Dynamic analysis of taut mooring systems

• Main Author: Rachel Amanda Netto
• Other Authors: Low Ying Min
• Format: Final Year Project
• Language: English
• Published: 2013
• Subjects: DRNTU::Engineering::Civil engineering::Structures and design
• Online Access: http://hdl.handle.net/10356/52894
• Institution: Nanyang Technological University

The Final Year Project aims to analyse taut mooring systems under dynamic conditions. As the oil and gas industry ventures into increasing depths offshore, the environmental conditions become ever more challenging. A need to better understand and improve the technology is essential in ensuring productivity and cost efficiency. A floating platform is generally used in deep water and comprises of 3 main components – the vessel, the risers and the moorings. The taut mooring system is a relatively new concept in holding a floating platform in place as compared to the use of steel catenary spread moorings or tension leg platforms. The benefits of such a system include a smaller footprint on the seabed as compared to the steel catenary spread moorings and it is less costly as compared to using a tensioned leg platform, of which requires a foundation blanket to be installed. In this project, a floating structure is modelled on Orcaflex and the taut mooring lines are studied. To stipulate actual conditions that the system will experience, input data is collected from various sources with justifications. Fatigue damage is an important aspect in offshore structures, as it is subjected to constant cyclical dynamic loadings. With a wave scatter diagram, various wave conditions were used to run fatigue analysis on the taut mooring lines. The result of fatigue damage on the system modelled is then analysed. Parametric studies are later conducted on the modelled system. Such studies would better aid in understanding what parameters would affect the serviceability of the lines and improve cost efficiency.