FPSO vessels have a track
record of providing cost-effective production
in remote locations where no pipelines and export
infrastructure exist; in water depths where conventional
fixed platforms are not feasible; and for smaller
fields with reservoir uncertainty where the installation
of long term fixed infrastructure is not viable.
Swire Production Solutions recognises that the
maximisation of parcel size is often a key requirement
for operators, so the tanker hull is selected
to maximise storage, whilst maintaining a cost
effective mooring system. The Swire FPSO is designed
using a tanker hull with storage of up to 125,000
tonnes deadweight. Depending on the size of the
export tanker, Handymax or Panamax tanker hulls
can be used, or Aframax.
Swire Production Solutions aims to lease repositionable
FPSOs on fixed term contracts to oil companies.
The Swire Modular FPSO is based around a sub-surface
riser buoy design or a balcony riser system, depending
on the field location and met ocean conditions.
The FPSO would be either spread moored or use
a simple dry turret mooring designed by LMC, as
illustrated. The process suite located on deck
is connected to subsurface pipelines either through
a simple riser buoy or a conventional riser balcony
arrangement. Well stream fluids, power and control
signals from the geo-stationary riser(s) are transferred
direct to the FPSO’s piping and cabling
system.
The Swire Modular FPSO can be designed to be
disconnectable, so that at the approach of a cyclonic
storm or other potential adverse weather, the
riser system can be rapidly disconnected and lowered
to where it is supported by the riser buoy some
50 metres below the surface of the sea. The FPSO
then unmoors and seeks shelter or to port to discharge.
The merits of this system lie in the simplified
riser system with either no or a simple dry swivel
and a mooring that is practical, effective but
also can be far more cost effective than mooring
systems designed for permanent facilities.
The moorings for the Swire Modular FPSO can be
designed around a London Marine Consultants’
“Admiralty Mooring” in deeper water
if required. The existing mooring design work
has been performed for water depths of between
30m and 500m.
A more robust system for a permanent life of
field installation can be supplied if required. |
