rig
A Jack-up rig is a self-contained combination drilling rig and floating barge, which has been fitted with long legs that are raised when moving and lowered to the sea bed when on location. The rig is limited to operating in water depths of a maximum of about 400 feet (depending on the rig) – which is sufficient for many parts of the North Sea. Like the semi-submersible it is moved from location to location by tugs.

Drill Ship
A Drill ship is a maritime vessel that has been fitted with drilling equipment. They can move under their own power and, though not as stable as semi-submersible platforms, they can drill in deep water. A drill ship is held in position over the well by a combination of its own engines turning powerful screws in the hull and global positioning satellite (GPS) technology.

Floating Production and Storage Offloading Vessel (FPSO’s)
A FPSO is a type of floating tank system used by the offshore oil and gas industry. They are often converted oil tankers – although increasingly they are purpose built – which attach to a sea bed wellhead from which they produce and store the oil. The oil is then offloaded to another tanker for transport to the refinery. They are particularly used for production from small reservoirs where it would be too expensive to build a production platform – one of the major advantages is that the FPSO is re-usable as it can be moved from well to well.

Flotels
Flotels are literally floating accommodation units. They are quite often converted from semi-submersible platforms; these are then moored alongside a production platform or other type of rig, and connected to them via a long gangway. This is one way of keeping the accommodation, leisure and catering facilities remote from the working areas which is a legal requirement in the North Sea.