Abstract:
A system for connecting a gullwing to a catwalk comprising a gullwing pin movable in an indexer groove that enables a foot pad of the gullwing to remain stationary relative to the catwalk when the gullwing is raised or lowered.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a continuation of U.S. patent application Ser. No. 14/207,092, filed Mar. 12, 2014, which claims benefit of U.S. Provisional Patent Application No. 61/780,588, filed Mar. 13, 2013, the contents of which are herein incorporated by reference in their entirety. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    Embodiments of the invention generally relate to catwalks for conveying pipe to a drill floor from a lower section of a drilling rig or drill site. Specifically, embodiments of the invention relate to an apparatus for attaching a “gullwing” to the catwalk so that the gullwing pad will not move toward and away from the catwalk as the gullwing is raised and lowered during the conveying of pipe to the catwalk trough. 
         [0004]    2. Description of the Related Art 
         [0005]    In a drilling operation or rig work-over operation, whether on a water-based or land-based drilling rig, pipe for the drilling operation, casing, or other tubulars are often stored at or supplied from a level that is lower than the drill floor. Operators typically use a “catwalk” to convey the pipe from the lower level to the drill floor. The pipe is typically mechanically transported (e.g. pushed and/or pulled) in a v-shaped trough, from a level below the rig floor to the rig floor. 
         [0006]    Before they are positioned in the catwalk trough and transported to the drill floor, multiple sections of pipe or other tubulars can be positioned on multiple “gullwings” positioned adjacent to the catwalk. The ends of the gullwings positioned away from the catwalk are hydraulically raised to create a slope in the direction of the catwalk and trough. Prior art components known as indexers cause a single section of pipe to roll to the trough. 
         [0007]    One problem with existing gullwings is that the pads for the gullwing feet will shift away from the catwalk when the gullwing is raised, and will shift toward the catwalk when the gullwing is lowered. This creates a potentially dangerous situation in that the sliding pads could potentially injure workers working nearby, wear down the ground below the gullwing (thus causing the pipe to be stored in an uneven position), or wear out the feet pads. Accordingly, it would be useful to have a system for connecting the gullwing to the catwalk which would minimize the movement of the gullwing pads when the gullwing is raised and lowered. 
       SUMMARY OF THE INVENTION 
       [0008]    Embodiments of the invention provide a system for connecting a gullwing to a catwalk in which a gullwing pin is allowed to move in relation to the connection point in the catwalk instead of causing a gullwing foot pad to move relative to the ground. The system also allows for the quick removal of the gullwing from the catwalk by lifting the gullwing vertical relative to the catwalk. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]    So that the manner in which the above recited aspects of the invention can be understood in detail, a more particular description of embodiments of the invention, briefly summarized above, may be had by reference to embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments. 
           [0010]      FIG. 1A  shows a catwalk in the position in which pipe is loaded onto the catwalk or unloaded from the catwalk. 
           [0011]      FIG. 1B  shows the catwalk in an elevated position in which pipe is being conveyed to or from the drill floor. 
           [0012]      FIG. 2  shows a cross section of a catwalk where a gullwing is connected to an indexer module for the catwalk and, at the opposite end of the gullwing, a hydraulic cylinder that pushes against a pad to lower one side of the gullwing. 
           [0013]      FIG. 3  shows the hydraulic cylinder and pad illustrated in  FIG. 2 . 
           [0014]      FIG. 4  is a closer view of the end of the gullwing connected to the catwalk. 
           [0015]      FIG. 5  is a cut-away view of a gullwing pin in a pin slot in the catwalk. 
           [0016]      FIG. 6  is a top view of the pin slot. 
           [0017]      FIG. 7  is a view of the gullwing pin position adjacent to a top knuckle of the gullwing. 
       
    
    
     DETAILED DESCRIPTION 
       [0018]      FIG. 1A  shows gullwings  1  and  2  attached to catwalk  3 . Sections of pipe are positioned on gullwings  1  and  2 . Gullwings  1  and  2  are raised temporarily using hydraulics to allow a section of pipe to roll onto catwalk  3  and into trough  4 . The pipe is then conveyed to the drill center on a higher level drill floor using skate  5  as the catwalk  3  is raised to a position shown in  FIG. 1B . 
         [0019]      FIG. 2  shows a cross section of catwalk  3  and trough  4  where gullwing  1  is connected to catwalk  3  via indexer unit  6 . The connection of gullwing  2  to catwalk  3  is identical. Hydraulic cylinder  7  is positioned on gullwing foot pad  8 . Hydraulic cylinder  7  raises and lowers gullwing  1  by extending rod  9  against foot pad  8  as known in prior art systems. Gullwing pin  10 , which is positioned in slot  11  in indexer unit  6 , slides back and forth in slot  11  as gullwing  1  is raised and lowered by hydraulic cylinder  7 , allowing gullwing foot pad  8  to remain relatively still. 
         [0020]      FIG. 3  is a detailed view of hydraulic cylinder  7  attached to gullwing  1 . Hydraulic cylinder  7  raises gullwing  1  by extending rod  9  against foot pad  8 . 
         [0021]      FIG. 4  is a detailed view of gullwing  1  and gullwing pin  10  in slot  11 . Pin  10  is shown in a position when pipe is not being moved toward trough  4 . When gullwing  1  is raised, pin  10  moves toward point  11 A in slot  11  (e.g. in a lateral, substantially horizontal direction toward the catwalk  3 ). The gullwing  1  may support multiple sections of pipe when raised. At least one section of pipe rests against indexer pin  12 . Another indexer pushes the section of pipe over indexer pin  12 , and that section of pipe rolls toward trough  4 . When the indexer is retracted, the next section of pipe comes to rest against indexer pin  12 . After all of the pipe sections have has passed indexer pin  12 , gullwing  1  is lowered and pin  10  returns to its position shown in  FIG. 4 . 
         [0022]      FIG. 5  is a detailed view of pin  10  in slot  11 . Pin  10  moves toward point  11 A in slot  11  when gullwing  1  is raised. Gullwing knuckle  13  similarly moves toward section  11 B of slot  11  when gullwing  1  is raised. As a result of the movement of pin  10  and knuckle  13 , foot pad  8  shown in  FIGS. 2 and 3  stays relatively stationary. 
         [0023]      FIG. 6  is a top view of slot  11 . Areas  11 C and  11 D are the portions of slot  11  in which the pin  10  on the opposite side of knuckle  13  are inserted. Section  11 B is space for knuckle  13  to move into when gullwing  1  is raised and pin  10  moves within slot  11 . 
         [0024]      FIG. 7  is a top view of gullwing pin  10  positioned in gullwing  1  below gullwing knuckle  13 . Bushing  14 A is positioned in a hole below gullwing knuckle  13  and along with another bushing in a hole on the opposite side of the gullwing allows pin  10  to rotate within the holes as the gullwing  1  is moved up and down. This allows the pin  10  and knuckle  13  to move back and forth in slot  11  as described in reference to  FIGS. 4, 5 , and  6 . 
         [0025]    While the foregoing is directed to embodiments of the invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.