Tensile oil well heating cable and installation method

Abstract

The invention relates to the technical field of cable installation, in particular to a tensile oil well heating cable and an installation method. The heating cable comprises two cable bodies which are in butt joint, each cable body is externally connected with a locking assembly, the locking assembly comprises a first sleeve, and a limiting clamping sleeve, a locking clamping sleeve and a locking nut which are arranged outside the cable body in a sleeving mode are arranged in the first sleeve. The locking nut pushes the locking clamping sleeve to move towards the limiting clamping sleeve so that the limiting clamping sleeve can extrude the locking clamping sleeve inwards. The first sleeve is sleeved with a second sleeve, a first buffer spring is fixed to the end, facing the other cable, in the second sleeve, and a limiting plate capable of making contact with the first buffer spring is arranged on the periphery of the first sleeve. And the second sleeves corresponding to the two cables are fixedly connected through a connecting rod. According to the invention, the anti-pulling capability of the cable can be improved, and the stability of the cable in working environments such as oil wells can be maintained.

Description

Technical Field

[0001] The invention relates to the technical field of cable installation, and in particular to a tension-resistant oil well heating cable and an installation method. Background Art

[0002] Heating cable is a cable structure that uses electricity as energy and uses alloy resistance wire or carbon fiber heating element far infrared to generate electricity and heat. It is laid in places where heating and insulation are required to achieve the effect of heating or insulation. Heating cable uses single or multiple alloy heating wires as the heat source, high-purity, high-temperature, fused crystalline magnesium oxide as the thermal insulator, seamless continuous stainless steel or copper tube as the sheath, and is manufactured using a special production process. PE or low-smoke halogen-free jackets can be added to places with strong corrosion. Oil well heating cables are used to prevent wax from forming on the inner wall of the oil pipe, reduce crude oil viscosity, and change crude oil fluidity. The heating cable has the adjustability of oil outlet temperature and output power, and can be adjusted according to different oil well conditions to achieve the required crude oil temperature and realize automatic control.

[0003] Oil well heating cables are widely used in electric heating of high-viscosity oil, high-condensate oil, heavy oil, water injection wells, screw pump wells, SAGD wells, etc., as well as oil well, gas well, water well testing and other fields. They are also used in pipeline heating or heating, pipeline unblocking or thawing, boiler heating and other systems of petrochemical enterprises. Therefore, heating cables are usually made of materials with high high temperature resistance and corrosion resistance, and have high strength and tensile properties to cope with extreme environmental conditions. It is usually necessary to connect with other cable parts deep in the oil well to transmit electrical energy to the heating element and realize power supply. Cable connectors are key components that connect different parts of the cable. They ensure the continuity and reliability of power transmission. Therefore, the reliability of cable connectors is crucial to maintaining the continuity of oil well production. Their failure or damage may cause oil well production interruption and cause serious economic losses.

[0004] The Chinese invention patent, with the authorization announcement number CN117374873B, provides a high-strength tensile-resistant oil well heating cable, including a cable body and a docking box, wherein the front and rear sides of the docking box are fixedly connected with side connection blocks, and the side of the side connection block is provided with holes, and the cylindrical cavity of the docking box is provided with a movable sleeve with a cable body with a joint, and the sides of the two docking boxes are provided with auxiliary tensile components, and the main structure includes two docking boxes, and one end of the two docking boxes is provided with a mounting ring, and the outer wall of the mounting ring is provided with a main tensile component, and the main tensile component can clamp the outer wall of the cable at both ends of the cable connector. This invention provides a high-strength anti-pulling structure to prevent the heating cable from breaking or being damaged. The technical solution of the above invention patent still has some problems: the cable body is fixed by a clamping folding rod, and the connection between the clamping folding rod and the mounting block is not stable; the technical solution mainly adopts a rigid connection structure to improve stability, and this rigid connection structure is always subjected to tensile force, and its service life will be affected, and it is difficult to guarantee that it will suddenly break during use. Summary of the invention

[0005] In view of the technical problem in the prior art that heating cables may break or be damaged when subjected to tensile forces in environments such as oil wells, the present invention provides a tensile-resistant oil well heating cable and an installation method to improve the cable's anti-pulling ability and maintain its stability in working environments such as oil wells.

[0006] The present invention provides a tensile-resistant oil well heating cable, comprising two butt-jointed cable bodies, each of which is connected to a locking assembly, the locking assembly comprising a first sleeve, a first through hole for the cable body to pass through is provided in the axial direction of the first sleeve, a limiting ferrule and a locking ferrule are provided in the first sleeve, and the limiting ferrule and the locking ferrule are both sleeved on the cable body, a locking nut sleeved on the cable body is further provided on the side of the locking ferrule facing away from the limiting ferrule, and a thread matched with the locking nut is provided in the first sleeve. The locking sleeve includes a locking part, and the limiting sleeve includes a limiting part that cooperates with the locking part. The locking nut pushes the locking sleeve to move toward the limiting sleeve so that the limiting part squeezes the locking part inward; a second sleeve is arranged outside the first sleeve, and a second through hole is opened in the axial direction of the second sleeve for the cable body to pass through. A buffer spring 1 is fixed in the second sleeve at one end facing the other cable, and a limiting plate that can contact the buffer spring 1 is arranged on the outer periphery of the first sleeve; the second sleeves corresponding to the two cables are fixedly connected by a connecting rod.

[0007] Furthermore, the second sleeve includes a second cover and a second cylinder, a buffer spring 1 is fixed to one end of the second cover facing the second cylinder, and the second cover and the second cylinder are fixedly connected by bolts. The buffer spring 1 is arranged on the second cover for easy processing and installation.

[0008] Furthermore, the second sleeve includes a second cover body and a second cylinder body, a buffer spring 1 is fixed to one end of the second cylinder body facing the second cylinder body, and the second cover body and the second cylinder body are fixedly connected by bolts.

[0009] Furthermore, part of the first sleeve is located in the second cylinder, the locking nut is located outside the second cylinder, and the limit plate is arranged at one end of the first sleeve away from the locking nut. Part of the first sleeve is located in the second cylinder, the locking nut is located outside the second cylinder, and the position of the locking cable body can be close to the docking position of the two cable bodies, which is convenient for installation and saves materials.

[0010] Furthermore, the limiting ferrule includes a limiting portion, a limiting inclined surface is provided in the limiting portion, the locking ferrule includes a locking portion, the locking portion includes a plurality of locking plates arranged obliquely and cooperating with the limiting portion, the locking plates are arranged in an array along the circumferential direction, the inclination direction of the locking plates is the same as the inclination direction of the limiting inclined surface, and the inclination angle of the locking plates is smaller than the inclination angle of the limiting inclined surface. The limiting portion squeezes the locking plates toward the direction of the cable body, so that the connection between the locking plates and the cable body is more firm and stable.

[0011] Furthermore, a locking corrugation protruding inward is provided on the inner side of the locking plate, which can better lock the cable body, so that when the cable body is subjected to a large tensile force, it is less likely to move in its axial direction, thereby improving the tensile resistance.

[0012] Furthermore, the locking sleeve also includes a locking head, which is fixedly connected to the locking part; the limiting sleeve also includes a limiting head that cooperates with the locking head to limit the displacement stroke of the locking head, thereby preventing the locking part from moving toward the position of the limiting part so that the locking part is squeezed toward the cable body and damages the cable body.

[0013] Furthermore, a buffer spring 2 is fixed to the end of the second sleeve facing away from the other cable, a limit plate is located between the buffer spring 1 and the buffer spring 2, and the second sleeves corresponding to the two cables are fixedly connected by a connecting rod. No matter which direction the cable is subjected to tension, the elastic force of the two sets of springs in the butted cable bodies will buffer the tension on the cable, thus achieving a better buffering effect.

[0014] The outer periphery of the second cylinder is provided with a mounting plate connected to an external mounting frame or a wall, and a mounting hole is opened on the mounting plate. The second cylinder can be installed along the axial direction of the second cylinder or in a direction perpendicular to the axial direction of the second cylinder.

[0015] The present invention also provides a method for installing a tensile-resistant oil well heating cable, comprising the following steps: S1, sleeve the second cylinder body over the cable body; S2, sleeve the first sleeve over the cable body, pass the limiting sleeve and the locking sleeve through the cable body and into the first sleeve in sequence, and screw the locking nut through the cable body and into the first sleeve; S3, after the locking nut is in place, pass the second cover body through the cable body; S4, after the two cables are butt-jointed, the two second covers are fixedly connected to the second cylinder body with bolts, the position of the first sleeve is fixed following the position of the cable body, the position of the second cover body is adjusted to a position where the buffer spring does not deform and the limiting plate is in contact with the buffer spring, and then the second cylinders corresponding to the two cables are fixedly connected with a connecting rod.

[0016] The beneficial effects of the present invention are:

[0017] The locking nut pushes the locking sleeve to move toward the limiting sleeve so that the limiting part squeezes the locking part toward the cable body, so that the locking part and the cable body have a stable connection, and the connection between the cable body and the locking component is relatively firm and stable. A buffer spring is arranged in the second sleeve to interact with the first sleeve. When the cable body is subjected to tensile force, the first sleeve interacts with the buffer spring to resist the tensile force, thereby better improving the stability of the cable. The first sleeve can slide in the second sleeve, and the second sleeve plays a guiding role for the first sleeve, and can play a role in bundling cables in the working environment of the cable, thereby also improving the stability of the working state of the cable.

[0018] The side of the locking plate facing the cable body is in a corrugated curve shape, and the locking plate is squeezed toward the cable body. For the heating cable with PE material as the outer layer, the outer layer of the cable body can undergo a small deformation, and the locking corrugation can better lock the cable body, making it less likely to move in its axial direction when the cable body is subjected to a large tensile force, thereby improving the tensile resistance.

[0019] The cooperation between the buffer spring 1 in the second sleeve and the first sleeve serves as the first tensile defense line, and the connecting rod connection is provided as the second tensile defense line. When the cable is subjected to a large tensile force, it can resist the tensile force to a certain extent, and provide a certain displacement margin for the cable body to play a buffering role. When subjected to a large tensile force, it can still work stably to wait for maintenance personnel to inspect, thereby indirectly increasing the upper limit threshold of the tensile force that the cable can withstand.

[0020] Buffer spring 1 and buffer spring 2 are respectively arranged on the front and rear sides of the limit plate. No matter in which direction the cable is subjected to tension, the docked cable body will have two sets of spring forces to buffer the tension exerted on the cable, thereby achieving a better buffering effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0022] Figure 1 It is a schematic structural diagram of an embodiment of the present invention.

[0023] Figure 2 It is a schematic structural diagram of an embodiment of the present invention.

[0024] Figure 3 It is a schematic structural diagram of an embodiment of a locking assembly of the present invention.

[0025] Figure 4 The figure is a schematic structural diagram of an embodiment of a limit sleeve.

[0026] Figure 5 The figure is a schematic structural diagram of an embodiment of a locking plate.

[0027] Figure 6 It is a schematic structural diagram of an embodiment of a second sleeve and a locking assembly.

[0028] Figure 7 It is a schematic structural diagram of an embodiment of a second sleeve and a locking assembly.

[0029] Figure 8 It is a schematic structural diagram of an embodiment of a second sleeve and a locking assembly.

[0030] Fig. 9 It is a schematic structural diagram of an embodiment of a second sleeve and a locking assembly.

[0031] Explanation of main figure marks: 11-first sleeve, 12-limiting sleeve, 121-limiting part, 122-limiting head, 123-limiting slope, 13-locking sleeve, 131-locking plate, 132-locking head, 133-locking corrugation, 14-locking nut, 15-limiting plate, 16-first through hole, 2-second sleeve, 21-second cover body, 22-second cylinder body, 231-buffer spring one, 232-buffer spring two, 24-second through hole, 251-mounting plate, 252-mounting hole, 3-connecting rod, 4-cable body. DETAILED DESCRIPTION

[0032] In order to enable those skilled in the art to better understand the technical solutions in the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0033] like Figure 1-Figure 2 As shown, an embodiment of the present invention provides a tensile-resistant oil well heating cable, comprising two butt-jointed cable bodies 4. After the two cables are butt-jointed, a locking assembly is arranged outside each cable body 4 to adapt to the working environment in the oil well and improve its tensile strength. In this embodiment, the two butt-jointed cable bodies 4 are symmetrically arranged. Taking one of the cable bodies 4 as an example, the locking assembly comprises a first sleeve 11. A first through hole 16 for the cable body 4 to pass through is opened in the axial direction of the first sleeve 11. The cable body 4 enters from one end of the first sleeve 11 and passes out from the other end. A limiting sleeve 12 and a locking sleeve 13 are arranged in the first sleeve 11, and the limiting sleeve 12 and the locking sleeve 13 are both sleeved outside the cable body 4. The limiting sleeve 12 is arranged at one end of the first sleeve 11 and abuts against the wall at one end of the first sleeve 11, or a card groove and a card block can be arranged in the first sleeve 11 and the limiting sleeve 12 to limit the position of the limiting sleeve 12 installed in the first sleeve 11.

[0034] A locking nut 14 that is sleeved on the outside of the cable body 4 is also provided on the side of the locking sleeve 13 that is away from the limiting sleeve 12. A thread that cooperates with the locking nut 14 is provided on the inner surface of the end of the first sleeve 11. The locking nut 14 is set to a polygon for easy twisting with a wrench, or a socket is provided on the side wall of the locking nut 14 to cooperate with a lever to twist the locking nut 14. The limiting sleeve 12, the locking sleeve 13, and the locking nut 14 are sequentially prevented from the first sleeve 11 from one end. The locking nut 14 is screwed into the first sleeve 11. During the screwing process, the locking nut 14 pushes the locking sleeve 13 to move toward the limiting sleeve 12. The locking sleeve 13 includes a locking portion, and the limiting sleeve 12 includes a limiting portion 121 that cooperates with the locking portion. The locking nut 14 pushes the locking sleeve 13 to move toward the limiting sleeve 12 so that the limiting portion 121 squeezes the locking portion inward, thereby firmly connecting the locking portion to the cable body 4. Figure 3 and Figure 4As shown, in one embodiment, the limiting sleeve 12 includes a limiting portion 121, and a limiting inclined surface 123 is provided in the limiting portion 121. The limiting inclined surface 123 is circumferential, preferably the side of a truncated cone. The locking sleeve 13 includes a locking portion, and the locking portion includes a plurality of locking plates 131 arranged obliquely and cooperating with the limiting portion 121. The locking plates 131 are arranged in an array along the circumferential direction. The inclination direction of the locking plates 131 is the same as the inclination direction of the limiting inclined surface 123, and the inclination angle of the locking plates 131 is less than the inclination angle of the limiting inclined surface 123. In this embodiment, the inclination angle of the locking plate 131 is 12°, and the inclination angle of the limiting inclined surface 123 is 15°. The locking nut 14 is tightened Inserted into the first sleeve 11, during the screwing process, the locking nut 14 pushes the locking sleeve 13 to move toward the limiting sleeve 12, and the locking plate 131 enters the limiting portion 121. Since the inclined surface in the limiting portion 121 and the inclined surface of the locking plate 131 have an angle difference, under the force of the locking nut 14 being screwed in, the locking plate 131 is squeezed toward the direction of the cable body 4 by the limiting portion 121, so that the locking plate 131 exerts a greater pressure on the cable body 4 to play a locking role. There are multiple locking plates 131, and there is a certain distance or gap between them, so that the adjacent locking plates 131 will not affect each other during the squeezing process, thereby not affecting the locking effect. Figure 5 As shown, in a preferred embodiment, a locking corrugation 133 protruding inward is provided on the inward side of the locking plate 131. The locking corrugation 133 in this embodiment refers to the cross-section of the locking plate 131 along the axial direction of the first cylinder. The side of the locking plate 131 facing the cable body 4 is in a corrugated curve shape. The locking plate 131 is pressed toward the cable body 4, and the cable body 4 undergoes a slight deformation. The locking corrugation 133 can better lock the cable body 4, so that when the cable body 4 is subjected to a large tensile force, it is less likely to move in its axial direction, thereby improving the tensile resistance.

[0035] like Figure 3 As shown, in a preferred embodiment, the locking sleeve 13 also includes a locking head 132, which is fixedly connected to the locking part; the limiting sleeve 12 also includes a limiting head 122 that cooperates with the locking head 132 to limit the displacement stroke of the locking head 132. In the process of inserting the locking part into the limiting part 121, the locking head 132 gradually approaches the limiting head 122, and the position where the locking part contacts the limiting part 121 is the terminal position of the locking part, which prevents the locking part from being moved to the position of the limiting part 121 so that the locking part is squeezed toward the cable body 4 to damage the cable body 4. The dimensions of the locking part, the locking head 132, the limiting part 121, and the limiting head 122 can be obtained by the technicians through a limited number of experiments or calculations to adapt to the cable body 4 of different materials and sizes.

[0036] like Figure 6-Figure 9As shown, the locking assembly locks the cable body 4, the first sleeve 11 is provided with a second sleeve 2, the second sleeve 2 is provided with a second through hole 24 in the axial direction for the cable body 4 to pass through, a buffer spring 231 is fixed to one end of the second sleeve 2 facing the other cable, the outer periphery of the first sleeve 11 is provided with a limit plate 15 that can contact with the buffer spring 231, the second sleeve 2 includes a second cover body 21 and a second cylinder body 22, the second cover body 21 and the second cylinder body 22 are designed as separate bodies, after the first sleeve 11 is placed into the second cylinder body 22, the second cover body 21 and the second cylinder body 22 are connected and fixed with bolts, the first sleeve 11 is sealed in the second sleeve 2, in the second sleeve 2, the outer periphery of the first cylinder body is provided with a limit plate 15 that can contact with the buffer spring 231, the shape of the cross section of the second sleeve 2 is the same as the cross section at the limit plate 15 of the first sleeve 11, so as to ensure that the first sleeve 11 can slide in the second sleeve 2.

[0037] The second sleeves 2 corresponding to the two cables are fixedly connected by a connecting rod 3. The outer periphery of the second sleeve 2 is provided with a mounting plate 251 connected to an external mounting frame or a wall. The mounting plate 251 is provided with a mounting hole 252 for bolts to pass through and be fixed to an external bracket or a wall. In a preferred embodiment, the connecting rod 3 and the second sleeve 2 are connected and fixed by bolts and nuts, and the axial direction of the bolts is perpendicular to the axial direction of the connecting rod 3 to provide a more stable and firm connection. The connecting rod 3 realizes the rigid connection of the two butt-jointed cable bodies 4 to resist the tensile force on the cables. Under the rigid connection of the connecting rod 3, and the fixing action of the cable bodies 4 by the locking assembly, the relative positions of the two butt-jointed cable bodies 4 remain unchanged. When the cable is subjected to a small pulling force, one of the cable bodies 4 and the first sleeve 11 is subjected to a pulling force in the direction of the other cable body 4, and the cable body 4 drives the first sleeve 11 to move, and the first sleeve 11 moves to contact with the spring and presses one side of the spring to deform, thereby generating an elastic force opposite to the pulling force direction. The cooperation of the buffer spring 1 231 and the limit plate 15 provides a certain displacement margin for the first sleeve 11 and the cable body 4, so that the cable has the effect of resisting the pulling force, thereby maintaining the stability of the cable installation and use state. When the cable is subjected to a large pulling force, the buffer spring 1 231 or the buffer spring 2 232 produces a large deformation, and the second sleeve 2 also bears the resistance to the large pulling force. The fixing of the second sleeve 2 mounting plate 251 and the connection of the connecting rod 3 between the two second sleeves 2 jointly maintain the stability of the cable installation state. If there is no cooperation between the buffer spring 1 231 in the second sleeve 2 and the first sleeve 11, the pulling force on the cable will directly cause the cable body 4 and the locking assembly to move in the pulling force direction, making it easier for the cable to leave the original installation position, affecting the work and even causing damage. Therefore, in the tensile-resistant oil well heating cable of the present embodiment, the cooperation between the buffer spring 231 in the second sleeve 2 and the first sleeve 11 serves as the first tensile-resistant defense line, and the connecting rod 3 is provided as the second tensile-resistant defense line. When the cable is subjected to a large tensile force, it can resist the tensile force to a certain extent, and provide a certain displacement margin for the cable body 4 to play a buffering role. When subjected to a large tensile force, it can still work stably to wait for maintenance personnel to inspect, thereby indirectly increasing the tensile force threshold that the cable can withstand.

[0038] like Figure 8 As shown, in a preferred embodiment, a buffer spring 232 is fixed to one end of the second sleeve 2 facing away from the other cable, the limit plate 15 is located between the buffer spring 1 231 and the buffer spring 232, and the second sleeves 2 corresponding to the two cables are fixedly connected by a connecting rod 3. The buffer spring 1 231 and the buffer spring 2 232 are respectively arranged on the front and rear sides of the limit plate 15, and no matter which direction the cable is subjected to tension, the elastic force of the two sets of springs of the butted cable body 4 will buffer the tension of the cable, thereby playing a better buffering role.

[0039] The relative installation positions of the second cover 21, the second cylinder 22 and the first sleeve 11 are described in the following embodiments. Figure 6-Figure 8 As shown, in one embodiment of the present invention, the first sleeve 11 is entirely located inside the second sleeve 2 and can move inside the second sleeve 2 along the axial direction of the second sleeve 2. The second sleeve 2 includes a second cover 21 and a second cylinder 22. The second cover 21 and the second cylinder 22 are designed as separate bodies, and the two are connected and fixed by bolts and nuts. During installation, first insert the second cylinder 22 from one end of the cable body 4, and then insert the first sleeve 11 from the same end of the cable body 4. After the locking assembly of the first sleeve 11 is installed, slide the second cylinder 22 toward the first sleeve 11 so that the second cylinder 22 is sleeved outside the first sleeve 11, and then insert the cover from the same end of the cable body 4 to connect and fix it to the second cylinder 22. In this embodiment, the buffer spring 231 can be fixed to the second cover 21 or to the end of the second cylinder 22 away from the second cover 21. As shown Fig. 9 As shown, in one embodiment of the present invention, a portion of the first sleeve 11 is located in the second sleeve 2, and the other portion of the first sleeve 11 is located outside the second sleeve 2. The portion of the first sleeve 11 located in the second sleeve 2 can move along the axial direction of the second sleeve 2. The second sleeve 2 includes a second cover 21 and a second cylinder 22. The second cover 21 and the second cylinder 22 are designed as separate bodies, and the two are connected and fixed by bolts and nuts. When installing, first insert the second cylinder 22 from one end of the cable body 4, and then insert the first sleeve 11 from the same end of the cable body 4. After the locking assembly of the first sleeve 11 is installed, the second cylinder 22 is inserted. 22 slides toward the first sleeve 11 so that the second cylinder 22 covers part of the first sleeve 11 therein, and then the cover is inserted from the same end of the cable body 4 and passes through the other part of the first sleeve 11 and is connected and fixed to the second cylinder 22. In this embodiment, the buffer spring 1 231 can be fixed to the second cover 21 or to the end of the second cylinder 22 away from the second cover 21 or to one end of the limit plate 15 to set a buffer spring 1 231, and the other end of the limit plate 15 to set a buffer spring 232, and the buffer spring 1 231 and the buffer spring 232 are connected and fixed to the second cover 21 or the second cylinder 22. In the above two embodiments, the two butted cable bodies 4 are symmetrical to each other. When the first sleeve 11 moves in the second sleeve 2, the buffer spring on at least one side contacts the limit plate 15 to generate deformation and provide elastic force to resist the pulling force. If a buffer spring 1 231 and a buffer spring 232 are provided, when the first sleeve 11 moves in the second sleeve 2, the buffer springs on both sides contact the limit plate 15 to generate deformation and provide elastic force to resist the pulling force. In the above embodiments, the installation order and position of the second cylinder 22 and the second cover 21 can be interchanged, which is also within the protection scope of the present invention.

[0040] One embodiment of the present invention provides a method for installing a tensile-resistant oil well heating cable, comprising the following steps: S1, sleeve the second cylinder 22 on the outside of the cable body 4; S2, sleeve the first sleeve 11 on the outside of the cable body 4, pass the limiting sleeve 12 and the locking sleeve 13 through the cable body 4 and enter the first sleeve 11 in sequence, and pass the locking nut 14 through the cable body 4 and screw it into the first sleeve 11; S3, after the locking nut 14 is in place, pass the second cover 21 through the cable body 4; S4, after the two cables are docked, the two second covers 21 and the second cylinder 22 are fixedly connected using bolts, the position of the first sleeve 11 follows the position of the cable body 4, and the position of the second cover 21 is adjusted to a position where the buffer spring 231 does not deform and the limiting plate 15 is in contact with the buffer spring 231, and then the second cylinders 22 corresponding to the two cables are fixedly connected using a connecting rod 3.

[0041] Although the present invention has been described in detail with reference to the accompanying drawings and in combination with the preferred embodiments, the present invention is not limited thereto. Without departing from the spirit and essence of the present invention, a person of ordinary skill in the art may make various equivalent modifications or substitutions to the embodiments of the present invention, and these modifications or substitutions shall be within the scope of the present invention. Any person of ordinary skill in the art may easily think of changes or substitutions within the technical scope disclosed by the present invention, and these shall be within the scope of protection of the present invention.

Claims

1. A tensile-resistant oil well heating cable, comprising two butt-jointed cable bodies, characterized in that: Each cable body is connected to a locking assembly, the locking assembly comprising a first sleeve, a first through hole for the cable body to pass through is opened in the axial direction of the first sleeve, a limiting sleeve and a locking sleeve are arranged in the first sleeve, and the limiting sleeve and the locking sleeve are both sleeved outside the cable body, and a locking nut sleeved outside the cable body is also arranged on the side of the locking sleeve facing away from the limiting sleeve, a thread matching with the locking nut is arranged in the first sleeve, the locking sleeve comprises a locking part, the limiting sleeve comprises a limiting part matching with the locking part, and the locking nut pushes the locking sleeve to move toward the limiting sleeve so that the limiting part squeezes the locking part inward; a second sleeve is arranged outside the first sleeve, and a second through hole for the cable body to pass through is opened in the axial direction of the second sleeve, a buffer spring 1 is fixed in the second sleeve at one end facing the other cable, and a limiting plate capable of contacting the buffer spring 1 is arranged on the outer periphery of the first sleeve; the second sleeves corresponding to the two cables are fixedly connected by a connecting rod.

2. A tensile-resistant oil well heating cable as claimed in claim 1, characterized in that: The second sleeve comprises a second cover body and a second cylinder body. A buffer spring 1 is fixed to one end of the second cover body facing the second cylinder body. The second cover body and the second cylinder body are fixedly connected by bolts.

3. A tensile-resistant oil well heating cable as claimed in claim 1, characterized in that: The second sleeve comprises a second cover body and a second cylinder body. A buffer spring 1 is fixed to one end of the second cylinder body facing the second cylinder body. The second cover body and the second cylinder body are fixedly connected by bolts.

4. A tensile-resistant oil well heating cable as claimed in claim 2, characterized in that: Part of the first sleeve is located in the second cylinder, the locking nut is located outside the second cylinder, and the limiting plate is arranged at an end of the first sleeve away from the locking nut.

5. The tensile-resistant oil well heating cable according to claim 1, characterized in that: The limiting sleeve includes a limiting portion, a limiting inclined surface is provided in the limiting portion, the locking sleeve includes a locking portion, the locking portion includes a plurality of locking plates arranged obliquely and cooperating with the limiting portion, the locking plates are arranged in an array along the circumferential direction, the inclination direction of the locking plates is the same as the inclination direction of the limiting inclined surface, and the inclination angle of the locking plates is smaller than the inclination angle of the limiting inclined surface.

6. A tensile-resistant oil well heating cable as claimed in claim 5, characterized in that: The inwardly facing side of the locking plate is provided with an inwardly protruding locking corrugation.

7. A tensile-resistant oil well heating cable as claimed in claim 5, characterized in that: The locking sleeve also includes a locking head, which is fixedly connected to the locking part; the limiting sleeve also includes a limiting head that cooperates with the locking head to limit the displacement stroke of the locking head.

8. The tensile-resistant oil well heating cable according to claim 1, characterized in that: A buffer spring 2 is fixed to one end of the second sleeve facing away from the other cable, a limit plate is located between the buffer spring 1 and the buffer spring 2, and the second sleeves corresponding to the two cables are fixedly connected by a connecting rod.

9. A tensile-resistant oil well heating cable as claimed in claim 1, characterized in that: The outer periphery of the second cylinder is provided with a mounting plate connected to an external mounting frame or a wall, and a mounting hole is opened on the mounting plate.

10. A method for installing a tensile-resistant oil well heating cable, characterized in that: The following steps are involved: S1, sleeve the second cylinder onto the cable body; S2, sleeve the first sleeve on the cable body, pass the limit sleeve and the locking sleeve through the cable body and into the first sleeve in sequence, and screw the locking nut through the cable body and into the first sleeve; S3, after the locking nut is in place, pass the second cover through the cable body; S4, after the two cables are butt-jointed, the two second covers are fixedly connected to the second cylinders with bolts, the position of the first sleeve is fixed following the position of the cable body, the position of the second cover is adjusted to a position where the buffer spring does not deform and the limit plate contacts the buffer spring, and then the second cylinders corresponding to the two cables are fixedly connected with a connecting rod.

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