Pressure balanced connector termination

A pressure-balanced electrical cable assembly including a connector body, an electrical conductor positioned within the connector body, an interior chamber defined within the connector body, a dielectric fluid medium contained within the chamber, and a shuttle delimiting at least a portion of the chamber to prevent the escapement of the dielectric fluid from the chamber. The shuttle is moveable in response to differences between a pressure within the chamber and a pressure outside of the chamber.

FIELD OF THE INVENTION

This invention generally relates to a pressure-balanced electrical connector having a chamber filled with dielectric fluid.

BACKGROUND OF THE INVENTION

In providing electrical power to different types of wells, the connector systems will be exposed to rapidly varying pressures, temperatures and deleterious gases, each of which can cause internal sealing arrangements in a power cable or a power connector to fail.

Power cables, which may be used for electric submersible pumps (ESP) in oil wells, are typically constructed with a copper conductor, an insulator that surrounds the copper conductor, and a lead sheath that surrounds the insulator. Lead-sheathed power cables are known and disclosed in, for example, U.S. Pat. No. 4,780,574 to Neuroth and U.S. Pat. No. 5,760,334 to Ziemek, each of which are incorporated by reference herein in their entirety.

The lead material of the lead sheath protects the insulator of the power cable from damage resulting from the deleterious gases of the harsh oil well environment. The lead material of the lead sheath may also protect rubber sealing elements that are used to terminate these power cables. The rubber sealing elements are particularly vulnerable to explosive decompression and other types of damage caused by the gases.

Lead is commonly used because it is substantially impermeable to gas and moisture, inexpensive, flexible, ductile and easily removable. However, many of these qualities also make the lead sheath susceptible to damage upon changes in pressure and temperature if attempts are made to rigidly attach the lead sheath to a metal shell of a connector.

The invention described herein maintains the gas permeation protection provided by the lead material while offering a robust solution that can better withstand mechanical handling as well as changes in pressure and temperature.

SUMMARY OF THE INVENTION

The above-described gas permeation protection is provided by a pressure balanced chamber of dielectric fluid, such as grease, oil or silicone, surrounding the connector termination.

According to one aspect of the invention, a pressure-balanced electrical cable assembly includes a connector body, an electrical conductor positioned within the connector body, an interior chamber defined within the connector body, a dielectric fluid medium contained within the chamber, and a shuttle delimiting at least a portion of the chamber to prevent the escapement of the dielectric fluid from the chamber. The shuttle is moveable in response to differences between a pressure within the chamber and a pressure outside of the chamber.

According to another aspect of the invention, the pressure-balanced electrical cable assembly includes a holder defining a wall of the chamber. The holder includes a first opening through which an electrical conductor is positioned, and a second opening in which the moveable shuttle is positioned.

According to yet another aspect of the invention, the holder includes at least three openings, and a first shuttle is positioned in a first opening of the at least three openings of the holder, a second shuttle is positioned in a second opening of the at least three openings of the holder, and an electrical conductor is positioned within a third opening of the at least three openings of the holder.

These and other aspects of the present invention will become clear from the detailed discussion below when taken into consideration with the drawings. It is to be understood that the following discussion is intended merely to illustrate the preferred embodiment of the present invention. However, the present invention is not limited to the illustrated embodiment, but is limited solely by the claims appended to this specification.

DETAILED DESCRIPTION OF THE INVENTION

The invention will next be illustrated with reference to the figures. Such figures are intended to be illustrative rather than limiting and are included herewith to facilitate explanation of the present invention. In the figures, like item numbers refer to like elements throughout. Also, in the figures, many of the components of the power cable assembly are shown in cross-section and have a cylindrical shape.

As used herein, the term ‘proximal’ refers to a position that is near a connection point11,111,211or311, and the term ‘distal’ refers to a position that is distant from the connection point11,111,211or311.

FIGS. 1A and 1Bdepict a cross-sectional view of a power cable assembly10according to one exemplary embodiment of the invention. InFIG. 1B, the power cable assembly10ofFIG. 1Ais shown exposed to external fluid pressure. The power cable assembly10generally includes a power cable sub-assembly2that is configured to be connected to a power cable4by a sleeve assembly40.

is The power cable sub-assembly2comprises several interconnected components including a power cable3that is electrically and mechanically connected to a socket5, and an outer sleeve9that surrounds the socket5and the terminal end of the power cable3. The power cable sub-assembly2is configured to be connected to the power cable4. More particularly, the socket5of the power cable sub-assembly2is configured to receive the terminal end7of the copper conductor6of the power cable4. Power and/or signals can be transferred between the power cable sub-assembly2and the power cable4at a power connection point11that is defined at the intersection of the socket5and the terminal end7of the copper conductor6.

The power cable4includes the copper conductor6, an EPDM insulative shield24that surrounds the copper conductor6, and a lead barrier26that is molded over the EPDM insulative shield24. The lead barrier26protects the EPDM insulative shield24from exposure to harmful gasses and liquids that surround the power cable10in use. The lead barrier26is an optional component of the power cable4and may be omitted.

The power cable4also includes a stainless steel tube28that surrounds the lead barrier26, a rubber boot seal30that is positioned over the ends of the EPDM insulative shield24and the lead barrier26, and a compression ring32that is positioned over the boot seal30. The tube28, the rubber boot seal30and the compression ring32may or may not be considered as forming part of the power cable4. Alternatively, those components may be considered as separable parts that form part of either the sleeve assembly40or part of the cable assembly10.

The tube28provides a smooth surface upon which a shuttle18can translate, as will be described in greater detail later. The interior surface of the tube28may be adhered to the outer surface of the lead barrier26by a metal filled epoxy. One end of the tube28is positioned within a chamber14and is spaced apart from the boot seal30. The opposite end of the tube28extends outside of the chamber14.

The rubber boot seal30, which is susceptible to damage upon contact with deleterious gases emanating outside of the chamber14, is protected by dielectric fluid that is contained within the chamber14. The boot seal30may be adhered to the exterior surface of either one or both of the insulative shield24and the lead barrier26by a metal filled epoxy.

The boot seal30is positioned on the power cable4such that its proximal end face30′ is positioned flush with the proximal end face of the insulative shield24. The boot seal30also includes an exterior shoulder upon which a flange32′ of the compression ring32is seated. The flange32′ of the compression ring32is sandwiched between the boot seal30and a flange41of the outer sleeve12.

Referring now to the features of the sleeve assembly40, the sleeve assembly40is configured to releasably connect the power cable sub-assembly2to the power cable4. For that reason, the sleeve assembly40may also be referred to herein as a ‘connector.’ The sleeve assembly40also prevents the boot seal30from exposure to harmful gases and liquids that surround the power cable10in use.

The sleeve assembly40generally includes a tubular-shaped outer sleeve12, which is optionally composed of stainless steel, and a tubular-shaped shuttle18, which is optionally composed of an elastomeric material, such as rubber. The outer surface of the shuttle18is sealingly positioned against an inner surface20of the outer sleeve12, and the inner surface of the shuttle18is sealingly positioned against an outer surface of the tube28. A flange43is disposed at the distal end of the interior surface of the outer sleeve12to prevent detachment of the shuttle18from the outer sleeve12. The shuttle18includes a hole through which the stainless steel tube28of the power cable4passes.

An annular chamber14is defined between the interior surface20of the outer sleeve12and at least a portion of the exterior surfaces of the tube28, the boot seal30and the lead barrier26. The annular chamber14is filled with dielectric silicone grease or other dielectric fluid, as depicted by bubbles, by an operator. One or more surfaces of the boot seal30, lead barrier26, compression ring32, insulative shield24, shuttle18are at least partially immersed in the dielectric fluid. The dielectric fluid prevents the ingress of harmful liquids and gases into the chamber14.

The chamber14is delimited by the shuttle18. In operation, as shown inFIG. 1B, the shuttle18moves leftward when it is exposed to external pressure as any air pockets or compressible elements within the dielectric fluid will contract in volume (note difference in bubble size betweenFIGS. 1A and 1B). The shuttle18may return to its initial position once the external pressure subsides. This is referred to as a “pressure balanced” chamber.

At the proximal end of the sleeve assembly40, the boot seal30and the compression ring32prevent escapement of the grease from the chamber14. At the distal end of the sleeve assembly40, the O-ring shuttle18seals against the surfaces of the sleeve12and the tube28to prevent escapement of the grease from the chamber14.

The shuttle18includes a hole through which the stainless steel tube28of the power cable4passes. The outer surface of the shuttle18is positioned against the inner surface20of the outer sleeve12. An elastomeric O-ring31is mounted in a channel that is formed on the interior surface of the shuttle18. The O-ring31is positioned to bear on the exterior surface of the tube28to prevent the escapement of fluid at the interface between the interior surface of the shuttle18and the exterior surface of the tube28. Another elastomeric O-ring33is mounted in a channel that is formed on the exterior surface of the shuttle18. The O-ring33is positioned to bear on the interior surface of the outer sleeve12to prevent the escapement of fluid at the interface between the exterior surface of the shuttle18and the interior surface of the outer sleeve12. Alternatively, the O-rings31and33may be replaced by C-rings that are formed of a metallic material.

Mechanical threads42are provided on the interior surface of the proximal end of the outer sleeve12for connecting the sleeve assembly40with mating threads on the power cable sub-assembly2. Specifically, the mechanical threads42are configured for releasably engaging mating threads on the exterior surface of the mating sleeve9of the power cable sub-assembly2. Item42may represent any connection means, such as a fastener, pin, slot, plug, socket, retainer, lock, adhesive, bolt, nut, engaging surface, engageable surface, magnet, or joint, for example.

FIG. 2depicts an O-ring44that is positioned at the interface between the terminal end of the outer sleeve12and a channel46that is defined at the proximal end of the mating sleeve9of the power cable sub-assembly2. The O-ring44prevents the escapement of fluid at the interface between the sleeves9and12. The O-ring44may be replaced by a metallic C-ring, if so desired.

Referring back toFIGS. 1A,1B and2, and according to one exemplary method of assembling the power cable assembly10, the shuttle18is positioned inside the outer sleeve12. The tube28is mounted to the power cable4. The tube28and the power cable4are then positioned through the hole in the seal18. The rubber boot seal30and the compression ring32are mounted to the power cable4. Before mating the sleeves9and12together, a pre-determined amount of dielectric fluid is distributed into the chamber14. The threads42of the outer sleeve12of the sleeve assembly40are then engaged with the mating threads of the mating sleeve9of the power cable sub-assembly2. Upon engaging those mechanical threads, a shoulder41of the outer sleeve12bears against the distal end of the compression ring32, which bears against the boot seal30, thereby compressing the proximal end face of the boot seal30against the proximal end face of the socket5of the power cable sub-assembly2.

At the same time, the terminal end7of the copper conductor6of the power cable4seats in the recess of the socket5of the power cable sub-assembly2, thereby creating a power connection between the power cable sub-assembly2and the power cable4. Also, at the same time, the proximal ends of both the boot seal30and the insulative shield24bear against (but are disconnected from) the terminal end of the socket5of the power cable sub-assembly2. The power cable assembly10is ready for use, and the power cable assembly10may be immersed in an oil well, or other environment.

The sleeve assembly40may be sold and distributed along with the power cable4. That assembly may be supplied with or without a supply of dielectric fluid.

The sleeve assembly40may also be sold and distributed as a kit for retrofitting an existing power cable assembly. The kit would include, at a minimum, the outer sleeve12and the shuttle18. The kit may also include the tube28, the rubber boot seal30, the compression ring32and/or a supply of dielectric fluid.

It should be understood that the materials recited herein may vary, the methods by which components are formed may vary, and the ways by which the components are connected together may vary.

FIG. 3Adepicts a cross-sectional view of another power cable assembly110having multiple conductors106, according to another exemplary embodiment of the invention.FIG. 3Bdepicts the power cable assembly110ofFIG. 3Aexposed to external pressure. Many of the details of the power cable assembly10also apply to the power cable assembly110, and only the differences between those power cable assemblies will be described hereinafter.

The power cable assembly110generally includes a power cable sub-assembly104that is configured to be connected to an insulator102(or a mating power cable) by a sleeve assembly.140. The power cable104includes a plurality of discrete conductors106(three shown). The power cable104also includes a tube128that surrounds the conductors106.

The tube128provides a smooth surface upon which a first shuttle118acan translate, as will be described in greater detail later. The interior surface of the tube128may be adhered to the conductors106by a metal filled epoxy, for example. One end of the tube128is positioned within a chamber114a, and the opposite end of the tube128extends outside of the chamber114a.

Referring now to the features of the sleeve assembly140, the sleeve assembly140is configured to releasably connect the power cable104to the insulator102. For that reason, the sleeve assembly140may also be referred to herein as a ‘connector.’ The sleeve assembly140also shields the conductors106from exposure to harmful gases and liquids that surround the power cable assembly110in use.

The sleeve assembly140generally includes a two-piece tubular-shaped outer sleeve112aand112b(referred to collectively as outer sleeve112), each of which is optionally composed of stainless steel, and two tubular-shaped shuttles118aand118b, which are optionally composed of an elastomeric material such as rubber. The shuttles118aand118bare positioned against an inner surface120of the outer sleeve112. Angled surface145of the outer sleeve112aprevents detachment of the shuttle118afrom the outer sleeve112. Stops143aand143bare disposed along the outer sleeve112bto prevent detachment of the shuttle118bfrom the outer sleeve112.

Unlike the sleeve assembly40, the sleeve assembly140includes two fluid filled chambers114aand114b(referred to collectively as chambers114) and two shuttles118aand118b(referred to collectively as shuttles118) for the purpose of redundancy.

The shuttle118aincludes a hole through which the tube128of the power cable104passes. The shuttle118aslides along the surface of the tube128in response to pressures emanating external to the power cable assembly110, as evidenced by comparingFIGS. 3A and 3B.

The other shuttle118bincludes several holes, and a grommet147that is fixedly positioned in each hole. The number of holes and grommets corresponds to the number of conductors106. Each conductor106of the cable104passes through an opening in one of the grommets147, as shown. The grommets147of the shuttle118bslide along the surface of the individual conductors106in response to pressures emanating external to the power cable assembly110, as evidenced by comparingFIGS. 3A and 3B. Thus, the grommets147translate along with the shuttle118bin response to external pressure.

One chamber114ais defined between the shuttles118aand118b, and the other chamber114bis defined between the shuttle118band the insulator102. The annular chambers114aand114bare each filled with dielectric silicone grease or other dielectric fluid, as depicted by bubbles. The conductors106are at least partially immersed in the dielectric fluid. The dielectric fluid prevents the ingress of harmful liquids and gases into the chambers114aand114b.

In operation, as shown inFIGS. 3B, the shuttles118aand118bmove rightward when the shuttle118ais exposed to external pressure as any air pockets or compressible elements within the dielectric fluid will contract in volume (note to difference in bubble size betweenFIGS. 3A and 3B). The shuttles118aand118bmay return to their initial positions inFIG. 3Aonce the external pressure subsides. This is referred to as a “pressure balanced” chamber.

As noted above, two shuttles118and two chambers114are provided for the purpose of redundancy. In the event that the first shuttle118afails, thereby resulting in contamination of the chamber114a, a second failure would have to occur for the contamination to reach the other chamber114b.

As an alternative to the embodiment shown inFIGS. 3A and 3B, the grommets147are fixed to the conductors106such that grommets147and the shuttle118bcan not translate over the conductors106; and a moveable seal (not shown) is positioned over the seal118b. The moveable seal would translate over the seal118bin response to external pressure.

FIG. 4Adepicts a cross-sectional view of a power cable assembly210having multiple conductors206(three, for example), according to still another exemplary embodiment of the invention. Many of the details of the power cable assembly10also apply to the power cable assembly210, and the primary differences between those power cable assemblies will be described hereinafter.

The cable assembly210includes a connector body202defining an interior space213. The connector body202may also be referred to herein as a sleeve, conduit, tube or shell. A pressure balanced chamber216(referred to hereinafter as chamber216) is defined within the interior space213. The chamber216has a substantial cylindrical shape, and also partially extends within the proximal end of the shuttle tube assemblies215, as best shown inFIG. 4A. The chamber216is defined at a location between the connection point211and the shuttle tube and cable holder220. The proximal face220aof the shuttle tube and cable holder220forms the distal boundary wall of the chamber216. The chamber216is filled with a dielectric fluid medium, for example. The dielectric fluid medium may be gas impermeable. Air bubbles are depicted in the chamber216inFIG. 4A.

It should be understood that the boundaries of the chamber216do not necessarily have to be defined by the outermost cylinder (i.e., body202) of the power cable assembly210. The chamber216could be defined by a component of the cable assembly210that is positioned interior of the connector body202.

FIG. 4Bdepicts the shuttle tube and cable holder220(referred to hereinafter as holder220) of the power cable assembly210. The holder220of the power cable assembly210is positioned within the interior space of the connector body202. The holder220comprises a cylindrical body having a proximal face220a, a distal face220b, and a revolved outer surface extending between the faces. A series of openings212(three, for example) are defined through the body of the holder220to accommodate respective conductors206. The openings212are spaced in a radial direction from the longitudinal axis of the holder220and are spaced in a circumferential direction about the holder220(e.g., by 120 degrees). The spacing may be even in the radial and circumferential directions. The cable assembly210may include any number of conductors206and corresponding openings212.

A single electrical conductor206is positioned in each opening212. Although not shown, an O-ring may be positioned on the circumference of each conductor206to prevent the passage of fluid at the interface between the exterior revolved surface of the conductor206and the interior revolved surface of the opening212through which the conductor206is positioned.

A series of counter-bored openings219(three, for example) are defined through the body of the holder220to accommodate respective shuttle tube assemblies215. The openings219are spaced in a radial direction from the longitudinal axis of the holder220, and are spaced in a circumferential direction about the holder220(e.g., by 120 degrees). The spacing may be even in the radial and circumferential directions.

The openings219are separate from and disconnected from the openings212. The openings212and219are alternately positioned in a circumferential direction about the holder220, such that each opening219is positioned between adjacent openings212, and vice versa.

An O-ring203is positioned on the circumference of the holder220to prevent the passage of fluid at the interface between the exterior revolved surface of the holder220and the interior revolved surface of the connector body202.

Turning now to the features of the shuttle tube assemblies215, each shuttle tube assembly215generally includes a tube217mounted within an opening219defined in the holder220, a moveable shuttle218positioned within the interior of the tube217that is biased by a spring221, and a plug232that is fixedly mounted to the distal end of the tube217.

The hollow tube217of each shuttle tube assembly215is fixedly mounted within the opening219of the holder220. The distal end of the hollow tube217protrudes from the distal end220bof the holder220. The hollow tube217includes a shoulder225that bears on an interior shoulder of the opening219of the holder220. The shoulder225marks the separation between the proximal interior region223aand the distal interior region223bof the tube217. The proximal interior region223aforms part of the chamber216that contains the dielectric medium.

The movable shuttle218of each shuttle tube assembly215comprises a cylindrical shaped solid body. The shuttle218is positioned within the distal interior region223bof the hollow tube217. An O-ring is positioned on the circumference of the movable shuttle218to prevent the passage of fluid at the interface between the exterior revolved surface of the shuttle218and the interior revolved surface of the tube217. A spring221biases the shuttle218toward the chamber216. The shuttle218is capable of translating within the distal interior region223bof the hollow tube217between the shoulder225and the plug230.

The plug230of each shuttle tube assembly215is fixedly mounted to the distal end of the tube217. A passage232is defined through the plug230to permit the passage of fluid within the tube217, such that the distal end face of the shuttle218is exposed to fluids or gasses within either the well environment or atmosphere, for example.

The proximal end face of the shuttle218is exposed to the dielectric medium that is contained within the portion of the chamber216that extends into the proximal interior region223aof the tube217. The proximal end face of the shuttle218at least partially delimits, i.e., forms the boundary of, the chamber216. Thus, the proximal end face of the shuttle218is exposed to the dielectric medium, whereas the distal end face of the shuttle218is not exposed to the dielectric medium. The distal end face of the shuttle218may be exposed to either the well environment or atmosphere, for example.

In operation, when the dielectric medium within the pressure balanced chamber216expands or contracts due to temperature and/or pressure, the shuttle218translates within the tube217in response to differences between a pressure within the chamber216and a pressure within the distal interior region223bof the tube217. Translation of the shuttle218is limited between the shoulder225and the plug218. The dielectric medium provides a dielectric barrier, which may be gas impermeable, that shields elastomers (not shown) that are located proximal of the chamber216and creates the dielectric isolation of the connector system.

Unlike the shuttle18of the power cable assembly10, the shuttles218of the power cable assembly210are not moveably positioned over the conductors206, or any other component, of the cable assembly210. Separating the shuttles218from the other components of the cable assembly210eliminates the possibility that the shuttle218could bind on another component.

FIG. 5depicts a cross-sectional view of a power cable assembly310, according to still another exemplary embodiment of the invention. Many of the details of the power cable assembly10apply to the power cable assembly310, and the primary differences between those power cable assemblies will be described hereinafter.

The power cable assembly310has a substantially symmetrical design and generally includes a single-conductor power cable303that is connected to another single-conductor power cable304by a double-ended socket305. The double-ended socket305transfers power and/or signals between the power cables303and304at the power connection point311.

Each power cable303and304includes a copper conductor306, a pin307that is fixedly mounted to the proximal end of the conductor306, an insulative shield.324that surrounds the copper conductor306, and a lead barrier326that is positioned over the insulative shield324. The lead barrier326protects the insulative shield324from exposure to harmful gasses and liquids that surround the power cable310in use. The lead barrier326is an optional component of the power cables303and304and may be omitted.

The power cable assembly310also includes a tube328that surrounds each lead barrier326. The tube328may be composed of stainless steel, for example. An attached flange330is positioned over the proximal end of each tube328. The attached flange330is also sandwiched between a distal end of a sleeve315and a internal shoulder formed on a connector shell312a. The tubes328and the attached flange330may or may not be considered as forming part of the respective power cables303and304. Alternatively, those components may be considered as separable parts that form part of the power cable assembly310.

The double-ended socket305is positioned within a dielectric insulative sleeve313. The dielectric insulative sleeve313has a hollow cylindrical body. One end of the dielectric insulative sleeve313is captivated by the flange330of the power cable304, and the opposite end of the sleeve313partially surrounds and overlaps another dielectric insulative sleeve315. The sleeve315also has a hollow cylindrical body. The sleeve315is captivated by the attached flange330of the power cable303. The dielectric insulative sleeves313and315may be composed of any dielectric insulative material.

The dielectric insulative sleeve313is positioned within a male to male connector340. The connector340has a hollow cylindrical body including male threads that are defined at opposite ends thereof. The connector shell312athat is associated with the power cable303includes female threads at its proximal end that are threadedly connected to one threaded end of the connector340. Similarly, the connector shell312bassociated with the power cable304includes female threads at its proximal end that are threadedly connected to the opposite threaded end of the connector340.

The power cable assembly310includes two pressure balanced chambers314that are each delimited by a moveable shuttle318. Although only the chamber314and the shuttle318that are associated with the power cable303will be described hereinafter, it should be understood that the chamber314and the shuttle318that are associated with the power cable304are structurally and functionally equivalent to their counterparts associated with the power cable303.

Referring now to the pressure balanced chamber314associated with the power cable303, an annular space301is formed between the revolved surfaces of the connector shell312aand the tube328. A tubular-shaped shuttle318is positioned within the annular space301, and is sealingly compressed between an inner surface of the connector shell312aand outer surface of the tube328. The tube328provides a smooth surface upon which the shuttle318can translate.

The shuttle318divides the annular space301between the pressure balanced chamber314and an annular space319. The chamber314is filled with a dielectric fluid medium, which is depicted by bubbles inFIG. 5. No fluid is contained within the annular space319. The shuttle318prevents the passage of fluid between the space319and the chamber314.

In operation, the shuttle318associated with the power cable303moves rightward when it is exposed to external pressure as any air pockets or compressible elements within the dielectric fluid will contract in volume. The power cable assembly310is shown exposed to external pressure inFIG. 5. The shuttle318associated with the power cable303may return to its initial position once the external pressure subsides. It should be understood that the other shuttle318moves leftward when it is exposed to external pressure, and moves rightward to return to its initial position once the external pressure subsides. The dual pressure balanced chamber design provides redundancy if one of the shuttles318were to fail or become bound in place. The remaining shuttle318and pressure balanced chamber314would assume the pressure balancing functionality of the power cable assembly310.

The pressure balanced chambers314respond to rapid decompression and pressure impulses caused by the activation and deactivation of an electrical submersible pump to which the power cable assembly310may be connected.

Testing has shown that the dielectric fluid chambers314either limit or prevent well fluid that has penetrated the lead barrier326(or other lead barrier outside of the cable assembly310) from penetrating the power connection point311(or another critical point) and causing a high voltage short to ground.

Testing has also shown that the power cable assembly310is particularly suitable for well temperatures above 500 degrees Fahrenheit. Because such high temperatures rapidly degrade elastomeric materials, the power cable assembly310employs a minimal amount of elastomers as compared with the other cable embodiments that are described herein.

Although the invention is illustrated and described herein with reference to specific embodiments, the invention is not intended to be limited to the details shown. Rather, various modifications may be made in the details within the scope and range of equivalents of the claims and without departing from the spirit of the invention. For example, if the cables4and104are sufficiently smooth and cylindrical, and the shuttles18and118aare sufficiently compliant, the tubes28and128, respectively, may be omitted without sacrificing operational performance. The invention described herein is not limited to electrical power cables for oil wells. The details of the invention may be applied to any type of termination, wire, cable or cord that is used for any application.