Design Considerations for FPSO Redeployment –
FPSO Congress 2015
Presentation by - Noel Denton

Background to FPSO Redeployment
Challenges of FPSO Redeployment
Case Study: Front Puffin
Case Study: OSX-1
Case Study: Berantai
Conclusions
Design Considerations for FPSO Redeployment
Contents

Background FPSO Redeployment
History
FPSO East Fortune (Songa Floating Production) conversion to
FPSO Berantai (Petrofac Floating Production)
• FPSOs offered the industry a
technology that could provide a large
processing facility with the ability to
redeploy
• Redeployments have been achieved
successfully on a number of occasions
in the industry – but it is not always as
straightforward as it seems.
• There have been 24 redeployments in
the last 10 years
• Some vessels have been redeployed
on multiple occasions
• The range of modifications required
can be from minimal to extensive such
as new topsides and jumboisation of
the hull – this requires a lot of careful
planning at the start.

Background of FPSO Redeployment
From Crystal Sea (Crystal Production), to BW Carmen
(BWO) to BW Athena (BWO)

Background of FPSO Redeployment
Why an FPSO?
• Potentially fastest route to first oil when compared to other
equivalent topsides substructure options
• Leased option can improve project economics especially for
shorter field lifes
• Short field life or uncertain reservoir performance makes leasing
with extension options attractive
• Lack of infrastructure for export and flexibility to deliver product to
the global market
• Offers the option to be disconnectable in regions with adverse
weather
• Readily deployable in a range of water depths from shallow to
deepwater
• Large topsides carrying capacity
• Storage available to mitigate process interruptions

Background of FPSO Redeployment
Why redeploy?
• Shortened project execution schedule leading to earlier first oil
• Potential reduced day-rate when compared to fresh conversion /
new build
• Proven service history

Challenges for FPSO Redeployment
Technical
Hull
• Global strength and fatigue needs to be checked including stability check if new
modules are added;
• Steel replacement for life extension and coating repairs;
• Change of class / flag / regulatory regime can require modifications to the hull and
accommodation which are difficult to estimate until arrival at the shipyard.
Mooring
• Is the mooring type applicable for the new deployment:
• Is the water depth suitable for a disconnectable mooring?
• Does the FPSO require to be spread moored or turret moored?
• Is the turret suitable:
• Are the loads similar?
• Are the number of risers and umbilicals similar?

Challenges for FPSO Redeployment
Technical
Topsides:
• It is more than just checking the name plate capacities!
• Gas compression systems are sensitive to composition and changes to pressure
ratios;
• Material selection should be verified based on CO2 and H2S content. It is also
important to establish a baseline condition for the vessels and piping to establish
remaining life;
• Flare system design;
• Flow limitation through the turret and swivel paths including erosion issues for
sand content;
• Water cut;
• Is it a heavy crude?
• Increased power requirements
• Increased heat load
• Tertiary treatment required

Challenges for FPSO Redeployment
Technical
Topsides:
• Change in regulatory requirements:
• Are there additional requirements for the topsides?
• Is a safety case required?

Case Studies

FPSO Front Puffin
Background
• The FP was converted in 2007 from
Shuttle Tanker to FPSO and then
deployed as an FPSO for Puffin field
• FPSO Front Puffin was deployed at
AC/P22 Block North of Western
Australia
• FPSO Front Puffin is now to be
redeployed to the Aje Field in West
Africa
• The mooring and hull require minimal
modification despite moving from
Australia to West Africa
• The topsides require additional modules
to fulfill the field requirements
Case Study
FPSO Front Puffin (Rubicon Offshore International)

FPSO Front Puffin
Modifications
• Replacement of existing gas lift compressor
package with new package.
• Addition of gas dehydration package
• Addition of fiscal metering skid
• Addition of subsea chemical injection package
• Upgrade of methanol injection package
• Addition of subsea master control system
• Addition of subsea hydraulic power unit
• Upgrade of control system for new packages
• Upgrade of power distribution system for new
packages
• Integration piping
• FEED study for pre-engineering for future
upgrade scope (gas fuelled power generation)
Case Study
FPSO Front Puffin (Rubicon Offshore International)

FPSO Front Puffin
Challenges and solutions
• Gap analysis – At the earliest opportunity conduct a
gap analysis to quantify the scope and identify any
major hurdles.
• Gas compression – replace existing units and add
a gas dehydration unit
• Change in Fiscal Regime – New gas metering
required
• Congested deck area requiring careful analysis of
support locations and tie-in points – utilisation of
3D modelling to ensure efficient implementation
• Multiple contractors – Successful use of the
integrated team approach to minimise interface
issues
• Upgrade of existing facility – Close liaison with
operations to ensure as built information is robust
when being implements into new configuration
Case Study
FPSO Front Puffin (Rubicon Offshore International)

OSX-1 FPSO
Background
Case Study
FPSO: OSX-1 FPSO
Location: Brazil
Client: Keppel / BW Offshore
Upgrade of the new-build Nexus 1 FPSO to
make it suitable for the OSX Waimea heavy oil
field (API 17.6) offshore Brazil
Involves 7 new modules including
• Inlet Manifold
• Crude Heating
• Water Injection
• Fuel Gas Compression
• Power Module

OSX-1 FPSO
Background
• The Nexus-1 FPSO was developed as a
harsh environment generic FPSO
• Although it was never deployed, it can
be seen that even a generic FPSO
required extensive upgrade to make it
suitable for its eventual deployment
• The Nexus-1 FPSO became the OSX-1
• The heavy oil characteristics meant that
extensive heating and tertiary treatment
were required to achieve the crude
specification
Case Study

everything in pink is a change
OSX-1 FPSO
• Extensive modification was required to
the topsides
Modifications
Case Study

OSX-1 FPSO
Tertiary Treatment / Options for Treatment for Heavy Oil
• VIEC Internals – These can be
retrofitted to existing separators to
improve separation of oil and water
• Compact Electrostatic Coalescer – This
can be used upstream of existing
separation to promote increased droplet
sizes to improve separation
• Modified Internals for the Electrostatic
Coalescer – This can be used to
increase the allowable water cut and/or
to improve separation
• Centrifuge – An established technology
for treatment of heavy oils / tar
Case Study

FPSO: Berantai
Location: Malaysia
Client: Keppel / Petrofac / Petronas
Upgrade of the East Fortune FPSO to make it
suitable for Berantai Field in Malaysia
Includes 9 new modules
(approximately 5000 Te)upgrading
Berantai FPSO
Background

Berantai FPSO
Background
• FPSO Berantai was developed from the
FPSO East Fortune
• FPSO East Fortune was a generic
FPSO which was never deployed
• As with OSX-1 although it was a generic
FPSO it required extensive modification
for its eventual deployment
• The historic difficulty of successfully
employing the generic FPSO concept
demonstrates the fundamental difficulty
of matching the topsides to the field
(other economic factors also impacted
the success of the concept)
• The versatility of load bearing capacity
of the ship-shaped hull is demonstrated
by the dramatic increase in the topsides
between the two concepts.
Case Study
FPSO East Fortune (Songa Floating Production) conversion to
FPSO Berantai (Petrofac Floating Production)

Berantai FPSO
Before and After
FPSO before upgrade FPSO after upgrade

FPSO Redeployment
Conclusions
• The FPSO remains an attractive option for field development due to its inherent
ability to be redeployed
• When considering redeployment the entire FPSO needs to be examined through
thorough gap analysis – mooring, risers, hull, marine systems, safety systems,
accommodation and topsides.
• Although redeployment is not necessarily straightforward with careful planning
and robust engineering it can be achieved successfully

Noel Denton
T 96271998
n.denton@penspen.com