Abstract:
A connector that is usable with a subterranean well includes a flange member and a tube. The flange member is adapted to form a connection with a submersible component. The tube is adapted to connect to the flange member and receive a cable that has a conductor that is surrounded by an insulative layer. The tube is crimped into the insulative layer.

Description:
BACKGROUND 
   The present invention generally relates to a pothead assembly. 
   A typical subterranean well includes submersible equipment to which wet electrical connections are made. For example, referring to  FIG. 1 , a production system  10  of a subterranean well may include a tubular string  12  that extends inside a casing string  14  and through a production zone  20  of the well. The string  12  typically has a central passageway for purposes of communicating well fluid to the surface of the well. To aid in producing this well fluid, the string  12  may include a submersible pump  22 . 
   The submersible pump  22  may operate from power that is provided from the surface of the well by one or more electrical cables  16 . For example, for a three-phase pump, three electrical cables  16  may extend from the surface of the well along the string  12  to the pump  22 . 
   Due to the very nature of its operation, the submersible pump  22  is surrounded by well fluid. A connection assembly  25 , or pothead, is used to connect the electrical power cables  16  to the motorhead of the pump  22 . The sealed connections formed by the pothead  25  should ideally maintain their integrity even in the relatively high temperature and pressure that are present in the well. The integrity of the sealed connections may be affected by the relative movement that occurs between the cables  16  and the submersible pump  22 . 
   Thus, there exists a continuing need for a pothead that maintains its integrity in the wellbore environment. 
   SUMMARY 
   In an embodiment of the invention, a connector that is usable with a well includes a flange member and a tube. The flange member is adapted to form a connection with a submersible component. The tube is adapted to connect to the flange member and receive a cable that has a conductor that is surrounded by an insulative layer. The tube is crimped into the insulative layer. 
   In another embodiment of the invention, a technique that is usable with a well includes connecting an outer jacket of a cable to a flange member; attaching the flange member to a submersible component; and forming a crimped connection between the flanged member and an insulative layer of the cable. 
   In yet another embodiment of the invention, a system that is usable with a well includes a submersible component, a cable, a flange member and a tube. The cable has a conductor that is surrounded by an insulative layer. The flange member is adapted to form a connection with the submersible component. The tube is adapted to connect the flange member to the submersible component and receive the cable. The tube is crimped into the insulative layer of the cable. 
   Advantages and other features of the invention will become apparent from the following description, drawing and claims. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a schematic diagram of a pumping system of the prior art. 
       FIG. 2  is an exploded cross-sectional view illustrating a pothead assembly according to an embodiment of the invention. 
       FIG. 3  is a cross-sectional view illustrating a connection between a tube of the pothead assembly and an exposed connection end of an electrical cable according to an embodiment of the invention. 
       FIGS. 4 ,  5  and  6  depict a flow diagram illustrating a technique to assemble the pothead assembly according to an embodiment of the invention. 
   

   DETAILED DESCRIPTION 
   Referring to  FIG. 2 , an embodiment  30  of a pothead assembly in accordance with the invention is constructed to form mechanical and sealed connections between motor lead extensions and a motorhead of a submersible component (a submersible pump, for example) inside a well (a subterranean or subsea well). In some embodiments of the invention, the pothead assembly  30  includes a flange insert  32  that sealably attaches to a housing  200  of the submersible component. The flange insert  32  includes a protruding section  34  that is generally coaxial with a longitudinal axis  190  of the pothead assembly  30  and is constructed to be inserted into a mating opening  202  of the housing  200 . 
   When the protruding section  34  is inserted into the opening  202 , an O-ring  36  (that circumscribes the longitudinal axis  190  and resides in an annular groove of the protruding section  34 ) forms a seal between the flange insert  32  and the housing  200 . As described further below, the flange insert  32  provides a structure of the pothead assembly  30 , which is used to both seal one or more electrical cables  100  (one cable being depicted in  FIG. 2 ) to the housing  200  as well as provide mechanical connections between the cable  100  and the housing  200 . 
   More specifically, in some embodiments of the invention, the flange insert  32  includes openings  42  (openings  42   a  and  42   b  depicted in  FIG. 2 , as examples) through which (as described below) sealed connections are formed between the cables  100  and the submersible component. More specifically, these sealed connections allow motor lead extension connectors  104  (one connector  104  being depicted in  FIG. 2 ) to be electrically connected to associated electrical receptacles (not shown) of a motorhead of the submersible component, in some embodiments of the invention. As depicted in  FIG. 2 , the openings  42  are each eccentric with respect to the longitudinal axis  190  of the pothead assembly  30 , in some embodiments of the invention. 
   For purposes of illustrating the pothead assembly  30  by way of a specific example, the connection of the electrical cable  100  through the opening  42   a  is depicted in  FIG. 2  and described below. It is noted that other electrical cables  100  may be connected in a similar manner (and thus, extend through the other openings  42 ) in some embodiments of the invention. For example, in some embodiments of the invention, the pothead assembly  30  may be used to connect three electrical cables  100  to the submersible component, and these three cables  100  may supply, for example, three-phase power to the submersible component. 
   As depicted in  FIG. 2 , the electrical cable  100  extends through the opening  42   a  so that when the pothead assembly  30  is fully assembled, an exposed end  102  of the electrical cable  100  is contained in the opening  42   a . The terminology “exposed” means that a protective and electrically conductive outer jacket (not depicted in  FIG. 2 ) of the cable  100  is removed, exposing a dielectric, or electrically insulative, layer  112  (a PEEK layer, for example) of the cable  100 . As shown in  FIG. 2 , the insulative layer  112  surrounds an inner electrical wire  114  of the cable  100 . 
   The openings  42  receive flared tubes  70  (flared tubes  70   a  and  70   b , depicted as examples in  FIG. 2 ) that are sealed (as described below) to the flange insert  32 . As depicted in  FIG. 2 , the opening  42   a  receives a flared tube  70   a  that is coaxial with the axis  190 . As its name implies, each flared tube  70  includes a flared opening  74 . The flared opening  74  facilitates insertion of the exposed end  102  of the cable  100  into the flared tube  70  and also facilitates insertion of a small tube  80  (a thin-walled tube made from Monel, for example) into the flared tube  70 . 
   More particularly, in some embodiments of the invention, the small tube  80  has an outer diameter that is closely sized to the inner diameter of the flared tube  70  and an inner diameter that is closely sized to the outer diameter of the exposed end  102  of the cable  100 . Therefore, in the fully assembled state of the pothead assembly  30 , the exposed end  102  of the cable  100  extends through and is sealed to (as described below) the small tube  80 ; the small tube  80  is located inside and is sealed to the flared tube  70 ; and the flared tube  70  is at least partially recessed into the opening  42  and sealed to the main body of the flange insert  32 . 
   As described further below, in the assembly of the pothead assembly  30 , each tube  80  is slid onto the exposed end  102  of the respective cable  100 , and then the small tube  80  is radially crimped so that the resultant annular grooves that are formed from the crimping extend into the insulative layer  112  of the cable  100 . These annular grooves secure the cable  100  to prevent relative movement between the cable  100  and the pothead assembly  30 . Additionally, as further described below, the crimping of the small tube  80  to the cable  100  provides a redundant seal around the exposed end  102  of the cable  100 . 
   Referring to both  FIGS. 2 and 3 , as a more specific example, in some embodiments of the invention, the exposed end  102  of the cable  100  may be configured in the following manner before being inserted into the flared tube  70 . The small tube  80  is first slid over the exposed end  102  so that, in accordance with some embodiments of the invention, one end  141  of the small tube  80  abuts or at least comes in close proximity to a lead jacket  140  of the cable  100 , as depicted in  FIG. 3 . Thus, the junction of the lead jacket  140  and the free end  102  forms the beginning of the remaining  110  fully encased portion of the cable  100 , which extends toward the surface of the well. The lead jacket  140 , as shown in  FIG. 3 , circumscribes the insulative layer  112 . 
   The small tube  80  may be crimped at one or more locations. For example, as depicted in  FIG. 3 , in some embodiments of the invention, the crimping may form at least two annular grooves  82  in the small tube  80 , and these annular grooves  82  circumscribe the electrical wire  114  and extend into (as depicted at reference numerals  83 ) the insulative layer  112 . Near the end  141  of the tube  80 , a seam  142  may be formed for purposes of mechanically connecting and sealing the tube  80  to the lead jacket  140 . For example, in some embodiments of the invention, the seam  142  may be a solder seam. However, other types of seams may be formed between the tube  80  and the lead jacket  140 , in other embodiments of the invention. 
   In some embodiments of the invention, each annular groove  82  may be formed using a pipe cutter that has a sufficiently dull blade so that as the pipe cutter is rotated about the tube  80 , the pipe cutter forms the annular groove  82  in the wall of the tube  80  instead of cutting through the wall. Other techniques may be used to crimp the tube  80  and form one or more of the annular grooves  82 , in other embodiments of the invention. 
   At an end  84  of the tube  80  opposite from the end  141  that abuts the lead jacket  140 , the tube  80  is designed to be inserted into the flared tube  70  (see  FIG. 2 ). Furthermore, at this end  84  of the tube  80 , a mechanical and sealed connection may be formed between the exterior surface of the tube  80  and the surrounding surface of the flared tube  70 . As a more specific example, in some embodiments of the invention, a solder seam may be formed between the exterior surface of the tube  80  (at the end  84 ) and the interior surface of the flared tube  70 , where the flared tube  70  extends from the opening  42 . For example, a 95/5 solder may be used in conjunction with an inorganic acid flux to solder each small tube  80  inside its associated flared tube  70 , in some embodiments of the invention. 
   Referring to  FIG. 2 , among the other features of the pothead assembly  30 , in some embodiments of the invention, another fluid seal may be formed between the insulative layer  112  and the flange insert  32 . More specifically, in accordance with some embodiments of the invention, the flange insert  32  includes an O-ring chamber  52  that includes annular O-ring grooves  50  that are each sized to receive one of the O-rings  60 . Thus, each O-ring groove  50  and the corresponding O-ring  60  (when installed in the groove  50 ) are concentric with the opening  42 . 
   For each opening  42 , an annular shoulder  45  defines an inner stop for the opening  42  to limit the distance in which the flared tube  70  may be inserted into the opening  42  from an exterior face  38  (i.e., the face of the flange insert  32  opposite from the face that contacts the housing  200 ) of the flange insert  32 . Each O-ring groove  50  is located behind each associated annular shoulder  45  for purposes of positioning the O-ring  60  to extend around the insulative layer  112  of the cable  100 . Thus, referring also to  FIG. 3 , when the exposed end  102  of the cable  100  is inserted through the flanged insert  32 , the O-ring  60  closely circumscribes the insulative layer  112  between the end  84  of the tube  80  and the connector  104 . 
   Referring back to  FIG. 2 , for purposes of retaining the O-rings  60  within the O-ring grooves  50 , in some embodiments of the invention, the pothead assembly  30  includes an O-ring cover  81  that is constructed to be closely received in the O-ring chamber  52 . The O-ring cover  81 , in turn, includes openings  82  that are coaxial with the openings  42  (when the cover  81  is assembled to the flange insert  32 ) but are sized to retain the O-rings  60  inside the O-ring chamber  52 . Thus, the connector  104  and a portion of the free end  102  extend beyond the opening  82  so that an appropriate electrical connection (a connection into a motorhead of the submersible component, for example) may be made with the electrical connector  104 . 
   In some embodiments of the invention, the pothead assembly  30  may include a housing  90  that attaches to the exterior face  38  of the flange insert  32 . More specifically, the housing  90  includes a recessed portion  91  that is inset to mate with the flange insert  32  that fits therein. The connector housing  90  is generally coaxial with the longitudinal axis  190  of the pothead assembly  30  when the pothead assembly  30  is assembled, and the housing  90  includes an inner chamber  94  that circumscribes the above-described connections between the electrical cables  100  and the tubes  70  and  80 . After the above-described connections have been made between the tubes  70  and  80  and the electrical cable  100 , the chamber  94  may be filled with a sealant, such as a stainless steel epoxy (as an example). 
   Among the other features of the pothead assembly  30 , in some embodiments of the invention, the connector housing  90  may include one or more openings  92  for purposes of accepting bolts (not shown in  FIG. 2 ) to attach the flange insert  32  to the connector housing  90 . Furthermore, in some embodiments of the invention, the flange insert  32  may include one or more openings  56 , and the housing  200  may include one or more openings  205 , all of which may be used for purposes of receiving bolts to connect the flange insert  32  to the housing  200 . 
   Referring to  FIG. 4 , to summarize, in accordance with embodiments of the invention, a technique  300  may be used to assemble the pothead assembly  30 . Pursuant to the technique  300 , the lead jackets  140  of the electrical cables  100  are terminated to form the exposed ends  102 , as depicted in block  302 . The connectors  104  are also attached to the exposed ends  104 . Next, the small tubes  80  are slid over the exposed ends  102  so that the lead jackets  140  contact or at least come near the ends  141  of the tubes  80 , pursuant to block  304 . It is noted that in other embodiments of the invention, the tube  80  may have (at least near the end  141 ) an inner diameter that is sized to closely slide over the end of the lead jacket  140 . Thus, many variations are possible and are within the scope of the appended claims. 
   Continuing with the description of the technique  300 , after the tubes  80  are slid onto the exposed ends  102 , sealed connections are formed between the tubes  80  and the lead jackets  140 , pursuant to block  306 . For example, in some embodiments of the invention, solder seams may be formed between the tubes  80  and the lead jackets  140 . The tubes  80  are then crimped to engage the insulative layers  112 , as depicted in block  308 . 
   The technique  300  includes sliding the connector housing  90  onto the electrical cables  100  past the exposed ends  102 , as depicted in block  310 . It is noted that block  310 , as well as other blocks depicted in the technique  300 , may be performed in a different order, in that the order that is shown pursuant to the technique  300  is merely for illustrating one out of many possible embodiments of the invention. 
   Referring to  FIG. 5 , the technique  300  includes forming (block  314 ) sealed connections between the flared tubes  70  and the flange insert  32 . For example, in some embodiments of the invention, the flared tubes  70  may be inserted into the openings  40  and then soldered to the surrounding body of the flange insert  32 . The exposed ends  102  of the cables  100  are inserted (block  316 ) through the flared tubes  70  and through the openings  50  and  52  so that the tubes  80  are partially inserted into the flared tubes  70 . In this position, sealed connections may then be formed between the tubes  70  and  80 , as depicted in block  318 . As a more specific example, in some embodiments of the invention, the tubes  70  and  80  may be soldered together using 95/5 solder and inorganic acid flux. 
   O-rings  60  may then be inserted (block  320 ) over the exposed ends  102  that extend from the flange insert  32  so that the O-rings  60  reside in the annular O-ring grooves  50 . Subsequently, the O-ring cover  81  may be placed in the O-ring chamber  52  and assembled to the flange insert  32  to secure the O-rings  60  in place, as depicted in block  324 . Next, in accordance with some embodiments of the invention, the housing  90  is assembled (block  328 ) to the flange insert  32 , and the cavity  94  of the housing  90  is filled (block  332 ) with a sealant, such as stainless steel epoxy, for example. Other sealants may be used, in other embodiments of the invention. 
   While the present invention has been described with respect to a limited number of embodiments, those skilled in the art, having the benefit of this disclosure, will appreciate numerous modifications and variations therefrom. It is intended that the appended claims cover all such modifications and variations as fall within the true spirit and scope of this present invention.