Efficient Integrated Analysis Methods for Deepwater Platforms

Abstract

Deep Water Floating Production Systems is an integrated dynamic system of risers, moorings and a floater responding in a complex way to loading from wind, waves and currents. The great challenge in selecting the proper strategies for efficient analysis is addressed in terms of analysis techniques and principles of selecting analysis approach. Available analysis methods are discussed with emphasis on treatment of important non-linear effects. A large potential for reduction of the computational efforts involved has been identified based on a careful selection of response model and method of analysis. Efficient analysis will therefore to a large extent depend on the analysts' experience regarding physical system behavior and insight on available analysis methods. A userfriendly computer implementation of advanced as well as simplified methods is hence the basis for cost efficient analysis of Deep Water Production Platforms. Structural reliability analysis is a consistent way of handling uncertainties. This methodology provides a probabilistic basis for decision making under uncertainty with due consideration of cost. Application of methodologies for tension leg platforms, semi-submersibles, deep draft floaters and more conventional ship shaped units are discussed.

Coupled analysis of offshore floating systems

“…Similar tools have also been described by Wichers and Huijsmans [5], and Luo and Baudic [6]. General aspects on the use of coupled analysis in a wide area of offshore applications were presented by Løken et al [7]. The use of coupled analysis to illustrate particular effects has been demonstrated by Astrup et al [8].…”

“…Key response characteristics of the systems are also described, which are crucial to take into account when performing coupled analysis on the different systems. The following is based partly on descriptions in [7,9,10].…”

Coupled Dynamic Analysis of Platforms, Risers, and Moorings

“…This has resulted in recent efforts of the industry focused on the fully coupled dynamic motion analysis of floating platforms (1)(2)(3)(4) to be used in deep waters. Accurate motion analysis of platforms in deep waters requires that a fully integrated risers, moorings, and platform dynamic model be used.…”