A TLP Solution for 8000 Ft Water Depth

Abstract

A Tension Leg Platform (TLP) solution is proposed for dry tree applications in ultra-deep water depths (∼8000 ft). Major challenges for a TLP associated with the ultra deep environment are addressed with an innovative air spring – mass vibration absorber (VAB) system introduced by SBM Atlantia. The tendon system for the TLP therefore is able to scale essentially linearly with the water depth, instead of quadratically for a conventional TLP. This paper details the integrated platform design issues, including the hull, tendon design and the coupled motion analysis approach. It also discusses the system weight and dimension scales for typical applications and the constructability in terms of their upper bound limits compared with existing platforms. A design example is presented for the offshore Brazil Santos Basin environment at 8000 ft water depth with consistent current and relatively large fatigue sea states.

A New Energy-Absorbing Device for Motion Suppression in Deep-Sea Floating Platforms

“…Researchers have proposed various devices to control the vibration of a floating platform. Vibration-induced vertical motion of TLPs can be balanced by using absorbers with air springs [9][10][11]. Zhu et al [12] and Ou et al [13] proposed the Moveable Heave Plate (MHS) to simulate the mooring damping system to suppress the heave motion of a semi-submersible platform.…”

The effect of an orifice plate with different orifice numbers and shapes on the damping characteristics of a dual-chamber air spring

“…Additionally, Jing et al [10,11] proposed a method of nonlinear characteristic output spectrum (nCOS) to effectively solve the issue of air springs in a nonlinear vehicle suspension system based on the Volterra series expansion system principle. Rijken, Bian, Spillane, et al [12][13][14] investigated the adoption of a vibration-absorbing system composed of a dual-chamber air spring and a liquid column to suppress the resonant response of a marine platform. They investigated the influence of a circular orifice ratio on the structural damping.…”

The Stiffness and Damping Characteristics of a Dual-Chamber Air Spring Device Applied to Motion Suppression of Marine Structures

“…Dual-chamber air springs are an effective energy-absorbing device used as a key component for vibration isolation. Rijken, Bian, and Spillane et al [13][14][15] applied a system of vibration absorbers using dual-chamber air springs and water columns to suppress resonant motions and studied the effects of the orifice ratio for structural damping. Bachrach and Rivin [16] studied the complex dynamic stiffness of the damper spring, a function of the excitation frequency.…”