Finite Element Analysis of Guyed Offshore Monotower Subjected to Extreme Environment in Malaysian Water

Abstract:

This paper presents the finite element structural sensitivity analysis of a cable guyed monotower known as the Tarpon Monopod when subjected to extreme environments in Malaysian waters. A hydrodynamic loading and static platform response analysis is performed in SACS v5.3 to gauge the structural robustness in extreme Malaysian metocean conditions. A Stokes Fifth Order Wave Theory was employed to obtain wave kinematics and dynamics for load computation. The Tarpon Monopod design is reviewed generically. An actual platform located in 60m water depth within Malaysian waters is modelled for analysis. Four different guying cable scenarios are considered which are the fully guyed condition (three guy cables pinned), two guy cables condition (one wire loss), one guy cable condition (two wire loss) and free standing condition (total loss of guy wires) are presented. The environmental load sets are simulated at different headings using 45 degree steps. The results suggest that the structural caisson contributes little to the lateral stiffness of the platform. The Tarpon Monopod has little structural redundancy and its integrity is highly dependent on guy wire condition and environmental load headings.

• Periodical: Applied Mechanics and Materials (Volume 711)
• Pages: 535-541
• DOI: https://doi.org/10.4028/www.scientific.net/AMM.711.535
• Online since: December 2014
• Authors: Mohd Affiq Jamaluddin*, Mohd Shahir Liew, Kurian V. John, Lee Hsiu Eik
• Keywords: Guy Cable, SACS v5.3, Sensitivity Analysis, Static Response, Structural Robustness, Tarpon Monopod

References

[1] Information on Minimal Platforms: Oil and Gas Prices, New Concepts, Technology Renew Interest in Minimal Facilities, http: /www. offshore-mag. com/index. html.

[2] Information on Marginal Fields – Investment Opportunities in Oil & Gas, www. inhousecommunity. com.

[3] Tarpon Monotower Develops Further From 37 Field Application: submitted to Oil and Gas Journal (1999).

[4] Information on http: /epicsoftware. com/index. php/tarpon_systems.

[5] Information on Tarpon System Presentation, Tarpon System, http: /www. tarponsystems. com.

[6] M. Pilotto, B. F. Ronalds, R. Stocker: Non-linear Dynamic Analysis with Deterministic and Random Seas: The Case of Minimum Platforms (IEEE 2004).

DOI: 10.1109/oceans.2003.178369

[7] Internet resources on http: /www. bentley. com/en-US.

[8] L. H. Eik and M. S. Liew: A Study on the Structural Failure Mechanism and Reserve Strength Ratio of Tarpon Monopods (Trans Tech Publications, Switzerland 2014).

DOI: 10.4028/www.scientific.net/amm.567.191

[9] American Petroleum Institute (API) Recommended Practice (RP) 2A-WSD, 21 Edition, December (2000).

[10] PETRONAS, Design of Fixed Offshore Structure, PTS 34. 19. 10. 30, Revision 6, January (2010).

[11] R. W. Clough and J. Penzien: Dynamics of Structures, Second Edition (1993), p.38.