Abstract:
A piping riser protector for protectively covering the end portion of a riser assembly that includes a larger diameter central pipe and a plurality of smaller diameter peripheral pipes connected by a flange includes a polymeric body that protectively covers inner and outer surfaces of an end portion of the larger diameter pipe and provides enclosures that cover the exposed end portion of the smaller diameter pipe sections in between the end of each smaller diameter pipe section and the flange.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
   Priority of U.S. Provisional Patent Application Ser. No. 60/567,962, filed May 4, 2004, 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 protectors for the end portions of pipe assemblies or pipe bundles known or referred to as piping riser assemblies. More particularly, the present invention relates to an improved riser protector apparatus that can be used to protect end portions of riser assemblies that include a larger diameter central pipe and a plurality of smaller diameter pipes that are connected to and positioned generally parallel to and circumferentially spaced about the central larger diameter pipe, the protector being of a polymeric member that covers the inner bore and outer surface of an end portion of the larger diameter pipe and wherein a plurality of radially extending, circumferentially spaced covers with U shaped wall portions extend over and around an end portion of each of the plurality of smaller diameter pipes. 
   2. General Background of the Invention 
   Drilling for oil or natural gas in deep water requires the use of sophisticated buoyant risers. These risers typically contain a large inner pipe and smaller pipes attached to the larger pipe. Each riser section is installed offshore on a drilling vessel or platform. The connections between the smaller pipes are preferably a machine fit, being high tolerance connections that cannot be damaged. As you can imagine, each riser section is an expensive piece of equipment, and if the ends of the pipe get damaged, they cannot use that unit in the drill string. 
   Currently, protectors are in use that are made of steel. These prior art protectors cause major safety problems due to their weight. As a result, workers handling these protectors can be injured. Due to corrosion of the metal riser guards, as well as the denting that occurs from impacts, these guards have an extremely short service life. 
   BRIEF SUMMARY OF THE INVENTION 
   The present invention provides an improved riser protector that is constructed of light weight elastomers. The riser guard of the present invention is easier to install. Ease of installation creates a safer workplace. The present invention is constructed of a light weight material are used that virtually eliminates the chance for serious injury in the work place. 
   The present invention is an improvement on the overall protection of the riser ends. The elastomeric properties allow for energy absorption, which will resist impact much more efficiently. Current steel designs do not completely encapsulate the riser ends, which allows the exposed metal ends to corrode. The present invention provides an apparatus that closes the riser ends, minimizing corrosion. The elastomeric riser protector caps of the present invention can be reused since they are resistant to impact and corrosion. They can be constructed using material available in many colors, allowing for potential aids in alignments and installations. 
   The present invention provides a protector for a riser assembly that includes a plurality of pipe sections attached together to define a riser and a protector cover that is fitted to one end portion of the riser structure. The riser structure includes a central larger diameter pipe having an inner surface, an outer surface, and an open ended bore, a wall thickness and opposed ends. A plurality of smaller diameter peripheral pipes are provided each having an open ended bore. Flanges join the central larger and smaller peripheral pipes together to define a multi-pipe structure. Each of the flanges has a central opening occupied by the central larger diameter pipe and a plurality of circumferentially spaced apart peripheral openings that generally surround the central opening. At least some of the peripheral openings are occupies by a peripheral pipe, the structure having opposed end portions, one end portion being a pin end portion. 
   The present invention is in the form of a protective cover that is affixed to the central larger diameter pipe, the cover being a polymeric body that includes an inner cylindrical portion that occupies a part of the open ended bore and that is next to the inner surface, and an outer cylindrical portion that surrounds one of the opposed ends of the larger diameter pipe. A bead covers the pipe end and connects the inner and outer cylindrical portions of the polymeric body. A circular disk is connected to the inner cylindrical surface and occupies a position in the bore of the larger diameter pipe section, closing the bore. 
   The cover includes a plurality of radially extending enclosures that extend from the outer cylindrical portion to the periphery of the flanges. Each enclosure includes a longitudinally extending wall and a transversely extending wall that is connected to the longitudinally wall and to the outer cylindrical portion. Each enclosure provides an edge that is positioned next to a flange. 
   The polymeric body is preferably of a polyurethane material. Fasteners can be provided that connect the inner cylindrical portion to the inner surface of the large diameter pipe thus recessing the fasteners so that they are not easily damaged. The fasteners are preferably spaced circumferentially apart. 
   The inner cylindrical portion preferably provides multiple internal threaded openings. A fastener threadably attaches to the inner cylindrical portion at an internally threaded openings. The fasteners can be set screws (or bolts) that frictionally engage the inner surface of the larger diameter pipe. 
   The longitudinally extending wall can be generally U-shaped for each of the radially extending enclosures. 

   
     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 end view of a typical riser assembly that includes a larger diameter central pipe section, a plurality of circumferentially spaced smaller diameter pipe sections and a flange that attaches to all of the pipe sections, holding them in a spaced apart, generally parallel configuration; 
       FIG. 2  is an end view of the preferred embodiment of the apparatus of the present invention; 
       FIG. 3  is a sectional view taken along lines  3 - 3  of  FIG. 1 ; 
       FIG. 4  is a sectional view taken along line  4 - 4  of  FIG. 1 ; 
       FIG. 5  is a perspective view of the preferred embodiment of the apparatus of the present invention; 
       FIG. 6  is a sectional view taken along lines  6 - 6  of  FIG. 2 ; 
       FIG. 7  is a sectional view taken along lines  7 - 7  of  FIG. 2 ; and 
       FIG. 8  is a fragmentary sectional view of the preferred embodiment of the apparatus of the present invention. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
     FIGS. 2 ,  5 ,  6 , and  7  shown generally the preferred embodiment of the apparatus of the present invention designated generally by the numeral  10 . Riser system  10  includes a central larger diameter pipe  11 , a plurality of smaller diameter pipe sections or flow lines  20 ,  21 ,  22 ,  23 , a circular flange  16 , and a cover structure  50  that protectively covers an end portion of the central larger diameter pipe  11  and an end portion of each of the smaller diameter pipe sections  20 ,  21 ,  22 ,  23 . Each pipe section  20 ,  21 ,  22 ,  23  has a high tolerance connection at its end portion  24  that cannot be damaged. 
   Central large diameter pipe section  11  has an outer surface  12 , an inner surface  13  and an open ended bore  14 . Wehn assembled for use at an oil platform, central larger diameter pipe section  11  has a pipe end  15  that is connected (during use) to a similarly configured end (not shown) of another central large diameter pipe section of a different riser structure. As defined herein, riser structure  34  is a known, prior art structure that includes central larger diameter pipe section  11 , the plurality of smaller diameter pipe sections  20 ,  21 ,  22 ,  23  and flanges  16  that secure the pipe sections  11 ,  20 ,  21 ,  22 ,  23  together. While one end portion of a riser structure  34  shown in  FIGS. 1 ,  3 ,  4  and  5 , it should be understood that the opposing end portion is similarly configured, the overall riser structure  34  being well known. The end portion  35  of riser structure  34  shown in  FIGS. 1 ,  3 ,  4  and  5  is known in the industry as the pin end portion. Flange  16  provides opposed flat face portion  17 ,  18  and annular peripheral surface  19 . 
   Flange  16  provides a plurality of openings that enable a connection (for example, welded) to be made between the flange  16  and the various pipe sections  11 ,  20 ,  21 ,  22 ,  23 . 
   Central opening  25  is receptive of central larger diameter section  11 . Peripheral openings  26 ,  27 ,  28 ,  29  are receptive of the smaller diameter pipe sections  20 ,  21 ,  22 ,  23  respectively. Each of the smaller diameter pipe sections  20 ,  21 ,  22 ,  23  provides a central open ended bore. Pipe section  20  provides bore  30 . Pipe section  21  provides bore  31 . Pipe section  22  provides bore  32  and pipe section  23  provides bore  33 . Circular flange  16  provides additional openings  36 ,  37 ,  38 ,  39 ,  40 ,  41 ,  42 ,  43 . The openings  36 ,  37 ,  39 ,  40 ,  41  and  43  are bolt openings that enable bolted connections to be formed between the flange  16  of riser structure  34  and a similarly configured flange of another riser structure  34 . 
   For lifting the entire riser structure  34 , lift openings  38 ,  42  are provided. The openings  38 ,  42  can be of a slightly larger diameter than the openings  36 ,  37 ,  39 ,  40 ,  41 ,  43  that are bolt openings. 
   In  FIGS. 2 ,  5 - 8  cover  44  is comprised of an inner cylindrically shaped section  45  that is connected to an outer cylindrically shaped section  46  with a bead or an annular shoulder  47 . Circular disk section  48  extends from a lower edge  49  of inner cylindrically shaped  45  to form a closure to bore  14  as shown in  FIGS. 2 and 5 . 
   A plurality of radially extending enclosures  49 ,  50 ,  51 ,  52  are attached to and extend from outer cylindrically shaped section  46  of cover  44  as shown in  FIGS. 5 ,  6  and  7 . A different radially extending enclosure  49 ,  50 ,  52  is provided to protectively cover each of the small diameter pipe sections  20 ,  21 ,  22 ,  23 . The radially extending enclosure  49  protectively covers small diameter pipe section  20  and its end portion  24 . Similarly, radially extending enclosure  50  protectively covers small diameter pipe section  21 , enclosure  51  covering pipe section  22 , and enclosure  52  covering pipe section  23 . 
   Each of the radially extending enclosures  49 ,  50 ,  51 ,  52  includes a longitudinally extending wall  54  and a transversely extending wall  55 . The walls  54 ,  55  are joined together at connecting edge  53 . Longitudinally extending wall  54  can include curved portions and has an edge  56  that engages flat face  17  of circular flange  16  during use as shown in  FIGS. 6 and 7 . 
   In order to secure cover  44  to the pin end  35  of riser structure  34 , a plurality of set screws or bolts  57  can be provided as seen in  FIGS. 6-8 . Each set screw  57  can include an externally threaded portion  58 , an enlarged head  60 , and can form a connection with an internally threaded portion  61  of nut  59  that is embedded in inner cylindrically shaped section  45  of cover  44  (see  FIG. 8 ). Each set screw or bolt is preferably long enough (e.g. 3-6 inches) so that the bolts  57  function as handles for enabling a worker to carry and position the apparatus  10  by gripping the bolts  57 . 
   By manufacturing the entire cover  44  of a pliable yet tough material such as polyurethane, the cover  44  is very light and very durable. It does not dent when contacted by equipment or machinery. It enables a seal to be formed between each enclosure  49 ,  50 ,  51 ,  52  and flat face  17  of flange  16  as shown in  FIGS. 6 and 7 . It also provides a seal to the bore  14  of large diameter pipe section  11 , preventing corrosive material from communicating with the bore  14  of pipe section  7  or any of the bores of the small diameter pipe sections  20 ,  21 ,  22 ,  23 . 
   The following is a list of parts and materials suitable for use in the present invention. 
   PARTS LIST 
   
     
       
             
             
           
         
             
                 
             
             
               Part Number 
               Description 
             
             
                 
             
           
           
             
               10 
               riser system 
             
             
               11 
               central large diameter pipe section 
             
             
               12 
               outer surface 
             
             
               13 
               inner surface 
             
             
               14 
               open ended bore 
             
             
               15 
               pipe end 
             
             
               16 
               circular flange 
             
             
               17 
               flat face 
             
             
               18 
               flat face 
             
             
               19 
               annular peripheral surface 
             
             
               20 
               small diameter pipe section 
             
             
               21 
               small diameter pipe section 
             
             
               22 
               small diameter pipe section 
             
             
               23 
               small diameter pipe section 
             
             
               24 
               end portion 
             
             
               25 
               central opening 
             
             
               26 
               peripheral opening 
             
             
               27 
               peripheral opening 
             
             
               28 
               peripheral opening 
             
             
               29 
               peripheral opening 
             
             
               30 
               bore 
             
             
               31 
               bore 
             
             
               32 
               bore 
             
             
               33 
               bore 
             
             
               34 
               riser structure 
             
             
               35 
               end 
             
             
               36 
               opening 
             
             
               37 
               opening 
             
             
               38 
               opening 
             
             
               39 
               opening 
             
             
               40 
               opening 
             
             
               41 
               opening 
             
             
               42 
               opening 
             
             
               43 
               opening 
             
             
               44 
               cover 
             
             
               45 
               inner cylindrically shaped section 
             
             
               46 
               outer cylindrically shaped section 
             
             
               47 
               annular shoulder 
             
             
               48 
               circular disk 
             
             
               49 
               radially extending enclosure 
             
             
               50 
               radially extending enclosure 
             
             
               51 
               radially extending enclosure 
             
             
               52 
               radially extending enclosure 
             
             
               53 
               connecting edge 
             
             
               54 
               longitudinally extending wall 
             
             
               55 
               transversely extending wall 
             
             
               56 
               edge 
             
             
               57 
               set screw/bolt 
             
             
               58 
               externally threaded portion 
             
             
               59 
               embedded nut 
             
             
               60 
               head 
             
             
               61 
               internally threaded portion 
             
             
                 
             
           
        
       
     
   
   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.