TECHNICAL FIELD
[0001] The present disclosure relates to an existing Liquefied Natural Gas (LNG) carrier
that can be reconstructed or converted through a jumboisation technique by adding
a new built structural block which contains a LNG storage tank facility/Liquefied
Natural Gas process facility for liquefaction production/regasification modules on
deck space. As liquefaction production modules require more deck space, additional
deck space may be provided by adding one or more new built sponsons on either one
or both sides of an existing LNG carrier hull.
BACKGROUND
[0002] When the charterer period of an existing LNG carrier comes to an end, the existing
LNG carrier may be laid up or scrapped if a life extension program for continuous
services as a LNG carrier or other purposes is not available. The availability of
a life extension program depends on the condition of the LNG carrier. In one possible
life extension program for an existing LNG carrier, a new lease of life for a floating
LNG production/Regasification facility onboard is provided as an added asset to the
existing LNG carrier to further extend the life period of the existing LNG carrier.
[0003] In order to enlarge a ship or increase the storage capacity of an existing crude
oil tanker, cruise vessel or bulk carrier, jumboisation technique is adopted by adding
an entire section to the ship or crude oil tanker, cruise vessel or bulk carrier.
In addition, crude oil tanker vessels may be converted to Floating Production Storage
and Offloading (FPSO) units, which are utilized by many operators around the world
since there are markets for this kind of conversions. Similar to this kind of conversion,
the existing LNG carriers may also be converted into offshore or near shore gas process
production/ regasification facilities for smaller gas process facilities.
[0004] However, on an existing LNG carrier, there is no sufficient deck space or required
storage capacity to accommodate LNG production facility. Although some existing LNG
carriers may accommodate a small scale Regasification facility, since all new built
Floating storage and Regasification Units (FSRU) come with bigger storage capacities
and regasification facilities, the existing LNG carriers cannot be utilized to accommodate
a new built FSRU due to lack of enough storage capacity and sufficient deck space.
Because of this reason, some existing LNG carriers are even scrapped. It is a great
wastage of resources.
[0005] Current market requires a bigger storage capacity to accommodate Floating LNG production/
regasification facilities, either they go for a new built Floating LNG production
facility (FLNG) I FSRU vessel or having an existing LNG carrier with a Floating Regasification
facility with additional floating storage unit (FSU) vessel either at Jetty terminal
or side by side mooring to compete with new built FSRU vessels, as these are conventionally
carried out at the offshore or near shore terminals. Similarly new built Floating
LNG production barge/Vessel with additional FSU vessel at jetty terminal or side by
side mooring to compete with new build FLNG vessels, as these are conventionally carried
out at the offshore or near shore terminals.
[0006] WO2009/104091 A2 describes a method for constructing a vessel with drilling capability out of a pre-existing
FPSO vessel.
WO2012/072292 describes a floating LNG plant constructed from a converted LNG carrier and comprising
at least one sponson.
WO2010/059059 describes a device for floating production of LNG, constructed from a LNG carrier,
a projecting hull structure, and a LNG production system.
SUMMARY OF THE INVENTION
[0007] In accordance with an aspect of the invention, there is provided a method for constructing
an FLNG or FSRU, the method comprising: separating a first existing LNG carrier to
form a forward section and an aft section; fabricating structural block prior to separating
the first existing LNG carrier, the structural block includes a gas process facility,
the gas process facility includes a regasification plant or a liquefaction plant;
(c) placing the said structural block into a space between the forward section and
the aft section, the structural block having a front end and a rear end; (d) joining
the forward section to the front end of the structural block and joining the aft section
to the rear end of the structural block to form a new integrated vessel; and (e) placing
at least one sponson on a side of the new integrated vessel. Alternatively, a sponson
is placed on each side of the new integrated vessel. For ease of reference, each side
of the vessel may be the left and right side of the vessel.
[0008] Preferably, the structural block and sponson include one or more LNG storage tanks.
More preferably, the LNG storage tank is selected from a group consisting of a MOSS
type tank, a Gaztransport & Technigaz (GTT) tank, a self-supporting prismatic type
8 (SPB) tank, an independent type A tank and an independent type C tank.
[0009] Preferably, the structural block is fabricated at a first site, the sponsons are
fabricated at a second site, and separating the first existing vessel is carried out
at a third site, wherein the first, second and third sites are independently operable
from each other. The structural block is fabricated at a site while the first existing
vessel is absent from the site. The sponsons may be fabricated at a site while the
first existing vessel is absent from the site.
[0010] Preferably, the structural block is a structure section of a second existing LNG
carrier. Prior to fabricating the structural block from the second existing LNG carrier,
characteristics of the first existing LNG carrier for fabrication of the structural
block are first determined.
[0011] The method of claim 1 further comprising, prior to separating the first existing
LNG carrier, determining characteristics of the first existing LNG carrier for fabrication
of the structural block.
[0012] Preferably, the sponsons may be the same size or of different sizes depending on
the process facilities in them.
[0013] Preferably, the sponsons includes a ballast tank. Advantageously, a ballast tank
may provide buoyancy.
[0014] Preferably, the structural block includes at least one LNG storage tank having a
containment system different from that of the first existing LNG carrier.
[0015] In accordance with another aspect of the invention, there is provided a method for
constructing an FLNG, FSRU or a LNG carrier, the method comprising: separating a first
existing LNG carrier to form a forward section and an aft section; fabricating a structural
block prior to separating the first existing LNG carrier, the structural block includes
a gas process facility, the gas process facility includes a regasification plant or
a liquefaction plant; joining a structural block with one of the forward section and
the aft section to form a new integrated vessel; and placing at least one sponson
on each side of the new integrated vessel.
[0016] Preferably, the structural block and sponson include one or more LNG storage tanks.
More preferably, the LNG storage tank is selected from a group consisting of a MOSS
type tank, a Gaztransport & Technigaz (GTT) tank, a self-supporting prismatic type
B (SPB) tank, an independent type A tank and an independent type C tank.
[0017] Preferably, the structural block is fabricated at a first site, the sponsons are
fabricated at a second site, and separating the first existing vessel is carried out
at a third site, wherein the first, second and third sites are independently operable
from each other. The structural block is fabricated at a site while the first existing
vessel is absent from the site. The structural block is a structure section of a second
existing LNG carrier.
[0018] Preferably, the structural block includes a bow section of a second LNG carrier,
the forward section of the first existing LNG carrier is a bow of the first existing
LNG carrier, the method comprising jointing the structural block to the aft section
of the first LNG carrier to form the new integrated LNG carrier. The structural block
further includes a turret built on the bow section.
[0019] Preferably, the structural block includes a stern section of a second LNG carrier,
the aft section of the first existing LNG carrier is a stern of the first existing
LNG carrier, the method comprising jointing the structural block to the forward section
of the first LNG carrier to form the new integrated LNG carrier.
[0020] Preferably, the method further comprising, prior to separating the first existing
LNG carrier, determining characteristics of the first existing LNG carrier for fabrication
of the structural block.
[0021] The object of the present disclosure is hence to provide a service life extension
program for an existing LNG carrier to both accommodate additional storage facilities
and create more deck space for gas process production/regasification facilities.
[0022] The present disclosure relates to creating additional LNG storage space and deck
space for gas process production/regasification modules, which is achieved by enlarging
an existing LNG carrier by jumboisation technique and then by adding newly built sponsons
which are proposed to be integrated with the existing LNG carrier to increase the
value of the existing LNG carrier without needing to purchase or build an entirely
new floater.
[0023] According to one embodiment of the invention, a newly built structural block is prefabricated
with LNG storage space. The structural block may contain at least one LNG storage
tank having a containment system which may be same as or different from that of the
existing LNG carrier. Most of the existing LNG carriers are either MOSS type containment
systems or membrane type containment systems, only few LNG carriers are built using
other types of containment system. New additional space created for LNG storage can
be either one of the two types of containment system and it depends on the gas process
facilities. MOSS type containment system cannot be utilized because of spherical doom
and we don't have deck space for gas process production facility. Membrane type tank,
IHI SPB tank, Type C pressurized tank and other international approved new containment
systems can be utilized for new LNG storage space and deck space for gas process production/regasification
facility.
[0024] Jumboisation technique requires re-engineering and integration of existing storage
system to newly added system that offset safe flexibility and functionality asset.
An existing LNG carrier is cut apart to form a forward section and an aft section
which include existing cryogenic pipelines, electrical cables, bulkhead, stiffeners,
longitudinal and transverse beam which need to be reinforced and hook up with new
structural block and connect with new pipeline, electrical cables, etc. Necessary
steps should be followed while integrating an existing storage system with a new built
storage system.
[0025] After integration, the existing LNG carrier and new built storage space, deck space
can be utilized for gas process production/regasification facility or machinery space
for other uses. For bigger LNG production facilities which the deck space is still
not enough to accommodate the production modules after jumboisation, a new built sponson(s)
is provided to both sides of the integrated ship hull or one side of integrated ship
hull. This sponson will provide additional deck space for gas process production/regasification
facility, Type C LNG containment system or mechanical deck space for other uses.
[0026] Different cutting locations on an existing LNG carrier from fwd section until bow
section have been proposed in this invention to integrate the existing LNG carrier
with a new built LNG storage space and other existing hookup. In order to merge the
shape of the newly added sponson(s) with the shape of the existing LNG carrier hull,
proper steps need to be carried out. Since the existing LNG carrier may be cut at
different locations, the size of the sponson(s) also changes accordingly, some places
requiring at least one sponson on one side. One side of the sponson can be used as
ballast tank for stability of the Integrated LNG carrier.
[0027] New built structural block fabrication can be done in-house for membrane tank, Keppel
holds license to build such tank in Keppel yard. If new built structural block uses
IHI (Ishikawajima-Harima Heavy Industries Prismatic IMO type B LNG tanks) SPB (self-supporting
prismatic type B) tank then it will be fabricated in IHI yard, after completion of
the complete structural block, it will be deployed to Keppel yard for integrating
with the existing LNG carrier. During fabrication of the new built structural block,
the existing LNG carrier does not need to be present at yard. This will allow the
existing LNG carriers to continue to operate as LNG transportation vessel during the
fabrication period of the new structural block. New built structural block may be
fabricated based on optimized working schedule, construction sequence and coordination
with the existing LNG carrier work process.
[0028] Upon near completion of the new structural block, the existing LNG carrier will be
dry-docked for cutting of the hull for vessel assembly. When the existing hull is
separated into a forward and an aft section, either one or both sections are moved
away from each other to form a space between them. The new structural block is then
placed into the created space and joined to the forward and aft sections, by welding,
to form an integrated storage space to the existing LNG carrier. This new structural
block provides the new dimension to the existing LNG carrier by increasing the storage
space and deck space for gas process production/regasification facility or other machinery
space.
[0029] Newly built sponsons can serve several purposes based on user's requirements; it
can serve as type C LNG storage system, machinery space, deck space for gas process
production/regasification facility, ballast tank, etc. Sponsons can be installed on
both sides of the ship hull or one side of the ship hull. The new built sponsons may
be in different size and shape based on deck space required and the cutting location.
[0030] The new built structural block contains a LNG storage space which may be merged with
the ship hull of the existing LNG carrier or slightly extend the space on both sides
of the new-built structural block to provide additional LNG storage space as well
deck space. The new built sponson(s) should be built based on new built extended structural
block. The extended new built structural block will be integrated with the new built
sponson(s), accordingly some places are required for at least one sponson on one side
of the ship hull.
[0031] Embodiments of the present disclosure can provide the following advantages:
- The new integration to an existing LNG carrier provide additional LNG storage spaces,
create new additional deck space for process production/regasification facility &
utilities, add new sponson(s) on both sides of the ship hull of the existing LNG carrier
to provide additional space which can be utilized for other additional machinery space.
- The existing LNG carrier is only needed during vessel assembly period in the yard,
which minimizes the period for the existing LNG carrier to be present in a yard. This
will maximize the utilization of the existing LNG carrier.
- The newly integrated LNG carrier can be utilized as gas process production/regasification
facility.
- This integration will also provide a new lease of life for a floating LNG production/regasification
platform or asset.
BRIEF DESCRIPTION OF THE DRAWINGS
[0032] These and other aspects of the present disclosure will be described in detail with
reference to the accompanying drawings, in which:
Fig.1A is a partial cross sectional view of an existing LNG carrier;
Fig.1B is a partial top view of the existing LNG carrier of Fig.1A;
Fig. 1C shows a method for integrating an existing LNG carrier according to one embodiment
of the present disclosure;
Fig.2A is a partial cross sectional side view showing the integrating process of an
integrated LNG carrier using an existing LNG carrier of Fig.1A and a new built structural
block according to one embodiment of the present disclosure;
Fig.2B is a partial top view of the integrating process of an integrated LNG carrier
of Fig.2A;
Fig.2C is a partial cross sectional side view of an integrated LNG carrier according
to the process shown in Fig.2A and Fig.2B;
Fig.2D is a partial top view of an integrated LNG carrier according to the process
shown in Fig.2A and Fig.2B;
Fig.2E is a partial cross sectional side view showing the process of integrating new
built sponsons with the integrated LNG carrier of Fig.2C according to another embodiment
of the present disclosure;
Fig.2F is a partial top view showing the process of integrating new built sponsons
with the integrated LNG carrier of Fig.2E;
Fig.2G is a partial cross sectional side view of an integrated LNG carrier according
to the process shown in Fig. 2E and Fig. 2F;
Fig.2H is a partial top view of an integrated LNG carrier according to the process
shown in Fig.2E and Fig.2F;
Fig.3A is a partial cross sectional side view showing the integrating process of an
integrated LNG carrier using an existing LNG carrier of Fig.1A and a new built structural
block according to an alternative embodiment of the present disclosure;
Fig.3B is a partial top view of the integrating process of an integrated LNG carrier
of Fig.3A;
Fig.3C is a partial cross sectional side view of an integrated LNG carrier according
to the process shown in Fig.3A and Fig.3B;
Fig.3D is a partial top view of an integrated LNG carrier according to the process
shown in Fig.3A and Fig.3B;
Fig.3E is a partial cross sectional side view showing the process of integrating new
built sponsons with the integrated LNG carrier of Fig.3C according to another embodiment
of the present disclosure;
Fig.3F is a partial top view showing the process of integrating new built sponsons
with the integrated LNG carrier of Fig.3E;
Fig.3G is a partial cross sectional side view of an integrated LNG carrier according
to the process shown in Fig. 3E and Fig. 3F;
Fig.3H is a partial top view of an integrated LNG carrier according to the process
shown in Fig. 3E and Fig. 3F;
Fig.4A is a partial cross sectional side view showing the integrating process of an
integrated LNG carrier using an existing LNG carrier of Fig.1A and a new built structural
block according to an alternative embodiment of the present disclosure;
Fig.4B is a partial top view of the integrating process of an integrated LNG carrier
of Fig.4A;
Fig.4C is a partial cross sectional side view of an integrated LNG carrier according
to the process shown in Fig.4A and Fig.4B;
Fig.4D is a partial top view of an integrated LNG carrier according to the process
shown in Fig.4A and Fig.4B;
Fig.4E is a partial cross sectional side view showing the process of integrating new
built sponsons with the integrated LNG carrier of Fig.4C according to another embodiment
of the present disclosure;
Fig.4F is a partial top view showing the process of integrating new built sponsons
with the integrated LNG carrier of Fig. 4E;
Fig.4G is a partial cross sectional side view of an integrated LNG carrier according
to the process shown in Fig. 4E and Fig. 4F;
Fig.4H is a partial top view of an integrated LNG carrier according to the process
shown in Fig. 4E and Fig. 4F;
Fig.5A is a partial cross sectional side view showing the integrating process of an
integrated LNG carrier using an existing LNG carrier of Fig.1A and a new built structural
block according to an alternative embodiment of the present disclosure;
Fig.5B is a partial top view showing the integrating process of an integrated LNG
carrier of Fig.5A;
Fig.5C is a partial cross sectional side view of an integrated LNG carrier according
to the process shown in Fig.5A and Fig.5B;
Fig.5D is a partial top view of the integrated LNG carrier according to the process
shown in Fig.5A and Fig.5B;
Fig.5E is a partial cross sectional side view showing the process of integrating new
built sponsons with the integrated LNG carrier of Fig.5C according to another embodiment
of the present disclosure;
Fig.5F is a partial top view of showing the process of integrating new built sponsons
with the integrated LNG carrier of Fig.5E;
Fig.5G is a partial cross sectional side view of an integrated LNG carrier according
to the process shown in Fig. 5E and Fig. 5F;
Fig.5H is a partial top view of the integrated LNG carrier of Fig.5G;
Fig.6A is a partial cross sectional side view showing the integrating process of an
integrated LNG carrier using an existing LNG carrier of Fig.1A and a new built structural
block according to an alternative embodiment of the present disclosure;
Fig.6B is a partial top view showing the integrating process of an integrated LNG
carrier of Fig.6A;
Fig.6C is a partial cross sectional side view of an integrated LNG carrier according
to the process shown in Fig.6A and Fig.6B;
Fig.6D is a partial top view of the integrated LNG carrier of Fig.6C;
Fig.6E is a partial cross sectional side view showing the process of integrating new
built sponsons with the integrated LNG carrier of Fig.6C according to another embodiment
of the present disclosure;
Fig.6F is a partial top view showing the process of integrating new built sponsons
with the integrated LNG carrier of Fig.6E;
Fig.6G is a partial cross sectional side view of an integrated LNG carrier according
to the process shown in Fig. 6E and Fig. 6F;
Fig.6H is a partial top view of the integrated LNG carrier of Fig.6G;
Fig.7A is a partial cross sectional side view showing the integrating process of an
integrated LNG carrier using an existing LNG carrier of Fig.1A and a new built structural
block according to an alternative embodiment of the present disclosure;
Fig.7B is a partial top view showing the integrating process of an integrated LNG
carrier of Fig.7A;
Fig.7C is a partial cross sectional side view of an integrated LNG carrier according
to the process shown in Fig.7A and Fig.7B;
Fig.7D is a partial top view of the integrated LNG carrier of Fig.7C;
Fig.7E is a partial cross sectional side view showing the process of integrating new
built sponsons with the integrated LNG carrier of Fig.7C according to another embodiment
of the present disclosure;
Fig.7F is a partial top view showing the process of integrating new built sponsons
with the integrated LNG carrier of Fig.7E;
Fig.7G is a partial cross sectional side view of an integrated LNG carrier according
to the process shown in Fig. 7E and Fig. 7F;
Fig.7H is a partial top view of the integrated LNG carrier of Fig.7G;
Fig.8A is a partial cross sectional side view showing the integrating process of an
integrated LNG carrier using an existing LNG carrier of Fig.1A and a new built structural
block according to an alternative embodiment of the present disclosure;
Fig.8B is a partial top view showing the integrating process of an integrated LNG
carrier of Fig.7A;
Fig.8C is a partial cross sectional side view of an integrated LNG carrier according
to the process shown in Fig.8A and Fig.8B;
Fig.8D is a partial top view of the integrated LNG carrier of Fig.8C;
Fig.8E is a partial cross sectional side view showing the process of integrating new
built sponsons with the integrated LNG carrier of Fig.8C according to another embodiment
of the present disclosure;
Fig.8F is a partial top view showing the process of integrating new built sponsons
with the integrated LNG carrier of Fig.8E;
Fig.8G is a partial cross sectional side view of an integrated LNG carrier according
to the process shown in Fig. 8E and Fig. 8F;
Fig.8H is a partial top view of the integrated LNG carrier of Fig.8G;
Fig.9A is a partial cross sectional side view showing the integrating process of an
integrated LNG carrier using an existing LNG carrier of Fig.1A and a new built structural
block according to an alternative embodiment of the present disclosure;
Fig.9B is a partial top view showing the integrating process of an integrated LNG
carrier of Fig.9A;
Fig.9C is a partial cross sectional side view of an integrated LNG carrier according
to the process shown in Fig.9A and Fig.9B;
Fig.9D is a partial top view of the integrated LNG carrier of Fig.9C;
Fig.9E is a partial cross sectional side view showing the process of integrating new
built sponsons with the integrated LNG carrier of Fig.9C according to another embodiment
of the present disclosure;
Fig.9F is a partial top view showing the process of integrating new built sponsons
with the integrated LNG carrier of Fig.9E;
Fig.9G is a partial cross sectional side view of an integrated LNG carrier according
to the process shown in Fig. 9E and Fig. 9F;
Fig.9H is a partial top view of the integrated LNG carrier of Fig.9G;
Fig.10A is a partial cross sectional side view showing the integrating process of
an integrated LNG carrier using an existing LNG carrier of Fig.1A and a new built
structural block according to an alternative embodiment of the present disclosure;
Fig.10B is a partial top view showing the integrating process of an integrated LNG
carrier of Fig.10A;
Fig. 10C is a partial cross sectional side view of an integrated LNG carrier according
to the process shown in Fig.10A and Fig.10B;
Fig.10D is a partial top view of the integrated LNG carrier of Fig.10C;
Fig.10E is a partial cross sectional side view showing the process of integrating
new built sponsons with the integrated LNG carrier of Fig.10C according to another
embodiment of the present disclosure;
Fig.10F is a partial top view showing the process of integrating new built sponsons
with the integrated LNG carrier of Fig.10E;
Fig.10G is a partial cross sectional side view of an integrated LNG carrier according
to the process shown in Fig. 10E and Fig. 10F;
Fig.10H is a partial top view of the integrated LNG carrier of Fig.10G;
Fig.11A is a partial cross sectional side view showing the integrating process of
an integrated LNG carrier using an existing LNG carrier of Fig.1A and a new built
structural block according to an alternative embodiment of the present disclosure;
Fig.11B is a partial top view showing the integrating process of an integrated LNG
carrier of Fig.11A;
Fig.11C is a partial cross sectional side view of an integrated LNG carrier according
to the process shown in Fig.11A and Fig.11B;
Fig.11D is a partial top view of the integrated LNG carrier of Fig.11C;
Fig.11E is a partial cross sectional side view showing the process of integrating
new built sponsons with the integrated LNG carrier of Fig.11C according to another
embodiment of the present disclosure;
Fig.11F is a partial top view showing the process of integrating new built sponsons
with the integrated LNG carrier of Fig.11E;
Fig.11G is a partial cross sectional side view of an integrated LNG carrier according
to the process shown in Fig. 11E and Fig. 11F;
Fig.11H is a partial top view of the integrated LNG carrier of Fig.11G;
Fig.12A is a partial cross sectional side view showing the integrating process of
an integrated LNG carrier using an existing LNG carrier of Fig.1A and a new built
structural block according to an alternative embodiment of the present disclosure;
Fig.12B is a partial top view showing the integrating process of an integrated LNG
carrier of Fig.12A;
Fig.12C is a partial cross sectional side view of an integrated LNG carrier according
to the process shown in Fig.12A and Fig.12B;
Fig.12D is a partial top view of the integrated LNG carrier of Fig.12C;
Fig.12E is a partial cross sectional side view showing the process of integrating
new built sponsons with the integrated LNG carrier of Fig.12C according to another
embodiment of the present disclosure;
Fig.12F is a partial top view showing the process of integrating new built sponsons
with the integrated LNG carrier of Fig.12E;
Fig.12G is a partial cross sectional side view of an integrated LNG carrier according
to the process shown in Fig. 12E and Fig. 12F;
Fig.12H is a partial top view of the integrated LNG carrier of Fig.12G;
Fig.13A is a partial cross sectional side view showing the integrating process of
an integrated LNG carrier using an existing LNG carrier of Fig.1A and a new built
structural block according to an alternative embodiment of the present disclosure;
Fig.13B is a partial top view showing the integrating process of an integrated LNG
carrier of Fig.13A;
Fig.13C is a partial cross sectional side view of an integrated LNG carrier according
to the process shown in Fig.13A and Fig.13B;
Fig.13D is a partial top view of the integrated LNG carrier of Fig.13C;
Fig.13E is a partial cross sectional side view showing the process of integrating
new built sponsons with the integrated LNG carrier of Fig.13C according to another
embodiment of the present disclosure;
Fig.13F is a partial top view showing the process of integrating new built sponsons
with the integrated LNG carrier of Fig.13E;
Fig.13G is a partial cross sectional side view of an integrated LNG carrier according
to the process shown in Fig. 13E and Fig. 13F;
Fig.13H is a partial top view of the integrated LNG carrier of Fig.13G;
Fig.14A is a partial cross sectional side view showing the integrating process of
an integrated LNG carrier using an existing LNG carrier of Fig.1A and a new built
structural block according to an alternative embodiment of the present disclosure;
Fig.14B is a partial top view showing the integrating process of an integrated LNG
carrier of Fig.14A;
Fig.14C is a partial cross sectional side view of an integrated LNG carrier according
to the process shown in Fig.14A and Fig.14B;
Fig.14D is a partial top view of the integrated LNG carrier of Fig.14C;
Fig.14E is a partial cross sectional side view showing the process of integrating
new built sponsons with the integrated LNG carrier of Fig.14C according to another
embodiment of the present disclosure;
Fig.14F is a partial top view showing the process of integrating new built sponsons
with the integrated LNG carrier of Fig.14E;
Fig.14G is a partial cross sectional side view of an integrated LNG carrier according
to the process shown in Fig. 14E and Fig. 14F;
Fig.14H is a partial top view of the integrated LNG carrier of Fig.14G;
Fig.15A is a partial cross sectional side view showing the integrating process of
an integrated LNG carrier using an existing LNG carrier of Fig.1A and a new built
structural block according to an alternative embodiment of the present disclosure;
Fig.15B is a partial top view showing the integrating process of an integrated LNG
carrier of Fig.15A;
Fig.15C is a partial cross sectional side view of an integrated LNG carrier according
to the process shown in Fig.15A and Fig.15B;
Fig.15D is a partial top view of the integrated LNG carrier of Fig.15C;
Fig.15E is a partial cross sectional side view showing the process of integrating
new built sponsons with the integrated LNG carrier of Fig.15C according to another
embodiment of the present disclosure;
Fig.15F is a partial top view showing the process of integrating new built sponsons
with the integrated LNG carrier of Fig.15E;
Fig.15G is a partial cross sectional side view of an integrated LNG carrier according
to the process shown in Fig. 15E and Fig. 15F;
Fig.15H is a partial top view of the integrated LNG carrier of Fig.15G.
DETAILED DESCRIPTION OF THE INVENTION
[0033] In the following description, numerous specific details are set forth in order to
provide a thorough understanding of various illustrative embodiments of the invention.
It will be understood, however, to one skilled in the art, that embodiments of the
invention may be practiced without some or all of these specific details. It is understood
that the terminology used herein is for the purpose of describing particular embodiments
only, and is not intended to limit the scope of the invention. In the drawings, like
reference numerals refer to same or similar functionalities or features throughout
the several views.
[0034] Before cutting an existing LNG carrier, some of the major procedures need to be followed
on the existing LNG carrier. All systems which contain flammable or toxic vapours
or inert gas should be gas-freed, and a gas-free certificate must be obtained from
a competent person, before or immediately upon entry into a port for cutting. Before
commencing any hot work, the yard would normally be expected to take its own precautions
and arrange for the issue of certificates allowing hot work to be carried out.
[0035] All equipment on board should be checked internally for the presence of flammable
or toxic vapours or inert gas and should be purged if necessary before work proceeds.
It is usually necessary to gas-free deck storage tanks before hot work can be commenced
in the vicinity, the following precaution should be observed:
- All pipe connections to the cargo system should be disconnected and securely blanked
- Smoking and hot work should not be allowed in the restricted area
- No work should be permitted on the tanks or their fittings
- Tank pipework and fittings should be protected from mechanical damage particular care
is necessary if cranes are being used nearby
- All electrical connections should be totally shutdown
- All electrical cable connections at cutting area need to be properly secured the ends
- Any ventilation ducting connections at cutting area need to be properly secured at
all time
- Any lift craft on the deck at cutting area need to be relocated to a different location.
[0036] Once the pre-check procedure is followed, an existing LNG carrier is brought into
yard for cutting operation as elaborated below. Cutting an existing LNG carrier involves
severing and splicing all the coordination system, including cables, cryogenic pipes
and ducts; this job should not be underestimated. Once an existing LNG carrier is
cut, the shortest portion will be moved away by using a heavy lifting crane. The forward
section and aft section of an existing LNG carrier have many topside cryogenic pipelines
carrying LNG at -163 degrees Celsuis if any leak in the pipelines, it will damage
the structure of the existing LNG carrier. Once the existing LNG carrier is cut, it
is needed to immediately blank the line on both forward and aft sections. All electrical
cables, junction box terminal, ventilation ducting, etc. need to be properly secured
at all times.
[0037] A new structural block will be fabricated based on the existing LNG carrier cutting
dimension as well required LNG storage capacity, deck space requirement for gas processing
production/regasification facility and utility. The longitudinal strength limits of
the hull grider determine the elongation size. The increase in the longitudinal bending
moment will require a corresponding amount of additional steel in order to maintain
the required modulus.
[0038] The following steps are required for the ship hull and structural part of the conversion:
- The longitudinal strength of the existing LNG carrier has to be evaluated. The maximum
allowable bending moment can become a showstopper if the ship hull is already designed
to its optimum and cannot sustain any additional length.
- A damage stability study needs to be carried out in order to determine the location
of the new structural block.
- The evacuation arrangements need to be sorted out when planning the new inserted structural
block arrangement.
- The location of the vent mast needs to be considered in order to avoid disruption
on the upper decks.
[0039] Jumboisation technique requires re-engineering, integration of an existing storage
system to a newly added system that offsets safe flexibility and functionality asset.
Outfitting is the process of installing parts and various subassemblies (e.g., piping
systems, ventilation equipment, and electrical components) on the new built block
prior to joining the new built block with the existing LNG carrier at the stage of
erection of a vessel. The existing LNG carrier's power supply will need to be recalculated
due to the increased load.
[0040] Once jumboisation is done, then the following necessary steps need to be carried
out: necessary steps carried out to the existing cryogenic pipeline and the new cryogenic
pipeline. In addition, the atmospheric pressure of the existing tank and new tank
might differ, so proper necessary step may be taken while transferring LNG from the
existing tank to a new storage tank. The pump capacity of the existing LNG storage
tank might be affected while doing jumboisation as a new structural block increases
its deck space and cryogenic line pipes, it needs to carry out reengineering work
to size up the pump or having additional tank to make up the loss during LNG transfer.
Similarly, re-engineering work needs to be carried out for machinery, electrical system,
hull structure, outfitting and required reinforcement.
[0041] The present jumboisation is not only a technical solution of using an existing LNG
carrier for newly integrated additional storage space and increasing deck space for
pas processing production/regasification facility, utility and machinery space for
other uses but also financially feasible compared to the new built LNG production/regasification
vessel. Through using the present disclosure, certain existing LNG carriers may widen
their opportunity to serve as gas process production/regasification facility with
additional LNG storage capacity and extend life of their service.
[0042] Turning to the Figures, Fig.1A and Fig.1B show an existing LNG carrier based on which
jumboisation method according to one embodiment of the present disclosure may be applied.
Existing LNG carrier 10 includes a bow 101, a stern 110 and a midship between bow
101 and stern 110. The midship includes five segments 102, 104, 106,108 and 109. Each
segment has a corresponding first, second, third & fourth LNG storage tank and wheel
house 112, 114, 116, 118 and 120 built therein. Each individual LNG storage tank has
its fixed storage capacity and hence the total storage and transportation capacity
of the LNG carrier is the sum of capacity of all the individual LNG storage tanks.
[0043] A method 250 for integrating an existing LNG carrier according to one embodiment
of the present disclosure comprises the following steps, as shown in Fig. 1C:
In Step 252, a new built structural block will be fabricated or provided as a prefabrication
unit from other sources. Then in Step 254, an existing LNG carrier is cut apart into
a forward section and an aft section. After that in Step 256, the new built structural
block is placed into a space created between an existing LNG carrier cut apart forward
and an aft section and, then in Step 258, the new built structural block is jumboized
to the forward and an aft section to form an integrated LNG carrier. Besides the steps
above, in Step 260, one or more new built sponsons may be fabricated to be integrated
with the integrated LNG carrier, as shown in Step 262.
[0044] Before proceeding to cut an existing LNG carrier, measurements and/or site inspections
may be carried out to determine the characteristics of an existing LNG carrier, e.g.
the dimensions of an existing LNG carrier width, longitudinal & transverse beam location,
stiffeners, and existing cryogenic & utility pipelines, cable tray, hookup points
and connection interfaces, etc. such information will be used for the fabrication
of the new built structural block to ensure compatibility.
[0045] Further details of this and other embodiments will be illustrated below in conjunction
with the accompanying drawings.
[0046] As shown in Fig. 2A and Fig. 2B, a new built structural block 200 will be fabricated
using either one of the containment systems, i.e. MOSS type containment system or
membrane type containment system or provided as a prefabrication unit from other sources.
When the fabrication of a new built structural block is completed, the existing LNG
carrier 10 may be brought to the shipyard dry dock to undergo the cutting. Once cutting
is done, then either forward or aft section will be moved away to create space and
then jumboize the new built structural block with the existing LNG carrier.
[0047] In the embodiment shown in Fig. 2A and Fig. 2B, cutting is performed between stern
110 and the fourth LNG storage tank 118, forming a forward section 201 which includes
bow 101, first 112, second 114, third 116 & fourth LNG storage tank 118 and aft section
202 which includes stern 110 and wheel house 120. A newly created space 205 is formed
between the forward section 201 and the aft section 202. The new built structural
block 200 is then placed in space 205 by floating or a heavy lift crane, with the
forward section 201 jumboized to front end 203 of the new built structural block 200,
the aft section 202 jumboized to rear end 204 of the new built structural block 200
. Upon jumboizing, the new built structural block 200 together with the forward section
201 and aft section 202, form an integrated LNG carrier 20 with the new built structural
block 200 integrated to an existing LNG carrier, as shown in Fig.2C and Fig.2D
[0048] In the other embodiment shown in Fig 2E and Fig. 2F, new built sponsons in different
size configuration on both sides of ship hull will be fabricated. New built sponsons
on port side 350 and starboard side 300 with different size configuration will be
fabricated separately and integrated with the LNG carrier 20 to form a newly integrated
LNG carrier 30, as shown in Fig 2G and Fig 2H.
The LNG storage tank of the new built structural block 200 may be same as or different
from that in the existing LNG carrier. LNG containment system of the LNG storage tank
may be selected from a group consisting of a MOSS type spherical tank, a Gaztransport
& Technigaz (GTT) membrane tank, IHI self-supporting prismatic type B SPB tank and
an independent type A tank.
[0049] The present disclosure provides a newly integrated LNG carrier by a new built structural
block and one or more new built sponsons which provide additional LNG storage, create
deck space for gas process production/regasification facility, utilities and deck
space for other machinery usage. This integration also provides new life extension
to the existing LNG carrier to serve for current industrial demand with a much shorter
delivery schedule than that of required to build new floater from sketch, and also
reduces capital expenditure.
[0050] According to another embodiment, an existing LNG carrier may be cutting at different
location into forward and aft sections, for integration of a new built structural
block there between. Later the integrated LNG carrier will again integrate with at
least one new built sponson to form a newly Integrated LNG carrier.
[0051] As shown in Fig. 3A to 3H, an existing LNG carrier 10 is cut apart into forward section
206 and an aft section 207. Cutting is performed between a third LNG storage tank
116 and fourth LNG storage tank 118, hence the forward section 206 includes the bow
101, first, second and third LNG storage tank 112, 114 and 116. The aft section 207
includes stern 110, wheel house 120, and fourth LNG storage tank 118. A new built
structural block 210 will be fabricated and then placed into the space 208 created
between forward section 206 and aft section 207, and jumboized forward and aft section
206 & 207 to form an integrated LNG carrier 22 with the new built structural block
210 integrated to the existing LNG carrier 10, as shown in Fig. 3C and Fig. 3D.
[0052] In the other embodiment shown in Fig 3E and Fig. 3F, new built sponsons in different
size configuration on both sides of the ship hull will be fabricated. New built sponsons
on port side 350 and starboard side 300 with different size configuration will be
fabricated separately and integrated with the integrated LNG carrier 22 to form a
newly integrated LNG carrier 32, as shown in Fig 3G and Fig 3H.
[0053] Alternatively, as shown in respective Fig. 4A to 4H, 5A to 5H and 6A to 6H, an existing
LNG carrier 10 may be cut apart into forward section 211, 216, 221 and an aft section
212, 217, 222. In Fig. 4A to 4H, cutting is performed between second LNG storage tank
114 and third LNG storage tank 116 at a mid-ship section. In Fig. 5A to 5H, cutting
is performed between first LNG storage tank 112 and second LNG storage tank 114 at
forward section. In Fig 6A to 6H, cutting is performed between bow 101 and first LNG
storage tank 112 at forward bow section. A new built structural block 215, 220, 225
is fabricated and then placed at the space 213, 218, 223 formed by cutting of an existing
LNG carrier 10, finally jumboized the cut-apart forward 211, 216, 221 and aft section
212, 217, 222 to form an integrated LNG carrier 24 (Fig. 4C, 4D), 26(Fig. 5C, 5D),
28 (Fig. 5C, 5D).In the other embodiment shown in Fig 4E & Fig. 4F, Fig. 5E & Fig.
5F,and Fig. 6E & Fig. 6F, new built sponsons in different size configuration on both
sides of the ship hull are fabricated. New built sponsons on port side 350 and starboard
side 300 with different size configuration will be fabricated separately and integrated
with the integrated LNG carrier 24, 26 & 28 to form a newly integrated LNG carrier
34, 36 & 38.
[0054] In a further embodiment, as shown in Fig. 7A to 7H, a new built structural block
230 will be fabricated. An existing LNG carrier 10 is cut apart into forward section
226 and an aft section 227, creating a space 228 there between. Forward section includes
first, second, third & fourth LNG storage tank 112,114,116 & 118, wheel house 120
and stern 110. An aft section includes a new bow section 600 which may or may not
build with turret 700. Turret 700 provides a non-rotating platform for supporting
the mooring lines and flexible risers dedicated for gas export/import and associated
control/service lines. The new structural block 200 is then placed in the space 228
and jumboized forward section 226 and the new built aft bow section 600 to form an
integrated LNG carrier 40, as shown in Fig, 7C & Fig. 70.
[0055] In the other embodiment shown in Fig 7E and Fig. 7F, new built sponsons in different
size configuration on both sides of ship hull will be fabricated. New built sponsons
on port side 350 and starboard side 300 with different size configuration will be
fabricated separately and integrated with the integrated LNG carrier 40 to form a
newly integrated LNG carrier 50, as shown in Fig 7G and Fig 7H.
[0056] In another further embodiment, as shown in Fig. 8A to 8H, a new built structural
block 235 will be fabricated. An existing LNG carrier 10 is cut apart into forward
section 231 and an aft section 232, creating a space 233 there between. Aft section
includes new stern 650 and forward section includes bow 101, first, second, third
and fourth LNG storage tank 112, 114, 116 & 118 and wheel house 120. New stern 650
which can be fabricated along with new structural block and then joined with aft section
232. The new structural block 200 is then placed in the space 233 and jumboized to
forward section 231 and aft section 232 or new stern section 650 to form an integrated
LNG carrier 42 as shown in Fig. 8C and Fig. 80.
[0057] In the other embodiment shown in Fig 8E and Fig. 8F, new built sponsons in different
size configuration on both sides of ship hull will be fabricated. New built sponsons
on port side 350 and starboard side 300 with different size configuration will be
fabricated separately and integrated with the integrated LNG carrier 42 to form a
newly integrated LNG carrier 52, as shown in Fig 8G and Fig 8H.
[0058] As shown in Fig. 9A and Fig. 9B, a new built structural block 400 will be fabricated
using either one of the containment systems or provided as a prefabrication unit from
other sources. The new built structural block has a similar design to the earlier
ones but this structural block width is extended on both starboard and port side with
same or different width from the ship hull. When the fabrication of a new built structural
block 400 is completed, the existing LNG carrier 10 may be brought to the shipyard
dry dock to undergo the cutting. Once cutting is done, then either forward or aft
section will be moved away to create space and then jumboized the new built structural
block 400 with an existing LNG carrier 10.
[0059] In the embodiment shown in Fig. 9A and Fig. 9B, cutting is performed between stern
110 and the fourth LNG storage tank 118, forming a forward section 201 which includes
bow 101, first 112, second 114, third 116 & fourth LNG storage tank 118 and aft section
202 which includes stern 110 and wheel house 120. A newly created space 401 is formed
between forward section 201 and an aft section 202. The new built structural block
400 is then placed in space 401 by floating or a heavy lift crane, with the forward
section 201 jumboized to front end 403 of new built structural block 400, the aft
section 202 jumboized to rear end 404 of the new built structural block 400. Upon
jumboizing, the new built structural block 400 together with the forward section 201
and aft section 202 to form an integrated LNG carrier 44 with the new built structural
block 400 integrated to an existing LNG carrier 10, as shown in Fig.9C and Fig.9D
[0060] In the other embodiment shown in Fig 9E and Fig. 9F, new built sponsons will be fabricated
based on the existing LNG carrier 10 and new built structural block 400. New built
sponsons may include more than one sponson on both starboard side 800 & 801 and port
side 821 & 822 of ship hull in different size configuration which will be fabricated
separately and integrated with the integrated LNG carrier 44 to form a newly integrated
LNG carrier 54, as shown in Fig 9G and Fig 9H.
[0061] Alternatively, as shown in respective Fig. 10A to 10H, 11A to 11H, 12A to 12H and
13A to 13H, an existing LNG carrier 10 may be cut apart into forward section 206,
211, 216 and 221 and an aft section 207,412, 417 and 222. In Fig. 10A to 10H, cutting
is performed between third LNG storage tank 116 and fourth LNG storage tank 118. In
Fig. 11A to 11H, cutting is performed between second LNG storage tank 114 and third
LNG storage tank 116 at amidship section. In Fig. 12A to 12H, cutting is performed
between first LNG storage tank 112 and second LNG storage tank 114 at forward section.
In Fig 13A to 13H, cutting is performed between bow 101 and first LNG storage tank
112 at forward bow section. A new built structural block 405, 410, 415 and 420 is
then placed at the space 406, 411, 416 and 421 formed by cutting of an existing LNG
carrier 10, jumboized the cut-apart forward section 206, 211, 216 and 221 and aft
section 207, 212, 217 and 222 to form an integrated LNG carrier 46 (see Fig. 10C,
10D), 48 (see Fig. 11C, 11D), 62 (see Fig. 12C, 12D) & 64 (see Fig. 13C, 13D).
[0062] In the other embodiments shown in Fig. 10E & Fig, 10F, Fig. 11E & Fig. 11F, Fig.
12E & Fig. 12F and Fig. 13E & Fig. 13F, new built sponsons will be fabricated based
on the existing LNG carrier 10 and new built structural block 405, 410, 415 & 420.
New built sponsons may include more than one sponson on both starboard sides 803 &
804, 805 & 806, 807 & 808 and 810; port side 823 & 824, 825 & 826, 827 & 828and 830
of the ship hull in different size configuration which will be fabricated separately
and integrated with the integrated LNG carrier 46, 48, 62 & 64 to form a newly integrated
LNG carrier 56, 58, 72 & 74, as shown in Fig 10G & Fig 10H, Fig 11G & Fig 11H, Fig
12G & Fig 12H and Fig 13G & Fig 13H.
[0063] In a further embodiment, as shown in Fig. 14A to 14H, a new built structural block
425 will be fabricated. An existing LNG carrier 10 is cut apart into forward section
226 and an aft section 227, creating a space 426 there between. Forward section 226
includes first, second, third & fourth LNG storage tank 112,114,116 & 118, wheel house
120 and stern 110. The aft section 227 includes a new bow section 800 which may or
may not build with turret 900. Turret 900 provides a non-rotating platform for supporting
the mooring lines and flexible risers dedicated for gas export/import and associated
control/service lines. The new structural block 425 is then placed in the space 426
and jumboized forward section 226 and new built aft bow section 800 to form an integrated
LNG carrier 66, as shown in Fig. 14C & Fig. 14D.
[0064] In the other embodiment shown in Fig 14E and Fig. 14F, new built sponsons on both
sides of the ship hull in different size configuration will be fabricated. New built
sponsons on port side 815 and starboard side 835 with different size configuration
will be fabricated separately and integrated with Integrated LNG carrier 66 to form
a newly integrated LNG carrier 76, as shown in Fig 14G and Fig 14H.
[0065] In another further embodiment, as shown in Fig. 15A to 15H, a new built structural
block 430 will be fabricated. An existing LNG carrier 10 is cut apart into forward
section 231 and an aft section 232, creating a space 233 there between. Forward section
231 includes new stern 850 and aft section 232 includes bow 101, first, second, third
and fourth LNG storage tank 112, 114, 116 & 118 and wheel house 120. New stern 850
which can be fabricated along with the new built structural block 430 and then joined
with aft section 232. The new built structural block 430 is then placed in the space
431 and jumboized forward section 231 and aft section 232 or new built stern 850 to
form an integrated LNG carrier 68, as shown in Fig. 15C and Fig. 15D.
[0066] In the other embodiment shown in Fig 15E and Fig. 15F, new built sponsons on both
sides of the ship hull in different size configuration will be fabricated. New built
sponsons on port side 820 and starboard side 840 with different size configuration
will be fabricated separately and integrated with the integrated LNG carrier 68 to
form a newly integrated LNG carrier 78, as shown in Fig 15G and Fig 15H.
[0067] Other embodiments will be apparent to those skilled in the art from consideration
of the specification and practice of the invention. Furthermore, certain terminology
has been used for the purposes of descriptive clarity, and not to limit the disclosed
embodiments of the invention. The embodiments and features described above should
be considered exemplary.