U.S. patent application number 12/163198 was filed with the patent office on 2009-01-01 for system and method for aligning and engaging a topside to a floating substructure.
This patent application is currently assigned to Horton Technologies, LLC. Invention is credited to Lyle David Finn.
Application Number | 20090003936 12/163198 |
Document ID | / |
Family ID | 40160722 |
Filed Date | 2009-01-01 |
United States Patent
Application |
20090003936 |
Kind Code |
A1 |
Finn; Lyle David |
January 1, 2009 |
System and Method for Aligning and Engaging a Topside to a Floating
Substructure
Abstract
Systems and methods for aligning and engaging a topside with a
fixed or floating substructure during float-over installation of
the topside are disclosed. Some system embodiments include an
alignment member coupled to the substructure, an extendable member
coupled to the topside, the extendable member having a receptacle
configured to receive the alignment member, and a damping system.
In some embodiments, the damping system includes a piston-rod
assembly having a piston slideably disposed with a housing, wherein
a first chamber and a second chamber are formed, and a rod coupled
between the piston and the extendable member, a source of
pressurized gas coupled to the first chamber, and an accumulator
containing fluid coupled to the second chamber.
Inventors: |
Finn; Lyle David;
(Sugarland, TX) |
Correspondence
Address: |
CONLEY ROSE, P.C.;David A. Rose
P. O. BOX 3267
HOUSTON
TX
77253-3267
US
|
Assignee: |
Horton Technologies, LLC
Houston
TX
|
Family ID: |
40160722 |
Appl. No.: |
12/163198 |
Filed: |
June 27, 2008 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60946647 |
Jun 27, 2007 |
|
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Current U.S.
Class: |
405/202 |
Current CPC
Class: |
E02B 17/04 20130101 |
Class at
Publication: |
405/202 |
International
Class: |
E02B 17/00 20060101
E02B017/00 |
Claims
1. A system for engaging a topside with a substructure during
float-over installation of the topside, the system comprising: an
alignment member coupled to the substructure; an extendable member
coupled to the topside, the extendable member having a receptacle
configured to receive the alignment member; and a damping system
configured to move the extendable member into engagement with the
substructure, wherein the alignment member is received within the
receptacle.
2. The system of claim 1, wherein the damping system is further
configured to: apply force to the extendable member; and resist
force from the extendable member.
3. The system of claim 2, wherein the damping system is configured
to resist force from the extendable member due to downward movement
of the topside relative to the substructure.
4. The system of claim 2, wherein the damping system is configured
to apply force to the extendable member when the topside moves
upward relative to the substructure.
5. The system of claim 2, wherein the damping system is further
configured to allow the extendable member to retract with relative
vertical movement of the topside and the substructure are less than
a predetermined amount.
6. The system of claim 2, wherein the extendable member remains
engaged with the substructure under the force applied to the
extendable member.
7. A system for engaging a topside with a substructure during
float-over installation of the topside, the system comprising: an
alignment member coupled to the substructure; an extendable member
coupled to the topside, the extendable member having a receptacle
configured to receive the alignment member; and a damping system
comprising: a piston-rod assembly comprising: a piston slideably
disposed with a housing, wherein a first chamber and a second
chamber are formed; and a rod coupled between the piston and the
extendable member; a source of pressurized gas coupled to the first
chamber; and an accumulator containing fluid coupled to the second
chamber.
8. The system of claim 7, wherein the damping system is configured
to resist force from the extendable member by injecting pressurized
gas into the first chamber, wherein the pressurized gas reacts
against the force of the extendable member.
9. The system of claim 8, wherein the damping system is further
configured to allow the pressurized gas in the first chamber to
compress under the force of the extendable member.
10. The system of claim 9, wherein the damping system is further
configured to exhaust a portion of the pressurized gas from the
first chamber when compressed.
11. The system of claim 9, wherein fluid is drawn into the second
chamber as the pressurized gas is compressed.
12. The system of claim 9, wherein the extendable member is
retractable as the pressurized gas is compressed.
13. The system of claim 7, wherein the damping system is configured
to apply force to the extendable member by injecting pressurized
gas into the first chamber, wherein the pressurized gas exerts
force against the piston.
14. The system of claim 13, wherein the extendable member is
extendable under the force applied by the pressurized gas against
the piston.
15. The system of claim 14, wherein the damping system is further
configured to exhaust fluid from the second chamber into the
accumulator as the extendable member extends.
16. The system of claim 14, wherein the extendable member remains
engaged with the substructure under the force applied by the
pressurized gas against the piston.
17. The system of claim 14, wherein pressurized gas is drawn into
the first chamber as the extendable member extends.
18. A method for engaging a topside with a substructure during
float-over installation of the topside, the method comprising:
extending a member having a receptacle from the topside to engage
an alignment member coupled to the substructure; applying force to
the member to resist downward motion of the topside relative to the
substructure; and applying force to the member to maintain
engagement of the member with the substructure in response to
upward motion of the topside relative to the substructure.
19. The method of claim 18, further comprising retracting the
member when the relative vertical movement between the topside and
the substructure reaches a predetermined amount as the substructure
is deballasted.
20. The method of claim 18, wherein the extending comprises
injecting a pressurized gas into a first chamber, wherein the
pressurized gas exerts force on a piston coupled to the extendable
member, wherein the piston translates.
21. The method of claim 20, further comprising exhausting fluid
from a second chamber as the piston translates.
22. The method of claim 18, wherein the applying force to the
member to resist downward motion comprises injecting a pressurized
gas into a chamber, wherein the pressurized gas exerts force
against a piston coupled to the extendable member.
23. The method of claim 18, wherein the applying force to the
member to maintain engagement comprises injecting a pressurized gas
into a chamber, wherein the pressurized gas exerts force on a
piston coupled to the extendable member, wherein the piston
translates.
24. The method of claim 23, further comprising exhausting fluid
from a second chamber as the piston translates.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims benefit of U.S. provisional
application Ser. No. 60/946,647 filed Jun. 27, 2007, and entitled
"Big Foot and Docking Probe," which is hereby incorporated herein
by reference in its entirety for all purposes.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not applicable.
BACKGROUND OF THE INVENTION
[0003] Embodiments of the invention relate to systems and methods
for installing a topside or deck on a substructure to form a fixed
or floating offshore platform. More particularly, embodiments of
the invention relate to a novel system and method for aligning the
topside with the substructure and engaging the two structures prior
to load transfer of the topside to the substructure during
float-over installation of the topside.
[0004] Float-over installations offer opportunities to install
heavy topsides beyond the lifting capacity of available crane
vessels on offshore substructures located in remote areas. A
float-over installation includes four primary procedures. The first
procedure involves transporting the topside or deck to the offshore
substructure. Typically, the topside is placed on a barge or heavy
transport vessel and towed to the substructure.
[0005] The second procedure involves docking the transport barge to
the installed substructure. The barge is maneuvered into the slot
of the substructure, such that the topside is floated over and
substantially aligned with the substructure. Once in the slot,
mooring lines, sometimes in combination with a rendering system,
are utilized to suppress surge and sway motions of the barge. After
the mooring lines are set, deballasting of the substructure
commences. The third procedure involves transferring the load of
the topside from the barge to the substructure, and is a critical
phase of the float-over installation. Deballasting of the
substructure continues as the substructure rises toward the
topside. Once the topside and the substructure reach close
proximity, the two bodies may impact each other repeatedly due to
wave action. Such impacts may damage the structures when the
relative motion between the two bodies is not controlled. As
deballasting of the substructure continues, the weight of the
topside is gradually transferred from the barge to the
substructure. After a critical fraction of the weight is
transferred, the relative motion between the two bodies ceases. At
that point, the two structures move as a single unit, and the
possibility of damage due to hard impact is eliminated. Therefore,
it is desirable to complete the load transfer up to the critical
fraction as quickly as possible. After the topside is fully
supported by the substructure, the legs of the two structures are
coupled by welding legs extending downward from the topside to legs
extending upward from the substructure. To achieve the high quality
welds required to withstand the harsh load regimes of offshore
environments, proper alignment of the topside with the substructure
during the float-over operation is critical.
[0006] The final procedure involves separating the barge from the
topside, and is also a critical phase of the float-over
installation. The substructure is deballasted further until the
topside separates from the barge. At and immediately after
separation, the relative motions between barge and topside pose a
danger of damage due to impact between these bodies. That danger
can be minimized by rapid separation of the barge and the topside.
To promote such rapid separation, the topside may be supported on
the barge by a number of loadout shoes. At the appropriate time,
the loadout shoes are actuated to quickly collapse or retract,
thereby providing rapid separation between the barge and the
topside. These systems, however, have a propensity to malfunction
and permit hard contact between the loadout shoes and the topside.
In any event, hard contact between the barge and the topside may
continue until the substructure is deballasted to provide
sufficient separation between the barge and the topside. After
which point, the barge is towed from the installation site.
[0007] Thus, embodiments of the invention are directed to apparatus
and methods that seek to overcome these and other limitations of
the prior art.
SUMMARY OF THE PREFERRED EMBODIMENTS
[0008] A docking system and method for aligning a topside with an
installed substructure and engaging the two structures prior to
load transfer of the topside to the substructure during float-over
installation of the topside are disclosed. Some system embodiments
include an alignment member coupled to the substructure, an
extendable member coupled to the topside, the extendable member
having a receptacle configured to receive the alignment member, and
a damping system configured to move the extendable member into
engagement with the substructure, wherein the alignment member is
received within the receptacle.
[0009] In some embodiments, the damping system includes a
piston-rod assembly having a piston slideably disposed with a
housing, wherein a first chamber and a second chamber are formed.
The damping system further includes a rod coupled between the
piston and the extendable member, a source of pressurized gas
coupled to the first chamber, and an accumulator containing fluid
coupled to the second chamber.
[0010] Some method embodiments for engaging a topside with a
substructure during float-over installation of the topside include
extending a member having a receptacle from the topside to engage
an alignment member coupled to the substructure, applying force to
the member to resist downward motion of the topside relative to the
substructure, and applying force to the member to maintain
engagement of the member with the substructure in response to
upward motion of the topside relative to the substructure.
[0011] Thus, the embodiments of the invention comprise a
combination of features and advantages that enable substantial
enhancement of float-over installation systems and methods. These
and various other characteristics and advantages of the invention
will be readily apparent to those skilled in the art upon reading
the following detailed description of the preferred embodiments of
the invention and by referring to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] For a detailed description of the preferred embodiments of
the invention, reference will now be made to the accompanying
drawings in which:
[0013] FIG. 1 is a cross-sectional view of a docking system in
accordance with embodiments of the invention;
[0014] FIG. 2 is a cross-sectional view of an installed
substructure including some components of the docking system of
FIG. 1;
[0015] FIG. 3 is a cross-sectional view of a topside including the
remaining components of the docking system of FIG. 1 floated over
the substructure of FIG. 2; and
[0016] FIG. 4 is a cross-sectional view of the docking system of
FIG. 1 extended to align and engage the topside with the
substructure of FIG. 3.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0017] Various embodiments of the invention will flow be described
with reference to the accompanying drawings, wherein like reference
numerals are used for like parts throughout the several views. The
drawing figures are not necessarily to scale. Certain features of
the invention may be shown exaggerated in scale or in somewhat
schematic form, and some details of conventional elements may not
be shown in the interest of clarity and conciseness.
[0018] Preferred embodiments of the invention relate to a docking
system and method for aligning and engaging a topside with an
installed fixed or floating substructure prior to load transfer of
the topside to the substructure during float-over installation of
the topside. The invention is susceptible to embodiments of
different forms. There are shown in the drawings, and herein will
be described in detail, specific embodiments of the invention with
the understanding that the disclosure is to be considered an
exemplification of the principles of the invention and is not
intended to limit the invention to that illustrated and described
herein. It is to be fully recognized that the different teachings
of the embodiments discussed below may be employed separately or in
any suitable combination to produce desired results.
[0019] FIG. 1 depicts a representative cross-section of a topside
or deck 100 in proximity to a representative cross-section of a
substructure 105 for a semi-submersible offshore platform, such as
a multicolumn floating (MCF) platform. As described above, during
float-over installation of topside 100 on substructure 105, topside
100 is floated over and substantially aligned with substructure 105
using a barge. Substructure 105 is then deballasted to engage or
dock with and lift topside 100 from the barge, thereby assembling
the semi-submersible platform. FIG. 1 illustrates the position of
topside 100 relative to substructure 105 prior to docking of
topside 100 with substructure 105. Embodiments of the invention are
directed to a docking system 110 that enables alignment and
engagement of topside 100 with substructure 105 during the docking
procedure. Topside 100 includes an upper surface 115 and a deck
column member 120 extending therefrom. Substructure 105 includes an
upper surface 125.
[0020] Docking system 110 includes a damping system 130 with a
docking pin 135 coupled thereto, an alignment member 140, and a
plurality of centralizers 145. Damping system 130 is coupled to and
supported by upper surface 115 of topside 100. Docking pin 135 is
suspended from damping system 130 into deck column member 120 of
topside 100. Further, docking pin 135 includes a receptacle 225 at
its lower end 150 configured to receive alignment member 140
therein. To maintain the substantially vertical orientation of
docking pin 135 within deck column member 120 and minimize bending
loads to docking pin 135, centralizers 145 are disposed along the
interior surface deck column member 120 proximate both ends of deck
column member 120. Alignment member 140 is coupled to upper surface
125 of substructure 105. Damping system 130 is selectably
actuatable to extend docking pin 135 within deck column member 120
toward alignment member 140. While alignment member 140 may assume
virtually any shape the envelope of alignment member 140 is
selected such that alignment member 140 fits within receptacle 225
of docking pin 135 when docking pin 135 is lowered over alignment
member 140 to engage upper surface 125 of substructure 105.
[0021] In this exemplary embodiment, damping system 130 includes
two piston-rod assemblies 160, each assembly 160 slidingly disposed
within a housing 165. Other embodiments of damping system 120 may
include only a single piston-rod assembly 160 or more than two such
assemblies 160. Housings 165 are supported by a structure 155
coupled to surface 115 of topside 100 and substantially concentric
to deck column member 120. In other embodiments, housings 165 may
be disposed within deck column member 120. Each assembly 160
includes a piston 170 that sealingly engages the inner surface of
housing 165, dividing housing 165 into an upper clamber 175 (best
viewed in FIG. 2) and a lower chamber 180. A rod 185 is coupled to
each piston 170 and extends downward through lower chamber 180, the
base of housing 165, and support structure 155 to a plate 190
coupled to the upper end 200 of docking pin 135. Each piston 170 is
slideable within housing 165, depending on the pressure of fluid
contained within chambers 175, 180. As pistons 170 translate within
housings 165 in reaction to changes in fluid pressure, rods 185
similarly translate, sliding upward or downward relative to
housings 165 and support structure 155, within deck column member
120.
[0022] Damping system 130 further includes a source of pressurized
gas 205, such as but not limited to one or more bottles of
pressurized nitrogen 210, and a fluid accumulator 215 containing an
incompressible fluid 220, such as but not limited to oil.
Pressurized gas source 205 is coupled to upper chambers 175, and
accumulator 215 coupled to lower chamber 180. Gas source 205 is
selectably actuatable to inject pressurized gas 210 into upper
chambers 175, causing the pressure in chambers 175 to increase. As
the pressure within chambers 175 increases, the force exerted on
pistons 170 by gas 210 exceeds fluid pressure within chambers 180,
at which point pistons 170 translate downward within housings 165.
When pistons 170 translate downward, docking pin 135 also
translates downward or extends within deck column member 120, and
fluid 220 contained within lower chambers 180 of housings 165 is
forced from housings 165 into accumulator 215. Conversely, when a
force is applied to lower end 150 of docking pin 135 in excess of
the force exerted against pistons 170 by gas 200, docking pin 135
translates upward within deck column member 120, causing pistons
170 to displace upward within housings 165. As pistons 170
translate upward, gas 210 contained within upper chambers 175 is
vented from housings 165, and fluid 220 is drawn from accumulator
215 into lower chambers 180. Gas 210 vented from upper chambers 175
may exhaust from housings 165 through relief valves (not shown)
coupled to upper chambers 175 to the surrounding atmosphere or
return to gas source 205.
[0023] Components of docking system 110 are installed on or within
topside 100 or substructure 105, as appropriate, prior to transport
of topside 100 and substructure 105 to the desired offshore
installation site. Substructure 105, with alignment member 140
coupled thereto, is then towed to the installation site, as shown
in FIG. 2. Upon reaching the installation site, substructure 105
ballasted to the desired depth, as shown in FIG. 3. Topside 100,
with the remaining components of docking system 110 coupled
thereto, is next towed to substructure 105 and floated over
substructure 105 using a barge 107, as previously described and
shown. After topside 100 is substantially aligned over substructure
105, the docking procedure begins.
[0024] Substructure 105 is deballasted such that substructure 105
rises upward to engage topside 100. As will be described, docking
system 110 enables alignment of topside 100 with substructure 105
and eliminates the banging of topside 100 against substructure 105
experienced during a conventional docking procedure. Referring
again to FIG. 1, substructure 105 is deballasted such that
substructure 105 is positioned proximate topside 100, yet not close
enough to permit topside 100 to contact or bang against
substructure 105 as barge 107 (FIG. 3) supporting topside 100 moves
with the motion of the surrounding water 230 (FIG. 3).
[0025] Next, damping system 130 is actuated to extend docking pin
135 downward through deck column member 120 toward alignment member
140. Compressed gas 210 is injected into upper chambers 175 of
housings 165, causing pistons 170, and thus docking pin 135, to
displace downward. Turning now to FIG. 4, docking pin 135 is shown
fully extended by damping system 130. Also, as shown, deballasting
of substructure 105 has brought docking pin 135 into contact with
upper surface 125 of substructure 105, such that alignment member
140 is received within receptacle 225 of docking pin 135. Once
docking pin 135 is seated over alignment member 140 in this manner,
lateral movement of topside 100 relative to substructure 105 is
prevented. Thus, topside 100 is laterally aligned relative to
substructure 105. Due to the structural integrity of docking pin
135 and its ability to withstand lateral loads exerted on it by
alignment member 140 as topside 100 shifts laterally relative to
substructure 105, docking pin 135 remains aligned over alignment
member 140 for the remainder of the docking procedure.
[0026] However, because the load of topside 100 has not yet been
transferred to substructure 105, topside 105 continues to move
vertically relative to substructure 105 due to the motion of barge
107. Docking system 110 accommodates the relative vertical movement
of topside 100, while at the same time, maintains engagement of
docking pin 135 with substructure 105 over alignment member 140 and
prevents banging of topside 100 against substructure 105. As barge
107 supporting topside 100 falls with the surrounding water 230,
the contact force between docking pin 135 and substructure 105
increases. When this force exceeds the force exerted against
pistons 170 by gas 210 in upper chambers 175, docking pin 135
translates upward within deck column member 120. Due to the
presence of pressurized gas 210 in upper chambers 175, translation
of docking pin 135 in this manner is smooth and limited. As docking
pin 135 translates upward, gas source 205 controls the pressure of
gas 210 in upper chambers 175 to provide sufficient force on
docking pin 135 such that docking pin 135 remains in contact with
substructure 105. At the same time, gas 210 is compressed by the
upward translation of docking pin 135. The compression of gas 210
enables gas 210 to absorb the energy of relative movement between
topside 100 and substructure 105 and to resist any tendency for
topside 100 to impact or bang against substructure 105. Thus,
damping system 130 maintains engagement of docking pin 135 with
substructure 105 and simultaneously prevents banging of topside 100
against substructure 105.
[0027] Conversely, as barge 107 rises with the surrounding water
230, the contact load between docking pin 135 and substructure 105
decreases. When the force exerted by pressure of gas 210 in upper
chambers 175 on pistons 170 exceeds the force on docking pin 135,
docking pin 135 translates downward within deck column member 120.
Due to the presence of fluid 220 in lower chambers 180, translation
of docking pin 135 in this manner is smooth. As docking pin 135
translates downward, gas source 205 controls the pressure of gas
210 in upper chambers 175 to provide sufficient force on docking
pin 135 such that docking pin 135 remains in contact with
substructure 105. Thus, as topside 100 rises and falls relative to
substructure 105, damping system 130 responds continuously to
maintain engagement of docking pin 135 with substructure 105.
Further, damping system 130 absorbs and resists the force exerted
on docking pin 135 due to vertical displacement of topside 100
relative to substructure 105 so that topside 100 does not bang
against substructure 105.
[0028] Meanwhile, the docking procedure continues with further
deballasting of substructure 105. Substructure 105 continues to
rise relative to topside 100. As the two structures 100, 105
approach one another, damping system 130 continues to absorb the
energy from relative vertical movement of structures 100, 105 and
to resist downward movements of topside 100 relative to
substructure 105 due to motions of barge 107, as described above.
When the relative movement of topside 100 and substructure 105 is
small, damping system 130 responds to allow docking pin 135 to
translate smoothly upward within deck column member 120 until
substructure 105 contacts topside 100.
[0029] After substructure 105 contacts topside 100, continued
deballasting of substructure 105 enables load transfer of topside
100 from the barge to substructure 105. In other words,
substructure 105 begins to lift topside 100 front the barge. When
approximately twenty percent of the topside load has been
transferred to substructure 105, the relative motion of topside 100
and substructure 105 is very small, meaning topside 100 and
substructure 105 move together as a single body. At this point,
topside 100 can be safely set down on substructure 105. Further
deballasting of substructure 105 enables complete transfer of the
topside load from the barge to substructure 105. When the load of
topside 100 is completely supported by substructure 105, the
docking procedure is complete. Topside 100 may then be coupled to
substructure 105 through welding or other means, and the barge
subsequently released from topside 100.
[0030] While preferred embodiments have been shown and described,
modifications thereof can be made by one skilled in the art without
departing from the scope or teachings herein. The embodiments
described herein are exemplary only and are not limiting. Many
variations and modifications of the systems are possible and are
within the scope of the invention. For example, the relative
dimensions of various parts, the materials from which the various
parts are made, and other parameters can be varied. Accordingly,
the scope of protection is not limited to the embodiments described
herein, but is only limited by the claims that follow, the scope of
which shall include all equivalents of the subject matter of the
claims.
* * * * *