Downhole inductive heating metal melt plugging tool and method

Abstract

The application discloses a downhole induction heating metal melting plugging tool and method, and belongs to the technical field of oil and gas wellbore plugging. The downhole induction heating metal melting plugging tool comprises a suspension end cover, an upper shell and a lower shell, the upper shell and the lower shell are sequentially provided with a power supply control assembly, a heat dissipation assembly and an induction heating assembly along an axial direction; alloy material is melted by an electric induction heating mode to perform plugging work on a wellbore, and efficient wellbore plugging can be realized; and alloy with high strength and low melting point can be selected as wellbore plugging material. The technical scheme provided by the application can quickly and effectively complete wellbore plugging operation, has the advantages of fast heating speed, high efficiency, small heat loss, easy automation control and green environmental protection, and significantly improves the efficiency of wellbore plugging operation.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of oil and gas well plugging, in particular to a downhole induction heating metal melting plugging tool and method. BACKGROUND

[0002] With the gradual entry of some oilfields in China into the middle and late production period, the number of old wells that are shut down, shut in or even abandoned due to casing deformation and cement sheath sealing failure increases year by year. These shut down, shut in and abandoned wells have the following safety hazards: first, casing deformation or damage causes production stoppage and scrap, casing corrosion perforation, underground water channeling between different layers and surface water seepage into the wellbore and channeling into fresh water layers or permeable formations connected to fresh water layers and surface, and pollution of underground water sources; second, wells with problems such as welding blind plates on casing splices and wellhead packers have problems such as inability to measure and release pressure, and once the wellbore pressure changes, oil and gas leakage or blowout accidents are likely to occur; third, open wells without wellhead control are prone to major blowout accidents.

[0003] Using appropriate wellbore plugging materials to prevent fluid from channeling through the casing or the annulus between the casing and the wellbore helps to prevent safety hazards in shut down, shut in and abandoned wells. The commonly used wellbore plugging material is cement, which is used to set cement plugs in the wellbore to isolate production layers and prevent oil, gas and water from migrating from the well bottom to the wellhead. When cement is used for wellbore plugging, due to the influence of cement slurry density and hardening time, accidents such as lost circulation, "flag pole insertion" and "sausage filling" are likely to occur during cementing. In addition, due to the large difference in elastic parameters between the cement plug and the casing, deformation is not coordinated under external loads such as ground stress and temperature changes, leading to cement plug sealing failure, especially the cement plug and the cementing surface of the casing and the formation, which is prone to peeling, thus losing the sealing function.

[0004] With the deepening of oilfield development and the deepening of safety and environmental protection concepts, more and more abandoned wells need to be plugged due to the need for oilfield production layout adjustment and safety hazard control. In patent CN11587479A, a method of melting metal material by combustion to form a plugging plug is disclosed, but this method has uncertain factors such as uncontrollable combustion melting process and uncontrollable temperature. Therefore, it is of great significance to provide a simple, safe and efficient wellbore plugging tool and method. Electromagnetic induction heating technology has the advantages of fast heating speed, high thermal efficiency, easy automation control and green environmental protection. Using electromagnetic induction heating can quickly melt alloy materials to complete wellbore plugging, and the operation process is simple, greatly improving the plugging effect. SUMMARY

[0005] This invention provides a downhole induction heating metal melting plugging tool and method, which uses electromagnetic induction heating to quickly melt alloy materials to complete wellbore plugging operations. The operation process is simple, the plugging effect is greatly improved, the operation steps of wellbore plugging operations are simplified, and the efficiency of wellbore plugging operations is significantly improved.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] This invention provides a downhole induction heating metal melting plugging tool, characterized in that it includes a suspension end cap, an upper shell, and a lower shell, wherein a power control component, a heat dissipation component, and an induction heating component are sequentially arranged along the axial direction in the upper shell and the lower shell;

[0008] The power control component is fixedly disposed inside the upper housing. The power control component includes an insulating base, a power board, a heat-conducting plate, and a heat-conducting pipe. The insulating base is fixedly disposed on the inner side wall of the upper housing. The power board of the power control component is mounted on the insulating base. The power board is fixedly connected to the heat-conducting plate. The heat-conducting plate is fixedly connected to the heat-conducting pipe. A plug for connecting a transmission cable is provided at the upper end of the insulating base, and a plug for connecting an output cable is provided at the lower end of the insulating base.

[0009] The heat dissipation assembly is fixedly disposed between the upper housing and the lower housing. The heat dissipation assembly includes a circulation pump, a heat dissipation cylinder, a heat dissipation pipe, and heat dissipation fins. The upper end of the heat dissipation cylinder is threaded and fixedly connected to the lower end of the upper housing. The lower end of the heat dissipation cylinder is threaded and fixedly connected to the upper end of the lower housing. A portion of the heat dissipation pipe is disposed inside the heat dissipation cylinder, and the other portion of the heat dissipation pipe is disposed on the outer surface of the heat dissipation cylinder. The heat dissipation fins are installed on the outer wall of the heat dissipation cylinder.

[0010] The induction heating assembly is fixedly installed inside the lower housing. The induction heating assembly includes a heating cylinder, an induction coil, a heat-conducting solenoid, and a heat insulation cylinder. The lower end of the heating cylinder is fixedly and detachably connected to the lower end of the central hole of the lower housing. The heating cylinder includes a heat insulation end cap, a hollow outer cylinder, and an anti-drop ring. The heat insulation end cap is fixedly connected to the upper end of the hollow outer cylinder by threads. The heat insulation cylinder includes an inner heat insulation cylinder and an outer heat insulation cylinder. The inner heat insulation cylinder is coaxially sleeved on the outside of the heating cylinder, and the outer heat insulation cylinder is coaxially sleeved on the outside of the inner heat insulation cylinder. The induction coil and the heat-conducting solenoid are coaxially spirally wound in the annular space between the inner and outer heat insulation cylinders. The induction coil and the heat-conducting solenoid are located at the end of the heating cylinder near the anti-drop ring.

[0011] In the above-mentioned metal spraying type in-situ repair tool for downhole casing, optionally, the lower end of the heat-insulating end cap, the inner wall of the hollow outer cylinder and the upper end of the anti-drop ring form a cylindrical receiving cavity, and the cylindrical receiving cavity is provided with alloy material for well casing plugging.

[0012] In the above-mentioned metal spraying type in-situ repair tool for downhole casing, the alloy material can be configured as powder, granules or disc and placed inside the alloy material receiving cavity, and the alloy material can be integrally cast into the alloy material receiving cavity.

[0013] In the above-mentioned metal spraying type in-situ repair tool for downhole casing, optionally, the heat dissipation fins are in the shape of circular rings, the heat dissipation fins are coaxially and evenly distributed on the outer wall of the heat dissipation cylinder, and the heat dissipation pipes arranged on the outer side of the heat dissipation cylinder are U-shaped and interlaced between the heat dissipation fins.

[0014] In the aforementioned metal spraying type in-situ repair tool for downhole casing, optionally, the induction coil and the heat-conducting solenoid are alternately wound in the annulus between the inner and outer heat insulation cylinders.

[0015] In the above-mentioned metal spraying type in-situ repair tool for downhole casing, optionally, the heat dissipation cylinder is provided with an upper sealing end cap and a lower sealing end cap, the lower part of the upper sealing end cap, the interior of the heat dissipation cylinder and the upper part of the lower sealing end cap form a cavity, and the cavity of the heat dissipation cylinder contains coolant.

[0016] In the aforementioned metal spraying type in-situ repair tool for downhole casing, optionally, two circulation pumps are configured. One of the two circulation pumps is placed in the upper housing of the heat dissipation cylinder, and the other of the two circulation pumps is placed in the lower housing of the heat dissipation cylinder. The upper end of the circulation pump located in the upper housing is connected to the heat conduction pipe of the power control component, and the lower end is connected to the heat dissipation cylinder cavity and the heat dissipation pipe through a pipeline. The upper end of the circulation pump located in the lower housing is connected to the heat dissipation cylinder cavity and the heat dissipation pipe through a pipeline, and the lower end is connected to the heat conduction solenoid of the induction heating component.

[0017] In the aforementioned metal spraying type in-situ repair tool for downhole casing, optionally, the coolant is introduced into the heat-conducting pipe, the heat dissipation pipe, and the heat-conducting solenoid via two circulating pumps.

[0018] Optionally, in the above-mentioned metal spraying type in-situ repair tool for downhole casing, the upper end of the heat-insulating end cap is provided with a cable connector, the upper end of the cable connector is connected to the output cable of the power control component, and the lower end of the cable connector is connected to the induction coil.

[0019] In the aforementioned metal spraying type in-situ repair tool for downhole casing, optionally, the downhole induction heating metal melting sealing method includes the following steps:

[0020] S1. Pretreatment: A bridge plug is placed at the wellbore sealing location, a groove is milled inside the casing at the wellbore sealing location, and the oil and iron filings remaining on the inner wall of the casing and the upper end face of the bridge plug are cleaned.

[0021] S2. Assemble the downhole induction heating metal melting plugging tool and lower it into the wellbore at the plugging location via a wire rope or coiled tubing.

[0022] S3. The power supply equipment is activated on the surface, transmitting surface electricity to the downhole induction heating metal melting sealing tool via cable. The power control component converts the surface-transmitted electricity into a current suitable for the induction heating component, which is then transmitted to the induction coil. Electromagnetic induction is generated at the induction coil, creating eddy currents within the heating cylinder. This generates heat, melting the alloy material inside the heating cylinder. After complete melting, the alloy material flows into the wellbore through the central hole of the anti-drop ring. Simultaneously, two circulating pumps are controlled to operate, pumping coolant from the heat sink into the heat pipe. This removes the heat generated by the power control component and the induction coil, exchanging heat with the low-temperature fluid inside the wellbore, thus lowering the operating temperature of the power control component and the induction coil.

[0023] S4. After the alloy material has completely melted and flowed into the wellbore, the downhole induction heating metal melting plugging tool is pulled out. As the temperature of the liquid alloy flowing into the wellbore gradually decreases, the liquid alloy gradually solidifies, forming a columnar plugging alloy plug above the bridge plug, thus completing the wellbore plugging.

[0024] The above-described technical solution of the present invention has at least the following beneficial effects:

[0025] The downhole induction heating metal melting plugging tool and method provided by this invention utilizes electromagnetic induction heating to rapidly melt alloy materials for wellbore plugging, simplifying the operation steps and significantly improving the efficiency of wellbore plugging operations. By selecting a high-strength, low-melting-point alloy as the wellbore plugging material, it effectively solves the problems of well leakage, "flagpole" (where the plug is inserted too deeply into the casing), and "sausage-like" blockage that are prone to occur during cement-based plugging. It also prevents the cemented surface between the plug and the casing and formation from peeling off, thus improving the wellbore plugging effect. Furthermore, this downhole induction heating metal melting plugging tool has fewer moving parts, is stable and reliable, has a short overall structure, and has a wide range of applications. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 This is a cross-sectional view of the structure of the downhole induction heating metal melting plugging tool provided in an embodiment of the present invention;

[0028] Figure 2 A schematic diagram of the induction heating assembly of the downhole induction heating metal melting plugging tool provided in an embodiment of the present invention;

[0029] Figure 3 A schematic diagram of the heat dissipation assembly of the downhole induction heating metal melting plugging tool provided in an embodiment of the present invention;

[0030] Figure 4 This is a flowchart of a downhole induction heating metal melting plugging method provided in an embodiment of the present invention;

[0031] Figures 5a-5e This is a schematic diagram of the pretreatment process of the downhole induction heating metal melting plugging tool provided in an embodiment of the present invention working in the wellbore;

[0032] Explanation of reference numerals in the attached figures:

[0033] 1-Tool body, 2-Power control assembly, 3-Heat dissipation assembly, 4-Induction heating assembly, 11-Suspension end cap, 12-Upper housing, 13-Lower housing, 21-Insulating base, 22-Power board, 23-Heat conduction plate, 24-Heat conduction pipe, 25-Input connector, 26-Output connector, 311-Upper circulation pump, 312-Lower circulation pump, 32-Heat dissipation cylinder, 33-Heat dissipation pipe, 34-Heat dissipation fins, 351-Sealed end cap on heat dissipation cylinder, 352 - Lower sealing end cap of the heat sink cylinder, 41- Heating cylinder end cap, 42- Heating cylinder, 43- Induction coil, 44- Thermal solenoid, 451- Insulating inner cylinder, 452- Insulating outer cylinder, 46- Anti-drop ring, 471- Alloy material granules, 472- Alloy material disc, 473- Alloy sealing plug, 51- Ground surface, 52- Casing, 53- Cement ring, 54- Wellbore to be sealed, 55- Groove, 61- Insulating sand layer, 62- Bridge plug, 7- Wire rope and cable Detailed Implementation

[0034] As described in the background section, with the continuous development of oilfields and the deepening of safety and environmental protection concepts, more and more abandoned wells need to be plugged due to the need for adjustments to oilfield production layout and the management of safety hazards. When cement is used for wellbore plugging, accidents such as well leakage, "flagpole insertion," and "sausage filling" are prone to occur during the cement injection process due to the influence of cement slurry density and hardening time. Furthermore, the cement plug, casing, and formation bonding surface are prone to peeling, thus losing their sealing effect.

[0035] To address the aforementioned technical problems, this invention provides a downhole induction heating metal melting plugging tool and method. It uses electromagnetic induction heating to rapidly melt alloy materials to complete wellbore plugging operations. The operation process is simple, the plugging effect is greatly improved, the operation steps of wellbore plugging operations are simplified, and the efficiency of wellbore plugging operations is significantly improved.

[0036] To make the above-mentioned objectives, features, and advantages of the embodiments of the present invention more apparent and understandable, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0037] like Figure 1 As shown, the downhole induction heating metal melting plugging tool 1 provided in this embodiment of the invention includes a suspension end cap 11, an upper housing 12 and a lower housing 13. A power control component 2 is fixedly installed in the central hole of the upper housing 12, and an induction heating component 4 is fixedly installed in the central hole of the lower housing 13. The heat dissipation component 4 is fixedly connected between the upper housing 12 and the lower housing 13. The suspension end cap 11 is fixedly connected to the upper end of the upper housing by threads.

[0038] The power control assembly 2 includes an insulating base 21, a power board 22, a heat-conducting plate 23, and a heat-conducting pipe 24. The insulating base 21 is fixedly installed on the inner side wall of the upper housing 12. The power board 22 of the power control assembly 2 is fixedly installed on the insulating base 21. The power board 22 is fixedly connected to the heat-conducting plate 23 and the heat-conducting pipe 24. The upper end of the insulating base 21 is provided with a plug for connecting the transmission cable, and the lower end of the insulating base 21 is provided with a plug for connecting the output cable.

[0039] The heat dissipation assembly 3 includes a circulation pump 31, a heat dissipation cylinder 32, a heat dissipation pipe 33, and heat dissipation fins 34. The upper end of the heat dissipation cylinder 32 is threaded and fixedly and detachably connected to the lower end of the upper housing 12. The lower end of the heat dissipation cylinder 32 is threaded and fixedly and detachably connected to the upper end of the lower housing 13. A portion of the heat dissipation pipe 33 is disposed inside the heat dissipation cylinder 32, and the other portion of the heat dissipation pipe 33 is arranged on the outer surface of the heat dissipation cylinder 32. The heat dissipation fins 34 are installed on the outer wall of the heat dissipation cylinder 32.

[0040] Combination Figure 1 and Figure 2 The induction heating assembly 4 includes a heating cylinder end cap 41, a heating cylinder 42, an induction coil 43, a heat-conducting solenoid 44, a heat insulation cylinder 45, and an anti-drop ring 46. The lower end of the heating cylinder 42 is fixedly and detachably connected to the lower end of the center hole of the lower housing 13. The heating cylinder end cap 41 is fixedly connected to the upper end of the heating cylinder 42 by threads. The anti-drop ring 46 is fixedly connected to the inner side of the lower end of the heating cylinder 42 by threads. The heat insulation cylinder 45 includes an inner heat insulation cylinder 451 and an outer heat insulation cylinder 452. The inner heat insulation cylinder 451 is coaxially sleeved on the outside of the heating cylinder 42, and the outer heat insulation cylinder 452 is coaxially sleeved on the outside of the inner heat insulation cylinder 451. The induction coil 43 and the heat-conducting solenoid 44 are coaxially spirally wound in the annular space between the inner heat insulation cylinder 451 and the outer heat insulation cylinder 452. The induction coil 43 and the heat-conducting solenoid 44 are wound alternately.

[0041] Combination Figure 3 and Figure 4 The lower end of the heating cylinder end cap 41, the inner wall of the heating cylinder 42, and the upper end of the anti-drop ring 46 form a cylindrical receiving cavity. An alloy material 47 for wellbore sealing is disposed within the receiving cavity. The alloy material 47 can be in powder, granular form 471, or disc-shaped form 472 and placed inside the receiving cavity. Alternatively, the alloy material 47 can be integrally cast into the receiving cavity.

[0042] like Figures 5a-5e As shown, the heat dissipation fins 34 are in the shape of circular rings and are evenly distributed coaxially along the outer wall of the heat dissipation cylinder 32. The heat dissipation pipes 33 arranged on the outside of the heat dissipation cylinder 32 are arranged in a U-shape between the heat dissipation fins 34 to increase the heat exchange area.

[0043] Furthermore, the heat sink 32 is provided with an upper sealing end cap 351 and a lower sealing end cap 352. The lower part of the upper sealing end cap 351, the interior of the heat sink 32, and the upper part of the lower sealing end cap 352 form a cavity 353, which contains coolant.

[0044] Furthermore, two circulation pumps, 311 and 312, are configured. One of the circulation pumps, 311, is installed inside the upper housing 12 above the sealing end cover 351 of the heat sink, and the other circulation pump, 312, is installed inside the lower housing 13 below the sealing end cover 352 of the heat sink. The two ends of the circulation pump 311, located in the upper housing, are connected to the heat conduction pipe 24 of the power control component, the heat sink cavity 353, and the heat dissipation pipe 33, respectively, forming a first coolant circulation channel. The two ends of the circulation pump 312, located in the lower housing, are connected to the heat sink cavity 353, the heat dissipation pipe 33, and the heat conduction solenoid 43 of the induction heating component, respectively, forming a second coolant circulation channel. Coolant is introduced into the first and second coolant circulation channels through circulation pumps 311 and 312, respectively. During the operation of the tool, the heat generated by the power control component 2 and the induction coil 42 is exchanged to the fluid inside the wellbore, reducing the operating temperature of the power control component 2 and the induction coil 42, thereby improving the overall working efficiency of the tool.

[0045] The downhole induction heating metal melting plugging tool provided in this invention can be applied to wellbore plugging operations. The following is a description of the tool. Figure 4 and Figures 5a-5e The process of downhole induction heating metal melting and plugging is described and explained, such as... Figure 5a and 5b As shown, before the operation, a bridge plug 62 is placed at the wellbore sealing position 54. A groove 55 is milled inside the casing at the wellbore sealing position, and residual oil and iron filings on the inner wall 53 of the casing and the upper surface of the bridge plug 62 are cleaned. After cleaning, a heat-insulating sand layer 61 is laid on top of the bridge plug 62. Then, after the downhole induction heating metal melting sealing tool is assembled, it is lowered into the wellbore to be sealed position 54 using a wire rope or coiled tubing 7. Figure 5c As shown.

[0046] The power supply equipment is activated on the ground, transmitting surface electrical energy to the induction heating metal melting sealing tool 1 underground via cable 7. The power control component 2 converts the surface-transmitted electrical energy into a current suitable for the induction heating component 4, which is then transmitted to the induction coil 43. Electromagnetic induction is generated at the induction coil 43, forming eddy currents within the heating cylinder. This generates heat that melts the alloy materials 471 and 472 inside the heating cylinder. After the alloy materials are completely melted, they flow into the wellbore through the central hole of the anti-drop ring 46. Figure 5d As shown. At the same time, the two circulating pumps 311 and 312 are controlled to operate, pumping the coolant in the heat sink into the heat pipe, dissipating the heat generated by the power control components and induction coil, and exchanging heat with the low-temperature fluid in the wellbore, thereby reducing the operating temperature of the power control components and induction coil.

[0047] After the alloy materials 471 and 472 have completely melted and flowed into the wellbore, the downhole induction heating metal melting plugging tool 1 is removed. As the temperature of the liquid alloy flowing into the wellbore gradually decreases, the liquid alloy gradually solidifies, forming a columnar plugging alloy plug 473 above the bridge plug 62, thus completing the wellbore plugging. Figure 5e As shown.

[0048] This invention provides a downhole induction heating metal melting plugging tool and method. By transmitting electrical energy from the surface to the wellbore, electromagnetic induction heating is used to melt alloy materials downhole to complete the wellbore plugging operation. This simplifies the operation steps of wellbore plugging and significantly improves the efficiency of wellbore plugging operations. Furthermore, the tool has fewer moving parts, is stable and reliable, has a simple overall structure, and has a wide range of applications.

[0049] In the description of this invention, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0050] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0051] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the first feature and the second feature can mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Furthermore, "above," "over," and "on top" of the first feature and the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the first feature and the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0052] The various embodiments or implementation methods described in this specification are presented in a progressive manner. Each embodiment focuses on the differences from other embodiments, and the same or similar parts between the embodiments can be referred to each other.

[0053] It should be noted that the embodiments referred to in the specification, such as "one embodiment," "embodiment," "exemplary embodiment," and "some embodiments," may include specific features, structures, or characteristics, but not every embodiment necessarily includes that specific feature, structure, or characteristic. Furthermore, such phrases do not necessarily refer to the same embodiment. Moreover, when a specific feature, structure, or characteristic is described in connection with an embodiment, implementing such a feature, structure, or characteristic in conjunction with other embodiments, whether explicitly described or not, is within the knowledge scope of those skilled in the art.

[0054] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions 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 downhole induction heating metal melting plugging tool, characterized in that, It includes a suspension end cap, an upper housing, and a lower housing, wherein a power control component, a heat dissipation component, and an induction heating component are sequentially arranged along the axial direction in the upper housing and the lower housing; The power control component is fixedly disposed inside the upper housing. The power control component includes an insulating base, a power board, a heat-conducting plate, and a heat-conducting pipe. The insulating base is fixedly disposed on the inner side wall of the upper housing. The power board of the power control component is mounted on the insulating base. The power board is fixedly connected to the heat-conducting plate. The heat-conducting plate is fixedly connected to the heat-conducting pipe. A plug for connecting a transmission cable is provided at the upper end of the insulating base, and a plug for connecting an output cable is provided at the lower end of the insulating base. The heat dissipation assembly is fixedly disposed between the upper housing and the lower housing. The heat dissipation assembly includes a circulating pump, a heat dissipation cylinder, a heat dissipation pipe, and heat dissipation fins. The upper end of the heat dissipation cylinder is threaded and fixedly connected to the lower end of the upper housing, and the lower end of the heat dissipation cylinder is threaded and fixedly connected to the upper end of the lower housing. A portion of the heat dissipation pipe is disposed inside the heat dissipation cylinder, and the other portion of the heat dissipation pipe is disposed on the outer surface of the heat dissipation cylinder. The heat dissipation fins are installed on the outer wall of the heat dissipation cylinder. The heat dissipation cylinder is provided with an upper sealing end cap and a lower sealing end cap. The lower part of the upper sealing end cap, the interior of the heat dissipation cylinder, and the upper part of the lower sealing end cap form a heat dissipation cylinder cavity, which contains coolant. The induction heating assembly is fixedly installed inside the lower housing. The induction heating assembly includes a heating cylinder, an induction coil, a heat-conducting solenoid, and a heat insulation cylinder. The lower end of the heating cylinder is fixedly and detachably connected to the lower end of the central hole of the lower housing. The heating cylinder includes a heat insulation end cap, a hollow outer cylinder, and an anti-drop ring. The heat insulation end cap is fixedly connected to the upper end of the hollow outer cylinder by threads. The heat insulation cylinder includes an inner heat insulation cylinder and an outer heat insulation cylinder. The inner heat insulation cylinder is coaxially sleeved on the outside of the heating cylinder, and the outer heat insulation cylinder is coaxially sleeved on the outside of the inner heat insulation cylinder. The induction coil and the heat-conducting solenoid are coaxially spirally wound in the annular space between the inner and outer heat insulation cylinders. The induction coil and the heat-conducting solenoid are located at the end of the heating cylinder near the anti-drop ring. The lower end of the heat insulation end cap, the inner wall of the hollow outer cylinder, and the upper end of the anti-drop ring form a cylindrical alloy material receiving cavity. Alloy material for wellbore sealing is disposed in the cylindrical alloy material receiving cavity.

2. The downhole induction heating metal melting plugging tool as described in claim 1, characterized in that, The alloy material is placed in the alloy material receiving cavity in the form of powder, granules or disc, and the alloy material is cast into the alloy material receiving cavity as a whole.

3. The downhole induction heating metal melting plugging tool as described in claim 1, characterized in that, The heat dissipation fins are circular ring-shaped and are evenly distributed coaxially along the outer wall of the heat dissipation cylinder. The heat dissipation pipes arranged on the outside of the heat dissipation cylinder are U-shaped and interspersed between the heat dissipation fins.

4. The downhole induction heating metal melting plugging tool as described in claim 1, characterized in that, The induction coil and the heat-conducting solenoid are alternately wound in the annulus between the inner and outer heat insulation cylinders.

5. A downhole induction heating metal melting plugging tool as described in any one of claims 1 or 2 to 4, characterized in that, Two circulation pumps are configured. One of the circulation pumps is installed in the upper housing of the heat sink, and the other is installed in the lower housing of the heat sink. The upper end of the circulation pump located in the upper housing is connected to the heat pipe of the power control component, and the lower end is connected to the heat sink cavity and the heat pipe through a pipeline. The upper end of the circulation pump located in the lower housing is connected to the heat sink cavity and the heat pipe through a pipeline, and the lower end is connected to the heat-conducting solenoid of the induction heating component.

6. The downhole induction heating metal melting plugging tool as described in claim 5, characterized in that, The coolant is introduced into the heat pipe, the heat dissipation pipe, and the heat-conducting solenoid by two circulating pumps.

7. The downhole induction heating metal melting plugging tool as described in claim 1, characterized in that, The upper end of the heat insulation end cap is provided with a cable connector, the upper end of which is connected to the output cable of the power control component, and the lower end of which is connected to the induction coil.

8. A downhole induction heating metal melting plugging method using the tool described in any one of claims 1 to 7, characterized in that, Includes the following steps: S1. Pretreatment: A bridge plug is placed at the wellbore sealing location, a groove is milled inside the casing at the wellbore sealing location, and the oil and iron filings remaining on the inner wall of the casing and the upper end face of the bridge plug are cleaned. S2. Assemble the downhole induction heating metal melting plugging tool as provided in claims 1 to 7, and lower it into the wellbore at the plugging location via a wire rope or coiled tubing. S3. Start the power supply equipment on the ground and transmit the ground power to the induction heating metal melting sealing tool in the well via cable. The power control component converts the power transmitted from the ground into a current suitable for the induction heating component and transmits it to the induction coil. Electromagnetic induction is generated at the induction coil, forming eddy currents in the heating cylinder. This generates heat to melt the alloy material inside the heating cylinder. After the alloy material is completely melted, it flows into the wellbore through the center hole of the anti-drop ring. At the same time, control the two circulating pumps to work, pumping the coolant in the heat sink into the heat pipe, dissipating the heat generated by the power control component and the induction coil, and exchanging heat with the low temperature fluid in the wellbore to reduce the working temperature of the power control component and the induction coil. S4. After the alloy material has completely melted and flowed into the wellbore, the downhole induction heating metal melting plugging tool is pulled out. As the temperature of the liquid alloy flowing into the wellbore gradually decreases, the liquid alloy gradually solidifies, forming a columnar plugging alloy plug above the bridge plug, thus completing the wellbore plugging.

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