U.S. patent application number 10/224533 was filed with the patent office on 2003-04-17 for articulated multiple buoy marine platform apparatus and method of installation.
Invention is credited to Khachaturian, Jon.
Application Number | 20030072619 10/224533 |
Document ID | / |
Family ID | 26907713 |
Filed Date | 2003-04-17 |
United States Patent
Application |
20030072619 |
Kind Code |
A1 |
Khachaturian, Jon |
April 17, 2003 |
Articulated multiple buoy marine platform apparatus and method of
installation
Abstract
A marine platform (and method of installation) provides a
plurality of buoys, a platform having a peripheral portion that
includes a plurality of attachment positions, one attachment
position for each buoy, and an articulating connection that
connects each buoy to the platform at a respective attachment
position, the connection allowing for sea state induced buoy
motions while minimizing effect on the platform. A method of
installation places the platform (including oil and gas drilling
and/or production facility next to the buoys. Ballasting moves the
platform and buoys relative to one another until connections are
perfected between each buoy and the platform.
Inventors: |
Khachaturian, Jon; (New
Orleans, LA) |
Correspondence
Address: |
GARVEY SMITH NEHRBASS & DOODY, LLC
THREE LAKEWAY CENTER
3838 NORTH CAUSEWAY BLVD., SUITE 3290
METAIRIE
LA
70002
|
Family ID: |
26907713 |
Appl. No.: |
10/224533 |
Filed: |
August 20, 2002 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10224533 |
Aug 20, 2002 |
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09704998 |
Nov 2, 2000 |
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6435773 |
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60213034 |
Jun 21, 2000 |
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Current U.S.
Class: |
405/205 ;
175/8 |
Current CPC
Class: |
B63B 1/048 20130101;
B63B 77/00 20200101; B63B 1/107 20130101; B63B 2035/442 20130101;
B63B 35/4413 20130101; B63B 2021/505 20130101 |
Class at
Publication: |
405/205 ;
175/8 |
International
Class: |
E02D 023/02 |
Claims
1. A method of installing an oil and gas well drilling or
production platform in an offshore deep water marine environment,
comprising the steps of: a) placing a plurality of buoys; b)
floating a platform in the marine environment having an oil and gas
well drilling or production facility to the location of the buoys,
the platform including a peripheral portion that includes a
plurality of connecting positions, one connecting position for each
buoy; and c) ballasting the platform and buoys relative to one
another until each buoy connects with the platform and
substantially all of the weight of the platform is supported by the
buoys.
2. The method of claim 1 further comprising the step of making
articulating connections that connect each buoy to the platform at
respective connecting positions, the plurality of articulating
connections allowing for buoy motions induced by sea movement while
reducing sea movement effect on the platform.
3. The method of claim 1 further comprising the step of mooring
each buoy with an anchor line.
4. The method of claim 2 wherein each of the articulating
connections includes correspondingly concave and convex engaging
portions.
5. The marine platform of claim 2 wherein the buoy has a convex
articulating portion and the platform has a concave articulating
portion and in step "c" the barge and buoys are ballasted until
concave and convex portions engage for each buoy and the
platform.
6. The marine platform of claim 2 wherein the buoy has a concave
articulating portion and the platform has a convex articulating
portion.
7. The method of claim 1 wherein each buoy has a height and a
diameter, the height being greater than the diameter, and further
comprising the step of positioning the barge in between at least
two buoys.
8. The method of claim 1 wherein there are at least three buoys and
at least three attachment positions.
9. The method of claim 1 wherein there are at least four buoys.
10. The method of claim 1 wherein the platform is comprised of a
trussed deck and wherein steps "b" and "c" include connecting each
buoy to the trussed deck.
11. The method of claim 1 further comprising the steps of providing
a single spar and transferring the platform from the buoys to the
single spar.
12. A method of installing an oil and gas well production platform
in an offshore deep water marine environment, comprising the steps
of: a) floating a multi-ton package to a selected offshore
location, the package having a plurality of connectors and wherein
the connectors are preliminarily positioned at a higher elevational
position; b) positioning a plurality of floating buoys at a
selected offshore location, each buoy having a buoy connector
portion at its upper end; c) preliminarily positioning the buoy
connectors at a selected elevational position; d) ballasting the
floating package and buoys relative to one another so that the
package connectors and the buoy connectors engage to define a
plurality of articulating connections and where substantially all
of the weight of the platform is supported by the buoys.
13. The method of claim 12 wherein step "a" comprises floating a
multi-ton package to a selected offshore location, the package
having an oil and gas well drilling facility thereon and a
plurality of connectors, and wherein the connectors are
preliminarily positioned at a higher elevational position.
14. The method of claim 12 wherein in step "d", the floating
package is ballasted from a higher elevational position to a lower
elevational position that engages the connectors of the package
with the buoy connectors.
15. The method of claim 12 wherein in step "d" the buoys are
ballasted from a lower position to a higher position that engages
the plurality of package connectors and plurality of buoy
connectors.
16. The method of claim 12 wherein in step "a" there is provided a
barge having a deck that supports the multi-ton package and step
"a" includes floating the multi-ton package and barge to a selected
offshore location.
17. The method of claim 12 wherein in step "d", the articulating
connections each include correspondingly shaped concave and convex
portions.
18. The method of claim 12 wherein the articulating connections
include universal joint connections.
19. The method of claim 12 wherein in steps "a" through "c", the
floating package is positioned in between first and second pairs of
the buoys.
20. The method of claim 12 wherein steps "a" through "c" include
positioning the package in between first and second pairs of the
buoys and wherein the buoys have submerged portions that do not
make contact with the floating package.
21. A method of installing an oil and gas well production platform
in an offshore deep water marine environment, comprising the steps
of: a) floating a multi-ton package to a selected offshore
location, the package having a plurality of connectors and wherein
the connectors are preliminarily positioned at a higher elevational
position; b) positioning a plurality of floating buoys at a
selected offshore location, each buoy having a buoy connector
portion at its upper end; c) preliminarily positioning the buoy
connectors at a selected elevational position; d) ballasting the
floating package and buoys relative to one another so that the
package connectors and the buoy connectors engage to define a
plurality of articulating connectors, including at least one
articulating connector for each floating buoy.
22. The method of claim 21 further comprising the steps of
providing a single spar and transferring the platform from the
buoys to the single spar.
23. The method of claim 22 further comprising the step of
ballasting the buoys and spar relative to one another during the
transfer.
24. The method of claim 21 further comprising the step of making
articulating connections that connect each buoy to the platform at
respective connecting positions, the plurality of articulating
connections allowing for buoy motions induced by sea movement while
reducing sea movement effect on the platform.
25. The method of claim 21 wherein each of the articulating
connections includes correspondingly concave and convex engaging
portions.
26. The marine platform of claim 21 wherein the buoy has a convex
articulating portion and the platform has a concave articulating
portion and in step "c" the barge and buoys are ballasted until
concave and convex portions engage for each buoy and the
platform.
27. The marine platform of claim 21 wherein the buoy has a concave
articulating portion and the platform has a convex articulating
portion.
28. The method of claim 21 wherein each buoy has a height and a
diameter, the height being greater than the diameter, and further
comprising the step of positioning the barge in between at least
two buoys.
29. The method of claim 21 wherein the platform is comprised of a
trussed deck and wherein steps "b" and "c" include connecting each
buoy to the trussed deck.
30. A method of installing an oil and gas well production platform
in an offshore deep water marine environment, comprising the steps
of: a) floating a multi-ton package to a selected offshore
location, the package having a plurality of connectors and wherein
the connectors are preliminarily positioned at a higher elevational
position; b) positioning a plurality of floating buoys at a
selected offshore location, each buoy having a buoy connector
portion at its upper end; c) preliminarily positioning the buoy
connectors at a selected elevational position; d) positioning a
floating spar next to the combination of buoys and multi-ton
package; and e) transferring the package from the buoys to the spar
by laterally moving the spar relative to the combination of buoys
and package until they are generally vertically aligned and then
lowering the package to the spar.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] Priority of U.S. Patent Application Serial No.
60/213,034,filed Jun. 21, 2000, and Ser. No. 09/693,470, filed Oct.
20, 2000, both incorporated herein by reference, are hereby
claimed.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not applicable
REFERENCE TO A "MICROFICHE APPENDIX"
[0003] Not applicable
BACKGROUND OF THE INVENTION
[0004] 1. Field of the Invention
[0005] The present invention relates to a method of installing a
floating marine platform in a deep water environment(over 1500 feet
of water). More particularly, the present invention relates to a
novel method of installing a marine platform using multiple buoys
that support a platform, wherein articulating connections form an
interface between the platform and the buoys. In an alternate
method, the multiple buoys can be used as part of an installation
method to place the marine platform upon a single spar support.
[0006] 2. General Background of the Invention
[0007] Many types of marine platforms have been designed, patented,
and/or used commercially. Marine platforms typically take the form
of either fixed platforms that include a large underwater support
structure or "jacket" or a floating platform having a submersible
support. Sometimes these platforms are called semi-submersible
rigs.
[0008] Jack-up barges are another type of platform that can be used
in an offshore marine environment for drilling/production. Jack-up
barges have a barge with long legs that can be powered up for
travel and powered down to elevate the barge above the water.
[0009] Other types of platforms for deep water (1500 feet or
deeper) have been patented. The September 2000 issue of Offshore
Magazine shows many floating offshore platforms for use in deep
water drilling and/or production. Some of the following patents
relate to offshore platforms, some of which are buoy type offshore
platforms, all of which are hereby incorporated herein by
reference. Other patents have issued that relate in general to
floating structures, and include some patents disclosing structures
that would not be suitable for use in oil and gas well drilling
and/or production.
1 ISSUE PATENT # DATE TITLE 2,952,234 09/13/60 Sectional Floating
Marine Platform 3,540,396 11/17/70 Offshore Well Apparatus and
System 3,982,492 09/1976 Floating Structure 4,286,538 09/01/81
Multipurpose Floating Structure 4,297,965 11/03/81 Tension leg
Structure for Tension Leg Platform 4,620,820 11/04/86 Tension Leg
Platform Anchoring Method and Apparatus 5,197,825 03/30/93 Tendon
for Anchoring a Semisubmersible Platform 5,423,632 06/13/95
Compliant Platform With Slide Connection Docking to Auxiliary
Vessel 5,439,060 08/08/95 Tensioned Riser Deepwater Tower 5,558,467
09/24,96 Deep Water offshore Apparatus 5,706,897 01/13/98 Drilling,
Production, Test, and Oil Storage Caisson 5,722,797 03/03/98
Floating Caisson for Offshore Production and Drilling 5,799,603
09/01/98 Shock-Absorbing System for Floating Platform 5,873,416
02/23/99 Drilling, Production, Test, and Oil Storage Caisson
5,931,602 08/03/99 Device for Oil Production at Great Depths at Sea
5,924,822 07/20/99 Method for Deck Installation on an Offshore
Substructure 6,012,873 01/11/00 Buoyant Leg Platform With
Retractable Gravity Base and Method of Anchoring and Relocating the
Same 6,027,286 02/22/00 Offshore Spar Production System and Method
for Creating a Controlled Tilt of the Caisson Axis GB 2 092 664
Ball-and-Socket Coupling for Use in Anchorage of Floating
Bodies
[0010] One of the problems with single floater type marine platform
constructions is that the single floater must be enormous, and thus
very expensive to manufacture, transport, and install. In a marine
environment, such a structure must support an oil and gas well
drilling rig or production platform weighing between 5,000 and
40,000 tons, for example (or even a package of between 500-100,000
tons).
BRIEF SUMMARY OF THE INVENTION
[0011] The present invention provides an improved offshore marine
platform (and method of installation) that can be used for drilling
for oil and/or gas or in the production of oil and gas from an
offshore environment. Such drilling and/or production facilities
typically weigh between 500-100,000 tons, more commonly between
3,000-50,000 tons.
[0012] The apparatus of the present invention thus provides a
marine platform that is comprised of a plurality of spaced apart
buoys and a superstructure having a periphery that includes a
plurality of attachment positions, one attachment position for each
buoy. An articulating connection joins each buoy to the platform
superstructure.
[0013] Each of the buoys will move due to current and/or wind
and/or wave action or due to other dynamic marine environmental
factors. "Articulating connection" as used herein should be
understood to mean any connection or joint that connects a buoy to
the superstructure, transmits axial and shear forces, and allows
the support buoy(s) to move relative to the superstructure without
separation, and wherein the bending moment transferred to the
superstructure from one of the so connected buoys or from multiple
of the so connected buoys is reduced, minimized or substantially
eliminated. "Articulating connection" is a joint movably connecting
a buoy to a superstructure wherein axial and tangential forces are
substantially transmitted, however, transfer of bending moment is
substantially reduced or minimized through the joint allowing
relative movement between the buoy and the superstructure.
[0014] An articulating connection connects each buoy to the
platform at a respective attachment position, the connection
allowing for sea state induced buoy motions while minimizing
effects on the platform.
[0015] The apparatus of the present invention provides a marine
platform that further comprises a mooring extending from a
plurality of the buoys for holding the platform and buoys to a
desired location.
[0016] In a preferred embodiment, the present invention provides a
marine platform wherein each of the articulating connections
includes corresponding concave and convex engaging portions. In
another embodiment, a universal type joint is disclosed.
[0017] In another embodiment a marine platform has buoys with
convex articulating portions and the platform has correspondingly
shaped concave articulating portions.
[0018] In a preferred embodiment, each buoy can be provided with a
concave articulating portion and the platform with a corresponding
convex articulating portion that engages a buoy.
[0019] In a preferred embodiment, each buoy has a height and a
diameter. In a preferred embodiment, the height is much greater
than the diameter for each of the buoys.
[0020] In the preferred embodiment, each buoy is preferably between
about 25 and 100 feet in diameter.
[0021] The apparatus of the present invention preferably provides a
plurality of buoys, wherein each buoy is between about 100 and 500
feet in height.
[0022] The buoys can be of a generally uniform diameter along a
majority of the buoy. However, each buoy can have a variable
diameter in an alternate embodiment.
[0023] In a preferred embodiment, each buoy is generally
cylindrically shaped. However, each buoy can be provided with
simply an upper end portion that is generally cylindrically
shaped.
[0024] In a preferred embodiment, there are at least three buoys
and at least three attachment positions, preferably four buoys and
four attachment positions.
[0025] In a preferred embodiment, each articulated connection is
preferably hemispherically shaped for the upper end portion of each
buoy and there is a correspondingly concavely shaped receptacle on
the platform that fits the surface of each hemispherically shaped
upper end portion.
[0026] In a preferred embodiment, the platform is comprised of a
trussed deck. The trussed deck preferably has lower horizontal
members, upper horizontal members and a plurality of inclined
members spanning between the upper and lower horizontal members,
and wherein the attachment positions are next to the lower
horizontal member.
[0027] In the preferred embodiment, the apparatus supports an oil
and gas well drilling and/or production platform weighing between
500 and 100,000 tons, more particularly, weighing between 3,000
tons and 50,000.
[0028] The apparatus of the present invention uses articulating
connections between the submerged portion of the buoy and the
superstructure to minimize or reduce topside, wave induced motions
during the structural life of the apparatus.
[0029] The apparatus of the present invention thus enables smaller,
multiple hull components to be used to support the superstructure
than a single column or single buoy floater.
[0030] With the present invention, the topside angular motion is
reduced and is less than the topside angular motion of a single
column floater of comparable weight.
[0031] With the present invention, there is substantially no
bending moment or minimum bending moment transferred between each
buoy and the structure being supported. The present invention thus
minimizes or substantially eliminates moment transfer at the
articulating connection that is formed between each buoy and the
structure being supported. The buoys are thus substantially free to
move in any direction relative to the supported structure or load
excepting motion that would separate a buoy from the supported
structure.
[0032] The present invention has particular utility in the
supporting of oil and gas well drilling facilities and oil and gas
well drilling production facilities. The apparatus of the present
invention has particular utility in very deep water, for example,
in excess of 1500 feet.
[0033] The present invention also has particular utility in
tropical environments (for example West Africa and Brazil) wherein
the environment produces long period swell action.
[0034] The present invention provides a method of installing an oil
and gas well facility such as a drilling facility or a production
facility on a platform in an offshore deepwater marine environment.
The term "deepwater" as used herein means water depths of in excess
of 1500 feet.
[0035] The method of the present invention contemplates the
placement of a plurality of buoys at a selected offshore location,
a portion of each of the buoys being underwater. A superstructure
extends above water and includes a platform having an oil and gas
well facility. Such a facility can include oil well drilling, oil
well production, or a combination of oil well drilling and
production. The platform and its facility can be floated to a
selected location. The platform includes a peripheral portion
having a plurality of attachment positions, one attachment position
for each buoy.
[0036] When the buoys and platform are located at a desired
position, the platform is ballasted relative to the buoys until the
buoys connect with the platform. This connection can be achieved by
either ballasting the platform downwardly (such as for example,
using a ballasted transport barge), or by ballasting the buoys to a
higher position so that they engage the supported platform.
[0037] In the preferred embodiment, the buoys can be elongated,
cylindrically shaped buoys, each having a diameter of for example,
25-100 feet and a height of preferably between about 100 and 500
feet. Each of the buoys can have an upper, smaller diameter portion
that includes a connector. In one embodiment, the connector can be
convex in shape and articulate with a correspondingly shaped
concave connector on the platform.
[0038] The platform can include a trussed deck that carries at or
near its periphery or corners, connectors that enable a connection
to be formed with the upper end portion of each buoy. As an
example, there can be provided four buoys and four connectors on
the trussed deck or platform.
[0039] If a trussed deck is employed, an oil well production
facility (drilling or production or a combination) can be supported
upon the trussed deck. The connector at the top of each buoy can be
any type of an articulating connection that forms an articulation
with the trussed deck or a connector on the trussed deck. Examples
include the ball and socket or concave/convex arrangement shown in
the drawings (FIGS. 1-12). Another example includes the universal
joint shown in the drawings (see FIGS. 13-14).
[0040] In an alternate method, the multiple buoys can be used as
part of an installation method to place the marine platform upon a
single spar support.
BRIEF DESCRIPTION OF THE DRAWINGS
[0041] For a further understanding of the nature, objects, and
advantages of the present invention, reference should be had to the
following detailed description, read in conjunction with the
following drawings, wherein like reference numerals denote like
elements and wherein:
[0042] FIG. 1 is an elevation view of a preferred embodiment of the
apparatus of the present invention;
[0043] FIG. 2 is a plan view of a preferred embodiment of the
apparatus of the present invention;
[0044] FIG. 3 is another elevation view of a preferred embodiment
of the apparatus of the present invention;
[0045] FIG. 4 is a sectional view taken along lines 4-4 of FIG.
2;
[0046] FIGS. 5-6 are fragmentary perspective views of the preferred
embodiment of the apparatus of the present invention illustrating
the articulating connection between a buoy and the platform;
and
[0047] FIGS. 7-8 show alternate mooring arrangements for the
apparatus of the present invention;
[0048] FIG. 9 is a partial elevation view of an alternate
embodiment of the apparatus of the present invention that features
buoys of variable diameter;
[0049] FIG. 10 is a sectional view taken along lines 10-10 of FIG.
9;
[0050] FIG. 10A is a sectional view taken along lines 10-10 of FIG.
9 and showing a buoy lower end portion that is square;
[0051] FIG. 11 is a partial elevation view of a third embodiment of
the apparatus of the present invention showing an alternate buoy
construction;
[0052] FIG. 12 is a perspective elevation view of a third
embodiment of the apparatus of the present invention showing an
alternate buoy construction;
[0053] FIGS. 13-14 are elevation views of a fourth embodiment of
the apparatus of the present invention showing an alternate
articulating connection between each buoy and the platform. FIG. 14
is rotated 90 degrees from FIG. 13 around the longitudinal axis of
the buoy;
[0054] FIG. 15 is an elevation view illustrating the method of the
present invention, specifically the first step of floating the
marine platform to a desired location next to a plurality of buoys
that will support the platform;
[0055] FIG. 16 is an elevation view illustrating the method of the
present invention, specifically the step of ballasting the buoys
relative to the barge during a connection of the buoys to the oil
and gas well drilling and/or production facility to be
supported;
[0056] FIG. 17 is an elevation view illustrating the method of the
present invention including the final step of ballasting the
combination of structure and plurality of buoys until a desired
elevational position is achieved;
[0057] FIG. 18 is a perspective view illustrating the first step of
the method of the present invention;
[0058] FIG. 19 is a perspective view illustrating the second step
of the method of the present invention;
[0059] FIG. 20 is a perspective view illustrating an alternate
method of the present invention wherein the apparatus of the
present invention is used to place a marine platform upon a single
spar support;
[0060] FIG. 21 is a perspective view illustrating an alternate
method of the present invention wherein the apparatus of the
present invention is used to place a marine platform upon a single
spar support;
[0061] FIG. 22 is an elevation view illustrating an alternate
method of the present invention wherein the apparatus of the
present invention is used to place a marine platform upon a single
spar support;
[0062] FIG. 23 is an elevation view illustrating an alternate
method of the present invention wherein the apparatus of the
present invention is used to place a marine platform upon a single
spar support;
[0063] FIG. 24 is an elevation view illustrating an alternate
method of the present invention, showing the platform after
placement upon a single spar and removal of all supporting
buoys.
DETAILED DESCRIPTION OF THE INVENTION
[0064] FIGS. 1-6 show a preferred embodiment of the apparatus of
the present invention designated generally by the numeral 10 in
FIGS. 1-4. In FIGS. 1-4, floating marine platform apparatus 10 is
shown in a marine environment or ocean 12 having a water surface
11. The apparatus 10 includes a plurality of buoys 13-16,
preferably four (optionally between three (3) and eight (8)), that
support a superstructure defined by the combination of platform 17
and drilling and/or producing facilities 53. Oil and gas well
producing facility as used herein shall include a facility used for
oil and gas well drilling or production, or a combination of
drilling and production.
[0065] Buoys 13-16 can be any desired shape, including the
alternate buoys shown in the drawings or buoys with configurations
like those in the September 2000 issue of Offshore Magazine.
Platform 17 can be any desired platform or rig, such as a trussed
deck constructed of a plurality of upper horizontal members 18, a
plurality of lower horizontal members 19, a plurality of vertical
members 20 and a plurality of diagonal members 21 to define a
trussed deck or platform 17. As shown in FIG. 1, platform 17 can
include any desired oil and gas drilling and/or production facility
53, such facilities (in combination with platform 17) defining a
superstructure weighing between about 500-100,000 tons, between
3,000-50,000 tons). (See FIGS. 3 and 8).
[0066] Each buoy 13-16 has an upper end portion 22 that can be
conically shaped at 23 (see FIGS. 5-6). An attachment portion 24
provides a convex upper surface 25 that receives a correspondingly
shaped concave surface 26 of connecting portion 27 of platform 17.
The concave surface 26 can be generally hemispherically shaped.
However, the concave surface 26 is curved to articulate upon the
surface 25.
[0067] Surface 26 is preferably smaller than a full hemispherical
surface, sized to articulate upon surface 25 even wherein there is
an angular variation that can be as much as 30 degrees (or more)
between the central longitudinal axis 29 of any one of the buoys
and a pure vertical plane. To address wear, bearing materials may
be used in the articulating connections which are conventionally
available. A preferred bearing material would be graphite
impregnated brass or bronze bushing.
[0068] The following equations can be used in sizing the buoys:
Heave Period T(heave)=2.pi..check mark.(M/K)
[0069] Where
[0070] M=total Heave mass;
[0071] K=Heave stiffness;
Heave Stiffness K=1/4.pi.D.sup.2G
[0072] Where
[0073] D=the diameter of the section of the buoy passing through
the water plane;
[0074] G=the unit weight of water (approximately 65 pounds per
cubic foot);
Heave Mass M=(Dry buoy mass)+(entrapped fluid mass)+(permanent
solid ballast mass)+(added virtual fluid mass)
[0075] The buoys may be constructed of stiffened steel plate, or
continuously cast (slip formed) concrete or through other
conventional construction techniques. Typically, a number of
internal stiffeners are included to provide the required overall
structural strength.
[0076] The attachment portion 24 at the upper end of each buoy
13-16 can be reinforced with a plurality of vertical plates 30 as
shown in FIG. 6. Likewise, the connection portion 27 of platform 17
can be provided with a plurality of internal reinforcing plates 35.
The plates 35 extend between upper curved plate 36 and lower curved
plate 37. A conical plate 38 can be attached to (or can be integral
with) upper curved plate 36 as shown in FIG. 6. A square harness
articulating connection (not shown) going around the primary
articulating connection may also be used.
[0077] Platform apparatus 10 can be secured to the sea bed 51 using
piling or anchors 52 and mooring lines 32, 41 (FIGS. 1-4, 8). In a
preferred embodiment (FIGS. 1-4), one or more mooring lines 32
extend from each buoy 13-16 at an upper padeye 31 to the sea bed
51. The mooring lines in FIGS. 1, 2, 3 and 4 extend between padeyes
31 and anchors 52 at sea bed 51.
[0078] In a preferred embodiment, a plurality of horizontal mooring
lines 34 extend between lower padeyes 33 on two buoys 13, 14 as
shown in FIG. 1. While the lower horizontal mooring lines 34 are
shown connecting to buoys 13, 14, it should be understood that each
pair of buoys (14-15, 15-16, 16-13) has a horizontal line 34
extending there between in the same configuration shown in FIG.
1.
[0079] FIG. 7 shows a first alternate embodiment of the present
invention, utilizing tensioned mooring lines 39 that extend between
connection points (eg. padeyes) 40 on each of the buoys 13-16 and
anchors (such as 52) embedded in the sea bed 51. In the embodiment
of FIG. 7, horizontal mooring lines 34 could optionally be provided
between each pair of buoys such as 13 and 14, or 14 and 15, or 15
and 16, or 16 and 13.
[0080] FIG. 8 shows an alternate arrangement wherein caternary
mooring lines 41 extend between padeyes 31 and the anchors 52 that
are anchored to the sea bed 51. In this embodiment, there are no
horizontal lines connecting the buoys.
[0081] The plan view of FIG. 2 shows various orientations that
could be used for either mooring lines 32 or mooring lines 41. One
arrangement provides a plurality of three mooring lines 32 or 41
attached to each buoy 13-16, the mooring lines 32 or 41 being
spaced about 120 degrees apart as shown in hard lines. In phantom
lines in FIG. 2, another geometry for the mooring lines 32, 41 is
shown, wherein there are two mooring lines for each spur that are
about 90 degrees apart.
[0082] The platform 17 is constructed of upper and lower sets of
horizontal members 18, 19; vertical members 20; and diagonal
members 21.
[0083] FIGS. 9, 10 and 10A show an alternate construction for each
of the buoys. It should be understood that a buoy such as one of
those shown in FIGS. 9, 10 or 10A could be used to replace any one
or all of the buoys 13-16 shown in FIGS. 1-4 and 5-6.
[0084] Buoy 42 can be provided with a variable diameter having a
smaller diameter cylindrical middle section 43, and a larger
diameter lower section 44 which can be for example, either
cylindrical (See FIG. 10) or squared (see FIG. 10A). The
cylindrical lower section 44 is shown in FIGS. 9 and 10, and the
squared lower section 45 shown in FIG. 10A.
[0085] Another buoy construction is shown in FIGS. 11 and 12. It
should be understood that the buoy shown in FIGS. 11 and 12 could
be used to replace any one or all of the plurality of buoys 13-16
of FIGS. 1-6. In FIGS. 11 and 12, the buoy 46 has a cylindrical
middle section 47, a conical upper section 48, and a trussed lower
section 49. Padeyes 50 on the upper end portion of trussed lower
section 49 can be used to support any of the afore described
mooring lines such as 32, 39, or 41. In the embodiment of FIGS. 11
and 12, each of the buoys 46 can have a similar construction and
configuration at the upper end portion to that of a preferred
embodiment shown in FIGS. 1-6, providing a conical upper section 48
and a attachment portion 24.
[0086] In FIGS. 13 and 14, there can be seen an alternate
articulating connection between platform 17 and a selected buoy 13
(or 14-16 or 42, or 46). A gimble or universal joint 62 arrangement
is shown in FIGS. 13 and 14, providing a first pinned connection at
54 and a second pinned connection at 55. The first pin 56 can be of
a larger diameter, having a central opening 58 through which the
second, smaller diameter pin 57 passes as shown. The central
longitudinal axes of the pins 54, 55 preferably intersect. Arrow 59
in FIGS. 13-14 shows that a buoy can optionally be made to rotate
relative to the gimbal connection shown. Bearing plates 78, 79 can
rotate relative to one another. To minimize frictional force
transference and wear, both pins 56, 57 can be mounted in
bearings.
[0087] Each of the buoys 13, 14, 15, 16 will move due to current
and/or wind and/or wave action or due to other dynamic marine
environmental factors. "Articulating connection" as used herein
should be understood to mean any connection or joint that connects
a buoy to the superstructure, transmits axial and shear forces, and
allows the support buoy(s) to move relative to the superstructure
without separation, and wherein the bending moment transferred to
the superstructure from one of the so connected buoys or from
multiple of the so connected buoys is reduced, minimized or
substantially eliminated.
[0088] In FIGS. 15-17 and 18-19, the method of the present
invention is disclosed. In FIG. 18, arrow 63 designates travel of a
transport barge 73 toward a plurality of buoys 13, 14, 15, 16 that
have been positioned at a desired location. Buoys 13, 14, 15, 16
are held in that position using for example, a plurality of anchor
lines 32 as shown in FIGS. 15-19.
[0089] Transport barge 73 provides an upper deck 74, a bottom 75, a
port side 76 and a starboard side 77. The barge 73 also has end
portions 64, 65. Transport barge 73 can be any suitable barge
having a length, width, and depth that are suitable for
transporting a multi-ton superstructure to a job site. Typically,
such a superstructure 53 mounted upon platform 17 will be a
multi-ton structure that is capable of performing oil and gas well
drilling activities and/or oil and gas well production
activities.
[0090] In FIG. 19, barge 73 has been positioned next to the
plurality of buoys 13, 14, 15, 16. As an example, FIGS. 18-19, the
transport barge 73 has been positioned so that the buoys 13, 16 are
on the starboard side 77 of transport barge 73. The buoys 14, 15
are positioned on the port side 76 of transport barge 73 as shown
in FIGS. 15-17 and 19.
[0091] Once in the position shown in FIGS. 15 and 19, a ballasting
operation moves the buoys 13, 14, 15, 16 into contact with the
platform 17 so that a connection is perfected. More specifically,
the attachment portions 24 of the respective buoys 13, 14, 15, 16
engage and form an articulating connection with the corresponding
connecting portions 27 of platform 17 as shown in FIGS. 15-17 and
in FIGS. 1-8 and 13-14.
[0092] Ballasting can be achieved by initially adding water to the
buoys 13, 14, 15, 16 so that they are at a lower position in the
water as shown in FIGS. 15 and 18-19. The water can then be pumped
from the interior of each of the buoys 13, 14, 15, 16 as indicated
schematically by the numeral 60 in FIG. 16. As water is removed
from the interior of each of the buoys 13-16, the water level 61 in
each of the buoys 13-16 will drop and each of the buoys 13-16 will
rise as indicated schematically by arrows 80 in FIG. 16.
[0093] Each of the buoys 13, 14, 15, 16 will be ballasted upwardly
in the direction of arrows 80 until its attachment portion 24 forms
a connection with the connecting portion 27 of platform 17.
Alternatively, the barge 73 can be positioned as shown in FIGS. 15
and 19. The barge 73 can then be lowered so that the barge 73,
platform 17 and drilling/production facility 53 lower with it until
the connection portions 27 of platform 17 rest upon the attachment
portions 24 of the buoys 13-16.
[0094] As still a further alternative, a combination of ballasting
of barge 73 and buoys 13, 14, 15, 16 can be used to connect each of
the attachment portions 24 of buoy 13, 14, 15, 16 to platform 17 so
that the attachments shown in FIGS. 1, 2, 3, 4, 7, 8 are achieved.
For example, barge 73 can be lowered using ballasting while buoys
13, 14, 15, 16 are simultaneously elevated using ballasting.
[0095] For the embodiment of FIGS. 13 and 14, a similar ballasting
arrangement can be provided wherein the pinned connections 54, 55
are added after the platform 17 and buoys 13, 14, 15, 16 are at the
proper elevational positions relative to one another.
[0096] Once the superstructure that includes platform 17 and
facility 53 is supported as shown in FIG. 17, the superstructure
(platform 17 and facility 53) can be placed upon a single spar
support 66 if desired using the apparatus 10 of the present
invention as a transfer apparatus.
[0097] After removal of barge 73 (see FIGS. 15-19), tow boats 69
can be used to tow each buoy 13, 14, 15, 16 to spar 66. For
example, each boat 69 can provide a tow line 70 attached to a buoy
13, 14, 15 or 16, or to deck 17 at a provided attachment 71.
[0098] In FIGS. 20, 21, and 22, the boats 69 pull buoys 13, 14, 15,
16 to a position as shown that overlays platform 17 with upper end
portion 67 of spar 66. Ballasting can then be used to either
elevate spar 66 or lower buoys 13, 14, 15, 16 (or a combination of
such ballasting can be used) to engage spar 66 upper end portion 67
with platform 17 as indicated by arrow 72 in FIG. 23.
[0099] Additional ballasting separates each buoy 13, 14, 15, 16
from platform 17 so that spar 66 alone supports platform 17 and its
facility 53 (see FIG. 24).
2 PARTS LIST PART NUMBER DESCRIPTION 10 floating marine platform
apparatus 11 water surface 12 ocean 13 buoy 14 buoy 15 buoy 16 buoy
17 platform 18 upper horizontal member 19 lower horizontal member
20 vertical member 21 diagonal member 22 upper end portion 23
conical shape 24 attachment portion 25 convex surface 26 concave
surface 27 connecting portion 28 central longitudinal axis 29 axis
30 internal reinforcing plate 31 upper padeye 32 mooring line 33
lower padeye 34 horizontal mooring line 35 internal reinforcing
plate 36 upper curved plate 37 lower curved plate 38 conical plate
39 tensioned mooring line 40 padeye 41 caternary mooring line 42
buoy 43 cylindrical middle section 44 cylindrical lower section 45
square lower section 46 buoy 47 cylindrical middle section 48
conical upper section 49 trussed lower section 50 padeye 51 sea bed
52 anchor 53 drilling/production facility 54 pinned connection 55
pinned connection 56 pin 57 pin 58 opening 59 arrow 60 water
discharge 61 water level 62 buoy interior 63 arrow 64 end portion
65 end portion 66 spar 67 upper end portion 68 arrow 69 tow boat 70
tow line 71 attachment 72 arrow 73 barge 74 barge deck 75 bottom 76
port side 77 starboard side 78 bearing plate 79 bearing plate 80
directional arrows
[0100] The foregoing embodiments are presented by way of example
only; the scope of the present invention is to be limited only by
the following claims.
* * * * *