Electric heating system for dropping and fishing cable

Abstract

The invention relates to the field of oil extraction, in particular to a cable dropping and fishing electric heating system, and aims to solve the technical problems of high cost and influence on oil extraction aging of a thermal well washing technology. The dropping-fishing cable electric heating system comprises an oil pipe, a dropping-fishing cable, a wellhead device and a frequency conversion control cabinet, one end of the oil pipe is connected with the wellhead device; a steel wire layer of the throwing-fishing cable in the oil pipe is electrically connected with the oil pipe through an underground contactor; one end, penetrating out of the oil pipe, of the throwing-fishing cable is electrically connected with the frequency conversion control cabinet; and the frequency conversion control cabinet is also electrically connected with the wellhead device. The dropping and fishing cable electric heating system can replace hot well washing, water injection and drainage are not needed, wax is removed through electrifying and heating of the steel wire layer, and the oil extraction aging is guaranteed.

Description

Technical Field

[0001] The invention relates to the field of oil production, and in particular to an electric heating system for a fishing cable. Background Art

[0002] The rodless oil production technology of cable fishing in the oil pipe refers to the process of lowering the cable into the oil pipe and supplying power to the downhole unit from the ground power distribution system through the cable through the downhole docking method, so as to lift the crude oil to the ground. In recent years, in order to break through the bottleneck of easy damage to external cables and high well control risks, completely eliminate the eccentric wear failure of oil well pipe rods, and solve the problems of long construction period, high well control risk, easy collision and frequent failure of armored cables tied to the oil pipe, various manufacturers have actively carried out tests on cable fishing in the oil pipe and plug connector components. Through continuous optimization and improvement, the long-term stable operation of the unit is guaranteed, and the large-scale and batch application of the technology of fishing in the oil pipe is realized.

[0003] For oil wells with high wax content, the production channel is easily blocked during oil production, causing frequent pump jams and shutdowns of rodless pumps. When the wax blockage is serious, it will also cause pump inspections, which not only increases the operating costs of the oil production unit, but also leads to the loss of recovered crude oil. In order to solve the problem of wax blockage in the flow channel, hot washing wells are generally used to solve it, but this not only requires the cost of hot washing, but also the injected hot water needs to be discharged, which seriously affects the efficiency of oil production. Summary of the invention

[0004] The purpose of the present invention is to provide a fishing cable electric heating system to solve the technical problems of high cost of hot well washing technology and influence on oil production time efficiency.

[0005] In order to solve the above technical problems, the technical solution provided by the present invention is:

[0006] The present invention provides a fishing cable electric heating system, comprising: an oil pipe, a fishing cable, a wellhead device and a frequency conversion control cabinet;

[0007] The oil pipe is sleeved on the fishing cable, and one end of the oil pipe is connected to the wellhead device;

[0008] The steel wire layer of the fishing cable in the oil pipe is electrically connected to the oil pipe through a downhole contactor, and one end of the fishing cable passing through the oil pipe is electrically connected to the frequency conversion control cabinet;

[0009] The frequency conversion control cabinet is also electrically connected to the wellhead device.

[0010] Furthermore, the fishing cable electric heating system also includes a wellhead sealed hanger, which includes an outer sleeve and slips and an insulating sleeve fixed in the outer sleeve;

[0011] The outer sleeve is connected to the wellhead device through a conversion joint, and is sleeved on the casting cable that passes through the wellhead device and the conversion joint from the oil pipe in sequence, and the inner walls of both ends of the outer sleeve are sealed with the outer sheath layer of the casting cable;

[0012] The slip and the insulating sleeve are both sleeved on the fishing cable, and the slip is fixed in the insulating sleeve, and the inner wall of the slip is in contact with the steel wire layer.

[0013] Further, the outer sleeve includes a first joint, a first connecting sleeve and a second connecting sleeve;

[0014] The inner walls of the first joint and the first connecting sleeve are both embedded with a plastic washer and a rubber cushion, and the plastic washer and the rubber cushion are distributed at intervals along the axial direction of the outer sleeve;

[0015] Two ends of the second connecting sleeve are respectively threadedly connected to the first joint and the first connecting sleeve;

[0016] Two ends of the insulating sleeve are respectively in contact with the first joint and the first connecting sleeve.

[0017] Furthermore, the insulating sleeve is divided into a seat sleeve and a pressing sleeve;

[0018] The slips are located in the seat cover;

[0019] One end of the seat sleeve is plugged into and matched with the first connecting sleeve, and the pressing sleeve is plugged into and matched with the other end of the seat sleeve, and both ends thereof are respectively in contact with the slip and the first joint.

[0020] Furthermore, the slips include two arc-shaped pressure plates, and the two arc-shaped pressure plates are connected by screws;

[0021] The inner wall of the arc-shaped pressing plate is provided with tooth-shaped flat teeth, and the tooth-shaped flat teeth are used to abut against the steel wire layer.

[0022] Furthermore, the fishing cable electric heating system also includes a conductor-connected sealed box, and the conductor-connected sealed box includes a conductor and a sealed box body;

[0023] The fishing cable passing through the wellhead sealed hanger from the conversion joint is passed through the sealing box body;

[0024] The conductor is disposed in the sealed box body, and one end of the conductor inside the sealed box body is electrically connected to the fishing cable, and the other end outside the sealed box body is electrically connected to the frequency conversion control cabinet;

[0025] The sealing box body is filled with insulating sealing grease.

[0026] Furthermore, a first through hole is provided on one side wall of the sealing box body;

[0027] The conductor interconnection type sealing box also includes a clamping conductor and a bakelite insulating pad;

[0028] The clamping conductor is located in the sealing box, clamped on the casting cable, and abutted against the steel wire layer;

[0029] One end of the conductor inside the sealed box is fixedly connected to the clamping conductor via a fixing screw;

[0030] The bakelite insulating pad is passed through the first through hole and sleeved on the conductor.

[0031] Furthermore, the conductor interconnecting sealing box further comprises a first rubber sealing pad and a first end top screw;

[0032] The first rubber sealing gasket is sleeved on the conductor and is located in the first through hole and abuts against the side wall of the first through hole;

[0033] The first end top screw is threadedly connected to the side wall of the first through hole to fix the first rubber sealing pad and the bakelite insulating pad to the sealing box body.

[0034] Furthermore, two opposite side walls of the sealed box body are each provided with a second through hole, and the fishing cable is passed through the second through hole;

[0035] The conductor interconnection type sealing box further comprises a second rubber sealing pad and a second end top screw;

[0036] The second rubber sealing gasket is sleeved on the fishing cable and is located in the second through hole and abuts against the side wall of the second through hole;

[0037] The second end top screw is threadedly connected to the side wall of the second through hole to fix the second rubber sealing pad to the sealing box body.

[0038] Further, the downhole contactor includes a fixed head and an elastic conductor;

[0039] There are two fixing heads, and both fixing heads are clamped on the steel wire layer;

[0040] The elastic conductor is connected between the two fixing heads and abuts against the oil pipe.

[0041] In summary, the technical effects that can be achieved by the electric heating system for fishing cables provided by the present invention are:

[0042] The salvaging cable electric heating system comprises an oil pipe, a salvaging cable, a wellhead device and a frequency conversion control cabinet; the oil pipe is sleeved on the salvaging cable, and one end of the oil pipe is connected to the wellhead device; the steel wire layer of the salvaging cable in the oil pipe is electrically connected to the oil pipe through a downhole contactor, and the end of the salvaging cable passing through the oil pipe is electrically connected to the frequency conversion control cabinet; the frequency conversion control cabinet is also electrically connected to the wellhead device.

[0043] In the electric heating system for fishing cables, the oil pipe, fishing cables, wellhead device and frequency conversion control cabinet form a loop. When the frequency conversion control cabinet supplies power, the steel wire layer is energized to generate heat and temperature regulation can be achieved to achieve the purpose of removing wax from the oil pipe. It can be seen that compared with the existing technology, the electric heating system for fishing cables can replace hot well washing, without water injection and drainage, and wax is removed by energizing the steel wire layer to generate heat, thus ensuring the timeliness of oil production. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0045] Figure 1 An assembly diagram of a fishing cable electric heating system provided by an embodiment of the present invention;

[0046] Figure 2 A cross-sectional view of a wellhead sealing hanger provided by an embodiment of the present invention;

[0047] Figure 3 A front view of a slip provided by an embodiment of the present invention;

[0048] Figure 4 For along Figure 3 Cross-sectional view in the AA direction;

[0049] Figure 5 A front view of a conductor interconnecting sealing box provided in an embodiment of the present invention;

[0050] Figure 6 For along Figure 5 Cross-sectional view in the BB direction;

[0051] Figure 7 A schematic diagram of the structure of a downhole contactor provided by an embodiment of the present invention;

[0052] Figure 8 A cross-sectional view of a fishing cable provided in an embodiment of the present invention.

[0053] Icon: 100-Tube;

[0054] 200-casting cable; 210-steel wire layer; 220-outer sheath layer;

[0055] 300-wellhead device; 400-frequency control cabinet;

[0056] 500-downhole contactor; 510-fixed head; 520-elastic conductor;

[0057] 600-wellhead sealed hanger; 610-outer sleeve; 620-slip; 630-insulating sleeve; 640-plastic gasket; 650-rubber cushion; 611-first joint; 612-first connecting sleeve; 613-second connecting sleeve; 614-second joint; 621-arc pressure plate; 631-seat sleeve; 632-pressing sleeve;

[0058] 700-conversion connector;

[0059] 800-conductor interconnecting sealing box; 810-conductor; 820-sealing box body; 830-clamping conductor; 840-bakelite insulating pad; 850-fixing screw; 860-first rubber sealing pad; 870-first end top screw; 880-second rubber sealing pad; 890-second end top screw;

[0060] 900-high pressure hose; 1000-ground wire. DETAILED DESCRIPTION

[0061] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, 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 part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0062] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0063] Some embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.

[0064] For oil wells with high wax content, the production channel is easily blocked during oil production, causing frequent pump jams and shutdowns of rodless pumps. When the wax blockage is serious, it will also cause pump inspections, which not only increases the operating costs of the oil production unit, but also leads to the loss of recovered crude oil. In order to solve the problem of wax blockage in the flow channel, hot washing wells are generally used to solve it, but this not only requires the cost of hot washing, but also the injected hot water needs to be discharged, which seriously affects the efficiency of oil production.

[0065] In view of this, the present invention provides an electric heating system for a salvaging cable, comprising an oil pipe 100, a salvaging cable 200, a wellhead device 300 and a frequency conversion control cabinet 400; the oil pipe 100 is sleeved on the salvaging cable 200, and one end of the oil pipe 100 is connected to the wellhead device 300; the steel wire layer 210 of the salvaging cable 200 in the oil pipe 100 is electrically connected to the oil pipe 100 through a downhole contactor 500, and one end of the salvaging cable 200 passing through the oil pipe 100 is electrically connected to the frequency conversion control cabinet 400; the frequency conversion control cabinet 400 is also electrically connected to the wellhead device 300.

[0066] In the electric heating system for the fishing cable, the oil pipe 100, the fishing cable 200, the wellhead device 300 and the frequency conversion control cabinet 400 form a loop. When the frequency conversion control cabinet 400 supplies power, the steel wire layer 210 is energized to generate heat, and temperature regulation can be achieved to achieve the purpose of removing wax in the oil pipe 100. It can be seen that compared with the prior art, the electric heating system for the fishing cable can replace hot well washing, without water injection and drainage, and wax is removed by energizing and heating the steel wire layer 210, thereby ensuring the timeliness of oil production.

[0067] The following combination Figures 1 to 8 The structure and shape of the electric heating system for the fishing cable provided in this embodiment are described in detail:

[0068] Regarding the downhole contactor 500, specifically:

[0069] refer to Figure 7 The downhole contactor 500 includes a fixed head 510 and an elastic conductor 520; the fixed head 510 is divided into an upper and a lower part, and is a split structure. Each fixed head 510 is composed of two sub-fixed heads, and the two sub-fixed heads are butt-jointed to clamp the steel wire layer 210, and are fixed to the salvage cable 200 by bolt connection; the elastic conductor 520 is connected between the upper and lower sub-fixed heads, and abuts against the oil pipe 100.

[0070] It should be noted here that the reference Figure 8 From the inside to the outside, the fishing cable 200 includes a conductor layer, an insulating layer, an inner sheath layer, a steel wire layer 210 and an outer sheath layer 220, wherein the steel wire layer 210 is a heating body, and the outer sheath layer 220 is an insulating layer, isolating the steel wire layer 210 to form an insulator with the outside world.

[0071] In the above, the fishing cable 200 is electrically connected to the oil pipe 100, and the oil pipe 100 is connected to the wellhead device 300. The two ends of the ground wire 1000 are respectively connected to the wellhead device 300 and the frequency conversion control cabinet 400, serving as one pole of the power supply.

[0072] For further reference, Figure 1 The electric heating system for the fishing cable also includes a wellhead sealed hanger 600, the lower end of which is connected to the conversion joint 700 (thread or flange), fixed above the wellhead, and the upper end is connected to the high-pressure hose 900 sleeved on the fishing cable 200, through which the fishing cable 200 runs. Here, the wellhead sealed hanger 600 plays the role of fixing the fishing cable 200 and preventing the fishing cable 200 from falling, and at the same time, it also seals the well fluid that enters between the steel wire layer 210 and the outer sheath layer 220 from the well to prevent the well fluid from overflowing the outer sheath layer 220; the high-pressure hose 900 protects the fishing cable 200 and can also seal a small amount of well fluid.

[0073] Regarding the wellhead seal hanger 600, specifically:

[0074] refer to Figures 2 to 4 The wellhead sealed hanger 600 includes an outer sleeve 610 and a slip 620 and an insulating sleeve 630 fixed in the outer sleeve 610; the outer sleeve 610 is connected to the wellhead device 300 through a conversion joint 700, and is sleeved on the salvage cable 200 that passes through the wellhead device 300 and the conversion joint 700 from the oil pipe 100 in sequence, and the inner walls of the two ends of the outer sleeve 610 are sealed with the outer sheath layer 220 of the salvage cable 200; the slip 620 and the insulating sleeve 630 are both sleeved on the salvage cable 200, and the slip 620 is fixed in the insulating sleeve 630, and its inner wall is in contact with the steel wire layer 210.

[0075] Specifically, Figure 2 For example, the outer sleeve 610 includes a first joint 611, a first connecting sleeve 612 and a second connecting sleeve 613; the inner walls of the first joint 611 and the first connecting sleeve 612 are both embedded with plastic washers 640 and rubber cushions 650, the plastic washers 640 and the rubber cushions 650 are distributed at intervals along the axial direction of the outer sleeve 610, and the rubber cushions 650 form a seal with the outer jacket layer 220; the upper and lower ends of the second connecting sleeve 613 are respectively threadedly connected to the first joint 611 and the first connecting sleeve 612; the lower end of the first connecting sleeve 612 is threadedly connected to the second joint 614, and the wellhead sealed hanger 600 is connected to the conversion joint 700 through the second joint 614.

[0076] Following the above, combined Figure 3 and Figure 4As shown, the slip 620 includes two arc-shaped pressing plates 621, which are screwed together; the inner wall of the arc-shaped pressing plate 621 is provided with serrated flat teeth, and when the fishing cable 200 passes through the slip 620, the outer sheath layer 220 of the corresponding length is stripped off according to the length of the slip 620, so that the steel wire layer 210 is fully in contact with the serrated flat teeth and is tightly bitten. Figure 2 The insulating sleeve 630 is divided into a seat sleeve 631 and a pressing sleeve 632; the slip 620 is in the seat sleeve 631; one end of the seat sleeve 631 is plugged into the first connecting sleeve 612, and the pressing sleeve 632 is plugged into the other end of the seat sleeve 631, and its two ends are respectively abutted against the slip 620 and the first joint 611.

[0077] For further reference, Figure 1 The electric heating system for the fishing cable also includes a conductor interconnecting sealing box 800, in which a clamping conductor 830 is arranged. The clamping conductor 830 is made of copper and fixed on the steel wire layer 210 as the other pole of the power supply. The functions of the conductor interconnecting sealing box 800 are to seal the outer sheath layer 220 of the fishing cable 200 to prevent the well fluid from overflowing, and to prevent the well fluid from overflowing the sealing box body 820 by pouring insulating sealing grease inside the sealing box body 820.

[0078] Regarding the conductor interconnecting sealed box 800, specifically:

[0079] refer to Figure 5 and Figure 6 The conductor-connected sealing box 800 includes a conductor 810 and a sealing box body 820; the salvage cable 200 that passes through the wellhead sealed hanger 600 from the conversion joint 700 is passed through the sealing box body 820; the conductor 810 is passed through the sealing box body 820, and its end inside the sealing box body 820 is electrically connected to the salvage cable 200, and its end outside the sealing box body 820 is electrically connected to the frequency conversion control cabinet 400; the sealing box body 820 is filled with insulating sealing grease.

[0080] Specifically, refer to Figure 6, a first through hole is provided on one side wall of the sealing box body 820; the conductor interconnecting sealing box 800 also includes a clamping conductor 830 and a bakelite insulating pad 840; the clamping conductor 830 is in the sealing box body 820 and is clamped on the salvage cable 200. Here, according to the width of the clamping conductor 830, the outer sheath layer 220 needs to be stripped to the same width, and the clamping conductor 830 is fully in contact with and pressed against the exposed steel wire layer 210; one end of the conductor 810 in the sealing box body 820 is fixedly connected to the clamping conductor 830 by a fixing screw 850; the bakelite insulating pad 840 is passed through the first through hole and is sleeved on the conductor 810. With this design, the electrical connection between the conductor 810 and the salvage cable 200 is achieved, and the conductor 810 is isolated from the outside world, reducing the risk of electrical accidents.

[0081] As mentioned above, the conductor interconnecting sealing box 800 also includes a first rubber sealing pad 860 and a first end top screw 870; the first rubber sealing pad 860 is sleeved on the conductor 810, and is located in the first through hole, and abuts against the side wall of the first through hole; the first end top screw 870 is threadedly connected to the side wall of the first through hole to fix the first rubber sealing pad 860 and the bakelite insulating pad 840 to the sealing box body 820.

[0082] Continuing with the above, second through holes are provided on the two opposite side walls of the sealing box body 820, and the salvage cable 200 is inserted into the second through holes; the conductor-connected sealing box 800 also includes a second rubber sealing pad 880 and a second end top screw 890; the salvage cable 200 enters the sealing box body 820 through the second through hole on the left, passes through the clamping conductor 830, and then passes out from the second through hole on the right; the rubber sealing pad is pressed into the second through hole, and the end top screw is threadedly connected to the side wall of the second through hole, thereby pressing the rubber sealing pad, so that the rubber sealing pad is in full contact with the outer sheath layer 220 to form a seal.

[0083] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A fishing cable electric heating system, It is characterized in that include: Oil pipe (100), fishing cable (200), wellhead device (300) and frequency conversion control cabinet (400); The oil pipe (100) is sleeved on the fishing cable (200), and one end of the oil pipe is connected to the wellhead device (300); The steel wire layer (210) of the salvaging cable (200) in the oil pipe (100) is electrically connected to the oil pipe (100) via a downhole contactor (500), and one end of the salvaging cable (200) passing through the oil pipe (100) is electrically connected to the frequency conversion control cabinet (400); The frequency conversion control cabinet (400) is also electrically connected to the wellhead device (300).

2. The electric heating system for fishing cable according to claim 1, It is characterized in that The fishing cable electric heating system also includes a wellhead sealed hanger (600), wherein the wellhead sealed hanger (600) includes an outer sleeve (610) and slips (620) and an insulating sleeve (630) fixed in the outer sleeve (610); The outer sleeve (610) is connected to the wellhead device (300) through a conversion joint (700), and is sleeved on the salvage cable (200) which passes through the wellhead device (300) and the conversion joint (700) from the oil pipe (100) in sequence, and the inner walls of both ends of the outer sleeve (610) are sealed with the outer sheath layer (220) of the salvage cable (200); The slip (620) and the insulating sleeve (630) are both sleeved on the fishing cable (200), and wherein: The slip (620) is fixed in the insulating sleeve (630), and the inner wall thereof abuts against the steel wire layer (210).

3. The electric heating system for fishing cable according to claim 2, It is characterized in that The outer sleeve (610) comprises a first joint (611), a first connecting sleeve (612) and a second connecting sleeve (613); The inner walls of the first joint (611) and the first connecting sleeve (612) are both embedded with a plastic washer (640) and a rubber cushion (650), and the plastic washer (640) and the rubber cushion (650) are distributed at intervals along the axial direction of the outer sleeve (610); Two ends of the second connecting sleeve (613) are respectively threadedly connected to the first joint (611) and the first connecting sleeve (612); Two ends of the insulating sleeve (630) are respectively in contact with the first joint (611) and the first connecting sleeve (612).

4. The electric heating system for fishing cable according to claim 3, It is characterized in that The insulating sleeve (630) is divided into a seat sleeve (631) and a pressing sleeve (632); The slip (620) is located inside the seat cover (631); One end of the seat sleeve (631) is plugged into and matched with the first connecting sleeve (612), and the pressing sleeve (632) is plugged into and matched with the other end of the seat sleeve (631), and both ends thereof are respectively abutted against the slip (620) and the first joint (611).

5. The electric heating system for fishing cable according to claim 2, It is characterized in that The slip (620) comprises two arc-shaped pressing plates (621), and the two arc-shaped pressing plates (621) are connected by screws; The inner wall of the arc-shaped pressing plate (621) is provided with tooth-shaped flat teeth, and the tooth-shaped flat teeth are used to abut against the steel wire layer (210).

6. The electric heating system for fishing cable according to claim 2, It is characterized in that The fishing cable electric heating system further comprises a conductor-connected sealed box (800), wherein the conductor-connected sealed box (800) comprises a conductor (810) and a sealed box body (820); The fishing cable (200) passing through the wellhead sealing hanger (600) from the conversion joint (700) is passed through the sealing box body (820); The conductor (810) is inserted into the sealed box body (820), and one end of the conductor located inside the sealed box body (820) is electrically connected to the casting cable (200), and one end of the conductor located outside the sealed box body (820) is electrically connected to the frequency conversion control cabinet (400); The sealing box body (820) is filled with insulating sealing grease.

7. The electric heating system for fishing cable according to claim 6, It is characterized in that A first through hole is provided on one side wall of the sealing box body (820); The conductor interconnecting sealing box (800) further comprises a clamping conductor (830) and a bakelite insulating pad (840); The clamping conductor (830) is located in the sealing box body (820), is clamped on the fishing cable (200), and is in contact with the steel wire layer (210); One end of the conductor (810) located in the sealed box body (820) is fixedly connected to the clamping conductor (830) via a fixing screw (850); The bakelite insulating pad (840) is inserted into the first through hole and sleeved on the conductor (810).

8. The electric heating system for fishing cables according to claim 7, It is characterized in that The conductor interconnecting sealing box (800) further comprises a first rubber sealing pad (860) and a first end top screw (870); The first rubber sealing pad (860) is sleeved on the conductor (810), is located in the first through hole, and abuts against the side wall of the first through hole; The first end top screw (870) is threadedly connected to the side wall of the first through hole to fix the first rubber sealing pad (860) and the bakelite insulating pad (840) to the sealing box body (820).

9. The electric heating system for fishing cables according to claim 6, It is characterized in that Two opposite side walls of the sealing box body (820) are each provided with a second through hole, and the salvaging cable (200) is passed through the second through hole; The conductor interconnecting sealing box (800) further comprises a second rubber sealing pad (880) and a second end top screw (890); The second rubber sealing pad (880) is sleeved on the fishing cable (200) and is located in the second through hole and abuts against the side wall of the second through hole; The second end top screw (890) is threadedly connected to the side wall of the second through hole to fix the second rubber sealing pad (880) to the sealing box body (820).

10. The electric heating system for fishing cables according to claim 1, It is characterized in that The downhole contactor (500) comprises a fixed head (510) and an elastic conductor (520); Two fixing heads (510) are provided, and both fixing heads (510) are clamped on the steel wire layer (210); The elastic conductor (520) is connected between the two fixing heads (510) and abuts against the oil pipe (100).

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