RU203568U1 - High temperature cable gland for submersible motor - Google Patents

Abstract

The utility model relates to the field of electrical engineering, to terminal connectors for cables in a liquid medium, and can be used in the design of cable glands for hermetically connecting cable lines to submersible electric motors designed to drive submersible pumps used in the oil industry for oil production. result: simplification of the design and increase of its reliability. The proposed high-temperature sleeve for the cable entry of a submersible electric motor, contains a housing and a shank filled with a compound of variable cross-section, connected to each other and fixed at the end of a conductive cable, each wire of which, passed through the through holes in the housing, is freed into parts its length from the lead protective sheath, sealed at the entrance to the housing and connected to the plug lug, while an insulator is wound on each wire, the ends of the wires, freed from the lead sheath and partially freed from the insulating x shells, brought out into the inner cavity of the body and connected by means of a threaded connection with plug lugs. In addition, the body and the shank, which is made by cold stamping from a thin-walled pipe, thereby providing a large internal space and the absence of corners and edges on the inner surface, which eliminates the possibility of damage to the cable during assembly, are interconnected by a continuous seam welding method, the insulator of the current-carrying conductor (TPZH) is made in the form of a sleeve, at one end of which a plug lug is fixed, and the other end is attached to the lead sheath of the cable and sealed with a high-temperature insulating tape, and the insulator additionally sealed with an O-ring located between the body and the socket of the plug lugs. The terminal block is made of metal, the O-ring is made of high temperature polymer material.

Description

The utility model relates to the field of electrical engineering, to terminal connectors for cables in a liquid medium, and can be used in the design of cable glands for hermetically connecting cable lines to submersible electric motors designed to drive submersible pumps used in the oil industry for oil production.

There are many types of cable gland couplings of a submersible electric motor described in the technical literature [see, for example, the International translator "Installations of submersible centrifugal pumps for oil production" - M .: Oil and Gas, 1999. S. 410-412], in patents for invention : RU 2251185 C2 dated 16.10.2002; RU 2264681 C2 dated November 14, 2003; RU 23192668 C2 dated 20.12.2004; US 2012/0100737 A1, 26.04.2012, which consist of:

metal body, which is made by casting with subsequent processing on metal-cutting equipment, the coupling body can be made of one single piece or consist of two parts connected with screws.

the ends of the insulated cable wires are located in the sleeve housing, connected to the plug lugs brought out through the holes to the socket of the plug lugs.

The tightness of the coupling body is also ensured by various types of sealing elements.

the tail part of the coupling body is poured with a sealing compound to mechanically hold the cable against movement.

During operation, when exposed to high temperatures, pressure, chemically aggressive well environment, the tightness of such couplings can be broken, which will lead to the penetration of well fluid to the current-carrying elements of the coupling.

The designs of the existing collars do not provide an adequate level of protection against the ingress of wellbore fluid. The designs do not use multi-stage protection, the tightness of the coupling is provided by one element, damage or destruction of which during the assembly of the coupling or operation leads to the penetration of well fluid and failure of the coupling.

Ring seals or gaskets that ensure the tightness of the couplings are placed between the metal body of the coupling and the elements of the cable structure with insulation or lead sheath. During the operation of the sleeve in well conditions, numerous heating cycles occur, including those with critical temperatures for the cable and sleeve materials. As a result of cyclic thermal expansion, the sleeve seals deform and change the geometric dimensions of the insulation and the lead sheath of the cable, so these elements do not have the ability of the seal material to reverse deformations and have a different coefficient of thermal expansion. As a result, the dimensions of the seal seats change, which causes depressurization and penetration of the well fluid sleeve.

The tail parts of the sleeve bodies, made by casting, have a limited internal space, as well as the presence of edges and corners formed after metalworking, which causes damage to the lead sheath and insulation of the cable cores when positioning the cable in the sleeve body during assembly, and as a result , the subsequent failure of the node. The process of assembling couplings itself does not provide the required level of quality control of the operations performed by the assembler. The low level of control over the assembly operations performed is due to the very design of the couplings, which limits the ability to conduct operational control.

Known high-temperature cable gland sleeve for a submersible electric motor (patent RU 2588608, H02G 15/04, publ. 10.07.2016), containing a housing and a compound-filled shank of variable cross-section, connected to each other and fixed by means of sealing elements and rings at the end of the conductive cable. Each cable wire is passed through through holes in the housing, freed for a part of its length from the lead protective sheath and connected to a plug lug mounted in the socket of plug lugs. On the end side of the body facing the shank, around the through holes there are protrusions in the form of bushings with a tapered section at the end.

The reasons that impede the achievement of the technical result indicated below when using known devices is the complexity in the manufacture and assembly of the coupling:

the body of the coupling consists of two parts made by casting and connected by screws; it requires high-precision processing on the metal-cutting equipment of the mating surfaces of both parts;

three conical elements made on the body of the clutch, for crimping the lead sheath, make this design even more technologically complex in metalworking;

compression of the lead sheath by the conical elements of the coupling does not provide guaranteed tightness, since the lead sheath can have variable values in thickness, which will negatively affect the quality of the reduction;

when the lead shell is expanded, due to insufficient elasticity of the shell material or the presence of foreign inclusions, there is a risk of damage to the shell in the form of micro ruptures (hidden defect), which are not visually detected and, during operation, will lead to liquid penetration;

during the operation of expanding the lead sheath, the introduction of a metal conical guide under the lead sheath, which can lead to damage to the insulation (hidden defect);

when assembling the structure, an uncontrolled displacement of the insulation can occur, which leads either to the impossibility of assembly, or to the formation of a gap between the insulator and the cable's own insulation;

low ability to control the quality of operations performed during the assembly of the coupling.

The noted disadvantages reduce the reliability and service life of the cable gland of the submersible electric motor.

The essence of the proposed device lies in the fact that the body and the shank, which is made by cold stamping from a thin-walled pipe, thereby providing a large internal space and the absence of corners and edges on the inner surface, which excludes the possibility of damage to the cable during assembly, are interconnected by continuous welding a seam, the TPG insulator is made in the form of a sleeve with an internal threaded part, by means of which it is screwed and fixed on the conductive core, before winding the insulator, a high-temperature dielectric sealant is applied to the part of the TPG with the insulation removed, which, when the insulator is screwed on, is distributed throughout the TPG, filling the voids between the TPG and insulator, ensuring the tightness of the connection along the conductive core, then a plug tip is screwed onto the TPG, on the other side, the end of the insulator wound on the TPG is sealed with a high-temperature insulating tape, forming two stages of protection against liquid penetration along the cable core, the first tape is high-temperature insulating tape, the second is high-temperature dielectric sealant, the tightness along the coupling body is ensured by two types of seals, forming two stages of protection, with O-rings, which are installed separately on each insulator TPZH, are sealed along the through holes in the housing for TPG, and the gasket is a seal located between the body and the terminal block. With this design, the seals do not have contact with the structural elements of the cable, insulation or lead sheath, which excludes their deformation and change in the size of the seals.

In addition, the socket of the plug lugs is made of metal, and the ring seals and the gasket are made of high-temperature rubber with an operating range from -50 ° C to + 250 ° C.

The use of the proposed invention provides the following technical result: simplifying the design and increasing its reliability.

The specified technical result in the implementation is achieved by the fact that the high-temperature sleeve for the cable entry of the submersible electric motor contains a housing and a shank filled with a compound of variable cross-section, connected to each other and fixed at the end of a conductive cable, each wire of which, passed through the through holes in the housing, is released into its part length from the lead protective sheath, sealed at the entrance to the housing and connected to the plug lug, while an insulator is wound on each wire, the ends of the wires, freed from the lead sheath and partially freed from the insulating sheaths, are brought into the inner cavity of the case and connected by means of a threaded connection with plug lugs.

The peculiarity lies in the fact that the body and the shank, which is made by cold stamping from a thin-walled pipe, thereby providing a large internal space and the absence of corners and edges on the inner surface, which excludes the possibility of damage to the cable during assembly, are connected by a continuous seam welding method, the conductive core insulator (TLC) is made in the form of a sleeve, at one end of which a plug lug is fixed, and the other end is attached to the lead sheath of the cable and sealed with a high-temperature insulating tape, and the insulator is additionally sealed with an O-ring located between the body and the socket of the plug lugs. The terminal block is made of metal, the O-ring is made of high temperature polymer material.

The design of the utility model is shown in the figures.

FIG. 1 is a longitudinal section of the device.

FIG. 2 - view A.

The device consists of a body 1, a shank 2 of variable cross-section, compound 3, a high-temperature insulating tape 4, an insulator 5 of a current-carrying conductor (TPZH), a plug lug 6, a block 7 of plug tips, a retaining ring 8, an O-ring 9, an O-ring TPZh 10. Cable 11 consists of conductive cores 12, insulation 13, lead sheath 14, sheath 15 of steel tape. High temperature sealant 16.

The connection of two parts of the body 1 with a shank of variable cross-section 2 into a single unit is carried out during the manufacture of the coupling body, by welding them together along the circumference of contact.

The assembly of the device is carried out using the following technology. The cable 11 is fixed in the device for assembling the cable gland sleeve and the sheath 15 is removed. The lead sheath 14 and insulation 13 are removed from the end of each conductive core 12. Threading is performed on the freed part of the TPG 12. Then, along the entire length of the open part of the TPZh 12 and the thread, a high-temperature sealant 16 is applied and the insulators TPZH 5. The section of each core 12, freed from the lead sheath 14, is wrapped with layers of high-temperature insulating tape 4, with a transition to the surface of the lead sheath 14 and insulator TPZh 5 Then the cores are positioned relative to the through holes in the coupling body. O-rings 10 are installed on the insulators 10. Then the cable cores with the wound insulators 5 from the shank side are inserted into the holes of the housing 1, put on the socket 7 of the plug lugs and install the locking ring 8. The device for assembling the couplings is used to compress the O-ring 9 until the ring is seated. locking 8 into the groove on the coupling housing. Plug lugs 6 are screwed onto the threaded ends of the conductive conductors 12. The inner cavity of the shank of variable cross-section 2 is filled with a high-temperature compound 3, for example, Thermoset EL-636 Erohu Encapsulate.

Thus, the proposed device makes it possible to simplify the design of the cable gland for a submersible electric motor, reduce the assembly time and increase its reliability.

The above description indicates the fulfillment of the following set of conditions when using the declared utility model:

means embodying the claimed utility model, in its implementation, is intended for use in structures of cable glands for hermetically connecting cable lines to submersible electric motors designed to drive submersible pumps used in the oil industry for oil production;

for the claimed device in the form as it is characterized in the stated formula of the utility model, the possibility of its implementation using the means and methods described in the application has been confirmed;

the means embodying the claimed utility model, when implemented, is capable of ensuring the achievement of the stated technical tasks as perceived by the applicant. Consequently, the claimed utility model meets the "industrial applicability" condition.

Claims (2)

1. A high-temperature sleeve for the cable entry of a submersible electric motor, containing a housing and a shank of variable cross-section filled with a compound, connected to each other and fixed at the end of a conductive cable, each wire of which, passed through through holes in the housing, is freed for a part of its length from a lead protective sheath, is sealed at the entrance to the body and connected to the plug lug, while an insulator is put on each wire, the ends of the wires, freed from the lead sheath and partially freed from the insulating sheaths, are brought out into the inner cavity of the body and connected by means of a threaded connection with plug lugs, characterized by the fact that that the body and the shank, which is made by cold stamping from a thin-walled pipe, thereby providing a large internal space and the absence of corners and edges on the inner surface, which excludes the possibility of damage to the cable during assembly, are connected by welding ki with a continuous seam, the insulator of the current-carrying conductor (TPZH) is made in the form of a sleeve, at one end of which a plug lug is fixed, and the other end is attached to the lead sheath of the cable and sealed with a high-temperature insulating tape, and the insulator is additionally sealed with an O-ring located between the body and the plug socket tips. 2. The coupling according to claim. 1, characterized in that the socket of the plug lugs is made of metal, the sealing ring is made of high-temperature polymer material.

Images