The complete paper is a comprehensive discussion of the development and deployment of the tension leg platform (TLP), one of the four major platform types that also include floating production, storage, and offloading (FPSO) vessels; semisubmersible floating production systems; and spar platforms. The authors summarize the evolution of the TLP during a nearly 4-decade span and provide a retrospective of the progression of TLP technology, including hull shapes, tendon connectors, flex elements, and riser systems.
A Design Driven by Function
Although the technology involved may be impressive, the authors remind that essentially it is merely a means of supporting a payload economically in deep water within required motion limits. The ultimate objective is to provide the most cost-effective, safe, reliable platform to meet functional requirements.
After almost 50 years of deepwater development, platform concepts have broadly stabilized into four categories of functionality: semisubmersibles, TLPs, spars, and ship-shaped FPSOs. Each of these concepts brings unique functionality with different cost/benefit tradeoffs.
The driver behind the TLP concept was straightforward from an operator’s perspective: Provide a platform that behaves like a fixed platform with regard to the wells (i.e., dry trees; direct vertical access to wells; minimal tensioner stroke, allowing an array of wells in close proximity without giant tensioner systems such as those found on drilling semisubmersibles; and enabling export risers) in water depths much deeper than any fixed platform.
This functionality, however, comes at a cost.
