Analysis of Motion on FPSO in Shallow Water with a Non- Collinear Environment

Abstract

The ship-shaped floating structures like FPSO has an ability to
produce, storage and offloading the oil but it is does not have the
drilling capability. Usually the FPSO in shallow water is
connected with the single point mooring systems such as Vertical
Anchor Leg Mooring (VALM) buoy systems. The objective of
this paper is calculate the response amplitude operators (RAO) of
spread moored FPSO with two mooring configuration and with
the effect of non-collinear environment of wave and current. The
analyses done by using ANSYS AQWA (version 14) software
with runs two types of analysis which is hydrodynamics
diffraction and hydrodynamics time response. The analysis also
focuses to calculate the RAO and normalized hawser line force of
FPSO and VALM systems. The result from the software has been
compared with the experiment result to validate it. The different
in meshing elements size also are taken into account. The analysis
also focuses to compare the RAO between single leg mooring
FPSO and spread moored FPSO with the same loading condition.
From the analysis, the RAO for 4 mooring FPSO is higher
compared than 8 mooring FPSO but the 8 mooring FPSO shows
high value of cable forces than 4 mooring FPSO. It also shows
the value of RAO of single leg mooring FPSO is higher compared
to the spread moored FPSO.