Loading...

Model Test to Evaluate Behavior of Seastar Platform in Waves

Kiany, Ali | 2015

737 Viewed
  1. Type of Document: M.Sc. Thesis
  2. Language: Farsi
  3. Document No: 46834 (08)
  4. University: Sharif University of Technology
  5. Department: Mechanical Engineering
  6. Advisor(s): Tabeshpour, Mohammad Reza; Seif, Mohammad Saeed
  7. Abstract:
  8. Tension leg platforms (TLP) are vertically moored with reserved buoyancy used for drilling and production in deep waters. Pre-tensioned tendons controls the heave, pitch and roll motions due to marine currents and waves efficiently. Seastar platforms are new generation of tension leg platforms that are similar to spar platforms that has the advantages of TLP besides spar simultaneously. This platform is usually considered as an alternative for large and cost consuming platforms. Seastar has a cylindrical surface piercing hull that creates the required buoyancy along with three submerged additional bodies. Pre-tensioned cables are attached to platform through these three submerged bodies. The sea star has so large amount of reserved buoyancy that it can support the weight equal to three times of the platform design load that is so considerable and promising when compared to spar platforms as just 0.6 of times design weight. Considering that smaller amount of steel is used in the construction of seastar platforms when compared to similar deep water units, the seastar platform would be so economic. Huge amount of oil resources are found in deepwater offshore regions of Caspian Sea and seastars have considerable advantages. Thus it is tried to study and analyze this type of platform to broaden the knowledge of offshore drilling unit designs in the country. Experimental modeling of sea star tension leg platform is performed in 250 m waterdepth through this thesis and platform motions due to incident waves are measured. The platform responses are studied in different incident wave angles and results are compared to numerical calculations for 215, 450 m by MOSES software. The main purpose of this thesis is to study the stability and response of sea star tensioned leg platform in high amplitude waves of deep water and effect of wave incident direction on linear and rotational displacements about three axes
  9. Keywords:
  10. Tension Leg Platform ; Regular Waves ; Model Test ; Mooring Lines Force ; Sea Star Platform

 Digital Object List

 Bookmark

No TOC