Coupled dynamics of SeaStar mini tension leg platform

• Published in: Ocean engineering Vol. 30; no. 6; pp. 709 - 737
• Main Authors: Bhattacharyya, S.K., Sreekumar, S., Idichandy, V.G.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier Ltd 01.04.2003; Elsevier
• Subjects: Applied sciences; Buildings. Public works; Coupled dynamic analysis; Deep water; Exact sciences and technology; Experiment; Finite element method; Hydraulic constructions; Marine; Morison equation; Nonlinear; Offshore structure (platforms, tanks, etc.); RAO; SeaStar; Stresses. Safety; Structural analysis. Stresses; TLP; Finite element method; Morison equation; RAO; Nonlinear; Experiment; TLP; Coupled dynamic analysis; Deep water; SeaStar; Structural design; Modal analysis; Coupled method; Displacement(deformation); Tension leg platform; Experimental study; Scale model; Natural frequency; Non linear model; Motion study; Numerical simulation; Dynamic model; Offshore structure
• ISSN: 0029-8018; 1873-5258
• DOI: 10.1016/S0029-8018(02)00061-6

The role of mini tension leg platforms (TLP) in oil exploration and production in marginal deepwater fields is becoming increasingly important. SeaStar is a mini TLP that combines the simplicity of a spar and favourable response features of a TLP. In this paper, the results of a detailed numerical investigation of the coupled dynamic behaviour of SeaStar are reported with special attention to platform-tether coupling. The numerical study has been carried out using a finite element computer code developed for the nonlinear dynamic analysis of compliant offshore platforms in the time domain using Morison type wave loading. A typical SeaStar platform has been considered at two water depths, 215 m and 1000 m. Experimental investigation was conducted for a scaled model corresponding to 215 m water depth for validation of the numerical model. The model-prototype correlation studies have been conducted using the numerical model. Response amplitude operators of motion and tether tension are presented for the two typical water depths and conclusions drawn.