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Foundation Design of The Buzzard Field
Pile Foundation Design of Fixed Jacket Platform
Zhangmou Li (2014215)
E-mail: [email protected]
Supervisor: Dr Bill Stewart
Introduction
The purpose of this project is design a foundation for a jacket
fixed platform in Buzzard field.
For the fixed structures, their foundations are classified with the
water depth where the structures located, which has four main
types: general multi-footing structures, deep foundation or pile
foundation, shallow foundations and anchoring system. Figure 1
gives the graphic explanation for different types of deepwater
structure.
transverse loadings and settlements are shown in Figure 3 (a).
in addition, the platform calculation module with the loading on
leg toes is given in the Figure3 (b).
(a)
(b)
Figure 3 soil distribution with properties and calculation module of the platform
Pile foundation design results
Figure 1 Seven types of offshore deepwater systems (Pongvithayapanu, 2010)
Buzzard Field
The Buzzard field was discovered in June 2001, which are
located in the central North Sea where is approximately 50 km
North-East of Peterhead of coast of Scotland with around 100 m
water depth. Figure 2 shows the overviews of Buzzard filed and
its location.
Figure 2. The Buzzard field and location (Energy-pedia news, 2010)
Geotechnical Investigation
The geotechnical investigation of Buzzard field was performed
by Fugro Limited. The basic properties of the soil which was
used to calculate the resistance to both compressive and
University of Glasgow, charity number SC004401
The foundation was designed in the worst circumstance based
on both API and EC7 methods, and the pile’s material was BS
4360 Grade 55C steel with 2.5 m in diameter.
Both of the foundations designed by American Petroleum
Institute (API) method and Eurocode 7 (EC7) method were
determined to contain 5 piles in group to carry the total loading
from the superstructure, however, they had different embedment:
for API method, the design embedment was over 36.6 m below
the seabed; while, for EC7 method, the design embedment was
only 24.1 m under the seabed. Also, they have a difference in
settlements, API foundation will settle a length of 340.2 mm, and
the EC7 foundation has a settlement of 155.9 mm. The both
values of settlements are acceptable for this project.
By comparing between API and EC7 method, there were three
facts had been observed from the results:
• The lateral behaviors of a pile is dominant compared with the
axial behaviors.
• API method is more conservative than EC7
• In EC 7 DA1 Combination 2 is more critical than
Combination 1
References
Energy-pedia news, 2010. UK: Output at Nexen's UKCS Buzzard oil field down due to production
problem. [Online] Available at: http://www.energy-pedia.com/news/united-kingdom/output-atnexens-ukcs-buzzard-oil-field-down-due-to-production-problem [Accessed 22 8 2013]
Pongvithayapanu, P., 2010. Offshore engineering: foundatioin of offshore structre. [Online]
Available at: http://www.imc.src.ku.ac.th/personnel/file_subject/20101122955391.pdf [Accessed
26 5 2013].