Abstract:
A jumper tube is connected to a shunt tube of a well screen assembly by positioning the jumper tube end to end, adjacent with the shunt tube. A spring clip is then flexed over a profile of a coupling and allowed to snap into gripping engagement of the coupling, thereby retaining the jumper tube relative to the first screen assembly.

Description:
CLAIM OF PRIORITY 
       [0001]    This application is a U.S. National Phase Application of and claims the benefit of priority to International Patent Application Serial No. PCT/US2013/023973, filed on Jan. 31, 2013, the entire contents of which are hereby incorporated by reference. 
     
    
     TECHNICAL FIELD 
       [0002]    This disclosure relates to coupling jumper tubes of well screen assemblies. 
       BACKGROUND 
       [0003]    Wells often use screen systems in their production string to filter solid particles (e.g., sand) greater than a permitted size. Some wells are gravel packed by placing gravel in the annulus around the well screen system. For example, in an open-hole completion, gravel is typically placed between the wall of the wellbore and the production string. Alternatively, in a cased-hole completion, gravel is placed between a perforated casing string and the production string. In both types of completions, formation fluids flow from the subterranean formation into the production string through the gravel pack and well screen system. 
         [0004]    The gravel is carried into the well with a carrier liquid in a slurry. Premature loss of the carrier liquid into the formation can result in an incomplete packing of the production interval and cause sand bridges to form in the annulus. Alternate flow paths through the well screen systems can be used to provide an alternate path around the sand bridges. For example, shunt tubes in the well screen assemblies and jumper tubes between the well screen assemblies can be used to bypass sand bridges. 
     
    
     
       DESCRIPTION OF DRAWINGS 
         [0005]      FIG. 1  is a schematic side view of a well system in accordance with the present disclosure; 
           [0006]      FIG. 2  is a perspective view of an example of a well screen system applicable to the well system of  FIG. 1 ; 
           [0007]      FIG. 3  is a detail side view of an example of installation of jumper tubes between the well screen assemblies of  FIG. 2 ; 
           [0008]      FIG. 4  is a detail side view of coupling sleeves being installed using spring clips in the well screen assemblies of  FIG. 2 ; and 
           [0009]      FIGS. 5A and 5B  are perspective views of example spring clips for connecting jumper tubes. 
       
    
    
       [0010]    Like reference symbols in the various drawings indicate like elements. 
       DETAILED DESCRIPTION 
       [0011]    In some implementations, in completing an open hole section of a well, a production string having one or more well screen assemblies is run into the open hole section of the well bore. The screen assemblies are axially spaced along the length of the string. Each screen assembly has a filtration screen that encircles a base pipe. The base pipe has portion with one or more apertures that allow communication of fluids through the screen, and a portion not apertured (i.e., fluid impermeable) outside of the screen. An apertured shroud is positioned around the exterior of the filtration screen. Shunt tubes run axially through the screen assembly from one end to the other, and are radially between the apertured shroud and base pipe. The ends of the filtration screen are capped with annular end rings. The screen assemblies thread end to end, and jumper tubes connect between the end rings to connect the shunt tubes of one screen assembly to the next. Another shroud is positioned around the jumper tubes between the screen assemblies. With the production string in place, the annulus around the well screen assemblies is “gravel packed.” In gravel packing, a particulate (e.g., gravel) laden slurry is pumped into the wellbore exterior the string. The particulate is deposited in the annulus around the screen assemblies, and the liquid in the slurry is pumped backed to the surface. 
         [0012]    The joints of well screen assembly are transported to the well site individually (i.e., not coupled together) and are made-up into the production string joint by joint as the string is run into the well. Thus, the jumper tubes are installed on the drilling rig floor after the screen assembly joints are threaded together. A spring clip can be provided to hold the jumper tube to the end ring to maintain connection of the jumper tube and shunt tube. In certain instances, engaging the spring clips to hold the jumper tube does not require tools (e.g., a screw driver, a wrench, and/or other hand tool) or may only require use of a hammer to secure the jumper tubes. Additionally, everything is attached to either the jumper tube or the well screen assembly, so there are no small parts to complicate the assembly or be dropped into the well. 
         [0013]      FIG. 1  is a schematic side view of a well system  100  in accordance with the present disclosure. The well system  100  is shown as being a horizontal well, having a wellbore  114  that extends substantially vertically from a wellhead  18  at the surface, then deviates to horizontal or substantially horizontal in the subterranean zone of interest  124 . A casing  116  is cemented in the vertical portion of the wellbore and coupled to the wellhead  118  at the surface  120 . The remainder of the wellbore  114  is completed open hole (i.e., without casing). A production string  122  extends from wellhead  118 , through the wellbore  114  and into the subterranean zone of interest  124 . 
         [0014]    A production packer  126  seals the annulus between the production string  122  and the casing  116 . Additional packers  126  can be provided between the screen assemblies  112 . The production string  122  operates in producing fluids (e.g., oil, gas, and/or other fluids) from the subterranean zone  124  to the surface  120 . The production string  122  includes one or more well screen assemblies  112  (three shown). In some instances, the annulus between the production string  122  and the open hole portion of the wellbore  114  may be packed with gravel and/or sand. The well screen assemblies  112  and gravel/sand packing allow communication of fluids between the interior of the production string  122  and the subterranean zone  124 . The gravel/sand packing provides a first stage of filtration against passage of particulate and larger fragments of the formation to the production string  122 . The well screen assemblies  112  provide a second stage of filtration, and are configured to filter against passage of particulate of a specified size and larger into the production string  122 . 
         [0015]    Although shown in the context of a horizontal well system  100 , the concepts herein can be applied to other well configurations, including vertical well systems having a vertical or substantial vertical wellbore, multi-lateral well systems having multiple wellbores deviating from a common wellbore and/or other well systems. 
         [0016]      FIG. 2  illustrates an example manner of connecting two well screen assemblies of an example well screen system  200  that can be used in the well system of  FIG. 1 . For convenience of description, the well screen system  200  is illustrated with its inner components exposed (i.e., the outer shroud  201  is shown in partial break away). The well screen system  200  includes a first well screen assembly  202  and a second well screen assembly  203 . The well screen assembly  202  includes a base pipe  205 ; and the well screen assembly  203  includes a base pipe  207 . The base pipes  205 ,  207  are coupled end to end to each other (e.g., threadingly and/or otherwise). The well screen assembly  202  further includes a screen  210  around the base pipe  205 . For example, the screen  210  can include one or more layers of sheet mesh or wire wrapped screen with a selected industry rating for filtering solid materials over a specified size. Similarly, the screen assembly  203  further includes a screen  212  similar to the screen  210 . 
         [0017]    An elongate shunt tube  224  is arranged axially along the base pipe  205  and terminated at an end ring  232  of the base pipe  205 . The shunt tube  224  extends to another end ring (not shown) at the opposite end of the base pipe  205 . The shunt tube  224  enables fluid to bypass during gravel packing operations. Similarly, the well screen assembly  203  includes an elongate shunt tube  226  that is arranged axially along the base pipe  207  and terminated at an end ring  234 . The shunt tube  226  may be substantially similar to the shunt tube  224 . 
         [0018]    As illustrated in  FIG. 2 , each well screen assembly  202  or  203  includes one or more shunt tubes (two shown). The shunt tubes can be radially positioned between the screen  210  and the outer shroud assembly  201 . In some implementations, the shunt tube  224  may be geometrically constrained to fit between the screen and the shroud, such that the cross section of the shunt tube  224  is not circular. In certain instances, the cross-section resembles a flat rounded rectangle. The shunt tubes  224 ,  226  are fluidically connected by an elongate jumper tube  220 . The jumper tube  220  can have a substantially similar cross section as the shunt tubes  224 ,  226  (e.g., shown resembling a flat rounded rectangle). The shunt tubes  224  or  226  and the jumper tube  220  can be connected using coupling sleeves  236 ,  246 . The coupling sleeves  236 ,  246  are shown in  FIG. 2  as carried on the jumper tubes  220 . In other instances, the sleeves  236 ,  246  could be carried on the shunt tubes  224 ,  226 . The jumper tubes  220  and the shut tubes  224 ,  226  can include an outer profile for carrying seals to form a liquid and/or gas tight seal with the coupling sleeves  236 ,  246 . 
         [0019]      FIG. 3  illustrates an example of installation of the jumper tube  220  between well screen assemblies  202 ,  203 . Each end of the jumper tube  220  may include a coupling sleeve  236  or  246 . After the screen assemblies  202 ,  203  are coupled together, the jumper tube  220  can be installed by first sealingly coupling one end (e.g., the coupling sleeve  236 ) with an end portion of the shunt tube  226  first and then sealingly coupling the other end (e.g., the coupling sleeve  246 ) with an end portion of the shunt tube  224 . The seal between the coupling sleeve  236  or  246  and the shunt tubes  224  or  226 , as well as the jumper tube  220  may be created using metal to rubber, metal to metal, or other seals. 
         [0020]    In the example, one coupling sleeve  236  may be affixed to the jumper tube  220 ; while the other coupling sleeve  246  can move along the longitudinal axis of the jumper tube  220 . Thus, the jumper tube  220  is placed with the coupling sleeve  236  ready to be coupled with the shunt tube  224 . The jumper tube  220  is then moved towards the shut tube  226 , and the coupling sleeve  236  is forced into position over an interface between the jumper tube  220  and the shunt tube  226 . The spring clip  230  is affixed to the end ring  232  and protrudes axially toward the other well screen assembly  203 . The coupling sleeve  236  and spring clip  230  are configured such that the coupling sleeve  236  forces the spring clip  230  to flex outward over a profile protruding from the side of the coupling sleeve  236  when the jumper tube  220  and coupling sleeve  236  are moved into position. With the jumper tube  220  and coupling sleeve  236  in final position, the spring clip  230  snaps into gripping engagement of the profile of the coupling sleeve  246  to secure one end of the jumper tube  220  to the shunt tube  226 . 
         [0021]    The spring clip  230  may include a wedge-shaped leading end (i.e., on the end opposite the end ring). The wedge-shaped end can be a true triangle or have a curved or other similar shape that is configured to help force the spring clip  230  to flex outward over the profile when the coupling sleeve  236  or  246  is pushed in place. Detail of the wedge-shaped end and the gripping engagement are illustrated in  FIG. 4 , discussed below. If the coupling sleeve  236  is oriented downward (i.e., with the jumper tube  220  extending upward) the weight of the jumper tube  220  can be used to force the profile of the coupling sleeve  236  into the spring clip  230 . There are no screws, bolts, nuts or any other small items that are needed to make up the connection; therefore no hand tools are needed. Additionally, everything is attached to either the jumper tube  220  or the well screen assembly, so there are no small parts to complicate the assembly or potentially be dropped into the well. 
         [0022]    After the coupling sleeve  236  is in place, the other end of the jumper tube (e.g., the coupling sleeve  246 ) is aligned with the shunt tube  226 . The coupling sleeve  246  is then telescopically extended over the shunt tube  224  into a coupling position, with its profile flexing the spring clip  230  outward as it moves. The spring clip  230  is affixed to the end ring  234  and protrudes axially toward the other well screen assembly  202 . The spring clip  230  snaps into gripping engagement of the profile on the coupling sleeve  246  as the coupling sleeve  246  is extended into final position to secure the jumper tube  220  to the shunt tube  224 . The force for telescopically extending the coupling sleeve  246  can be applied by the operator manually grasping the sleeve  246  with his hands and pushing the sleeve  246  into place. If additional force is required, a hammer may be used. However, as above, there are no screws, bolts, nuts or any other small items that are needed to make up the connection; therefore no hand tools are needed. Additionally, everything is attached to either the jumper tube  220  or the well screen assembly, so there are no small parts to complicate the assembly or potentially be dropped into the well. 
         [0023]    Notably, although discussed as being different configurations of coupling sleeves  236 ,  246 , in some implementations, the coupling sleeve  236  may be identical to the coupling sleeve  246 . Also, the order of installation of the coupling sleeves  236 ,  246  described above may be altered based on the specific embodiment of the coupling sleeve. 
         [0024]      FIG. 4  shows coupling sleeves  236  at the installed position grippingly engaged by the spring clip  230 . One of the coupling sleeves  236  is shown in half cross-section. As illustrated in the cross-sectioned coupling sleeve  236 , a protrusion  410  and a groove  412  define a profile on the side of the coupling sleeve  236  that is gripped by the spring clip  230 . The coupling sleeve  246  can have a similar profile. The groove  412  allows the spring clip  230  to apply locking force in the direction along the longitudinal axis of the jumper tube. For example, the spring clip  230  has a curved end that enters the groove  412  and rests on the sidewall of the groove  412 . The curved end holds the coupling sleeve  236  towards the shunt tube  226 . Resultantly, the spring clip  230  can perform substantially all retaining of the jumper tubes  220  during operation of the well screen system downhole. The end of the shunt tube  226  may include seal  428  that can seal with the coupling sleeve  426 . Various embodiments of the spring clip  230  may be implemented. Two specific examples are further illustrated in  FIGS. 5A and 5B . 
         [0025]      FIGS. 5A and 5B  illustrate examples of spring clips  500  and  550  for connecting jumper tubes that can be used as spring clip  230 . Each spring clip  500 ,  550  includes a mounting flange  505  that allows the spring clip  500 ,  550  to be affixed to the end ring or other structure of the well screen assembly. Each spring clip includes an engagement portion  520  that allows the spring clip  500 ,  550  to snap into and grippingly engage a profile of a coupling sleeve, providing locking forces along the longitudinal axis of a jumper tube. In  FIG. 5B , the spring clip  550  has a substantially flat portion  560  between the flange  505  and engagement portion  520 . In  FIG. 5A , the spring clip  500  has an angled portion  510  between the flange  505  and the engagement portion  520 . In certain instances, the spring clips  500 ,  550  are made from bent metal, e.g., spring steel or another metal. Although two specific examples of spring clips are illustrated in  FIGS. 5A and 5B , other implementations self-locking/securing mechanism are possible. 
         [0026]    A number of embodiments have been described. Nevertheless, it will be understood that various modifications may be made. Accordingly, other embodiments are within the scope of the following claims.