The Sanha LPG FPSO
By
Willem de Ruyter* – Single Buoy Moorings Inc, Project Manager
Sean Pellegrino - ChevronTexaco, Project Manager
Hervé Cariou – Single Buoy Moorings Inc, Engineering Project Manager
* Presenting author
1. Introduction: Project Information
A new era in the offshore industry will be ushered in with the start-up of the Sanha LPG FPSO. The
Sanha LPG FPSO represents the first time that a purpose built LPG processing plant will be installed
on a floating structure.
The Sanha LPG FPSO is a key part of the Sanha Condensate Project. The Sanha Condensate Project’s
objective is to eliminate routine gas flaring while collecting and injecting collected gas to increase oil
and LPG production in Areas B and C of Block 0, offshore Cabinda, West Africa. The project will
reduce routine flaring in Block 0 by more than 40 percent. The reduction in routine flaring will
eliminate 2.2 million tons of carbon dioxide emissions per year.
Figure 1 : West Africa
The Sanha Field is located offshore Cabinda, Angola approximately 30 miles offshore from the
onshore Cabinda Gulf Oil Company’s Malongo Terminal in Block 0. The Sanha Condensate Project will
have a peak production of over 100,000 barrels of liquid per day (oil, condensate and LPG).
ChevronTexaco’s Angolan affiliate, Cabinda Gulf Oil Company (Cabgoc) (39.2%) operates the block
on behalf of its partners, including Sonangol (41%), Total (10%), and ENI (9.8%). Cabgoc and
Sonasing (a joint venture between Sonangol and SBM) are to share in the operations of the Sanha
LPG FPSO.
Figure 2 - Sanha Condensate Project Facilities Overview
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The 260-meter long Sanha LPG FPSO has the ability to process over 37,000 barrels of LPG per day
into propane and butane products. The Sanha LPG FPSO receives the majority of the liquid LPG from
the nearby Sanha Condensate Complex and a smaller amount of LPG from the F-GIP facility. The
vessel refrigerates and stores 135,000 cubic meters of the propane and butane products in six
specialty LPG tanks. Offloading of the propane and butane products is performed by side-by-side
port or starboard operations or in a tandem arrangement. The Sanha LPG FPSO has accommodations
to house a crew compliment of 60 persons.
The Sanha LPG FPSO is a permanently single point moored vessel designed to remain anchored in the
Sanha Field for more than 20 years without dry-docking.
The Sanha LPG FPSO is the World’s largest in terms of LPG storage capacity and first New Build LPG
FPSO. The Sanha LPG FPSO has some of the largest and first of its kind equipment and is truly a
prototype.
2. Background
In early 2000, a small team of Single Buoy Moorings Inc. (SBM) and ChevronTexaco personnel
formed a joint team to develop the contractual and technical specifications for a commercial tender
package for the engineering, design and fabrication of the Sanha LPG FPSO. The philosophy was that
Sonasing (a joint partnership of SBM and Sonangol) would own the FPSO and lease the vessel to
Cabgoc for an eight-year period and that the vessel would be jointly operated with personnel from
both Cabgoc and Sonasing.
In May 2002, a contract was executed between SBM and Cabgoc for the design, procurement,
fabrication and transportation of the Sanha LPG FPSO. Concurrently, SBM executed a design,
procurement and fabrication contract with IHI Marine United Inc. for the Sanha LPG FPSO hull and
topsides. IHI Marine United Inc.’s responsibility included the delivery of the Sanha LPG FPSO with the
exception of the single point mooring system and turret. Two major subcontractors of IHI Marine
United Inc.’s were JGC for the engineering and construction of the depropanizer module and HKSE for
the engineering and construction of the refrigeration and reliquefaction plants. In addition to the
above contract, Cabgoc and SBM or one its affiliated companies have executed contracts for the
offshore installation, hook-up and commissioning; bareboat charter and the operating service
agreement relating to the Sanha LPG FPSO. Cabgoc and SBM formed an integrated ‘Company’
Project team for the monitoring of IHI Marine United Inc.’s and their subcontractor’s design and
fabrication of the Sanha LPG FPSO.
The first steel cutting for the Sanha LPG FPSO occurred in the IHI Marine United Kure, Japan
Shipyard in November 2002 with keel laying in February 2003.
Figure 3 - Keel Laying Ceremony
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Engineering, fabrication and procurement activities were carried out all over the world for the Sanha
LPG FPSO. The vessel launching from the Kure Shipyard dry dock occurred in November 2003.
Figure 4 - The World and the various locations
The vessel completed gas trials and sailed from Japan in November 2004. The vessel completed final
drydocking in Singapore in December 2004 and has arrived in Angola in late February 2005. First LPG
and hand-over to Operations is scheduled for April 2005.
3 Design Features
3.1 FPSO Overview
Figure 5 – The Sanha LPG FPSO
FPSO Main Particulars:
Loa 262.8m
Lpb 230.0m
Bmld 49.0m
Dmld 29.3m
Tmld 13.2m
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Classification:
A1 Liquefied Petroleum Gas Floating Processing, Storage and Offloading
System;
A1 Floating Offshore Installation – Depropanization, Refrigeration and
Reliquefaction Facilities;
Ship Type 2G (–50oC, 0.45 kg/cm2 g, 650 kg/m3), DLA, SFA; ACCU, IGS,
UWILD, PMS; DNV Notations: HELDK−SH, F-AMC
3.2 Hull Design and Cargo Containment system
The Sanha LPG FPSO features a purpose built, barge-shaped, double hull floater. Ballast tanks are
provided in the double bottom and in the sides, thus providing a double protection of the cargo tanks.
Figure 6 – Typical support Figure 7 – Typical Hull/tank transverse section
The Sanha LPG FPSO has six (6) insulated SPB (Self-standing Prismatic IMO Type B) tanks for storage
of both propane and butane products, stored separately after fractionation. The six tanks provide a
total storage capacity of 135,000 m3 at a design temperature of – 50 C and a design pressure of 0.45
barg. The SPB tanks, a proprietary IHI Marine United design, are made of low temperature carbon
steel. The cargo tank supports are made of reinforced plywood.
Figure 8 – Cargo hold space prior to tank erection
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One paramount criterion for the hull design is the sea-keeping behaviour of the FPSO. The
depropanizer column imposes very stringent motion limits to ensure the fractionation process delivers
“on-spec” propane product. After detailed studies it was decided that the FPSO should not roll more
than 5° and not pitch more than 1° up to the 10-year environmental conditions as predicted for the
Sanha site. An extensive model test program in a basin confirmed the FPSO motions calculations.
The FPSO is designed to stay on-station at the Sanha site for 20 years without drydocking. In order to
achieve this goal, onerous design criteria are imposed on the hull and topsides structures:
• The Hull and Topsides has a fatigue life of 20 years, based on North Atlantic environmental
conditions;
• The Hull and Topsides has a fatigue life of 30 years, based on the environmental conditions
of Sanha site;
• Not only the hull but also the topsides are designed for the North Atlantic 20-year return
conditions;
• The use of high tensile steel is restricted;
• A high quality coating system is applied in the ballast tanks.
Detailed strength and fatigue analyses were carried out to confirm that those criteria were being met.
Furthermore, the SPB technology is proven for its reliability, relying on detailed fatigue analyses and
crack propagation analyses.
Figure 9 – Hull/Tank Fine Mesh Model
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3.3 Mooring & Fluid Transfer System
The FPSO is permanently moored to the seabed by an external turret mooring system that was
designed and fabricated by SBM. The external turret mooring system is cantilevered from the bow
and comprises both a rotating and a fixed part. The two parts are connected via a main ‘slewing’
bearing, which allows the turntable to freely weathervane around the anchoring system so that the
FPSO can take up the position of least resistance to the prevailing weather at all times.
Figure 10 – Turret General Arrangement
The anchoring system consists of an array of nine (9) chain legs and nine (9) drag anchors. The drag
anchors are off SBM standard “MAG” design and each anchor weighs 28 tonnes and is among the
largest ever built by SBM.
Two 6” flexible risers lift the two incoming LPG feeds from the Pipeline End Manifold (PLEM) to the
turret. A 4” flexible riser is provided to supply Fuel Gas to the FPSO, to be burnt in the steam boilers.
Emergency Shutdown valves are provided on the PLEM to isolate the pipeline in case of emergency.
The fluid transfer system from the fixed to the rotating part of the turret consists of swivel stack of
two identical toroïdal swivels for the LPG feeds and one in-line pipe swivel for the Fuel Gas line. An
electric swivel transmits electrical power and control signals to the fixed part of the turret.
Figure 11 – Swivel stack General arrangement Figure 12 – LPG Toroidal Swivels
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3.4 Depropanizer Plant
The Depropanizer Plant is the heart of the FPSO. It is located slightly aft of the FPSO midship.
Figure 13 – Depropanizer Plant outline arrangement
The Depropanizer plant consists of the following main components:
• 1 x Inlet Surge Vessel,
• 3 x Surge Vessel Pumps
• 2 x 100% H2S Treatment Vessels
• 2 x 100% Inlet Filters
• 2 x Inlet/ Bottom Heat Exchangers
• 1 x Inlet/ Overhead Heat Exchanger
• 1 x Depropanizer Column (17barg/ 103°C) - (Mellapack Structured Packings)
• 2 x 50% Butane Reboilers (steam heated - thermo-syphoon type)
• 16 x Air-fin Condensers
• 1 x Propane Accumulator
• 2 x 100% Propane Reflux Pumps
• 1 x Cold Vent & Blow-down Tower (77m tall, fitted with a Kaldair ® type tip).
Mixed LPG streams consisting of propane and butane arrive at the FPSO via two 6-inch pipelines from
the Sanha Processing/Compression Platform in Area C and the Fox-GIP Platform in Area A. On board
the FPSO, these streams are metered. The LPG streams are treated to remove trace levels of H2S in
the H2S Removal Vessels.
The combined streams are then filtered and fractionated in the Depropanizer. The bottoms butane
stream coming off the Depropanizer is partially cooled in two Depropanizer Inlet /Bottoms Heat
Exchangers.
The butane is then cooled to storage temperature in the Butane Refrigeration Plant and then routed
to the FPSO cargo tanks for storage. Propane coming off the overhead of the Depropanizer is
condensed in the Depropanizer Condensers and then flow to the Depropanizer Accumulator.
Part of the propane stream returns to the column as reflux, while the remainder is partially cooled in
the Depropanizer Inlet/Overhead Product Heat Exchanger. The propane is then cooled to storage
temperature in the Propane Refrigeration Plant and routed to the cargo tanks for storage.
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The FPSO processing capability is 37,370 bpd, at 22 barg / 18°C inlet conditions.
In addition, the FPSO receives up to 14MMSCFD of Fuel Gas (methane), used as main fuel for the
boilers. The fuel gas stream is conditioned on the topsides in a scrubber and a heater.
3.5 Refrigeration and Reliquefaction Plants
The propane refrigeration consists of a 2-stage cooling plant, using a closed loop of commercial
propane as refrigerant. There are 3 cooling units (numbered C1~C3) in total, all using oil-flooded
screw compressors. The propane stream is cooled in two units arranged in series (C1 + C2 or C2
+C3). The propane refrigeration plant also supplies refrigerant to a trim cooler, which is used when
the depropanizer plant is operating at low turn-down rate.
Figure 14 – Typical Refrigeration Unit Skid
The propane refrigeration plant is installed in an enclosed deckhouse located on the topsides forward
of the depropanizer plant, over the pipe racks. The deckhouse is split into a compressor room and a
motor room. A gas-tight bulkhead separates the two subdivisions.
The butane refrigeration consists of a single stage cooling plant, using also a closed loop of
commercial propane as refrigerant. It consists only of 2 cooling units (C4~C5), using also Aerzener
oil-flooded screw compressors. The butane stream is cooled in either of the two units. The butane
refrigeration plant also supplies refrigerant to the reliquefaction plant.
All five refrigeration units C1~C5 are of the same design. Each skid consumes around 2 MW of
electrical power.
The reliquefaction plant is designed to separately handle the boil-off gas from the propane and
butane storage tanks. It is different from the design commonly applied on LPG tankers since it is of
the cascade type, using refrigerant from the butane refrigeration plant.
The propane reliquefaction plant consists of three units (numbered R1~R3). In normal operation, two
units are required to re-liquefy the propane vapors. R3 unit acts as stand-by unit both for the
propane and the butane reliquefaction. To achieve that dual function, the R3 compressor is fitted with
a two-speed electric motor.
The butane reliquefaction plant consists of a small direct type fresh water-cooled unit (R4).
All four reliquefaction skids are using oil-free screw compressors.
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Figure 15 – Typical reliquefaction unit skid
The reliquefaction plant is also installed in an elevated deckhouse located aft of the depropanizer
plant. It also houses the two butane refrigeration units. The building is of the same design as that of
the propane refrigeration plant.
3.6 Marine Systems
The Sanha LPG FPSO includes both a forward and an aft machinery room. The equipment fitted in
these two spaces supplies all of the utilities necessary for the accommodations and topsides
operations. FPSO utilities that are provided include approximately thirty (30) auxiliary systems such
as control air, utility air, inert gas, nitrogen, cooling water, fire water, potable water, sewage
treatment, hydraulic oil, fuel oil, etc. In this space alone, there are over 60 pumps, 1,200 valves, and
10,000 spool pieces of piping.
The key equipment installed in the forward machinery space includes three (3) dual fuel, “D”-type, 90
ton/hr. The boilers, the largest ever built of that type, provide superheated steam for power
generation in three (3) 9MW steam turbines and saturated steam for the topsides process heating
demand. Under all normal operating conditions, only two boilers shall be operating with the third
boiler on warm standby.
In addition to the key equipment above, a number of other auxiliary equipment are installed including
items such as purifiers, condensers, distilling plants, sewage treatment plants, incinerators, etc.
In the aft machinery space, a 4,000-HP tunnel thruster with variable pitch is installed. The function of
this thruster is to increase the fractionation system uptime and throughput by minimizing vessel
rolling and the associated negative impact this would have on production. Furthermore, it can also
adjust the FPSO heading before and during cargo export operations.
The aft machinery space also houses two diesel engine driven emergency fire and deluge pumps.
3.6.1 Power Generation and Distribution
The power generation system consists of the following components:
• 3 x 9 MW Steam Turbine Generators – each generator is sized for 50% of the maximum
electrical demand of the FPSO;
• 1 x 3 MW Essential Diesel Generator – the essential diesel generator is sized to run the
reliquefaction plant in case of steam plant shutdown.
• 1 x 850 kW Emergency Generator.
The layout of the power distribution system is as follows:
• Engine Room consumers are fed from switchboards/ MCC located in the Machinery Room
Control Center (MRCC), located in the forward machinery space;
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• Deck & Topsides consumers are fed from the main switchboard/ MCC room located at main
deck level of the accommodation.
• Critical consumers are fed via the UPS. The UPS and battery rooms are located on the top of
the accommodation.
3.6.2 Control and Safeguarding
The FPSO Monitoring & Control System (M&CS) consists of two sub-systems, namely the Process
Control System (PCS) and the Safety Shutdown System (SSS). The M&CS is a Distributed Control
System. The M&CS processes and displays over 11,000 data points collected throughout the FPSO.
Almost all FPSO systems can be controlled remotely from the M&CS. Man-machine interface stations
included in the M&CS are installed in the FPSO Control Center (FCC) in the Machinery Room Control
Center (MRCC) and in strategic rooms.
The FPSO Control & Safeguarding philosophy was carefully established at the early stage of the
project to ensure an optimum protection of personnel and of the asset, without hampering the
operability of the installation. The FPSO Fire & Gas Detection System is stand-alone and interfaces
with the SSS for safety actions and status monitoring. A selected amount of data is archived into a
historian server, and can be used to produce cargo export reports. Additionally, the historian server is
also connected to the FPSO computer network, thus providing the possibility to view any FPSO data
point available within the M&CS.
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3.6.3 Offloading
The Sanha LPG FPSO has a much greater offloading flexibility than any other turret-moored FPSO.
This outstanding flexibility includes:
• The capability of exporting cargo to LPG tankers moored either in tandem at the stern of the
unit or in side-by-side (SBS), on both sides of the FPSO.
• The capability of accommodating all sizes of export tankers, from small pressurized coastal
vessels of 2,000m3 capacity to fully refrigerated Very Large Gas Carriers (VLGC’s) of
85,000m3 capacity. The tandem mooring is even designed for future VLGC’s of 125,000m3
capacity.
• The capability of exporting to side-by-side moored refrigerated propane and butane export
tankers; with vapor return from the export tankers (starboard side only) back to the FPSO.
The stern tandem offloading system consists of the following main components:
• A cryogenic floating hose assembly of 12” diameter, approximately 200m long, connected from
one of the two the FPSO stern manifolds to the export tanker midship manifold;
• A mooring hawser that will connect the export tankers bow to a chain stopper located at the
stern of the FPSO.
For SBS offloading, export tankers will be moored with multiples lines, some of them to quick release
hooks (QRH) installed on the deck of the FPSO, the others to mooring winches suitably located on the
main deck. Due to the variety of tankers likely to moor alongside, not less than 48 QRHs and 7
winches are provided, offering an infinite number of mooring combinations. For VLGCs, which will be
of the same length as the FPSO, up to 16 mooring lines might be deployed at the same time.
The other main features of the SBS offloading system are as follows:
• Five (5) export manifolds on starboard side midship, respectively for refrigerated propane and
butane, propane and butane vapour return and pressurized butane.
• Three (3) export manifolds on portside midship, respectively for refrigerated propane,
refrigerated butane and pressurized butane.
• Two (2) 12” corrugated stainless hose strings for refrigerated products export.
• Two (2) 8” corrugated stainless hose strings for propane and butane vapour return.
• One (1) 6” rubber hose string for pressurized butane export.
• Two knuckle boom type hose-handling cranes on starboard side, used to hold the export hoses
between the FPSO and the export tankers. Up to four hose strings might be deployed at the same
time.
• One knuckle boom type hose handling crane on portside, for the same function.
3.7 Safety in Design
Various engineering safety studies were carried out at an early stage of the design to validate the
main technical choices. The most important ones included:
• A Fire & Explosion Analysis (FEA), aiming at simulating various Fire an Explosion scenarios and
their consequences on the asset. Some modifications of the topsides layout were made as a
result of that study, in order to mitigate the consequences of explosions overpressure.
• A Smoke & Gas Dispersion Analysis (SGDA) that confirmed that gas or smoke clouds resulting
respectively from accidental gas leaks and fires would disperse into the atmosphere without any
risk escalation.
• An Emergency Systems Survivability Analysis (ESSA) that evaluated qualitatively the robustness of
all safety systems.
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• An Emergency Escape & Rescue Analysis that studied qualitatively means of egress and rescue.
• Hazard & Operability Studies (HAZOP) and Hazard Identification Studies (HAZID) were conducted
during the design phase. All essential FPSO systems were extensively analysed by such HAZID
and HAZOP Techniques.
In addition, a pro-active safety behavior was adopted during design both by the designer and the
approval parties to detect and correct unsafe design features at the drawing board level. Special
attention was paid to avoiding tripping hazards, designing safe ladders, platforms, staircases etc.
4. Construction, Schedule and Present Status
4.1 Contracting.
As explained before, Cabgoc (ChevronTexaco) awarded a contract to SBM. for the engineering,
procurement, construction and commissioning of the LPG FPSO, for the offshore hook-up and
commissioning (incl. the sea-lines), bare boat charter and shared operation. SBM contracted the
design, procurement, construction and commissioning to IHI MU, Kure shipyard in Japan, except for
the turret mooring system, which was designed and built directly by SBM
Whilst contracting an FPSO can be and has been made in many different ways, the shipyard scope
was in this case particularly large. It included design development based on plans prepared by
ChevronTexaco and SBM in the pre-contract phase, procurement of FPSO equipment and materials,
including the refrigeration and re-liquefaction machinery, which was subcontracted by IHI to
Hamworthy KSE and the de-propaniser modules, which were subcontracted by IHI to Japan Gas
Corporation (JGC). In addition, IHI covered the interface management related to these items and
later the commissioning of the FPSO in Japan.
In this contracting strategy, one of the drivers has been an effort to reduce a potential costs increase
coming from interfaces related to the supply, installation and commissioning of the FPSO machinery
and equipment for hull and topsides.
4.2 Design and Construction
The detailed design at IHI, with the support from both ChevronTexaco and SBM Inc resulted in a
high-quality, but complex FPSO. The required hull fatigue life needed much analysis and inspection of
structural details. In addition, careful selection of the material grades was required in view of stresses
and service at low temperatures.
Another area of particular interest was the design of the M&CS, which eventually became most
complex with the number of I/O’s of the control system growing from 3,500 to 6,500 hard-wired I/O’s
(and 4,500 soft I/O’s).
The lightweight of the FPSO is approximately 48,000 tons.
The construction of the hull was not particularly difficult as the hull is basically similar to that of an
LPG carrier, although at a larger scale. No major problems were encountered. The refrigeration and
re-liquefaction plants were built in Norway shipped in modules to Japan and were installed on to the
hull before launching of the hull. The accommodation block was built as one unit of 3,000 tons and
lifted onto the hull soon after hull launching.
Topsides modules weight is also approx. 3,000 tons, the main item being the de-propaniser column.
Whilst the modules were built at another yard in Kure, the de-propaniser column was built in Korea.
The topsides modules were also installed onto the deck of the FPSO hull soon after launching the hull.
Special attention was paid to inspection of highly stressed and fatigue-sensitive details of the hull and
topsides structure. Classification of the FPSO was done by American Bureau of Shipping.
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Figure 16 – Launching of Hull
Figure 17 – Lifting the Accommodations block
Figure 18 – Lifting the Surge Vessel into Place
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4.3 Quality
Quality standards for FPSO’s are much higher than generally applied in shipbuilding. The reasons are
that FPSO’s are always to stay on location during it’s entire operational life, that repairs offshore are
very expensive and difficult to manage and that high uptime is required in view of production
continuity and the high investment.
The hull and cargo systems were built to marine standards, whereas the de-propaniser modules were
built to the offshore standards as is usual in the FPSO industry. The Sanha construction did achieve a
high level of quality of workmanship of construction and painting, with much attention to details.
A large amount of inspection was carried out. For example, the SPB-type cargo tanks, probably the
largest made in this type, required 100 % X-ray examination of the weldings.
4.4 Commissioning
Commissioning as practiced in the FPSO industry is close to the practices as used in the offshore
platform industry. The FPSO practice is very methodical in that commissioning is done in three stages,
i.e. Mechanical Completion (A-scope), Pre-commissioning (B-scope) and Commissioning (C-scope) in
succession and by system. In addition, each stage is fully documented.
This approach, when well used, ensures that accidents or damage to equipment are eliminated and
that documented proof is obtained that systems in their entirety operate as required.
Whilst shipyard-commissioning practices are generally different in approach, the shipyard did, with
much assistance of the SBM/ChevronTexaco site team, apply the FPSO industry practice successfully.
4.5 Project Management
Japan being an expensive place in the world, it was soon decided to minimize the number of staff to
be relocated to the shipyard. An efficient way of doing so was the combination of the SBM and
ChevronTexaco staff into a single team, thereby avoiding doubling the functions. The major
advantage of this approach, however, appeared to be that the combination of the different skills and
experiences of both Companies resulted in a highly competent team, whilst the contract lines of
communication could remain in force at the same time.
The team consisted of a total of approx. 30 persons during design and construction. The team also
already included certain key staff of the future operators. Towards the commissioning phase, more
operators were relocated to the shipyard so that they could participate with the commissioning
process and be trained with operation of the systems at the same time.
4.6 Schedule
The overall contract duration was approx. 30 months. The contract was formalised in May, 2002 and
was based on achieving Notice of Readiness in January, 2005.
A very rough breakdown of this period was as follows:
Plan actual
Detailed design, procurement 5m 5m
Steel delivery, block fabrication 5m 5m
Hull erection in drydock 5m 6m
Fitting out alongside 5m 7m
Shipyard commissioning 4m 4m
Tow to Angola 3m ongoing
HUC 2m
Total 29 m
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Steel cutting in Kure started in November, 2002, keel laying in April, 2003 and launching of the hull
followed in November, 2003. The hull erection took one month longer than planned and was mainly
caused by design changes coming from the plan approval process.
After launching of the hull in November, 2003, the installation of the accommodation block, process
vent and de-propaniser modules was completed by the end of December, 2003. Then the integration
activities, fitting out and mechanical completion followed. This last period took 2 months longer than
planned, mainly caused by the complexity of the unit.
Therefore, commissioning could only start in July, 2004 in earnest. Completion was achieved by the
early days of November 2004 instead of the planned date of early August 2004. Still a remarkable
performance by the shipyard, given the complexity and size of the LPG FPSO.
One other special activity was that a final dry-docking for painting was required at the end of the gas
trials and before tow-out of the FPSO to Angola. The reason was to have the paint system in
optimum condition before the start of her 20 year operational life without dry-docking since the
vessel was launched a year before her completion in Japan. This docking was initially planned to take
place in Japan, but was later moved to take place in Singapore.
After this final docking and painting, the tow continued to Angola. The anchoring system had already
been installed back in 2003, so HUC was started in March 2005 and is currently ongoing. Notice of
Readiness is expected to take place by mid-April 2005, which is 3 months later than planned.
Figure 19 – Topsides deck overview
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5 Conclusions
In concluding this paper, a few items of interest are worth mentioning:
An FPSO has always been and remains a challenge to manage, design and build. Despite many
challenges and a certain underestimation of what is involved, the shipyard performed remarkably
well, in particular since the Sanha LPG FPSO can be considered a prototype.
The selected policy of creating an integrated site team between SBM and ChevronTexaco worked very
well. It is believed that the best possible results were obtained in a most cost-effective manner.
High quality levels are essential in the FPSO industry in view of the required up-time, no drydocking
during her life and cost for repairs offshore. Such quality requirements are generally higher than is
found in the marine industry, in particular when offshore standards apply.
Commissioning required significant efforts by the Owner’s site team to effect proper and systematic
commissioning. The same was valid for interface management.
The LPG FPSO that was materialised under this contract is one of high standard. Whilst the concept is
probably a first, only equipment of proven technology has been used, albeit at a much larger scale
than applied before.
Finally, in its execution this project has been both challenging and very pleasant. Cooperation
between shipyard and a very international site team has always been excellent and has definitely
contributed to the success. It has been very rewarding to see that our approach to managing the
project was good.
Figures 20 and 21 – Naming Ceremony
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Figures 22, 23 and 24 – Sanha LPG FPSO Departure on Tow
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