Full Content is available to subscribers

Subscribe/Learn More  >

Motion Comparison Between a Conventional Deep Draft Semi-Submersible and a Dry Tree Semi-Submersible

[+] Author Affiliations
Anis Hussain, Edwin Nah, Rain Fu

Keppel Deepwater Technology Group, Singapore

Apurva Gupta

Keppel Offshore and Marine USA, Houston, TX

Paper No. OMAE2009-80006, pp. 785-792; 8 pages
  • ASME 2009 28th International Conference on Ocean, Offshore and Arctic Engineering
  • Volume 1: Offshore Technology
  • Honolulu, Hawaii, USA, May 31–June 5, 2009
  • Conference Sponsors: Ocean, Offshore and Arctic Engineering Division
  • ISBN: 978-0-7918-4341-3 | eISBN: 978-0-7918-3844-0
  • Copyright © 2009 by ASME


One of the major requirements for a floating vessel designed to support top tensioned risers is to have the heave response within a minimum specified range in extreme environments. The heave has a significant influence on the riser stroke. Usually floater designs aim to use conventional riser tensioners, available commercially, which typically have a maximum stroke range in the order of 30 to 35ft. One of the limitations of traditional Semi-submersible designs to support dry trees is that the heave ranges seen in central Gulf of Mexico (GoM) are outside the range that can apply a conventional tensioner. The Extendable Semi-submersible (E-Semi) utilizes a retractable Second Tier Pontoon (STP) to suppress heave motions and reduce its heave motion in order to support top tensioned risers in central GoM ultra deep waters. The design is based on an established deep draft Semi-submersible with the STP attached. This paper presents a comparison between motion characteristics of the deep draft Semi-submersible with and without the STP attached. The comparison is based on numerical computations to predict the responses together with model test results in the same environments. The analysis essentially shows the effectiveness of the STP is suppressing the heave motion.

Copyright © 2009 by ASME



Interactive Graphics


Country-Specific Mortality and Growth Failure in Infancy and Yound Children and Association With Material Stature

Use interactive graphics and maps to view and sort country-specific infant and early dhildhood mortality and growth failure data and their association with maternal

Citing articles are presented as examples only. In non-demo SCM6 implementation, integration with CrossRef’s "Cited By" API will populate this tab (http://www.crossref.org/citedby.html).

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In