A compliant tower (CT) is a fixed rig structure normally used for the offshore production of oil or gas.
The rig consists of narrow, flexible (compliant) towers and a piled foundation supporting a conventional deck for drilling and production operations.
Compliant towers are designed to sustain significant lateral deflections and forces, and are typically used in water depths ranging from 1,500 to 3,000 feet (450 to 900 m).
They demonstrate static stability but have a much greater degree of lateral deformation/flexibility vs land-base structures, up to 2.5% vs 0.5%[1] and are partially supported by buoyancy.
Compared with floating systems, such as tension-leg platforms and SPARs, the production risers are conventional and are subjected to less structural demands and flexing.