Abstract:
A technique to facilitate deployment of power cable and at least one capillary tube through a wellbore tool, such as a packer. The technique allows both the power cable and the at least one capillary tube to extend through a single pass-through opening in the wellbore tool.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS  
       [0001]    The following is based on and claims the priority of provisional application No. 60/260,416 filed Jan. 9, 2001. 
     
    
     
       FIELD OF THE INVENTION  
         [0002]    This invention generally relates to penetrators. Specifically, this invention relates to penetrators that enable the passage of a bundled ESP cable and at least one capillary tube through a single hole defined in a wellbore tool, such as a packer.  
         BACKGROUND OF THE INVENTION  
         [0003]    It is fairly common for downhole completions to include multiple capillary lines as well as ESP cables. These capillary lines and ESP cables must pass through wellbore tools, e.g. packers, that are also part of the completion. Prior art packers typically include only one pass-through bore, which pass-through bore receives the ESP cable (and not the capillary tubes). Thus, it is normally necessary to form additional pass-through bores through a packer during the manufacturing process to enable the pass-through of the capillary lines. Such additional bores typically require threads at the top end (and possibly the bottom end) to accommodate pressure fittings to create a pressure seal.  
           [0004]    However, depending on the packer type and size, the production tubing dimensions, and the number of ESP and capillary tube penetrations required, accommodating these additional bores can be a challenge due to space constraints. The bores also can affect the residual strength of the packer.  
           [0005]    It would be beneficial to provide a solution that enables the pass-through of at least one ESP cable as well as at least one capillary tube through a packer or other tool without having to include additional bores in the tool. It would also be beneficial to provide such a solution that utilizes standard packer and packer penetrator designs. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0006]    The invention will hereafter be described with reference to the accompanying drawings, wherein like reference numerals denote like elements, and:  
         [0007]    [0007]FIG. 1 is a longitudinal cross-sectional view of the adapter of this invention;  
         [0008]    [0008]FIG. 2 is a top view of the adapter, including the capillary tubes and fittings;  
         [0009]    [0009]FIG. 3 is a cross-sectional view taken along line  3 - 3  of FIG. 2; and  
         [0010]    [0010]FIG. 4 is a cross-sectional view taken along line  4 - 4  of FIG. 3. 
     
    
     DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS  
       [0011]    Referring generally to FIG. 1, an assembly  100  comprises a bundled cable  102 , a packer  108 , a tubing  110 , e.g. production tubing, and an adapter  10 . Packer  108  typically is sealed against a wellbore  5 , which may or may not be cased, by an appropriate seal  109 . Tubing  110  is connected to the packer bore  112  and is adapted to receive fluid flow therethrough.  
         [0012]    The bundled cable  102  may be an ESP cable that comprises a power cable for extending to and powering an electric submersible pump (not shown). To reach the pump, the ESP cable  102  passes through packer  108 . In prior art designs, a similar bundled ESP cable is spliced by a field splice, the spliced ESP flat cable is inserted through a packer penetrator, the penetrator is connected to a crossover, and the crossover is directly connected to the packer pass-through bore. The ESP flat cable thus extends through the penetrator and through the packer pass-through bore to the downhole pump.  
         [0013]    As illustrated in FIGS. 2 through 4, the bundled ESP cable  102  comprises, for example, an ESP flat cable  114  and one or more capillary tubes  116 . In FIG. 2, the bundled ESP cable  102  comprises two capillary tubes  116 . Generally, capillary tubes  116  are used to inject chemicals/fluid, to take bottom hole samples, or to vent trapped gas from downhole to surface.  
         [0014]    A field splice  118  unbundles the ESP cable  102  into the flat cable  114  and the capillary tube(s)  116 . The flat cable  114  is then inserted through a packer penetrator  104 , which penetrator is attached to a crossover  106 . However, unlike the prior art design in which the crossover is directly attached to the packer, the crossover  106  in this design is attached to a top end  12  of the adapter  10 . A bottom end  14  of the adapter  10  is then connected to a packer pass-through bore  16 .  
         [0015]    The ESP flat cable  114  passes through the penetrator  104  and crossover  106 , through the adapter  10  (as will be described herein), and through the packer pass-through bore  16 . The capillary tube(s)  116  pass outside of the penetrator  104  and crossover  106 , into the interior of the adapter  10  (as will be described herein), and through the packer pass-through bore  16 .  
         [0016]    Adapter  10  includes a body  11  and is constructed from a material that is compatible with the packer  108 , penetrator  104 , and crossover  106 , such as steel or stainless steel. The adapter bottom end  14  is sealingly engaged, such as by mating threads  50 , to the packer pass-through bore  16 . Moreover, the adapter top end  12  also is sealingly engaged, such as by mating threads  52 , to the bottom end  18  of the crossover  106  (see FIGS. 1 and 3). As is known in the art, the ESP flat cable  114  is sealingly engaged to the penetrator  104 .  
         [0017]    Adapter  10  comprises an exterior surface  22  and a passageway  20  extending through the adapter  10 . Passageway  20  receives the ESP flat cable  114  and the capillary tube(s)  116  and enables their extension through the packer pass-through bore  16 . Adapter  10  further comprises at least one capillary hole  24  extending from the exterior surface  22  to the passageway  20  thereby providing communication between the exterior and the interior of the adapter  10 . Each capillary hole  24  enables the connection of or the passage of a capillary tube  116  from the exterior of the adapter  10  to the passageway  20 . Thus, the number of capillary tube(s)  116  generally matches the number of capillary holes  24 . As shown in the Figures, e.g. FIGS. 2 and 3, the capillary hole(s)  24  may be disposed through wing elements  30  located on the adapter exterior surface  22 . In the embodiment shown in the Figures, each wing element  30  has one capillary hole  24 . In other embodiments (not shown), more than one capillary hole  24  may be included on a wing element  30 .  
         [0018]    As best seen in FIG. 3, a fitting  26  is sealingly engaged, such as by mating threads  54 , to each capillary hole  24 . Thus, as is known in the art, each fitting  26  is sealingly engaged to the adapter  10  (at the capillary hole  24 ), and the capillary tube  24  is sealingly engaged to the corresponding fitting  26 . It is noted that, for purposes of clarity, FIG. 3 shows the fittings  26  exploded from the capillary hole(s)  24 . It is understood that in assembled form each fitting sealingly engages its corresponding capillary hole.  
         [0019]    Thus, the ESP flat cable  114  which extends from the crossover  106  passes through the passageway  20  of the adapter  10  and through the packer pass-through bore  16 . The capillary tube(s)  116  extend from the bundled ESP cable  102 , exterior to the penetrator  104  and crossover  106 , into and through the capillary hole(s)  24 , through the passageway  20 , and though the packer pass-through bore  16 . Below the crossover  106 , capillary tube(s)  116  are guided alongside the ESP flat cable  114  (see also FIG. 4). The sealing engagements between the ESP flat cable  114  and the penetrator  104 , the crossover  106  and the adapter  10 , the adapter  10  and the packer pass-through bore  16 , the capillary tube(s)  116  and the fitting(s)  26 , and the fitting(s)  26  and the capillary hole(s)  24  all ensure that a pressure seal exists between the upperside and underside of the packer  108 .  
         [0020]    Adapter  10  may be used with either single, dual or other multi-bore tools, such as packers. Moreover, as shown in FIG. 1, more than one adapter  10  and ESP cable  102  may be used for each packer  108  (more than one ESP cable  102  is passed through the packer  108 ), in which case the packer  108  would have an equal number of packer pass-through bores  16 . In addition, although the adapter  10  has been described to enable the feedthrough of an ESP cable  102  and capillary tube(s)  116  through a packer  108 , it is understood that the adapter  10  may be utilized to enable the feedthrough of an ESP cable  102  and capillary tube(s)  116  through other tools (not only a packer).  
         [0021]    Thus, the adapter  10  and assembly  100  enables the feedthrough of ESP cable  102  and at least one capillary tube  116  without the need to include additional bores in the packer  108 . Moreover, adapter  10  can be used with standard industry packers  108 , penetrators  104 , and crossovers  106 . Therefore, the use of adapter  10  does not require additional investment or design modification.  
         [0022]    In view of the foregoing it is evident that the present invention is one well adapted to attain all of the objects and features hereinabove set forth, together with other objects and features which are inherent in the apparatus disclosed herein.  
         [0023]    As will be readily apparent to those skilled in the art, the present invention may be produced in other specific forms without departing from its spirit or essential characteristics. The present embodiment is, therefore, to be considered as merely illustrative and not restrictive, the scope of the invention being indicated by the claims rather than the foregoing description, and all changes which come within the meaning and range of equivalence of the claims are therefore intended to be embraced therein.