U.S. patent application number 12/372577 was filed with the patent office on 2009-08-20 for apparatus for off-shore processing of a hydrocarbon stream.
Invention is credited to Harke Jan MEEK, Michael George SAID, Ewoud VAN HAAFTEN, Aifeng YAO.
Application Number | 20090208294 12/372577 |
Document ID | / |
Family ID | 40955273 |
Filed Date | 2009-08-20 |
United States Patent
Application |
20090208294 |
Kind Code |
A1 |
YAO; Aifeng ; et
al. |
August 20, 2009 |
APPARATUS FOR OFF-SHORE PROCESSING OF A HYDROCARBON STREAM
Abstract
An apparatus for off-shore processing of a hydrocarbon stream,
at least comprising: a jack-up platform; one or more jack-up legs
rootable to a sea-bed; and one or more hydrocarbon stream
processing units on the jack-up platform.
Inventors: |
YAO; Aifeng; (Katy, TX)
; VAN HAAFTEN; Ewoud; (The Hague, NL) ; SAID;
Michael George; (Bangalore, IN) ; MEEK; Harke
Jan; (Houston, TX) |
Correspondence
Address: |
SHELL OIL COMPANY
P O BOX 2463
HOUSTON
TX
772522463
US
|
Family ID: |
40955273 |
Appl. No.: |
12/372577 |
Filed: |
February 17, 2009 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61029694 |
Feb 19, 2008 |
|
|
|
Current U.S.
Class: |
405/196 |
Current CPC
Class: |
E02B 17/021 20130101;
E02B 2017/006 20130101; F25J 2290/42 20130101; F25J 1/0259
20130101; F25J 1/0278 20130101; E02B 2017/0039 20130101; F25J
1/0022 20130101 |
Class at
Publication: |
405/196 |
International
Class: |
E02B 17/08 20060101
E02B017/08 |
Claims
1. An apparatus for off-shore processing of a hydrocarbon stream,
at least comprising: a jack-up platform; one or more jack-up legs
rootable to a sea-bed; and one or more hydrocarbon stream
processing units on the jack-up platform.
2. The apparatus as claimed in claim 1, wherein the one or more
hydrocarbon stream processing units comprise one or more
hydrocarbon stream liquefying units and/or one or more gasifying
units.
3. The apparatus as claimed in claim 1, further comprising one or
more liquefied hydrocarbon storage facilities.
4. The apparatus as claimed in claim 3, wherein the one or more
storage facilities comprise one or more LNG storage tanks.
5. The apparatus as claimed in claim 1, further comprising one or
more liquefied hydrocarbon transfer devices.
6. The apparatus as claimed in claim 1, further comprising one or
more well production facilities.
7. The apparatus as claimed in claim 1, further comprising one or
more hydrocarbon stream treatment facilities.
8. The apparatus as claimed in claim 1, wherein the jack-up
platform comprises one or more decks.
9. The apparatus as claimed in claim 1, wherein the jack-up
platform comprises one or more barges.
10. The apparatus as claimed in claim 9, wherein the one or more
barges comprise a decking portion for the location of one or more
of the one or more hydrocarbon stream processing units thereon.
11. The apparatus as claimed in claim 1, comprising two or more
jack-up legs.
12. The apparatus as claimed in claim 1, comprising two to six
jack-up legs.
13. The apparatus as claimed in claim 1, wherein the jack-up
platform is movable between a marine-transportation position and a
jacked-up operating position.
14. The apparatus as claimed in claim 1, comprising integrated
production, liquefaction, storage and off-loading facilities for a
natural gas stream.
15. The apparatus as claimed in claim 1, being relocatable.
16. The apparatus as claimed in claim 1, further comprising one or
more hydrocarbon drilling facilities.
17. The apparatus as claimed in claim 1, wherein the processing of
the hydrocarbon stream comprises treating and liquefying natural
gas to provide liquefied natural gas.
18. The apparatus as claimed in claim 1, wherein the processing of
the hydrocarbon stream comprises gasifying a liquefied natural gas
stream to provide a natural gas stream.
19. A method of cooling a hydrocarbon stream, comprising at least
the steps of: (i) providing a hydrocarbon stream to an off-shore
processing apparatus that at least comprises: a jack-up platform;
one or more jack-up legs rootable to a sea-bed; and one or more
hydrocarbon stream processing units at least comprising one or more
cooling units on the jack-up platform; and (ii) cooling the
hydrocarbon stream.
20. The method as claimed in claim 19, wherein the hydrocarbon
stream comprises natural gas.
21. The method as claimed in claim 19, wherein the cooling of the
hydrocarbon stream comprises liquefying the hydrocarbon stream.
22. The method as claimed in claim 19, for cooling and liquefying
natural gas to provide liquefied natural gas.
23. A method of gasifying a liquefied hydrocarbon stream,
comprising at least the steps of: (i) providing a liquefied
hydrocarbon stream to off-shore processing apparatus that at least
comprises: a jack-up platform; one or more jack-up legs rootable to
a sea-bed; and one or more hydrocarbon stream processing units at
least comprising one or more gasifying units on the jack-up
platform; and (ii) gasifying the liquefied hydrocarbon stream.
24. The method of claim 23, wherein the liquefied hydrocarbon
stream comprises liquefied natural gas.
25. The method of claim 23, wherein the gasifying comprises
re-gasifying.
26. A method of installing an apparatus for off-shore processing of
a hydrocarbon stream, the method comprising at least the steps of:
providing an apparatus at least comprising: a jack-up platform; one
or more jack-up legs rootable to a sea-bed; and one or more
hydrocarbon stream processing units on the jack-up platform;
transporting said apparatus across a sea; locating the apparatus;
rooting one or more jack-up legs of the apparatus with the sea-bed;
and raising the jack-up platform above sea level.
27. The method as claimed in claim 26, wherein the apparatus is
located in shallow water.
28. The method as claimed in claim 26, wherein the apparatus is
located near an underwater hydrocarbon stream source.
29. The method as claimed in claim 26, wherein the apparatus is
located in shallow water and located near an underwater hydrocarbon
stream source.
30. A method of developing an off-shore hydrocarbon stream
processing facility comprising at least the steps of: (a)
installing an apparatus for off-shore processing of a hydrocarbon
stream, the installing comprising: providing an apparatus at least
comprising: a jack-up platform; one or more jack-up legs rootable
to a sea-bed; and one or more hydrocarbon stream processing units
on the jack-up platform; transporting said apparatus across a sea;
locating the apparatus; rooting one or more jack-up legs of the
apparatus with the sea-bed; and raising the jack-up platform above
sea level; and (b) supplementing and/or replacing the apparatus by
one or more further and/or other off-shore hydrocarbon
installations, facilities and/or apparatus.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional
Application No. 61/029,694, filed on Feb. 19, 2008, which is
incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to apparatus for off-shore
processing of a hydrocarbon stream, optionally natural gas; a
method of cooling, optionally liquefying, a hydrocarbon stream
using such an apparatus; method of gasifying, optionally
re-gasifying, a liquefied hydrocarbon stream using such an
apparatus; a method of installing an apparatus for off-shore
processing a hydrocarbon stream; and a method of developing an
off-shore hydrocarbon stream processing facility.
BACKGROUND OF THE INVENTION
[0003] Natural gas is a useful fuel source, as well as being a
source of various hydrocarbon compounds. It is often desirable to
liquefy natural gas in a liquefied natural gas (LNG) plant at or
near the source of a natural gas stream.
[0004] LNG plants are traditionally `on-shore` using an underground
natural gas stream. However, some on-shore natural gas sources may
not allow location and/or operation of a convenient on-shore
production and/or liquefaction facility.
[0005] Some natural gas reserves are also `off-shore`, but many
such reserves are considered too small or too marginal or too
remote from existing infrastructure to be developed
economically.
[0006] `Floating` LNG vessels, often converted oil tankers, are
known for providing off-shore processing of off-shore natural gas
streams, but floating LNG tankers are still susceptible to the
surrounding marine environment, especially wind and wave
combinations, as well as requiring a mooring system.
[0007] U.S. Pat. No. 6,942,427 B1 describes a column-stabilised
floating structure with telescopic keel tank for off-shore
applications and method of installation. However, such a structure
is still dependent on the marine environment, i.e. the winds and
the waves, and still requires mooring.
SUMMARY OF THE INVENTION
[0008] An apparatus for off-shore processing of a hydrocarbon
stream, at least comprising: a jack-up platform; one or more
jack-up legs rootable to a sea-bed; and one or more hydrocarbon
stream processing units on the jack-up platform.
[0009] A method of cooling a hydrocarbon stream, comprising at
least the steps of: (i) providing a hydrocarbon stream to an
off-shore processing apparatus that at least comprises: a jack-up
platform; one or more jack-up legs rootable to a sea-bed; and one
or more hydrocarbon stream processing units at least comprising one
or more cooling units on the jack-up platform; and (ii) cooling the
hydrocarbon stream.
[0010] A method of gasifying a liquefied hydrocarbon stream,
comprising at least the steps of: (i) providing a liquefied
hydrocarbon stream to off-shore processing apparatus that at least
comprises: a jack-up platform; one or more jack-up legs rootable to
a sea-bed; and one or more hydrocarbon stream processing units at
least comprising one or more gasifying units on the jack-up
platform; and (ii) gasifying the liquefied hydrocarbon stream.
[0011] A method of installing an apparatus for off-shore processing
of a hydrocarbon stream, the method comprising at least the steps
of: providing an apparatus at least comprising: a jack-up platform;
one or more jack-up legs rootable to a sea-bed; and one or more
hydrocarbon stream processing units on the jack-up platform;
transporting said apparatus across a sea; locating the apparatus;
rooting one or more jack-up legs of the apparatus with the sea-bed;
and raising the jack-up platform above sea level.
[0012] A method of developing an off-shore hydrocarbon stream
processing facility comprising at least the steps of: (a)
installing an apparatus for off-shore processing of a hydrocarbon
stream, the installing comprising: providing an apparatus at least
comprising: a jack-up platform; one or more jack-up legs rootable
to a sea-bed; and one or more hydrocarbon stream processing units
on the jack-up platform; transporting said apparatus across a sea;
locating the apparatus; rooting one or more jack-up legs of the
apparatus with the sea-bed; and raising the jack-up platform above
sea level; and (b) supplementing and/or replacing the apparatus by
one or more further and/or other off-shore hydrocarbon
installations, facilities and/or apparatus.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] Embodiments and examples of the present invention will now
be described by way of example only and with reference to the
accompanying non-limited drawings in which:
[0014] FIG. 1 is a first diagrammatic side view of apparatus
according to one embodiment of the present invention;
[0015] FIGS. 2a-e are diagrammatic side views of transportation and
installation of apparatus shown in FIG. 1; and
[0016] FIG. 3 is diagrammatic plan view of apparatus of FIG. 1.
DETAILED DESCRIPTION OF THE INVENTION
[0017] The present invention provides apparatus for off-shore
processing of a hydrocarbon stream such as natural gas which is
rootable to a sea-bed to provide stability to the jack-up platform
in relation to the surrounding marine environment, (except in
extremis situations). This provides a stable non-moving platform
that can have a deck and support structure for the one or more
hydrocarbon stream processing units.
[0018] The present invention also provides apparatus which can
provide stability for one or more storage facilities such as LNG
tanks, thereby reducing problematic sloshing of LNG in a floating
storage facility.
[0019] The present invention can also provide a convenient import
and/or export terminal for a hydrocarbon stream. The present
invention has the flexibility to comprise any suitable hydrocarbon
processing units for any combination of processing, production,
treating, liquefying, gasifying, etc of a hydrocarbon stream or
streams supplied off-shore or from on-shore or both, as well as
being adaptable to change its hydrocarbon processing units for one
or more different operations in the same or a different
location.
[0020] The hydrocarbon stream may be any suitable gas stream to be
processed, but is usually a natural gas stream obtained from
natural gas or petroleum reservoirs. As an alternative the natural
gas stream may also be obtained from another source, also including
a synthetic source such as a Fischer-Tropsch process.
[0021] Usually the natural gas stream is comprised substantially of
methane. Preferably the hydrocarbon feed stream comprises at least
50 mol % methane, more preferably at least 80 mol % methane.
[0022] Depending on the source, the natural gas may contain varying
amounts of hydrocarbons heavier than methane such as ethane,
propane, butanes and pentanes, as well as some aromatic
hydrocarbons. The composition varies depending upon the type and
location of the gas. Hydrocarbons heavier than methane are
generally removed from natural gas prior to liquefaction for
several reasons, such as having different freezing or liquefaction
temperatures that may cause them to block parts of a methane
liquefaction plant. C2-4 hydrocarbons can be used as a source of
natural gas liquids.
[0023] The natural gas stream may also contain non-hydrocarbons
such as H.sub.2O, N.sub.2, CO.sub.2, Hg, H.sub.2S and other sulphur
compounds. If desired, the hydrocarbon stream containing the
natural gas may be pre-treated before involvement in a hydrocarbon
cooling process, or before use elsewhere and/or separately. This
pre-treatment may comprise reduction and/or removal of
non-hydrocarbons such as CO.sub.2 and H.sub.2S or other steps such
as early cooling, pre-pressurizing. As these steps are well known
to the person skilled in the art, their mechanisms are not further
discussed here.
[0024] Preferably, a hydrocarbon stream intended to be liquefied
undergoes at least the minimum pre-treatment required to
subsequently liquefy the hydrocarbon stream. Such a requirement for
liquefying natural gas is known in the art.
[0025] A liquefied hydrocarbon stream intended to be gasified or
regasified by the present invention may be any suitable stream,
usually LNG, for subsequent use as a gas, either for supply to a
particular user such as a power station or industrial facility, or
piped to a gas network for distribution. Such subsequent use is
usually on-shore.
[0026] FIG. 1 shows a first diagrammatic side view of apparatus for
on-shore processing a hydrocarbon stream according to one
embodiment of the present invention.
[0027] The apparatus 8 comprises a jack-up platform 10 comprising
one or more decks 32, and four jack-up legs 34.
[0028] A jack-up platform suitable for the present invention may
have any number of jack-up legs, based on the stability and
rigidity required, and the location of the apparatus. Commonly, a
jack-up platform has a symmetrical number of jack-up legs, which
may be an even number and/or evenly distributed around the
circumference of the jack-up platform and/or extending through the
jack-up platform.
[0029] In one embodiment of the present invention, the jack-up
platform 10 is rectilinear, such as a square or a rectangle, and is
attached to two to six jack-up legs 34, preferably four jack-up
legs 34, evenly located on opposite sides of the jack-up platform
10. Jack-up legs can have any suitable construction, two known
examples of which are cylindrical and trussed.
[0030] The jack-up platform 10 may comprise one or more barges. A
barge is generally a floating structure, commonly comprising steel
and/or concrete, and optionally having a relatively flat deck or
decking portion for the location of one or more processing units
thereon.
[0031] A barge may also comprise one or more spaces or locations
within itself, for the location of one or more other units or
facilities, such as one or more storage tanks, tanks for ballasting
water, machinery etc.
[0032] One deck 32 of the jack-up platform 10 preferably provides
the footprint and support for `topside` production, processing
and/or liquefaction facilities for a hydrocarbon stream on one or
more levels, as well as utilities equipment, offloading facilities,
control instruments and living quarters.
[0033] The jack-up platform 10 may have any suitable size, shape
and design. An example of a rectangular jack-up platform can have a
length of over 100 m, a width of 50-100 m and a depth of 10-30
m.
[0034] The jack-up platform 10 can have a footprint of at least
1000-5000 m.sup.2, and can extend beyond 10,000 or 20,000
m.sup.2.
[0035] The length of the jack-up legs 34 may be any suitable
dimension whilst still providing stability and a raised-up platform
10 above a sea level 52. The apparatus 8 may be used in seawater
depths from as little as 5, 10 or 20 metres, extending to sea
depths of 80, 100, 150 or even 200 metres. Any of these depths may
also define the term "shallow water", which is the usual location
of use of the apparatus of the present invention. That is, the
apparatus of the present invention may be transportable over any
water or marine surface of minimal depth where the jack-up legs are
raised, and then is usually located for installation and operation
in shallow water.
[0036] The suitability of apparatus 8 of the present invention can
be determined by analysis of the sea-bed 6, and the depth of water
at the relevant operating location.
[0037] The or each jack-up leg 34 is preferably anchored, for
example welded, to the jack-up platform 10. Each jack-up leg 34
preferably includes a movement mechanism. Preferably, the apparatus
8 also includes one or more corresponding movement mechanisms, such
as a jacking system known in the art, able to move the or each
jack-up leg 34 relative to the jack-up platform 10. Known jacking
systems include the use of cables, hydraulic ram and pistons,
and/or rack and pinion systems.
[0038] According to one embodiment of the present invention, the or
each jack-up leg 34 is movable relative to the jack-up platform 10
between a marine-transportation position 36 and a sea-bed routed
position 38. This is shown in more detail in FIGS. 2a-d.
[0039] In FIGS. 2a-c there is shown the jack-up legs 34 in a
marine-transportation position 36, generally extending upwardly
from the jack-up platform 10 during construction and transportation
of the apparatus 8 from an on-shore location shown in FIG. 2a to an
operating location shown in FIG. 2c. At the operating position 36,
the jack-up legs 34 are moved downwardly to the sea-bed 6, and a
portion of each jack-up leg is insertable into the sea-bed 6 so as
to be rooted therewith, i.e. sufficiently fixed to the seabed 6.
Preferably, each jack-up leg 34 supports an equal load. The base of
each jack-up leg 34 may comprise a foot. Suitable feet include mats
and spudcans 35. Mat footings are generally relatively flat, and
are usually used to set up a jack-up leg in a soft soil area with a
low-bearing capacity. Spudcan feet 35 generally involve a tapered
portion, better able to penetrate a sea-bed, and/or accommodate
uneven sea-beds.
[0040] With rooting of the jack-up legs 34 into the sea-bed 6,
continued relative movement between the jack-up legs 34 and the
jack-up platform 10 provides raising of the jack-up platform 10
above sea level 52 to an operating position 40, as shown in FIG.
2e.
[0041] Thus, FIGS. 2a-e show the general principles of installing
apparatus as herein defined, comprising at least the steps of:
[0042] providing the apparatus 8;
[0043] transporting said apparatus 8 across a sea 54;
[0044] locating the apparatus 8 to a suitable operating location,
such as near to an underwater hydrocarbon stream source or on-shore
connection (not shown);
[0045] rooting the jack-up legs 34 on the apparatus 8 with the
sea-bed 6; and
[0046] raising the jack-up platform 10 above sea level 52.
[0047] Once installed, the apparatus can use one or more
hydrocarbon stream processing units 12 on the jack-up platform
10.
[0048] FIG. 3 shows by way of example only and without limitation
various hydrocarbon stream processing units 12 that are locatable
on and/or in and/or with the jack-up platform 10. Such processing
units 12 can be related or connected by a central pipework system
or network 26.
[0049] Processing units 12 suitable for the present invention
include any hydrocarbon stream cooling and/or liquefying units,
suitably located in a dedicated area 13 on the deck 32. They can
include any number, type and configuration of apparatus, devices,
units and components able to cool and/or liquefy a hydrocarbon
stream such as natural gas. Cooling and liquefying a hydrocarbon
stream such as natural gas is known in the art, and is not further
described here. Such apparatus may include one or more heat
exchangers, refrigerant circuits or systems, compressors,
expanders, valves, separators, pumps, associated piping, etc, all
of which are known in the art, and which are not further described
herein.
[0050] One or more of the hydrocarbon stream liquefying units 13
may be provided in one or more liquefying trains in a manner known
in the art, optionally running partly or wholly in parallel, also
known in the art.
[0051] The or each hydrocarbon stream liquefying unit 13 may have
any suitable capacity, ranging from below 1 MTPA to above 1 MTPA,
such as in the range 1-3 MTPA.
[0052] Power required for at least one of the hydrocarbon stream
processing units 12, such as a liquefying unit 13, includes one or
more generators, turbines, etc known in the art, which are also
locatable on and/in the jack-up platform 10, for example in a
dedicated area 16 on the deck 32. One or more power generators such
as gas turbines, steam turbines, are able to provide power to one
or more units, facilities, devices, etc. on or in the apparatus
8.
[0053] The apparatus 8 may include one or more liquefied
hydrocarbon storage facilities 14, such as one or more LNG tanks,
located on and/in the jack-up platform 10.
[0054] The one or more storage facilities 14 may have any capacity
or volume, being above or below 10,000 m.sup.3, which is able to
store a liquefied hydrocarbon such as LNG, preferably at or near
atmospheric pressure. The volume or capacity of the storage
facilities may be related to the MTPA of the or each hydrocarbon
stream liquefying unit on the jack-up platform 10.
[0055] Alternatively and/or additionally, one or more separate
storage facilities (not shown) may be provided near the apparatus
8, such as one or more associated an/or neighbouring floating
storage facilities, such as a floating LNG tanker.
[0056] The apparatus 8 may include one or more offloading areas 24,
and one or more liquefied hydrocarbon transfer devices 42 such as
one or more known off-loading systems including a tandem soft yoke
mooring and off-loading (SYMO) system. The apparatus 8 may also
have side-by-side mooring, and one or more loading arms. The
apparatus may also have one or more boom-to-tanker (BTT) systems
and/or one or more bug sweep systems, all of which are known in the
art.
[0057] The or each liquefied hydrocarbon transfer device 42 may
include one or more flexible hoses or piping, intended to provide a
continuous fluid path between the apparatus 8, in particular one or
more of any liquefied hydrocarbon storage facilities 14, and a
nearby vessel such as an LNG tanker (not shown).
[0058] The apparatus 8 preferably comprises one or more well
production facilities. The apparatus may include a dry-well access
18 for gas production from one or more wells.
[0059] Any separation of water and/or condensate from a hydrocarbon
stream can be carried out by one more hydrocarbon stream treatment
facilities, such as: deep drying, mercury removal, acid gas
removal, phase separators, CO2 removal. In addition, there may be
one or more stabilization and/or fractionation processes such as
for NGL recovery and stabilization of a crude stream such as crude
oil, etc.
[0060] Processes and apparatus for such treatments are known in the
art. Examples shown in FIG. 3 include a deep drying and Hg removal
unit 20, and an acid gas removal unit 22.
[0061] The apparatus 8 of the present invention can be constructed
and/or completed on-shore, or at least at or near a shore facility
such as a dock. One or more of the hydrocarbon stream processing
units 12 could be assembled into suitably sized modules and/or on
skids to facilitate their commissioning and/or installation and/or
assembly with the apparatus 8.
[0062] For example, FIG. 2a shows the apparatus 8 at an on-shore
location 53 next to a marine environment such as a sea 54. FIG. 2b
then shows the apparatus 8 re-located into the sea 54, such that it
is in a marine-transportation position 36. FIG. 2c shows the marine
transportation of the apparatus 8 using one or more tugs 56 in a
manner known in the art.
[0063] Upon arrival at a suitable operating location or target
site, such as near an on-shore source, an on-shore supply line, or
an underwater hydrocarbon stream source (not shown), the jack-up
platform 10 can be held in position using anchored or free-running
tugs, whilst the jack-up legs 34 are lowered to the sea-bed 6 as
described hereinabove. Once the bottoms of the jack-up legs 34 are
rooted to the sea-bed 6 as described hereinabove, and as shown in
FIG. 2d, the jack-up platform 10 can be raised to a jacked-up
operating position 40 such that the jack-up platform 10 is separate
from the sea level 52, and is now prepared for one or more
hydrocarbon stream processes.
[0064] The apparatus 8 of the present invention is relocatable, by
reversing the operations as described above in relation to FIGS. 2e
to 2c, and using one or more tugs 56 to relocate the apparatus 8 to
a different target site, such as near another underwater
hydrocarbon stream source.
[0065] The apparatus 8 may include one or more ballast tanks,
production and accommodation facilities, and/or one or more
hydrocarbon drilling facilities 46, as well as other utilities
and/or facilities usual, expected and/or required for a
marine-environment location.
[0066] Hydrocarbon drilling facilities 46 provide a drilling
functionality to the apparatus of the present invention, which may
be permanently or temporarily a part of the apparatus, such as a
conjoined unit. Thus, the present invention may also provide a
hydrocarbon drilling operation, as well as integral processing of
the hydrocarbon stream on a stable but marine-based platform.
[0067] It is a particular advantage of the present invention that
the apparatus can be rapidly transported/located/deployed/operated
at a target site. In one way, the present invention provides a
`turn-key` apparatus ready for installation and operation at short
notice.
[0068] It is another advantage of the present invention that the
apparatus can be constructed and/or completed at a convenient
location anywhere around the world, generally at a convenient
marine-connected location, and then transported to the intended
operating site. Such a convenient construction location can be
remote from the operating site. This overcomes the problem of
having to construct and/or complete the hydrocarbon processing
apparatus, and/or any units, facilities, etc., therefor at the
intended operating site.
[0069] It is another advantage of the present invention that it is
useable in a number of different locations, such that it need not
be redundant once processing of a hydrocarbon stream at a
particular location is no longer required.
[0070] It is another advantage of the present invention that it
provides a stable platform to which one or more further or other
apparatus, units, installations and/or devices can be based and/or
connected to. This includes supplementing the apparatus of the
present invention with one or more floating, jack-up or more
permanent apparatus, installations or facilities where it is
desired to increase the hydrocarbon processing.
[0071] The present invention also provides a suitable initial
offshore hydrocarbon processing facility, which can be easily and
rapidly replaced and/or superseded by one or more other offshore
processing facilities, being floating, jack-up and/or permanent,
where a changed or different operation (usually increased
production) is desired.
[0072] In this way, the apparatus of the present invention provides
an initial location and/or base from which development of the
off-shore processing can be considered, prior to committing and/or
requiring further apparatus, etc. Such a situation may be due to
the development of a hydrocarbon stream source over time, from an
initial production volume, to a greater and/or more long term
production volume requiring a more permanent processing
facility.
[0073] Thus, the present invention also provides a method of
developing an off-shore hydrocarbon stream processing facility
comprising at least installing apparatus as herein defined, and
supplementing and/or replacing the apparatus by one or more other
installations. Such a method provides a modular approach to the
development of an off-shore hydrocarbon processing facility.
[0074] Where the apparatus comprises one or more hydrocarbon stream
gasifying or re-gasifying units, the apparatus operates as a liquid
hydrocarbon import terminal, able to be provided with a liquefied
hydrocarbon such as LNG, for example from a tanker, and to gasify
or re-gasify the liquefied hydrocarbon off-shore. The gas can then
be supplied to one or more on-shore facilities such as one or more
power generators and/or industrial facilities and/or gas
distribution networks and/or one or more long distance supply
pipelines.
[0075] The apparatus of the present invention preferably provides
integrated production, liquefaction, storage and/or off-loading
facilities for a natural gas stream. As a result, natural gas
production and liquefaction can be conducted simultaneously, which
is important for fast-track developments without substantial
pipeline cost. It also allows production of a hydrocarbon stream
directly from a source or sources such as an undersea reservoir,
and for liquefaction ready for export.
[0076] The apparatus of the present invention preferably also
provides integrated gasification and off-loading facilities for a
liquefied hydrocarbon stream such as LNG. As a result, natural gas
regassification can be conducted for on-shore supply without
requiring a fixed on-shore facility.
[0077] The apparatus of the present invention preferably has a
fixed, non-moving deck able to accommodate the processing
facilities and a loading system; hence it is less sensitive to
weather-imposed marine and operational downtime than for example a
floating solution.
[0078] The present invention can also allow dry-well access,
eliminating the need for a mooring system, and reduces the
investment for subsea infrastructure. The present invention can
also minimise offshore installation and commissioning work, and
could be built and integrated onshore as one complete unit before
marine transportation and installation.
[0079] The apparatus of the present invention is preferably is
self-installing, as a barge deck provides the necessary buoyancy
during towage from site to site offering minimal installation
cost.
[0080] The present invention is preferably also entirely removable,
making the environmental impact and abandonment cost minimal.
[0081] In one embodiment of the present invention, the apparatus
essentially consists of a floating steel barge that can be
jacked-up out of the water along four trussed legs. The deck of the
barge accommodates the gas production and liquefaction equipment,
utilities, power generation facility, living quarters, as well as a
tandem mooring and offloading system. It can also house natural gas
production wells and one or more onboard liquefaction plants. The
barge could also have an integrated membrane LNG storage tank and
it is intended to receive and berth LNG carriers.
[0082] As a stand-alone solution, the present invention has
embodiments to provide integrated functions encompassing one or
more of:
[0083] 1) Well production: It can have dry access to gas production
wells. Gas/liquid can be brought onboard via flow pipe and
metered.
[0084] 2) Gas reception: Gas, hydrocarbon liquids and corrosion
inhibitor and/or any heavy liquid hydrocarbons can be separated.
Liquid condensate stabilization and storage/offloading can be
provided. Gas can be metered. Optional feed gas compression could
be made.
[0085] 3) Feed Gas pre-treatment: Removal of CO.sub.2, H.sub.2S,
water vapour, mercury, and heavy hydrocarbon can be
implemented.
[0086] 4) Liquefaction: Natural gas can be liquefied using any
suitable process, for example, a so-called single mixed refrigerant
process.
[0087] 5) LNG storage: A membrane LNG tank or any other suitable
LNG tank can be housed within the barge.
[0088] 6) LNG offloading: Transfer of LNG from the tank to an
ocean-going LNG tanker can be made for example using tandem soft
yoke mooring and offloading (SYMO) system.
[0089] The present invention also extends to an apparatus for
off-shore processing a hydrocarbon stream such as natural gas,
comprising a jack-up platform, one or more jack-up legs rootable to
a sea-bed, and one or more hydrocarbon storage facilities such as
LNG storage tanks.
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