DEEPWATER CURRENT PROFILE DATA SOURCES FOR
RISER ENGINEERING OFFSHORE BRAZIL
Gus Jeans
Fugro GEOS, Wallingford, UK
Marc Prevosto
Ifremer, Brest, France
Liam Harrington-Missin
Fugro GEOS, Wallingford, UK
Christophe Maisondieu
Ifremer, Brest, France
Christelle Herry
Actimar, Brest, France
José Antonio M. Lima
Petrobras, Rio de Janeiro, Brazil
ABSTRACT
A variety of current profile data sources are compared for a
deepwater site offshore Brazil. These data were gathered for
consideration as part of the Worldwide Approximations of
Current Profiles (WACUP) Joint Industry Project, described
separately in OMAE2012-83348. The primary source of data
for current profile characterisation is site specific full water
column measurement. Sufficiently high vertical and temporal
resolutions are required to capture the dominant oceanographic
processes. Such in-situ data are generally expensive and time
consuming to collect, so there is an increasing tendency for
numerical model current data to be considered for engineering
applications. In addition to being relatively inexpensive and
quick to obtain, model data are also typically of much longer
duration. This potentially allows inter-annual variability and
rare extreme events to be captured. However, the accuracy and
reliability of numerical model data remains questionable, or
unproven, in many deepwater development regions. This paper
explores the suitability of such models to represent a deepwater
site offshore Brazil, in relation to the key oceanographic
processes revealed within the in-situ data.
1 INTRODUCTION
The objectives and methodology of the Worldwide
Approximations of Current Profiles (WACUP) Joint Industry
Project are described in a separate OMAE 2012 paper [1]. The
key objective is quantitative assessment of different current
profile reduction techniques for efficient and reliable riser
design.
The project considers current profile characterisation at
four different offshore development sites, one of which is the
Jubarte deepwater development offshore Brazil. The present
paper explores the various data sources considered for
representing the current profile at the Jubarte location.
It has become established best practice to derive current
profile data for engineering applications from site specific full
water column measurement. This provides the most reliable
quantification of the dominant oceanographic processes that
impact the site in question. Sufficiently high vertical and
temporal resolutions are required to capture the dominant
oceanographic processes.
However, in-situ measured current profile data have some
disadvantages compared to the various numerical model
sources that have become available in recent years. It is
Proceedings of the ASME 2012 31st International Conference on Ocean, Offshore and Arctic Engineering
OMAE2012
July 1-6, 2012, Rio de Janeiro, Brazil
OMAE2012-8
1 Copyright © 2012 by ASME