Abstract:
A marine platform 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 a 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. Each connection can provide first and second portions (or devices) and a load transfer mechanism that transfers load from the first portion to the second portion so that one of the portions (or devices) can be serviced.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]    This is a continuation-in-part of co-pending U.S. patent application Ser. No. 09/693,470, filed Oct. 20, 2000, which is incorporated herein by reference.  
         [0002]    Priority of U.S. Provisional Patent Application Serial No. 60/213,034, filed Jun. 21, 2000, incorporated herein by reference, is hereby claimed. 
     
    
     
       STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT  
         [0003]    Not applicable  
         REFERENCE TO A “MICROFICHE APPENDIX” 
         [0004]    Not applicable  
         BACKGROUND OF THE INVENTION  
         [0005]    1. Field of the Invention  
           [0006]    The present invention relates to floating marine platforms. More particularly, the present invention relates to a novel multiple buoy platform that supports a platform with a plurality of buoys and wherein a specially configured multiple device support enables replacement of one device while the other supports the platform.  
           [0007]    2. General Background of the Invention  
           [0008]    Many types of marine platforms have been designed, patented and 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.  
           [0009]    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.  
           [0010]    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.  
                                                         ISSUE           PATENT #   DATE   TITLE                                3,540,396   Nov. 17, 1970   Offshore Well Apparatus and System       4,297,965   Nov. 03, 1981   Tension leg Structure for Tension Leg               Platform       5,439,060   Aug. 08, 1995   Tensioned Riser Deepwater Tower       5,558,467   Sep. 24, 1996   Deep Water offshore Apparatus       5,706,897   Jan. 13, 1998   Drilling, Production, Test, and Oil               Storage Caisson       5,722,797   Mar. 03, 1998   Floating Caisson for Offshore               Production and Drilling       5,873,416   Feb. 23, 1999   Drilling, Production, Test, and Oil               Storage Caisson       5,924,822   Jul. 20, 1999   Method for Deck Installation on an               Offshore Substructure       6,012,873   Jan. 11, 2000   Buoyant Leg Platform With Retractable               Gravity Base and Method of Anchoring               and Relocating the Same       6,027,286   Feb. 22, 2000   Offshore Spar Production System and               Method for Creating a Controlled Tilt               of the Caisson Axis                  
 
           [0011]    One of the problems with the spar type construction is that the single spar must be enormous and thus very expensive to manufacture, transport, and install if it is supporting a 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  
         [0012]    The present invention provides an improved offshore marine platform 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.  
           [0013]    The apparatus of the present invention thus provides a marine platform that is comprised of a plurality of spaced apart buoys, the platform having a periphery that includes a plurality of attachment positions, one attachment position for each buoy.  
           [0014]    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.  
           [0015]    A connection (which can be 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.  
           [0016]    The apparatus of the present invention provides a marine platform that can further comprise a mooring extending from a plurality of the buoys for holding the platform and buoys to a desired location.  
           [0017]    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.  
           [0018]    In another embodiment a marine platform has buoys with convex articulating portions and the platform has correspondingly shaped concave articulating portions.  
           [0019]    In a preferred embodiment, each buoy can be provided with a concave articulating portion and the platform with a convex articulating portion.  
           [0020]    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.  
           [0021]    In the preferred embodiment, each buoy is preferably between 25 and 100 feet in diameter.  
           [0022]    The apparatus of the present invention preferably provides a plurality of buoys, wherein each buoy is between about 100 and 500 feet in height.  
           [0023]    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.  
           [0024]    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.  
           [0025]    In a preferred embodiment, there are at least three buoys and at least three attachment positions, preferably four buoys and four attachment positions.  
           [0026]    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.  
           [0027]    The connection can also be in the form of a universal joint. In an additional embodiment, the connection can be in the form of first and second devices that provide “backup” or redundancy that enables one device to be serviced while the other supports the platform. In this embodiment, a first universal joint preferably carries load between the platform and each buoy over the long period of time. In the event that the first device must be replaced or serviced, a jacking arrangement loads the other device so that the first device does not carry load and can be removed.  
           [0028]    The devices can include an inner device and an outer device. The “devices” can be articulating devices such as universal joints.  
           [0029]    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.  
           [0030]    In a 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.  
           [0031]    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.  
           [0032]    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.  
           [0033]    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.  
           [0034]    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.  
           [0035]    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.  
           [0036]    The present invention also has particular utility in tropical environments (for example West Africa and Brazil) wherein the environment produces long period swell action. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0037]    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:  
         [0038]    [0038]FIG. 1 is an elevation view of a preferred embodiment of the apparatus of the present invention;  
         [0039]    [0039]FIG. 2 is a plan view of a preferred embodiment of the apparatus of the present invention;  
         [0040]    [0040]FIG. 3 is an elevation view of a preferred embodiment of the apparatus of the present invention;  
         [0041]    [0041]FIG. 4 is another elevation view of a preferred embodiment of the apparatus of the present invention;  
         [0042]    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  
         [0043]    FIGS.  7 - 8  show alternate mooring arrangements for the apparatus of the present invention;  
         [0044]    [0044]FIG. 9 is a partial elevation view of an alternate embodiment of the apparatus of the present invention that features buoys of variable diameter;  
         [0045]    [0045]FIG. 10 is a sectional view taken along lines  10 - 10  of FIG. 9;  
         [0046]    [0046]FIG. 10A is a sectional view taken along lines  10 - 10  of FIG. 9 and showing a buoy lower end portion that is square;  
         [0047]    [0047]FIG. 11 is a partial elevation view of a third embodiment of the apparatus of the present invention showing an alternate buoy construction;  
         [0048]    [0048]FIG. 12 is a perspective elevation view of a third embodiment of the apparatus of the present invention showing an alternate buoy construction;  
         [0049]    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;  
         [0050]    [0050]FIG. 15 is a schematic elevation view of a fifth embodiment of the apparatus of the present invention;  
         [0051]    [0051]FIG. 16 is a partial elevation view of the fifth embodiment of the apparatus of the present invention;  
         [0052]    [0052]FIG. 17 is a side elevation view taken along lines  17 - 17  of FIG. 16;  
         [0053]    [0053]FIG. 18 is a partially cut away elevation view of the fifth embodiment of the apparatus of the present invention;  
         [0054]    [0054]FIG. 19 is a partially cut away elevation view of the fifth embodiment of the apparatus of the present invention;  
         [0055]    [0055]FIG. 20 is an elevation view of the fifth embodiment of the apparatus of the present invention showing an angled position of the platform relative to the buoys;  
         [0056]    [0056]FIG. 21 is an elevation view of the fifth embodiment of the apparatus of the present invention showing an angled position of the platform relative to the buoys;  
         [0057]    [0057]FIG. 22 is a partial elevation view of the fifth embodiment of the apparatus of the present invention illustrating removal of the pin for servicing the internal universal joints;  
         [0058]    [0058]FIG. 23 is another partial elevation view of the fifth embodiment of the apparatus of the present invention showing removal of the internal universal joint.  
         [0059]    [0059]FIG. 24 is a partial perspective, exploded view of the fifth embodiment of the apparatus of the present invention illustrating the internal universal joint; and  
         [0060]    [0060]FIG. 25 is a partial perspective, exploded view of the fifth embodiment of the apparatus of the present invention showing the external universal joint. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0061]    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.  
         [0062]    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, ( or between about 3,000-50,000 tons). (See FIGS. 3 and 8).  
         [0063]    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 . 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  28  of buoy  13  and a pure horizontal plane  29 . To address wear, bearing materials may be used in the articulating connections which are conventionally available. A preferred bearing material would be a graphite impregnated brass or bronze bushing.  
         [0064]    The following equations can be used in sizing the buoys: 
         Heave Period  T (heave)=2Π{square root}( M/K ) 
         [0065]    Where  
         [0066]    M=total Heave mass;  
         [0067]    K=Heave stiffness; 
         Heave Stiffness  K= 1/4Π D   2   G   
         [0068]    Where  
         [0069]    D=the diameter of the section of the buoy passing through the water plane;  
         [0070]    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) 
         [0071]    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.  
         [0072]    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.  
         [0073]    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 .  
         [0074]    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.  
         [0075]    [0075]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 .  
         [0076]    [0076]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 .  
         [0077]    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 buoy that are about 90 degrees apart.  
         [0078]    The platform  17  is constructed of upper and lower sets of horizontal members  18 ,  19 ; vertical members  20 ; and diagonal members  21 .  
         [0079]    [0079]FIGS. 9, 10 and  10 A 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  10 A could be used to replace any one or all of the buoys  13 - 16  shown in FIGS.  1 - 4  and  5 - 6 .  
         [0080]    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.  
         [0081]    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 .  
         [0082]    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  60 ,  61  can rotate relative to one another. To minimize frictional force transference and wear, both pins can be mounted in bearings.  
         [0083]    FIGS.  15 - 25  show the fifth embodiment of the apparatus of the present invention, designated generally by the numeral  63  in FIG. 15. Floating marine platform apparatus  63  is shown in FIG. 15 as including a platform  17  that can include a structural deck, package, platform, trussed deck or the like which has been shown in phantom lines in FIG. 15. It should be understood that platform  17  shown in FIG. 15 can include a structural deck  64  or any other structural frame that is known in the art for supporting an offshore oil and gas well drilling platform, and oil and gas well production facility, or an oil and gas well drilling and production facility  67 .  
         [0084]    Platform  17  can include thus a structural deck which is schematically illustrated using the numeral  64  in FIGS.  15 - 25  including a superstructure (e.g. with an oil drilling platform, oil production platform, crew quarters, heliport, vessels, and the like). A plurality of connections are shown, a connection interfacing between each buoy  13 ,  14 ,  15 ,  16  and the platform  17  to be supported.  
         [0085]    In the embodiment of FIGS.  15 - 25 , the connection that is positioned in between each buoy such as buoy  13  and platform  17  is preferably a connection that includes first and second connection devices and a load transfer mechanism that can transfer at least some of the platform load from one of the devices to the other device.  
         [0086]    In the fifth embodiment, these devices preferably include an internal device  65  (see FIG. 24) and an external device  66  (see FIG. 25). In the embodiment of FIGS.  15 - 25 , the internal  65  and external  66  devices are preferably articulating connections. In the embodiment of FIGS.  15 - 25 , the devices  65 ,  66  are preferably each universal joint connections.  
         [0087]    In the embodiment of FIGS.  15 - 25 , a load transfer mechanism enables load to be transferred from one of the devices  65  or  66  to the other device  65  or  66 . This load transfer mechanism is preferably a jacking system such as the plurality of hydraulic jacks  119  that are shown in the drawings.  
         [0088]    In FIG. 25, a deck opening  68  is shown through which the internal device  65  can be removed for servicing. The internal device  65  can be the device that typically carries a portion of the platform load for a majority of the time and transfers that load to its buoy such as buoy  13 . At deck opening  68 , padeyes  69  are provided each having an opening  70  as shown in FIG. 25.  
         [0089]    The details of construction of the internal device  65  are shown in FIG. 24. The internal device  65  includes a lower section  71 , and upper section  82 , and pins  77 ,  90 . The lower section  71  has a bottom  72  that transfers load to the upper surface  124  of buoy  13 . When load is to be transferred to the second device  66  of FIG. 25, a jacking mechanism such as the plurality of hydraulic jacks  119  lift the lower section  71  from upper surface  124  of buoy  13 , as shown in FIG. 22. A gap  123  is then present in between the upper surface  124  of buoy  13  and the bottom  72  of lower section  71 . In such a position (shown in FIG. 22), pin  120  can be removed and the internal device  65  can be lifted upwardly and withdrawn through opening  68  in structural deck  64 .  
         [0090]    Lower section  71  has sides  73 , a top  74  and a pair of padeyes  75  that are spaced apart and which extend from the top  74 . Each padeye  75  has pin opening  76 . A smaller pin  77  has enlarged head  78  and externally threaded section  79 . Nut  80  provides an internally threaded section  81  that enables the nut  80  to be threadably engaged to the pin  77  at threads  79 . Upper section  82  of internal device  65  provides sides  83  and payeyes  84  that extend downwardly as shown in FIG. 24, each padeye  84  providing a pin opening  85 .  
         [0091]    Upper section  82  provides a pair of spaced apart beams  86 , each having end portions  87 ,  88 . Each end portion  87 ,  88  provides a pin opening  97 . A larger pin  90  fits through openings  85  as indicated schematically by arrow  126  in FIG. 24. Pin  90  has enlarged head  91 , and externally threaded section  92 . Larger pin  90  also provides an opening  93  that is positioned in between externally threaded section  92  and head  91  as shown in FIG. 24.  
         [0092]    Nut  94  has internally threaded section  95  that enables the nut to be threadably engaged with the larger pin  90 . A gap  96  is provided in between the beams  86  so that padeyes  69  on structural deck  64  fit in between the spaced apart beams  86  in gap  96  as shown in the drawings (see FIGS. 16 and 18). In this position, the openings  70  of padeyes  69  align with the openings  97  of beams  86 . Pins  120  can then be placed through the aligned openings  70 ,  97 . Upon assembly of the device  65 , larger pin  90  is first passed through openings  85  of padeyes  84 . Nut  94  is then threadably engaged with pin  90  at correspondingly engaging threaded portions  92 ,  95 . The pin  77  is then placed through one of the openings  76  of padeye  75 , and then through opening  93  of larger pin  90  and then through the opposite opening  76  of padeye  75 . Nut  80  then retains smaller pin  77  by engaging the threaded portions  79 ,  81 . In this position, the internal device  65  defines a first universal joint (see FIG. 23) that can be removed as shown by arrow  128  in FIG. 23 for servicing.  
         [0093]    The devices  65 ,  66  can be universal joints as shown. Each of the universal joints each have multiple pins  77 , 90  (for device  65 ) and  110  (for device  66 ) with central longitudinal axes, the central axes of the pins  77 ,  90  and  110  of both universal joints occupying a common plane during use.  
         [0094]    When the internal device  65  is removed for servicing, the external device  66  carries a portion of the platform load between structural deck  64  and buoy  13 . The external device  66  is shown more particularly in FIG. 25. External device  66  includes a pair of spaced apart lower supports  98 , each having a pair of spaced apart padeyes  99 , each of the padeyes  99  providing a pin opening  100 .  
         [0095]    A pair of lower beams  101  are provided, a beam  101  being pivotally attached to each lower support  98  as shown in FIG. 25. Each lower beam  101  provides end portions  102 ,  103 , each of the end portions  102 ,  103  providing an upper surface  104  that carries a hydraulic jack  119 . Each of the lower beams  101  provides a beam opening  105  that receives a pin  110  when the opening  105  aligns with openings  100  of padeyes  99 .  
         [0096]    The external device  66  includes a pair of spaced apart supports  115  that are connected (eg. welded or bolted) to the underside of structural deck  64  for transferring load from the external device  66  to structural deck  64 . Upper beams  106  are pivotally attached to upper supports  115  using pins  110 . Each of the upper supports  115  has a pair of spaced apart padeyes  116 , each padeye  116  having an opening  117  for receiving a pin  110 . Each upper beam  106  provides end portions  107 ,  108  having a lower surface  109  that is engaged by an elevating portion  129  of hydraulic jack  119  when load is to be carried by the external device  66 . It should be understood that the hydraulic jacks  119  are commercially available such as from Enerpac.  
         [0097]    Each pin  110  has an enlarged head  111  and an externally threaded section  112 . Pins  110  are retained in position using nuts  113 . Each nut  113  has an internally threaded section  114  that engages the externally threaded section  112  of pin  110 . Each of the upper beams  106  has a beam opening  118  that receives pin  110 . In order to effect the pivotal connection between upper supports  115  and upper beams  106 , pins  110  are passed through the openings  117  of padeyes  116  and the beam openings  118 . The pins  110  are then secured by fastening a nut  113  to threaded section  112 .  
         [0098]    In the embodiment of FIGS.  15 - 25 , it is preferable that the internal device  65  carry load between a buoy (for example  13 ), and structural deck  64  a majority of the time. Therefore, there is typically a small gap between the elevating portion  129  of each jack  119  and the undersurface  109  of beam ends  107 ,  108 . In such a situation, the bottom  72  of lower section  71  of internal device  65  bears against the upper surface  124  of buoy  13 . In order to service the internal device  65  (or to replace it), the hydraulic jacks  119  are actuated so that elevating portion  129  elevates until the elevating portion  129  engages lower surface  109  of each beam end  107 ,  108 . Continued elevation of the jack  119  elevating portions  129  causes upper beams  106  to move away from lower beams  101 . Such elevating of the jacks  119  increases the distance between structural deck  64  and the upper surface  124  of each buoy  13 ,  14 ,  15 ,  16 . Eventually, the lower surface  72  of the lower section  71  rises above upper surface  124  of buoy  113  (see FIG. 22) thus removing platform load from the internal device  65 . Pin  120  is then removed by disassembly of retainer nut  122  from pin  120  as schematically indicated by arrow  89  in FIG. 22. A gap  123  between lower section  71  and buoy  13  is shown in FIG. 22. Arrow  128  in FIG. 23 schematically illustrates the lifting of internal device  65  upwardly for removal and servicing. The external device  66  in FIG. 23 now carries load between structural deck  64  and buoy  13 .  
         [0099]    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.  
                                                   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   plane       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   first pinned connection       55   second pinned connection       56   pin       57   pin       58   opening       59   arrow       60   bearing plate       61   bearing plate       62   universal joint       63   floating marine platform apparatus       64   structural deck       65   internal device       66   external device       67   facility       68   deck opening       69   padeye       70   opening       71   lower section       72   bottom       73   side       74   top       75   padeye       76   pin opening       77   smaller pin       78   enlarged head       79   externally threaded section       80   nut       81   internally threaded section       82   upper section       83   side       84   padeye       85   pin opening       86   beam       87   end portion       88   end portion       89   arrow       90   larger pin       91   enlarged head       92   externally threaded section       93   opening       94   nut       95   internally threaded section       96   gap       97   pin opening       98   lower support       99   padeye       100   pin opening       101   lower beam       102   end       103   end       104   upper surface       105   beam opening       106   upper beam       107   end       108   end       109   lower surface       110   pin       111   enlarged head       112   externally threaded section       113   nut       114   internally threaded section       115   upper support       116   padeye       117   pin opening       118   beam opening       119   jack       120   pin       121   enlarged head       122   retainer nut       123   gap       124   top of buoy       125   arrow       126   arrow       127   arrow       128   arrow       129   elevating portion                  
 
         [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.