Abstract:
A gooseneck conduit system for use with a telescoping joint of a subsea riser. In one embodiment, a riser telescoping joint includes a tube and a gooseneck conduit assembly affixed to the tube. The gooseneck conduit assembly includes a gooseneck conduit extending radially from the tube, and a tenon projecting from a rear face of the gooseneck conduit. The width of the tenon increases with distance from the rear face. The riser telescoping joint also includes a mortise channel extending along the length of the tube. The mortise channel is interlocks with the tenon and laterally secures the gooseneck conduit assembly to the tube.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a divisional of U.S. Application Ser. No. 13/274,947, filed on Oct. 17, 2011, which is a non-provisional of U.S. Provisional Application No. 61/500,914, filed on Jun. 24, 2011, both of which is hereby incorporated herein by reference in its entirety for all purposes. 
     
    
     BACKGROUND 
       [0002]    Offshore oil and gas operations often utilize a wellhead housing supported on the ocean floor and a blowout preventer stack secured to the wellhead housing&#39;s upper end. A blowout preventer stack is an assemblage of blowout preventers and valves used to control well bore pressure. The upper end of the blowout preventer stack has an end connection or riser adapter (often referred to as a lower marine riser packer or LMRP) that allows the blowout preventer stack to be connected to a series of pipes, known as riser, riser string, or riser pipe. Each segment of the riser string is connected in end-to-end relationship, allowing the riser string to extend upwardly to the drilling rig or drilling platform positioned over the wellhead housing. 
         [0003]    The riser string is supported at the ocean surface by the drilling rig. This support takes the form of a hydraulic tensioning system and telescoping (slip) joint that connect to the upper end of the riser string and maintain tension on the riser string. The telescoping joint is composed of a pair of concentric pipes, known as an inner and outer barrel, that are axially telescoping within each other. The lower end of the outer barrel connects to the upper end of the aforementioned riser string. The hydraulic tensioning system connects to a tension ring secured on the exterior of the outer barrel of the telescoping joint and thereby applies tension to the riser string. The upper end of the inner barrel of the telescoping joint is connected to the drilling platform. The axial telescoping of the inner barrel within the outer barrel of the telescoping joint compensates for relative elevation changes between the rig and wellhead housing as the rig moves up or down in response to the ocean waves. 
         [0004]    According to conventional practice, various auxiliary fluid lines are coupled to the exterior of the riser tube. Exemplary auxiliary fluid lines include choke, kill, booster, and hydraulic fluid lines. Choke and kill lines typically extend from the drilling rig to the wellhead to provide fluid communication for well control and circulation. The choke line is in fluid communication with the borehole at the wellhead and may bypass the riser to vent gases or other formation fluids directly to the surface. According to conventional practice, a surface-mounted choke valve is connected to the terminal end of the choke conduit line. The downhole back pressure can be maintained substantially in equilibrium with the hydrostatic pressure of the column of drilling fluid in the riser annulus by adjusting the discharge rate through the choke valve. 
         [0005]    The kill line is primarily used to control the density of the drilling mud. One method of controlling the density of the drilling mud is by the injection of relatively lighter drilling fluid through the kill line into the bottom of the riser to decrease the density of the drilling mud in the riser. On the other hand, if it is desired to increase mud density in the riser, a heavier drilling mud is injected through the kill line. 
         [0006]    The booster line allows additional mud to be pumped to a desired location so as to increase fluid velocity above that point and thereby improve the conveyance of drill cuttings to the surface. The booster line can also be used to modify the density of the mud in the annulus. By pumping lighter or heavier mud through the booster line, the average mud density above the booster connection point can be varied. While the auxiliary lines provide pressure control means to supplement the hydrostatic control resulting from the fluid column in the riser, the riser tube itself provides the primary fluid conduit to the surface. 
         [0007]    A hose or other fluid line connection to each auxiliary fluid line coupled to the exterior of the riser tube is provided at the telescoping joint via a pipe or equivalent fluid channel. The pipe is often curved or U-shaped, and is accordingly termed a “gooseneck” conduit. In the course of drilling operations, a gooseneck conduit may be detached from the riser, for example, for maintenance or to permit the raising of the riser through the drilling floor, and reattached to the riser to provide access to the auxiliary fluid lines. The gooseneck conduits are typically coupled to the auxiliary fluid lines via threaded connections. 
       SUMMARY 
       [0008]    A gooseneck conduit system for use with a telescoping joint of a subsea riser is disclosed herein. In one embodiment, a riser telescoping joint includes a tube and a gooseneck conduit assembly affixed to the tube. The gooseneck conduit assembly includes a gooseneck conduit extending radially from the tube, and a tenon projecting from a rear face of the gooseneck conduit. The width of the tenon increases with distance from the rear face. The riser telescoping joint also includes a mortise channel extending lengthwise along the tube. The mortise channel interlocks with the tenon to laterally secure the gooseneck conduit assembly to the tube. 
         [0009]    In another embodiment, a gooseneck conduit unit includes a plate, a gooseneck conduit, and a bumper. The gooseneck conduit is removably mounted to the plate. The bumper is coupled to a rear face of the gooseneck conduit. The bumper includes a tenon that guides the gooseneck conduit unit into position on a telescoping joint. 
         [0010]    In a further embodiment, a system includes a telescoping joint. The telescoping joint includes an alignment ring and a gooseneck conduit assembly. The alignment ring is circumferentially coupled to a tube of the telescoping joint. The alignment ring includes a longitudinal mortise channel. The gooseneck conduit assembly is coupled to the alignment ring. The gooseneck conduit assembly includes a gooseneck conduit and a tenon. The tenon slidingly engages sides of the mortise channel to secure the gooseneck conduit assembly to the alignment ring. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]    For a detailed description of exemplary embodiments of the invention, reference will now be made to the accompanying drawings in which: 
           [0012]      FIGS. 1A-1B  show a drilling system including a gooseneck conduit system in accordance with various embodiments; 
           [0013]      FIG. 2  shows a telescoping joint in accordance with various embodiments; 
           [0014]      FIG. 3  shows a top view of a plurality of gooseneck conduit assemblies in accordance with various embodiments; 
           [0015]      FIG. 4  shows an elevation view of a support collar and gooseneck conduit assemblies in accordance with various embodiments; 
           [0016]      FIG. 5  shows a perspective view of a support collar and gooseneck conduit assemblies in accordance with various embodiments; and 
           [0017]      FIG. 6  shows a cross sectional view of a support collar and gooseneck assemblies in accordance with various embodiments. 
       
    
    
     NOTATION AND NOMENCLATURE 
       [0018]    Certain terms are used throughout the following description and claims to refer to particular system components. As one skilled in the art will appreciate, companies may refer to a component by different names. This document does not intend to distinguish between components that differ in name but not function. In the following discussion and in the claims, the terms “including” and “comprising” are used in an open-ended fashion, and thus should be interpreted to mean “including, but not limited to . . . .” Also, the term “couple” or “couples” is intended to mean either an indirect or direct connection. Thus, if a first device couples to a second device, that connection may be through a direct connection, or through an indirect connection via other devices and connections. 
       DETAILED DESCRIPTION 
       [0019]    The following discussion is directed to various embodiments of the invention. The drawing figures are not necessarily to scale. Certain features of the embodiments may be shown exaggerated in scale or in somewhat schematic form and some details of conventional elements may not be shown in the interest of clarity and conciseness. Although one or more of these embodiments may be preferred, the embodiments disclosed should not be interpreted, or otherwise used, as limiting the scope of the disclosure, including the claims. It is to be fully recognized that the different teachings of the embodiments discussed below may be employed separately or in any suitable combination to produce desired results. In addition, one skilled in the art will understand that the following description has broad application, and the discussion of any embodiment is meant only to be exemplary of that embodiment, and not intended to intimate that the scope of the disclosure, including the claims, is limited to that embodiment. 
         [0020]    The size and weight of the gooseneck conduits, and the location of the attachment points of the conduits to the telescoping joint and the auxiliary fluid lines, makes installation and/or retrieval of the conduits a labor-intensive process. Consequently, gooseneck conduit handling operations can be time consuming and costly. Embodiments of the present disclosure include a gooseneck conduit system that reduces handling time and enhances operational safety. Embodiments of the conduit system disclosed herein can provide simultaneous connection of gooseneck conduits to a plurality of auxiliary fluid lines with no requirement for manual handling or connection operations. Embodiments include hydraulically and/or mechanically operated locking mechanisms that secure the conduit system to the telescoping joint and the auxiliary fluid lines. The conduit system may be hoisted into position on the telescoping joint, and attached to the telescoping joint and the auxiliary fluid lines via the provided locking mechanisms. Thus, embodiments allow gooseneck conduits to be quickly and safely attached to and/or removed from the telescoping joint. 
         [0021]      FIGS. 1A-1B  show a drilling system  100  in accordance with various embodiments. The drilling system  100  includes a drilling rig  126  with a riser string  122  and blowout preventer stack  112  used in oil and gas drilling operations connected to a wellhead housing  110 . The wellhead housing  110  is disposed on the ocean floor with blowout preventer stack  112  connected thereto by hydraulic connector  114 . The blowout preventer stack  112  includes multiple blowout preventers  116  and kill and choke valves  118  in a vertical arrangement to control well bore pressure in a manner known to those of skill in the art. Disposed on the upper end of blowout preventer stack  112  is riser adapter  120  to allow connection of the riser string  122  to the blowout preventer stack  112 . The riser string  122  is composed of multiple sections of pipe or riser joints  124  connected end to end and extending upwardly to drilling rig  126 . 
         [0022]    Drilling rig  126  further includes moon pool  128  having telescoping joint  130  disposed therein. Telescoping joint  130  includes inner barrel  132  which telescopes inside outer barrel  134  to allow relative motion between drilling rig  126  and wellhead housing  110 . Dual packer  135  is disposed at the upper end of outer barrel  134  and seals against the exterior of inner barrel  132 . Landing tool adapter joint  136  is connected between the upper end of riser string  122  and outer barrel  134  of telescoping joint  130 . Tension ring  138  is secured on the exterior of outer barrel  134  and connected by tension lines  140  to a hydraulic tensioning system as known to those skilled in the art. This arrangement allows tension to be applied by the hydraulic tensioning system to tension ring  138  and telescoping joint  130 . The tension is transmitted through landing tool adapter joint  136  to riser string  122  to support the riser string  122 . The upper end of inner barrel  132  is terminated by flex joint  142  and diverter  144  connecting to gimbal  146  and rotary table spider  148 . 
         [0023]    A support collar  150  is coupled to the telescoping joint  130 , and the auxiliary fluid lines  152  are terminated at seal subs retained by the support collar  150 . One or more gooseneck conduit assemblies  154  are coupled to the support collar  150  and to the auxiliary fluid lines  152  via the seal subs retained by the support collar  150 . Each conduit assembly  154  is a conduit unit that includes one or more gooseneck conduits  156 . A hose  158  or other fluid line is connected to each gooseneck conduit  156  for transfer of fluid between the gooseneck conduit  156  and the drilling rig  126 . In some embodiments, the connections between the hoses  158  and/or other rig fluid lines and the gooseneck conduits  156  are made on the rig floor, and thereafter the gooseneck conduit assembly  154  is lowered onto the telescoping joint  130 . 
         [0024]    The gooseneck conduit assembly  154  includes locking mechanisms that secure the conduit assembly  154  to the telescoping joint  130 . The conduit assembly  154  can be lowered onto the support collar  150  using a crane or hoist. In some embodiments, the conduit assembly  154  can be connected to hydraulic lines that actuate the locking mechanisms. Thus, embodiments allow the gooseneck conduits  156  to be quickly and safely fixed to and/or removed from the telescoping joint  130  while reducing the manual effort required to install and/or remove the gooseneck conduits  156 . 
         [0025]      FIG. 2  shows the telescoping joint  130  in accordance with various embodiments. The auxiliary fluid lines  152  are secured to the telescoping joint  130 . The uphole end of each auxiliary fluid line  152  is coupled to a seal sub  206  at the support collar  150 . The support collar  150  is coupled to and radially extends from the telescoping joint  130 . In some embodiments, the support collar  150  includes multiple connected sections (e.g., connected by bolts) that join to encircle the telescoping joint  130 . 
         [0026]    The gooseneck conduit assembly  154  includes one or more locking mechanisms, and a plurality of gooseneck conduits  156 . As the gooseneck conduit assembly  154  is positioned on the support collar  150 , each gooseneck conduit  156  engages a seal sub  206  and is coupled to an auxiliary fluid line  152 . The locking mechanisms secure the gooseneck conduit assembly  154  to the support collar  150 , and secure each gooseneck conduit  156  to a corresponding auxiliary fluid line  152 . In some embodiments, the locking mechanisms are hydraulically operated. In other embodiments, the locking mechanisms are mechanically operated. The locking mechanisms may be either hydraulically or mechanically operated in some embodiments. The gooseneck conduits  156  may include swivel flanges  208  for connecting the conduits  156  to fluid lines  158 . 
         [0027]      FIG. 3  shows a top view of a plurality of gooseneck conduit assemblies  154  in accordance with various embodiments. Each gooseneck conduit assembly  154  includes one or more gooseneck conduits  156 . Each gooseneck conduit assembly  154  includes a top plate  302  and fasteners  312  that connect the top plate  302  to underlying structures explained below. The gooseneck conduit assembly  154  includes a projection or tenon  306  for aligning and locking the gooseneck conduit assembly  154  to the telescoping joint  130 . Some embodiments of the gooseneck conduit assembly  154  include a tenon  306  coupled to each gooseneck conduit  156 . In some embodiments, the tenon  306  may be trapezoidal, or fan-shaped to form a dove-tail tenon. Other embodiments may include a differently shaped tenon  306 . The tenon  306  may be formed by a bumper attached to the rear face  318  of the gooseneck conduit  156 , with the bumper, and thus the tenon  306 , extending along the length of the rear face  318 . In some embodiments, the tenon  306  may be made of bronze or another suitable material. In some embodiments, the tenon  306  may be part of the gooseneck conduit  156 . 
         [0028]    An alignment guidance ring  316  is circumferentially attached to the telescoping joint  130 . The alignment guidance ring  316  includes channel mortises  304  that receive, guide the gooseneck conduits  156  into alignment with the seal subs  206 , and retain the tenons  306  as the gooseneck conduit assembly  154  is lowered onto the telescoping joint  130 . Consequently, the mortises  304  are shaped to mate with and slidingly engage the tenons  306  (i.e., a trapezoids, dove-tails, etc). The channel mortises  304  may narrow with proximity to the support collar  150  (with proximity to the bottom of the alignment ring  316 ). Similarly, the tenons  306  may narrow with distance from the top plate  302  (with proximity to the bottom of the rear face  318  of the gooseneck conduit  156 ). The tenons  306  and mortises  304  are dimensioned to securely interlock. 
         [0029]    The gooseneck conduit assembly  154  includes locking mechanisms that secure the gooseneck conduit assembly  154  to the telescoping joint  130 . Embodiments may include one or more locking mechanisms that are mechanically or hydraulically actuated. For example, embodiments may include a primary and a secondary locking mechanism. Hydraulic secondary backup locks  308  are included on some embodiments of the gooseneck conduit assembly  154 . The hydraulic secondary locks include a hydraulic cylinder that operates the lock. Other embodiments include mechanical secondary backup locks  310 . In some embodiments, the secondary backup locks secure the primary locking mechanisms into position. Lock state indicators  314  show the state of conduit assembly locks. For example, extended indicators  314  indicate a locked state, and retracted indicators  314  indicate an unlocked state. 
         [0030]      FIG. 4  shows an elevation view of the support collar  150  and gooseneck conduit assemblies  154  in accordance with various embodiments. The gooseneck conduit assembly  154 A includes two gooseneck conduits  156 , and is unlocked and separated from the telescoping joint  130 , and positioned above the support collar  150 . The gooseneck conduit assembly  154 B includes three gooseneck conduits  156 , and is secured to the telescoping joint  130  and associated seal subs  206 . Each gooseneck conduit  156  is replaceably fastened to a lower support plate  404  by bolts or other attachment devices. The upper support plate  302  is attached to the lower support plate  404 . The support collar  150  retains the seal subs  206  via clamps  412  attached to the support collar  150  by bolts or other fastening devices. 
         [0031]    The alignment and guidance ring  316  is secured to the telescoping joint  130 . The alignment and guidance ring  316  may be formed from a plurality of ring sections joined by bolts or other fastening devices. The alignment and guidance ring  316  includes a locking channel  406 . The gooseneck conduit assembly  154 B rests on surface  502  ( FIG. 5 ) of the alignment and guidance ring  316 , and as discussed above, the tenons  306  interlock with the mortises  304  to laterally secure the gooseneck conduit assembly  154 B. The locking member  408  extends from the gooseneck conduit assembly  154 B into the locking channel  406  to prevent movement of the gooseneck conduit assembly  154 B upward along the telescoping joint  130 . 
         [0032]      FIG. 5  shows a perspective view of the support collar  150  and the gooseneck conduit assemblies  154  as arranged in  FIG. 4 . 
         [0033]      FIG. 6  shows a cross-sectional view of the support collar  150  and gooseneck conduit assemblies  154  as arranged in  FIG. 4 . Embodiments of the gooseneck conduits assemblies  154  may include any combination of hydraulic and mechanical primary and secondary locks. The gooseneck conduit assembly  154 B includes a hydraulic primary lock  618  and a hydraulic secondary lock  308 . The components of the hydraulic primary lock  618  are disposed between the upper and lower support plates  302  and  404 . The hydraulic primary lock  618  includes a hydraulic cylinder  612  coupled to the locking member  408  for extension and retraction of the locking member  408 . 
         [0034]    The components of the hydraulic secondary lock  308  are secured to the upper plate  302  by hydraulic cylinder support plate  606 . The hydraulic secondary lock  308  includes a hydraulic cylinder  602  coupled to a locking pin  604  for extension and retraction of the locking pin  604 . When the locking member  408  has been extended, extension of the locking pin  604  secures the locking member  408  in the extended position. In some embodiments, the locking member  408  includes a passage  608 . The locking pin  604  extends into the passage  608  to secure the locking member  408  in the extended position. 
         [0035]    The gooseneck conduit assembly  154 A includes a hydraulic primary lock  618  and a mechanical secondary lock  310 . As described above, the components of the hydraulic primary lock  618 , including the hydraulic cylinder  612 , and the locking member  408 , are disposed between the upper and lower support plates  302  and  404 . In some embodiments, the locking member  408  may be retracted by mechanical rather than hydraulic means. For example, force may be applied to the state indicator  314  to retract the locking member  408  from the locking channel  406 . The mechanical secondary lock  310  comprises an opening  624  that allows a bolt or retention pin to be inserted into the passage  608  of the locking member  408  when the locking member  408  is extended. 
         [0036]    An upper split retainer  626  and a lower split retainer  622  are attached to the support collar  150  to reduce support collar  150  radial loading. The upper split retainer  626  is bolted to the upper side of the support collar  150 , and the lower split retainer  622  is bolted to the lower side of the support collar  150 . Each split retainer  626 ,  622  comprises two sections. The two sections of each retainer  626 ,  622  abut at a position 90° from the location where the support collar sections are joined. The upper split retainer  626  includes a tapered surface  628  on the inside diameter that retains and positions the support collar  150  on the telescoping joint  130 . The support collar  150  also includes a key structure (not shown) for aligning the support collar  150  with a keying structure of the telescoping joint and preventing rotation of the support collar  150  about the telescoping joint  130 . 
         [0037]    Each gooseneck conduit  156  includes an arcing passage  614  extending through the gooseneck conduit  156  for passing fluid between the auxiliary fluid line  152  and the hose  158 . The gooseneck conduit assembly  156  may be formed by a casting process, and the thickness of material between the passage  614  and the exterior surface of the gooseneck conduit  156  may exceed the diameter of the passage  614  (by 2-3 or more times in some embodiments) thereby enhancing the strength and service life of the gooseneck conduit  156 . The gooseneck conduit  156  includes a socket  630  that sealingly mates with the seal sub  206  to couple the gooseneck conduit  156  to the auxiliary fluid line  152 . The socket  630  includes grooves  616  for holding a sealing device, such as an O-ring, that seals the connection between the gooseneck conduit  156  and the sealing sub  206 . 
         [0038]    The above discussion is meant to be illustrative of the principles and various embodiments of the present invention. Numerous variations and modifications will become apparent to those skilled in the art once the above disclosure is fully appreciated. It is intended that the following claims be interpreted to embrace all such variations and modifications.