Abstract:
A method and apparatus for repairing a tubular member in an offshore marine environment provides a specially configured shell having shell halves, longitudinal seals, and optionally upper and lower seals. Additionally, the shell halves are each provided with a plurality of threaded fasteners that will help with shell alignment, holding the shell rigidly to the tubular member prior to grouting operations.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     Priority of U.S. Provisional Patent Application Ser. No. 61/300,335, filed Feb. 1, 2010, incorporated herein by reference, is hereby claimed. 
    
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     Not applicable 
     REFERENCE TO A “MICROFICHE APPENDIX” 
     Not applicable 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a method and apparatus for repairing a tubular member in an offshore marine environment. More particularly the present invention relates to an improved method and apparatus for repairing a tubular member in a marine environment with a specially configured shell clamped about a damaged area of the tubular member and the annulus between the damaged section and the shell is filled with grout. Inflatable seals can be used to seal the bore of the tubular member if the bore is to be filled with grout in between the inflatable seals. 
     2. General Background of the Invention 
     After a hurricane damages an offshore marine platform, the platforms can become weakened to the point where it poses a hazard to safe operation of activities on the platform such as oil and gas well drilling and production activities. In many cases, repair of one or more of the tubular members that form a part of an oil and gas well structure or other offshore structure or platform provides a viable alternative which enables the platform to be used once the repair is completed. 
     Patents have issued on methods of preparing tubular members on oil and gas wells. Examples include U.S. Pat. Nos. 6,536,991 and 6,997,260 issued to applicants herein. One early patent is the Papworth U.S. Pat. No. 4,068,483 entitled “Protective Sheath for Water-Eroded Wood Piling”. In the Papworth patent, the sheath is for a water-eroded wood piling. The sheath is a longitudinally split, flexible and resilient plastic casing with overlapping circumferentially end segments. The casing has a preformed, integral spout at its upper end into which wet concrete can be poured to fill the casing around the eroded section of the piling. Flexible bands clamp the casing tightly around the piling, and the spout has aligned openings in its opposite sides for passing the uppermost one of these bands. The casing may comprise two or more longitudinal sections in overlapped sealed engagement with each other end-to-end for enclosing a long eroded section of the piling. 
     In the Colbert U.S. Pat. No. 4,023,374, there is disclosed a repair sleeve for a marine pile and a method of applying same. The &#39;374 patent discloses a preformed molded fiberglass resin plastic repair sleeve for use on a marine or other submerged concrete pile and a method of applying the same. The sleeve is provided with at least one vertical seam consisting of inside interlocking reentrant bends which together establish an interlocking tongue and groove joint. The joint is maintained effective by self-tapping screws which are in engaged relation with steel closure clips or strips. The sleeve after assembly is centered about the pile undergoing repair and the continuous space which exists between the sleeve and the pile is filled with a suitable grout which, when hardened, encompasses the internal or inside portions of the joint under pressure and prevents unfastening of the seam. The vertical longitudinal extend of the sleeve is somewhat greater than the water depth of the partially submerged pile to which it is applied and; where a cylindrical concrete pile is concerned, the sleeve is molded on an arcuate bias so as to present an open gap enabling the sleeve to be readily slipped sidewise onto the pile by one or more divers and the gap thereafter closed in order to effect the interlocked joint. Where a square pile is undergoing repair, the sleeve assumes a conformable four-sided shape or, alternatively, it may be formed of two mating right angle sleeve sections having a pair of vertical inside interlocking joints or seams between their adjoining side margins. 
     The Straub U.S. Pat. No. 4,114,388 discloses a device for protecting a pile from ice formations collecting on it and subsequently abstracting the pile as a result of a variation of tide level including a tapered guard member secured to the pile. The guard member is firmly secured to the c pile by interconnecting stiffening members, horizontal stiffening rings, vertical fin members and compression rings which also serve to prevent deformation of the guard member taper as a result of interaction with the ice formations. The guard member comprises two sections connected by vertically extending tongue and groove joints. 
     The Moore U.S. Pat. No. 4,306,821 discloses a system for the restoring and reconditioning of structural piling. The system provides an outer form which is attachable to a portion of the piling which has been eroded or corroded and has lost some of its thickness and thus its overall strength. A diameter building filler is placed into the intra form space between the form and the piling, the filler providing a protective and structural coating to that portion of the piling where corrosion or damage has taken place. 
     Three patents have issued to Richard Snow and Milton Ellisor. These patents include U.S. Pat. Nos. 4,876,896; 4,892,410; and 4,993,876. The &#39;896 and &#39;410 patents discloses a method and apparatus for forming an encapsulation or encasement about a structural member that is said to be suited for use in a marine environment. A two-component polymer system for protective and repair encapsulation is pumpable in two separate strings to the location of the structural member to be encapsulated. The two reactive components are combined in a static mixer immediately prior to being injected within the surrounding translucent jacket. By combining the reactive components immediately prior to use, premature setup is avoided and the resulting grout may be directed to flow upwardly in the jacket for enhancing final properties. By suitable coloring of the components, visual monitoring of the final mixing and distribution in the translucent form or jacket of the encapsulation material may be monitored. A field test for determining bonding strength of the encapsulation polymer to the structural member is also disclosed in the &#39;876 patent and in the &#39;410 patent. The &#39;896 patent discloses a method of testing protective encapsulation of structural members. 
     Other patents that discuss repair methods are the Fox U.S. Pat. No. 4,091,301 and the Moran U.S. Pat. No. 967,952, both references cited in U.S. Pat. No. 6,536,991 naming applicants herein as inventors. U.S. Pat. No. 6,536,991 is incorporated herein by reference. 
     Other references that discuss repair methods are the following patents: U.S. Pat. No. 6,997,260: U.S. Pat. Nos. 5,395,972; 5,380,131; 5,388,317; 5,591,265; 5,722,463. Also of possible interest are GB2255583, JP61-155521; JP 6110634; JP2-140322. 
     BRIEF SUMMARY OF THE INVENTION 
     The present invention provides a method of structurally repairing or upgrading an underwater or marine member wherein the repairs are affected due to the shear bond strength of a grout product such as an epoxy/polymer grout. 
     The grout product can be placed in an annulus between the member and a repair mechanism or clamp of improved configuration. 
     The present invention provides a method and apparatus for repairing a tubular member in an offshore marine environment including a specially configured shell having shell halves, longitudinal seals, and optionally upper and lower seals. Additionally, the shell halves are each provided with a plurality of threaded fasteners that will help with shell alignment, holding the shell rigidly to the tubular member prior to grouting operations, and improve ultimate load capacity after the grout has been placed in a space in between the tubular member and the shell. 
     In the preferred embodiment, the shear bond strength of the epoxy/polymer grout between the clamp and the member is a range of between about 50 and 500 p.s.i. In some cases, surface preparation of surfaces that will be contacted by grout may include high pressure water (or bubble) blasting, grit blasting, and/or mechanical abrasion. 
     In the preferred embodiment, the method employs one or more rows of circumferentially and longitudinally spaced threaded fasteners which serve multiple structural functions. First, assisting with initial alignment of the shell, clamp or mechanism annulus spacing. When fully tightened or clamped against the underlying member (e.g. tubular member to be repaired), providing a rigid mechanical connection to insure proper grout placement and bonding while grout is going through its critical initial curing phase transformation from a liquid to a solid (e.g. between about 1 and 7 days or between about ½ and 30 days). After the grout is cured, these threaded fasteners help prevent deflection of the epoxy/polymer grout under load thus improving the shear bond strength and load capacity of the repaired member. In the preferred embodiment, the clamping force of the threaded fastener against the member is in the range of between about 10 and 70 percent yield strength of the fastener, more particularly between about 20 and 70 percent and even more particularly between about 30 and 70 percent of yield strength of the fastener. 
     Seal clamps placed at each end contain the grout within the repair clamp assembly. These may be used, fabricated for example, of steel and clamped to the member to be repaired and also attached to the repair clamp itself. Alternatively, foam seals saturated with a selected medium such as epoxy may be used as end seals to contain the grout within the repair clamp assembly. 
     The repair method of the present invention may be used on various shapes such as but not limited to: barrel clamp, K brace, T brace, X brace, Y brace, or as part of other types of clamps. 
     In the preferred method, the epoxy/polymer grout is placed from the bottom up using plural component batching and pumping equipment (i.e. the components of epoxy resin and hardener). 
     The method of the present invention can fill the structural member being repaired with grout or it cannot fill the structural member interior with grout. 
     The grout employed can be cementitious or epoxy. 
     In one embodiment, an inflatable plug or pig can be inserted inside the member being repaired, preferably two of such plugs or pigs at upper and lower positions. In this fashion, the plugs or pigs isolate the area to be grouted internally (i.e. tubular member bore). 
     The method of the present invention greatly reduces the installation time and, therefore, the cost as compared to more traditional methods such as post tensioned cementitious grouted clamps and/or wet welding. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
       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: 
         FIG. 1  is an elevation view of the preferred embodiment of the apparatus of the present invention and illustrating the method of the present invention; 
         FIG. 2  is a partial elevation view of the preferred embodiment of the apparatus of the present invention and illustrating the method of the present invention; 
         FIG. 3  is a perspective exploded view of the preferred embodiment of the apparatus of the present invention; 
         FIG. 4  is a partial sectional elevation view illustrating the method of the present invention and showing the apparatus of the present invention; 
         FIG. 5  is a partial sectional elevation view illustrating the method of the present invention and showing the apparatus of the present invention; 
         FIG. 6  is an elevation view of the preferred embodiment of the apparatus of the present invention showing a horizontal installation; 
         FIG. 7  is a sectional view taken along lines  7 - 7  of  FIG. 6 ; 
         FIG. 8  is an end view of the horizontal repair of  FIG. 6 ; 
         FIG. 9  is a partial elevation view of the preferred embodiment of the apparatus of the present invention illustrating the method of the present invention; 
         FIG. 10  is a plan view taken along lines  10 - 10  of  FIG. 1 ; 
         FIG. 11  is a fragmentary view illustrating an alternate construction for the repair of the apparatus of the present invention and illustrating the method of the present invention; 
         FIGS. 12 and 13  are elevation views illustrating the method of the present invention; and 
         FIGS. 14-18  are sectional elevation views illustrating the method of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The marine tubular repair system  10  of the present invention is shown generally in  FIGS. 1 and 10 . In  FIG. 1 , a marine jacket  11  is shown. Such jackets  11  are known in the art. They are typically used to support a platform such as an oil and gas well production platform. Jackets  11  can also be used to support drilling platforms. In  FIG. 1 , the jacket  11  is shown resting on the seabed  12  and extending up to and above water surface  13 . In  FIG. 1 , the marine jacket  11  supports platform  14  which can be an oil and gas drilling platform or an oil and gas well production platform. 
     Jackets  11  can be anchored to the seabed using a plurality of piling. In  FIG. 1 , the piling  15  extend through long vertical or inclined tubular members  16  of jacket. Jacket  11  includes other tubular members in addition to the long vertical/inclined tubular members  16 . These additional tubular members can include, for example, horizontal tubular member  17 , diagonal tubular members  18 , and diagonal horizontal tubular members  23 . 
     In  FIG. 1 , a plurality of risers or riser pipes  19  are shown extending between the seabed  12  and the water surface  13  such pipes can be conduits to oil/gas wells. 
     A shell or clamp assembly  20  as shown in  FIGS. 2-5 . Clamp assembly  20  includes a central clamp half section  30  which is mated to another section clamp half section  31 . Each of the central clamp half sections  30 ,  31  provides a curved surface which generally conforms to the outer surface of the tubular member to be repaired. The half section  30  has curved surface  32 . The half section  31  has curved surface  33 . Each of the central clamp half sections  30 ,  31  provides a pair or arcuate flanges including upper and lower arcuate flanges. The half section  30  has upper arcuate flange  34  and lower arcuate flange  35 . The half section  31  has upper arcuate flange  36  and lower arcuate flange  37 . Each of the clamp half sections  30 ,  31  has linear flanges. The clamp half section  30  has linear flanges  38 ,  39 . The clamp half section  31  has linear flanges  40 ,  41 . 
     A plurality of seals are provided as shown in  FIG. 3 . These include longitudinal seals  42 ,  43 . The longitudinal seal  42  is sandwiched between linear flanges  38 ,  40 . The seal  43  is sandwiched between linear flanges  39 ,  41 . Each of the longitudinal seals  42 ,  43  provides seal openings  44  that align with openings  45  of the linear flanges  38 - 41 . In this fashion, fasteners or like connections (e.g. bolted connections) can be inserted through the aligned linear flanges,  38 ,  40  and  39 ,  41  as well as through the openings  44  of the seals  42 ,  43 . The seals  42 ,  43  can be a foam seals saturated with a selected medium such as epoxy material. 
     A pair of upper clamp half sections and a pair of lower half sections are provided. The upper clamp half sections include upper half sections  46 ,  48 . The lower clamp half sections include lower half sections  47 ,  49 . Each of the clamp half sections  46 - 49  provides an arcuate plate  50 , a curved plate  51 , a pair of end plates  52 ,  53  and can include gussets  59 . Arcuate plate  50  and curved plate  51  can be welded together. End plates  52 ,  53  can also be welded to the combination of arcuate plate  50  and curved plate  51  as shown in  FIG. 3 . Each of the end plates  52 ,  53  has an opening  55 . Each of the arcuate plates  50  provides openings  54 . Each of the upper and lower arcuate flanges  34 - 37  provides openings  106  that align with the openings  54  of the arcuate plates  50  of the upper and lower half sections  46 - 49 . 
     End seals  60  (e.g. neoprene seals or foam seals saturated with a selected medium such as epoxy material) are placed in between end plates  52 ,  53  of the upper clamp half sections  46 ,  48 . Similarly, end seals  60  are placed in between the end plates,  52 ,  53  of the lower clamp half sections  47 ,  49  as shown in  FIG. 3 . In one embodiment the end seals can replace the upper and/or lower clamp half sections, such end seals being foam seals saturated with a medium (e.g. epoxy). 
     Upper and lower arcuate seals  56 ,  57  are provided. Upper arcuate seals  56  are placed in between an upper clamp half section  46  or  48  and a central clamp half section  30 ,  31 . Each of the upper and lower arcuate seals  56 ,  57  provides seal openings  58  that align with the openings  54 ,  106 . 
     Fastenered connections  62  are used to assemble the central clamp half sections  30 ,  31  together. Fastenered connections  62  are also used to assemble each of the upper and lower clamp half sections  46 - 49  to the central clamp half sections  30 ,  31  and to each other. The central clamp half sections  30 ,  31  can be connected with a hinge  63  as shown in  FIGS. 7 and 8 . 
     Injection ports  64  are provided for adding grout to an annulus  74  that is formed when the apparatus  10  is placed around all or part of a long vertical/inclined tubular  16 , a horizontal tubular  17 , or diagonal tubular  18 . In  FIGS. 2 ,  4  and  5 , a lower injection port  64  and a second lower injection port  65  are provided. The ventilation or vent ports  66 ,  67  are also provided as shown in  FIG. 2 . 
     Seals are place in between the upper and lower clamp half sections  46 ,  47 . These include an upper curved seal  68  and a lower curved seal  69  as shown on FIGS.  3  and  4 - 5 . A plurality of threaded fasteners  70  are provided. Each of the threaded fasteners  70  threadably engages an internally threaded fitting  71 . Each threaded fastener  70  includes a head  72  and an inner part  73  that extends into annulus  74  and engages the outer surface of a member  16 ,  17  or  18  to be repaired. This arrangement can be seen in  FIGS. 2-5 . The threaded fasteners  70  assist with maintaining thickness of the annulus  74  during placement of the shell half sections  30 ,  31 . The threaded fasteners  70  provide a rigid mechanical connection to insure proper grout placement and bonding with the grout while the grout is in the initial curing stage. In  FIG. 4 , arrow  75  illustrates the injection of grout via a valve line  78  into annulus  74  at injection port  64 . Arrow  76  illustrates the gradual flow of grout upwardly in the annulus  74  towards vent ports  66 ,  67 . A valved line  79  is provided at each of the vent ports  66 ,  67 . 
       FIGS. 6-8  show a horizontal tubular  17  that is to be repaired. In  FIGS. 6-8  a valved line  80  is provided for injecting grout  77  into annulus  74  as shown. Arrows  81  illustrate the gradual rise of grout  77  in annulus  74 . In the embodiment of  FIGS. 6-8 , the clamp assembly  21  is basically the same as the clamp assembly of  FIGS. 1-5 . The difference is that the clamp assembly  21  extends horizontally along horizontally extending member  17  as shown in  FIGS. 6-8 . Otherwise, the repair clamp assembly  21  includes central clamp half sections  30 ,  31  and upper and lower clamp half sections  46 - 49 . Longitudinal seals  82 ,  83  are shown, each seal  82 ,  83  being sandwiched between pairs of linear flanges  38 - 41  of the central clamp half sections  30 ,  31 . In  FIGS. 7 and 8 , longitudinal ribs  84 ,  85  can be provided on one or more of the linear flanges  38 - 41 , pressing against a seal  82 ,  83 . The seals  82 ,  83  can be foam seals saturated with a selected medium such as epoxy material. 
       FIGS. 9 and 10  show a K shaped clamp assembly  22 . In  FIGS. 9 and 10 , the clamp assembly  22  includes a pair of clamp half sections  86  that are fastenered together. Each clamp half section  86  includes a curved K shaped part  87  and a plurality of flanges  88 - 91 . The clamp assembly  22  provides fastenered connections, seals, upper and lower clamp half sections  46 - 49  as with the embodiments of  FIGS. 1-8 .  FIGS. 9 and 10  merely illustrate that the repair system of the present invention can be applied to a K shaped arrangement of horizontal tubular  17  and diagonal horizontal tubulars  23 . 
       FIGS. 11-13  show a clamp assembly  24  for replacing a damaged diagonal tubular  18 . In  FIG. 12 , the diagonal tubular  18  has a break  26 . Cuts are made at  27 ,  28  for enabling removal (arrow  29 ) of the damaged diagonal tubular  18 . In  FIG. 18 , a pair of clamp assemblies  24  are placed on long vertical/inclined tubular  16 ,  17  for supporting a new repair section  25 . The clamp  24  of  FIGS. 11-12  are shown in more detail in  FIG. 11 . The clamp  24  is of the same configuration as the clamps of  FIGS. 1-8 . However, in the clamp assembly  24 , the linear flanges  39 ,  41  are replaced with flanged plates  92 . The flange plates  92  enable a pinned connection  93  to be formed between clamp assembly  24  and the new repair section  25  as shown on  FIG. 11 . 
       FIGS. 14-18  illustrate the repair of a fractured tubular  95  having a fracture  96 . In  FIG. 14  a drill  94  is used to drill vertically spaced apart holes  102  as shown in  FIGS. 14-16 . Arrow  97  illustrates the penetration of the fracture tubular  95  using the drill  94  to drive a drill bit. In  FIG. 15 , a pair of plugs, pigs, or inflatable seals  98  are place above and below the fracture  96 . Air or fluid lines  100  can be used to inflate the members  98 ,  99 . In this fashion, the bore  101  of damaged or fractured tubular  95  is sealed above and below the fracture  96 . Clamp assembly  20  is then placed around the damaged member  95  at the fracture  96  as shown in  FIG. 16 . A tubular influent fitting  103  is attached to the damaged member  95  below clamp assembly  20 . A valved flow line  104  is fitted to the tubular influent fitting  103 . A vent fitting  105  is fastened to the damaged member  95  above clamp assembly  20  as shown in  FIG. 17 . In this fashion, grout  77  can be injected not only into the annulus  74  in between the clamp assembly  20  and the member  95  but also into the bore  101  of the damaged member  95  in between the inflatable members  98 ,  99  as shown in  FIGS. 17 and 18 . 
     
       
         
               
             
               
               
             
           
               
                   
               
               
                 PARTS LIST 
               
             
          
           
               
                 Part Number 
                 Description 
               
               
                   
               
               
                 10 
                 marine tubular repair system 
               
               
                 11 
                 jacket 
               
               
                 12 
                 seabed 
               
               
                 13 
                 water surface 
               
               
                 14 
                 platform 
               
               
                 15 
                 piling 
               
               
                 16 
                 long vertical/inclined tubular 
               
               
                   
                 member 
               
               
                 17 
                 horizontal tubular member 
               
               
                 18 
                 diagonal tubular member 
               
               
                 19 
                 riser/pipe 
               
               
                 20 
                 clamp assembly 
               
               
                 21 
                 clamp assembly 
               
               
                 22 
                 clamp assembly 
               
               
                 23 
                 diagonal horizontal tubular 
               
               
                   
                 member 
               
               
                 24 
                 clamp assembly 
               
               
                 25 
                 repair section 
               
               
                 26 
                 break 
               
               
                 27 
                 cut 
               
               
                 28 
                 cut 
               
               
                 29 
                 arrow 
               
               
                 30 
                 central clamp half section 
               
               
                 31 
                 central clamp half section 
               
               
                 32 
                 curved surface 
               
               
                 33 
                 curved surface 
               
               
                 34 
                 upper arcuate flange 
               
               
                 35 
                 lower arcuate flange 
               
               
                 36 
                 upper arcuate flange 
               
               
                 37 
                 lower arcuate flange 
               
               
                 38 
                 linear flange 
               
               
                 39 
                 linear flange 
               
               
                 40 
                 linear flange 
               
               
                 41 
                 linear flange 
               
               
                 42 
                 longitudinal seal 
               
               
                 43 
                 longitudinal seal 
               
               
                 44 
                 seal opening 
               
               
                 45 
                 flange opening 
               
               
                 46 
                 upper clamp half section 
               
               
                 47 
                 lower clamp half section 
               
               
                 48 
                 upper clamp half section 
               
               
                 49 
                 lower clamp half section 
               
               
                 50 
                 arcuate plate 
               
               
                 51 
                 curved plate 
               
               
                 52 
                 end plate 
               
               
                 53 
                 end plate 
               
               
                 54 
                 opening 
               
               
                 55 
                 opening 
               
               
                 56 
                 upper arcuate seal 
               
               
                 57 
                 lower arcuate seal 
               
               
                 58 
                 seal opening 
               
               
                 59 
                 gusset 
               
               
                 60 
                 end seal 
               
               
                 61 
                 opening 
               
               
                 62 
                 fastenered connection 
               
               
                 63 
                 hinge 
               
               
                 64 
                 injection port 
               
               
                 65 
                 injection port 
               
               
                 66 
                 vent port 
               
               
                 67 
                 vent port 
               
               
                 68 
                 upper curved seal 
               
               
                 69 
                 lower curved seal 
               
               
                 70 
                 threaded fastener 
               
               
                 71 
                 internally threaded fitting 
               
               
                 72 
                 head 
               
               
                 73 
                 inner part 
               
               
                 74 
                 annulus 
               
               
                 75 
                 arrow 
               
               
                 76 
                 arrow 
               
               
                 77 
                 grout 
               
               
                 78 
                 valved line 
               
               
                 79 
                 valved line 
               
               
                 80 
                 valved line 
               
               
                 81 
                 arrow 
               
               
                 82 
                 longitudinal seal 
               
               
                 83 
                 longitudinal seal 
               
               
                 84 
                 longitudinal rib 
               
               
                 85 
                 longitudinal rib 
               
               
                 86 
                 clamp half section 
               
               
                 87 
                 curved K shaped part 
               
               
                 88 
                 flange 
               
               
                 89 
                 flange 
               
               
                 90 
                 flange 
               
               
                 91 
                 flange 
               
               
                 92 
                 flanged plate 
               
               
                 93 
                 pinned connection 
               
               
                 94 
                 drill 
               
               
                 95 
                 fractured tubular 
               
               
                 96 
                 fracture 
               
               
                 97 
                 arrow 
               
               
                 98 
                 upper seal 
               
               
                 99 
                 lower seal 
               
               
                 100  
                 air/fluid line 
               
               
                 101  
                 bore 
               
               
                 102  
                 drilled hole 
               
               
                 103  
                 tubular influent fitting 
               
               
                 104  
                 valved flowline 
               
               
                 105  
                 vent fitting 
               
               
                 106  
                 opening 
               
               
                   
               
             
          
         
       
     
     All measurements disclosed herein are at standard temperature and pressure, at sea level on Earth, unless indicated otherwise. All materials used or intended to be used in a human being are biocompatible, unless indicated otherwise. 
     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.