This paper presents and compares the results of a research study for an ultra-deep water field development. A total of three riser configurations were modeled with the commonly used commercial software, and both extreme and fatigue analysis were performed. The advantage of tensioned step riser configuration, a patented and innovative riser configuration specially designed for ultra-deep water application, is demonstrated over other traditional configurations such as free-hanging configuration and double-hump lazy wave configuration.
The analysis results indicated that the proposed tensioned step riser configuration has largely favorable features in extreme and fatigue performance for deep water application. The tensioned step riser configuration should be treated as a strong candidate for ultra-deep water flexible developments under substantially harsh environmental loading with worse vessel responses.
