Tension Leg Platform (TLP)

Abstract

Tension leg platforms (TLPs) are floating structures moored to the seabed by multiple vertically arranged tension members called tendons . TLPs are mainly used as production and drilling platforms for offshore oil and gas field developments. Since the first TLP was put into service in the North Sea in 1984, a total of 26 TLPs have been installed in water depths ranging from 147 to 1425 m. TLPs are currently not considered viable beyond about 1800 m water depth due to the size and cost of the tendon system required for deeper water. Tendons are kept under tension by excess buoyancy of the hull. Their stiffness restrains the heave and pitch motions of the platform to a large extent. Due to the restrained heave and pitch motions, the main well control valves (i.e., the production trees) can be located on the platform. For most other floating platforms, the production trees have to be located on the seabed.