A repair device for damaged downhole oil casings

Abstract

The present invention relates to the technical field of oil casing repair, and particularly relates to a repair device for damaged downhole oil casings. A repair device for damaged downhole oil casings includes a fixed rod. The fixed rod is provided with a control terminal. The fixed rod is provided with symmetrically distributed retaining discs. The retaining disc on the side away from the casing opening is fixedly connected to the fixed rod, and the retaining disc on the side close to the casing opening is slidably connected to the fixed rod. A first tension spring is fixedly connected between the symmetrically distributed retaining discs. The symmetrically distributed retaining discs are each hinged with circumferentially equally spaced connecting rods. A support frame is hinged between the symmetrically distributed connecting rods. Symmetrically distributed guide wheels are rotatably connected within the support frame. By the elastic force of the first tension spring, the support frame, the connecting rods, and the retaining discs in the present invention align the central axis of the fixed rod with the central axis of the casing, ensuring that the repair device will not collide with the inner wall of the casing during the process of being lowered into the casing, thus avoiding the problem of casing damage.

Description

Technical Field

[0001] The present invention relates to the technical field of oil casing repair, and particularly to a repair device for damaged downhole oil casings. Background Art

[0002] During the process of oil extraction, casings are generally installed in oil wells to prevent the crushed stones on the well wall from falling and damaging the oil pipes, and also to facilitate subsequent cementing. However, during the installation of the casings, due to complex geological conditions, such as the oil well being a deviated well, a horizontal well, etc., the casing collides with the well wall during the process of being put into the oil well, resulting in damage.

[0003] In the prior art, for example, the patent with the publication number 201810199722.2 discloses a chemical repair device for oil casings. Its technical solution is as follows: a reaction sub-cylinder sleeve is fixedly connected to the outer wall of the central tube, and a thermite reaction agent is installed in the inner cavity of the reaction sub-cylinder sleeve. A plurality of inclined holes are provided on the outer wall of the reaction sub-cylinder sleeve, and the inclined holes are blocked by tin stoppers; a firing fixing sleeve, an igniter, an ignition lock ring, a combustible ball seat, a combustible sealing sleeve, and a plug body are sequentially installed in the inner cavity of the central tube from bottom to top. This device solves the problem that the initiation of the thermite reaction is through the input of a reaction induction string. An electric heating tube is provided at the bottom of the reaction induction string, and the thermite reaction raw material in the inner cavity of the refractory protection sleeve is heated by connecting a cable to the electric heating tube at the wellhead, and its construction process is relatively troublesome.

[0004] However, this device has the following problems:

[0005] First, during the process of putting the sleeve into the casing, it cannot be ensured that the device is in the centered position of the casing, resulting in the device being prone to collide with the inner wall of the casing and causing damage to the casing.

[0006] Second, the second packer of this device needs to be installed separately during the installation process, increasing the workload of the operator.

[0007] Third, the molten iron generated by the thermite reaction of this device forms a ring between the inner wall of the casing and the device. If only one damaged hole on the casing needs to be filled, it will cause waste of the thermite reaction agent and increase the amount of subsequent grinding.

[0008] Fourth, after the filling is completed, a mill shoe needs to be put into the sleeve to grind the inner wall of the sleeve, and the operation process is cumbersome. Summary of the Invention

[0009] In order to overcome the above technical problems, a wear-resistant repair device for damaged downhole oil casings is provided.

[0010] A repair device for damaged downhole oil casing, comprising a fixed rod. The fixed rod is provided with a control terminal and symmetrically distributed retaining discs. There is a casing in the oil well, and the casing is provided with holes. The retaining disc on the side away from the casing opening is fixedly connected to the fixed rod, and the retaining disc on the side close to the casing opening is slidably connected to the fixed rod. A first tension spring is fixedly connected between the symmetrically distributed retaining discs. The symmetrically distributed retaining discs are each hinged with connecting rods circumferentially and equally spaced. A support frame is hinged between adjacent upper and lower connecting rods. Symmetrically distributed guide wheels are rotatably connected inside the support frame. The fixed rod is provided with a positioning mechanism for detecting the position of the holes. The positioning mechanism is located on the right side of the lower part of the fixed rod, and a grouting assembly for plugging the holes is arranged on the positioning mechanism. The fixed rod is provided with a plugging assembly for plugging the casing. The plugging assembly is located at the lower end of the fixed rod. The plugging assembly includes a plugging housing fixedly connected to the lower end of the fixed rod. An airbag is fixedly connected to the plugging housing. The plugging housing is provided with a ventilation hole communicating with the airbag. A push plate slidably connected to the fixed rod is slidably connected inside the plugging housing. Protective sand is filled inside the plugging housing above the push plate. A second tension spring is fixedly connected between the push plate and the plugging housing. The fixed rod is a hollow rod with a sealed lower end. The fixed rod is provided with an air inlet hole, and the air inlet hole of the fixed rod is located below the push plate. The elastic force of the first tension spring makes the support frame, connecting rods and retaining discs coincide the central axis of the fixed rod with the central axis of the casing.

[0011] Preferably, the positioning mechanism includes a servo motor electrically connected to the control terminal. The servo motor is fixedly connected to the fixed rod. The output shaft of the servo motor is fixedly connected with a first gear. The fixed rod is rotatably connected with a rotating sleeve located below the retaining disc. The rotating sleeve is fixedly connected with a second gear meshing with the first gear. The rotating sleeve is fixedly connected with a first air storage housing. The first air storage housing is located on the right side of the rotating sleeve. An air pump electrically connected to the control terminal is fixedly connected to the first air storage housing. The air pump is communicated with a second air storage housing. A pressure sensor electrically connected to the control terminal is fixedly connected inside the second air storage housing. A first air duct and a second air duct are communicated between the first air storage housing and the second air storage housing. Solenoid valves electrically connected to the control terminal are arranged in both the first air duct and the second air duct. The first air storage housing is provided with a detection assembly for detecting the position of the holes. The rotating sleeve is provided with a grinding mechanism for grinding the casing. The first air storage housing is provided with an adjusting mechanism for positioning the holes.

[0012] Preferably, the detection component includes a plugging plate fixedly connected inside the first gas storage housing. A first piston disk is slidably connected to the side of the first gas storage housing away from the rotating sleeve. A limiting ring for limiting the first piston disk is fixedly connected inside the first gas storage housing. The plugging plate, the first piston disk, and the first gas storage housing cooperate to form a first cavity. The side of the plugging plate away from the first piston disk and the first gas storage housing cooperate to form a second cavity. A through hole is provided on the side of the first gas storage housing away from the plugging plate. A sliding tube fixedly connected to the first piston disk is slidably connected to the first gas storage housing. The sliding tube communicates with the first cavity. The sliding tube communicates with a rectangular housing, and the rectangular housing communicates with a plurality of third gas storage housings distributed at equal intervals. A sliding rod is slidably limited inside each of the third gas storage housings distributed at equal intervals. The sliding rod is fixedly connected to a second piston disk that is slidably connected to an adjacent third gas storage housing. A ball is rotatably connected to one end of the sliding rod away from the second piston disk. The frictional force between the second piston disk and the third gas storage housing is greater than the frictional force between the first piston disk and the first gas storage housing. The first gas storage housing is provided with an adjusting mechanism for positioning the hole.

[0013] Preferably, the adjusting mechanism includes a fourth gas storage housing fixedly connected to the first gas storage housing and communicating with the second cavity. A first spline rod is slidably connected inside the fourth gas storage housing. A third piston disk fixedly connected to the first spline rod is slidably connected to the fourth gas storage housing. A through hole is provided at one end of the fourth gas storage housing away from the first gas storage housing. An L-shaped rod is fixedly connected to one end of the first spline rod away from the fourth gas storage housing. A second spline rod is fixedly connected to the L-shaped rod. A sliding sleeve is slidably connected to the second spline rod. A U-shaped frame is fixedly connected to the sliding sleeve. A spring is fixedly connected between the U-shaped frame and the second spline rod. The U-shaped frame is provided with a grouting component for plugging the hole.

[0014] Preferably, the grouting component includes a limiting block fixedly connected to the U-shaped frame. The limiting block is provided with a limiting hole and a limiting groove. The limiting groove is located below the limiting hole. The distance between the limiting hole and the limiting groove is equal to the distance between two adjacent sliding rods. The diameter of the limiting hole is equal to the diameter of the sliding rod. A sealing frame is fixedly connected to the side of the limiting block close to the sleeve. A diversion tube is embedded in the limiting block. The diversion tube communicates with a material storage housing. Symmetrically distributed connecting disks are fixedly connected inside the material storage housing. Baffles circumferentially and equally spaced are fixedly connected between the symmetrically distributed connecting disks. The materials of the material storage housing, the connecting disks, and the baffles are all heat-insulating materials. The connecting disk close to the limiting block is provided with circumferentially distributed through holes. Blocking blocks are fixedly connected in the circumferentially distributed through holes of the connecting disk. The material of the blocking block is a combustible material. The circumferentially and equally spaced baffles and the circumferentially distributed blocking blocks are staggered. The connecting disk away from the limiting block is provided with circumferentially distributed clamping holes. Magnesium strips are installed in the circumferentially distributed clamping holes of the connecting disk. The circumferentially and equally spaced baffles and the circumferentially distributed magnesium strips are staggered. Thermite is filled in the material storage housing. The connecting disk away from the limiting block is provided with circumferentially distributed igniters. The circumferentially distributed igniters are respectively in contact with adjacent magnesium strips.

[0015] Preferably, one side of the sealing frame close to the inner wall of the casing is set as an arc surface for increasing the contact area between the sealing frame and the inner wall of the casing. The material of the sealing frame is a high-temperature resistant elastic material for increasing the sealing performance between the sealing frame and the casing.

[0016] Preferably, the top of the limiting groove is flush with the center point height of the limiting block for filling the hole.

[0017] Preferably, the grinding mechanism includes a fifth air storage housing fixedly connected to the rotating sleeve. The fifth air storage housing and the first air storage housing are at the same height and there is an included angle between them. A third air duct is connected between the fifth air storage housing and the second air storage housing. An electromagnetic valve electrically connected to the control terminal is arranged in the third air duct. A third spline rod is slidably connected to the fifth air storage housing. A fourth piston disk fixedly connected to the third spline rod is slidably connected in the fifth air storage housing. A through hole is arranged on one side of the fifth air storage housing away from the rotating sleeve. One end of the third spline rod away from the fourth piston disk is fixedly connected with a connecting frame. The connecting frame is rotatably connected with an electric roller electrically connected to the control terminal. A grinding housing for grinding the inner wall of the casing is arranged on the outer side of the electric roller. The connecting frame is rotatably connected with symmetrically distributed limiting rollers. The outer diameter of the limiting rollers is equal to the outer diameter of the grinding housing.

[0018] Preferably, the plugging housing is fixedly connected with an intercepting ring. The intercepting ring is provided with an inclined surface. The diameter of the upper side of the intercepting ring is larger than that of its lower side. There is a gap between the outer diameter of the intercepting ring and the inner wall of the casing. The material of the intercepting ring is an elastic material for intercepting the protective sand.

[0019] The present invention has the following advantages:

[0020] First, through the elastic force of the first tension spring, the support frame, the connecting rod and the retaining disk make the central axis of the fixing rod coincide with the central axis of the casing, ensuring that the repair device will not collide with the inner wall of the casing during the process of being lowered into the casing, thus avoiding the problem of casing damage.

[0021] Second, by directly installing the plugging component on the repair device instead of installing it separately, the process of installing the plugging component is reduced. And after the plugging component is installed, the filling of the protective sand is directly completed. When filling holes at different heights, there is no need to separately disassemble and reinstall. The plugging component moves simultaneously with the repair device for rapid plugging, saving the installation time of the plugging component.

[0022] Third, through the precise positioning of the holes and aligning the grouting component with the holes, the usage amount of the thermite reaction agent is reduced, facilitating the subsequent grinding of the inner wall of the casing by the grinding housing. And when the repair device is put into the well once, multiple holes are filled, avoiding frequent lowering of the repair device, reducing the complexity of the hole filling process, and facilitating the operation of the operator.

[0023] IV. By installing a grinding mechanism on this repair device, it can directly grind after the hole filling is completed, without the need to put the mill shoe into the casing for grinding, saving operation time. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a three-dimensional structure schematic diagram of the present invention.

[0025] Figure 2 It is a three-dimensional structure schematic diagram of components such as the retaining disc, support frame, and connecting rod of the present invention.

[0026] Figure 3 It is a three-dimensional structure schematic diagram of the positioning mechanism of the present invention.

[0027] Figure 4 It is a partial sectional view of the three-dimensional structure of the positioning mechanism of the present invention.

[0028] Figure 5 It is a three-dimensional structure schematic diagram of the detection component of the present invention.

[0029] Figure 6 It is the present invention Figure 5 The enlarged three-dimensional structure schematic diagram of part A in the present invention.

[0030] Figure 7 It is the present invention Figure 5 The enlarged three-dimensional structure schematic diagram of part B in the present invention.

[0031] Figure 8 It is a three-dimensional structure schematic diagram of the adjustment mechanism of the present invention.

[0032] Figure 9 It is a partial sectional view of the three-dimensional structure of the grouting component of the present invention.

[0033] Figure 10 It is a three-dimensional structure schematic diagram of the sealing frame of the present invention.

[0034] Figure 11 It is a partial sectional view of the three-dimensional structure of the sliding rod and the limit block of the present invention.

[0035] Figure 12 It is a partial sectional view of the three-dimensional structure of the grinding mechanism of the present invention.

[0036] Figure 13 It is a partial sectional view of the three-dimensional structure of the plugging component of the present invention.

[0037] In the attached drawing reference numerals: 1 - fixed rod, 101 - sleeve, 102 - hole, 2 - retaining disc, 3 - first tension spring, 4 - connecting rod, 5 - support frame, 6 - guide wheel, 701 - servo motor, 702 - first gear, 703 - rotating sleeve, 704 - second gear, 705 - first gas storage housing, 7051 - first cavity, 7052 - second cavity, 706 - air pump, 707 - second gas storage housing, 708 - pressure sensor, 709 - first gas pipe, 710 - second gas pipe, 711 - sealing plate, 712 - first piston disc, 713 - sliding pipe, 714 - rectangular housing, 715 - third gas storage housing, 716 - sliding rod, 717 - second piston disc, 801 - fourth gas storage housing, 802 - first spline rod, 803 - third piston disc, 804 - L-shaped rod, 805 - second spline rod, 806 - sliding sleeve, 807 - U-shaped frame, 808 - spring, 809 - limiting block, 8091 - limiting hole, 8092 - limiting groove, 810 - sealing frame, 811 - diversion pipe, 812 - material storage housing, 813 - connecting disc, 814 - baffle plate, 815 - blocking block, 816 - magnesium strip, 817 - igniter, 901 - fifth gas storage housing, 902 - third gas pipe, 903 - third spline rod, 904 - fourth piston disc, 905 - connecting frame, 906 - electric roller, 907 - limiting roller, 1001 - sealing housing, 1002 - airbag, 1003 - pushing disc, 1004 - second tension spring, 1005 - intercepting ring. Detailed implementation manners

[0038] The above solution will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are for illustrating the present application and not for limiting the scope of the present application. The implementation conditions adopted in the embodiments can be further adjusted according to the conditions of specific manufacturers, and the implementation conditions not specified are usually those in conventional experiments. Embodiment 1

[0039] A repair device for damaged underground oil casing, as Figure 1 and Figure 2As shown in the figure, it includes a fixed rod 1. The fixed rod 1 is provided with a control terminal (not shown in the figure). The fixed rod 1 is provided with two upper and lower symmetrically distributed retaining discs 2. A casing 101 is arranged in the oil well. The casing 101 is provided with holes 102. The lower retaining disc 2 is fixedly connected to the fixed rod 1, and the upper retaining disc 2 is slidably connected to the fixed rod 1. A first tension spring 3 is fixedly connected between the symmetrically distributed retaining discs 2. Three circumferentially equally spaced connecting rods 4 are hinged to the symmetrically distributed retaining discs 2. A support frame 5 is hinged between the upper and lower adjacent connecting rods 4. Due to the elastic force of the first tension spring 3, the support frame 5, the connecting rods 4 and the retaining discs 2 make the central axis of the fixed rod 1 coincide with the central axis of the casing 101, ensuring that the repair device will not collide with the inner wall of the casing 101 during the process of being lowered into the casing 101, causing damage to the casing 101. Two upper and lower symmetrically distributed guide wheels 6 are rotatably connected in the support frame 5. The fixed rod 1 is provided with a positioning mechanism for detecting the position of the hole 102. The positioning mechanism is located on the right side of the lower part of the fixed rod 1. The fixed rod 1 is provided with a plugging assembly for plugging the casing 101. The plugging assembly is located at the lower end of the fixed rod 1.

[0040] As Figures 3 - 7 shown, the positioning mechanism includes a servo motor 701 electrically connected to the control terminal. The servo motor 701 is welded to the fixed rod 1. The output shaft end of the servo motor 701 is spline-connected with a first gear 702. The fixed rod 1 is rotatably connected with a rotating sleeve 703 located below the retaining disc 2. The rotating sleeve 703 is welded with a second gear 704 meshing with the first gear 702. The middle part of the rotating sleeve 703 is fixedly connected with a first air storage housing 705. The first air storage housing 705 is located on the right side of the rotating sleeve 703. The right part of the lower side of the first air storage housing 705 is fixedly connected with an air pump 706 electrically connected to the control terminal through a support plate. The left side of the air pump 706 is communicated with a second air storage housing 707. A pressure sensor 708 electrically connected to the control terminal is fixedly connected in the second air storage housing 707 for detecting the pressure in the second air storage housing 707. A first air duct 709 and a second air duct 710 are communicated between the first air storage housing 705 and the second air storage housing 707. Solenoid valves electrically connected to the control terminal are arranged in both the first air duct 709 and the second air duct 710. The first air storage housing 705 is provided with a detection assembly for detecting the position of the hole 102. The rotating sleeve 703 is provided with a grinding mechanism for grinding the casing 101. The first air storage housing 705 is provided with an adjusting mechanism for positioning the hole 102.

[0041] As Figures 3 - 7As shown, the detection component includes a plugging plate 711, which is welded inside the first gas storage housing 705. A first piston disk 712 is slidably connected to the right side inside the first gas storage housing 705. A limiting ring for limiting the first piston disk 712 is welded inside the first gas storage housing 705, and the limiting ring is located on the left side of the first piston disk 712. The plugging plate 711, the first piston disk 712 and the first gas storage housing 705 cooperate to form a first cavity 7051. The first cavity 7051 is communicated with the second gas storage housing 707 through a first air duct 709. The left side surface of the first gas storage housing 705 and the plugging plate 711 cooperate to form a second cavity 7052. A through hole is provided on the right side surface of the first gas storage housing 705. When the first piston disk 712 moves to the right, the gas on the right side of the first piston disk 712 inside the first gas storage housing 705 is discharged through the through hole of the first gas storage housing 705. A sliding tube 713 that is slidably limited in the first gas storage housing 705 and is communicated with the first piston disk 712 is provided. The right end of the sliding tube 713 is communicated with a rectangular housing 714. The rectangular housing 714 is communicated with third gas storage housings 715 that are distributed equidistantly up and down. Slide bars 716 are slidably limited in the equidistantly distributed third gas storage housings 715. The left end of the slide bar 716 is welded with a second piston disk 717 that is slidably limited and connected to the adjacent third gas storage housing 715. The right end of the slide bar 716 is rotatably connected with a ball. The frictional force between the second piston disk 717 and the third gas storage housing 715 is greater than the frictional force between the first piston disk 712 and the first gas storage housing 705.

[0042] As Figure 3 , Figure 4 and Figures 8 - 11 shown, the adjusting mechanism includes a fourth gas storage housing 801, which is welded to the left side of the first gas storage housing 705 and is communicated with the second cavity 7052. A first spline rod 802 is slidably connected to the upper part of the fourth gas storage housing 801. A third piston disk 803 that is welded to the first spline rod 802 is slidably connected inside the fourth gas storage housing 801. A through hole is provided at the upper end of the fourth gas storage housing 801. The upper end of the first spline rod 802 is fixedly connected with an L-shaped rod 804. The L-shaped rod 804 is welded with a second spline rod 805. A sliding sleeve 806 is slidably connected to the right part of the second spline rod 805. The right end of the sliding sleeve 806 is fixedly connected with a U-shaped frame 807. A spring 808 is fixedly connected between the U-shaped frame 807 and the second spline rod 805. The spring 808 is located inside the sliding sleeve 806. The U-shaped frame 807 is provided with a grouting component for plugging the hole 102.

[0043] As Figures 8 - 11As shown, the grouting assembly includes a limit block 809, which is fixedly connected to the lower side of the U-shaped frame 807. A limit hole 8091 and a limit groove 8092 are provided on the left side of the limit block 809. The limit groove 8092 is located below the limit hole 8091, and the top of the limit groove 8092 is flush with the center point height of the limit block 809. The distance between the limit hole 8091 and the limit groove 8092 is equal to the distance between two adjacent slide bars 716, and the diameter of the limit hole 8091 is equal to the diameter of the slide bar 716. The slide bar 716 enters the limit hole 8091 to limit the limit block 809. A sealing frame 810 is fixedly connected to the right side of the limit block 809. One side of the sealing frame 810 close to the inner wall of the sleeve 101 is an arc surface, which increases the fitting area between the sealing frame 810 and the inner wall of the sleeve 101. The material of the sealing frame 810 is a high-temperature resistant elastic material. The sealing frame 810 deforms when squeezed against the inner wall of the sleeve 101, increasing the squeezing force between the sealing frame 810 and the inner wall of the sleeve 101, and is used to increase the sealing performance between the sealing frame 810 and the sleeve 101. A diversion pipe 811 is embedded in the limit block 809. The upper part of the diversion pipe 811 is communicated with a storage material shell 812. The storage material shell 812 is located inside the U-shaped frame 807. Symmetrically distributed connecting disks 813 are welded inside the storage material shell 812. Baffles 814 distributed circumferentially at equal intervals are welded between the symmetrically distributed connecting disks 813. The lower connecting disk 813 is provided with through holes distributed circumferentially. Blocking blocks 815 are installed in the through holes distributed circumferentially of the connecting disk 813. The material of the blocking block 815 is a combustible material. When the temperature inside the storage material shell 812 rises, the blocking block 815 melts due to heat, and the molten iron flows downward through the through holes of the lower connecting disk 813. The circumferentially equally spaced baffles 814 and the circumferentially distributed blocking blocks 815 are staggered. The materials of the storage material shell 812, the connecting disk 813 and the baffle 814 are all heat-insulating materials. The upper connecting disk 813 is provided with clamping holes distributed circumferentially. Magnesium strips 816 are installed in the clamping holes distributed circumferentially of the connecting disk 813. The circumferentially equally spaced baffles 814 and the circumferentially distributed magnesium strips 816 are staggered. The storage material shell 812 is filled with an aluminothermic reaction agent. The upper connecting disk 813 is provided with igniters 817 distributed circumferentially. The circumferentially distributed igniters 817 are respectively in contact with the adjacent magnesium strips 816.

[0044] As Figure 1 and Figure 13As shown in the figure, the plugging assembly includes a plugging housing 1001, the plugging housing 1001 is welded to the lower end of the fixed rod 1, an airbag 1002 is installed on the outer side of the plugging housing 1001, the plugging housing 1001 is provided with a ventilation hole communicating with the airbag 1002, gas is filled into the airbag 1002, the pressure in the airbag 1002 increases, and the airbag 1002 expands to plug the space between the plugging housing 1001 and the inner wall of the casing 101. A push plate 1003 that is slidably connected to the fixed rod 1 is slidably connected in the plugging housing 1001. The plugging housing 1001 is filled with protective sand located above the push plate 1003. A second tension spring 1004 is fixedly connected between the push plate 1003 and the plugging housing 1001. When the push plate 1003 moves upward, the second tension spring 1004 is stretched, and the push plate 1003 pushes the protective sand above it upward. The fixed rod 1 is a hollow rod with a closed lower end, the fixed rod 1 is provided with an air inlet hole, and the air inlet hole of the fixed rod 1 is located below the push plate 1003.

[0045] As Figure 1 and Figure 13 As shown in the figure, an intercepting ring 1005 is fixedly connected to the upper surface of the plugging housing 1001. The intercepting ring 1005 is provided with an inclined surface, the diameter of the upper side of the intercepting ring 1005 is larger than that of its lower side, there is a gap between the outer diameter of the intercepting ring 1005 and the inner wall of the casing 101, the material of the intercepting ring 1005 is an elastic material, there is protective sand above the intercepting ring 1005, the protective sand squeezes the intercepting ring 1005 to deform, and its outer side contacts the inner wall of the casing 101 to form a seal for intercepting the protective sand.

[0046] When it is necessary to repair the casing 101 with a hole 102, the operator first detects the approximate position of the hole 102, and then puts this repair device into the casing 101. The specific operation is as follows. The fixing rod 1 is the supporting part of this repair device. The operator moves this device above the opening of the casing 101 and slowly puts this repair device vertically into the well through the fixing rod 1 above the upper port of the casing 101. When the lower retaining disc 2 is flush with the upper port of the casing 101, the operator pulls up the upper retaining disc 2, and the first tension spring 3 is stretched. In the initial state, the distance between the support frame 5 and the central axis of the fixing rod 1 is greater than the radius of the casing 101. The upper retaining disc 2 drives the support frame 5 and the three lower connecting rods 4 to move upward through the three upper connecting rods 4. The three support frames 5 approach each other. When the distance between the support frame 5 and the central axis of the fixing rod 1 is less than the radius of the casing 101, the operator stops pulling the upper retaining disc 2 and puts this repair device into the casing 101. After this repair device enters the casing 101, the operator releases the upper retaining disc 2. Under the elastic force of the first tension spring 3, the upper retaining disc 2 is driven to move downward. When the guide wheels 6 on the three support frames 5 contact the inner wall of the casing 101, the upper retaining disc 2 no longer moves downward. Since the support frame 5 does not return to its initial position, the first tension spring 3 is in a stretched state. The elastic force of the first tension spring 3 makes the support frame 5, the connecting rod 4 and the retaining disc 2 coincide the central axis of the fixing rod 1 with the central axis of the casing 101, ensuring that this repair device will not collide with the inner wall of the casing 101 during the process of being lowered into the casing 101, causing damage to the casing 101. When the hole 102 is between the upper and lower side surfaces of the rectangular housing 714, the operator stops lowering the fixing rod 1 into the casing 101. During the process of putting this repair device into the casing 101, there is a gap between the intercepting ring 1005 and the inner wall of the casing 101, ensuring that this repair device can slide up and down in the casing 101. This repair device is put in place.

[0047] Subsequently, the operator fixes this repair device in the casing 101. The specific operation is as follows. The operator conveys air to the fixing rod 1 to pressurize it. As the pressure in the fixing rod 1 increases, the gas in the fixing rod 1 enters between the plugging housing 1001 and the push plate 1003 through the air inlet hole at its lower end. Due to the elastic force of the second tension spring 1004, the gas between the plugging housing 1001 and the push plate 1003 enters the airbag 1002 through the ventilation hole of the plugging housing 1001. The pressure in the airbag 1002 increases, and the airbag 1002 expands to seal between the plugging housing 1001 and the inner wall of the casing 101. Since there is high-pressure gas in the airbag 1002, the frictional force between the airbag 1002 and the inner wall of the casing 101 increases, supporting this repair device and preventing this repair device from sliding down along the inner wall of the casing 101. This repair device is fixed in the casing 101.

[0048] After the fixing of this repair device is completed, the operator fills the lower side of the hole 102 in the casing 101 with protective sand. The specific operation is as follows. After the airbag 1002 completes the plugging, continue to pressurize the fixing rod 1. The air pressure between the plugging housing 1001 and the push plate 1003 gradually increases, pushing the push plate 1003 to move upward. The second tension spring 1004 is stretched. The push plate 1003 pushes the protective sand above it upward. When the protective sand contacts the lower side of the inner surface of the intercepting ring 1005, as the push plate 1003 moves upward, the protective sand gradually fills it along the inner surface of the intercepting ring 1005. During the process of the protective sand gradually filling the inner surface of the intercepting ring 1005, due to the weight of the protective sand and the intercepting ring 1005 being made of elastic material, the protective sand squeezes the intercepting ring 1005 to deform, and its outer surface contacts the inner wall of the casing 101 to form a seal, preventing the upper protective sand from leaking through the gap between the intercepting ring 1005 and the inner wall of the casing 101. When the protective sand fills the upper sides of the push plate 1003 and the intercepting ring 1005, the operator stops pressurizing the fixing rod 1, and the filling of the protective sand is completed, preventing the high temperature on the upper side of the casing 101 from being transmitted to the lower-side petroleum.

[0049] After the protective sand filling is completed, the operator adjusts the positioning mechanism to the measurement state. The specific operation is as follows: The operator starts the air pump 706 through the control terminal to inflate the second air storage housing 707. In the initial state, the solenoid valve in the first air duct 709 is in the open state, and the solenoid valves in the second air duct 710 and the third air duct 902 are in the closed state. Since the second air storage housing 707, the first air duct 709, the first cavity 7051, the sliding tube 713, the rectangular housing 714, and the third air storage housing 715 are in a communicating state, the air pump 706 inflates the second air storage housing 707, and the pressure in the above cavities (the second air storage housing 707, the first air duct 709, the first cavity 7051, the sliding tube 713, the rectangular housing 714, and the third air storage housing 715) increases simultaneously. Since the frictional force between the second piston disk 717 and the third air storage housing 715 is greater than the frictional force between the first piston disk 712 and the first air storage housing 705, the first piston disk 712 slides relative to the first air storage housing 705, and the second piston disk 717 cannot slide relative to the third air storage housing 715. The first piston disk 712 drives the sliding tube 713, the rectangular housing 714, and the parts thereon to start moving to the right. The gas on the right side of the first piston disk 712 in the first air storage housing 705 is discharged through the through hole of the first air storage housing 705. When the ball on the slide bar 716 contacts the inner wall of the sleeve 101, the air pump 706 continues to fill the second air storage housing 707 with gas, and the pressure sensor 708 detects the pressure in the second air storage housing 707. When the data detected by the pressure sensor 708 reaches the measurement pressure (at this time, the pressure in the second air storage housing 707 reaches the frictional force when the second piston disk 717 slides relative to the third air storage housing 715, and due to the limitation of the sleeve 101 on the ball on the slide bar 716, the slide bar 716 cannot move to the right), the control terminal stops the air pump 706, and the positioning mechanism is adjusted to the measurement state.

[0050] After the positioning mechanism is adjusted to the measurement state, the operator starts the positioning mechanism to detect the position of the hole 102. The position of the hole 102 shown in the figure is only for illustration and not the actual position of the hole 102. The holes 102 are distributed at any position on the horizontal plane where the position of the sleeve 101 is shown in the figure. The control terminal starts the servo motor 701. The servo motor 701 drives the rotating sleeve 703 to rotate through the first gear 702 and the second gear 704. The rotating sleeve 703 drives the first air storage housing 705 and the parts thereon to rotate with the sliding rod 716. The balls on the sliding rod 716 are in close contact with the inner wall of the sleeve 101 and rotate. The balls on the sliding rod 716 reduce the friction between the sliding rod 716 and the sleeve 101 when the sliding rod 716 rotates, avoiding abrasion of the inner wall of the sleeve 101 when the sliding rod 716 rotates. Since the sliding rods 716 are arranged vertically, the vertically arranged sliding rods 716 perform a range scan on the inner wall of the sleeve 101 during rotation, and its detection range is an arc-shaped ring surface. When a row of sliding rods 716 rotates near the hole 102, as the sliding rod 716 rotates, the sliding rod 716 closest to the hole 102 gradually penetrates into the hole 102. The second piston disk 717 drives the sliding rod 716 to approach the hole 102. The gas on the right side of the second piston disk 717 in the third air storage housing 715 is discharged through the through hole of the third air storage housing 715. At this time, due to the movement of the second piston disk 717, the volume in the third air storage housing 715 increases and the pressure decreases. Therefore, the pressure detected by the pressure sensor 708 in the second air storage housing 707 decreases. When the pressure data detected by the pressure sensor 708 suddenly decreases, the control terminal stops the servo motor 701. At this time, the sliding rod 716 aligned with the hole 102 is in the protruding state, and the remaining sliding rods 716 all remain in the initial state.

[0051] Subsequently, the control terminal starts the air pump 706 to pump out the gas in the second air storage housing 707. The pressure in the second air storage housing 707 decreases. The pressure in the second air storage housing 707 decreases from the pressure when the second piston disk 717 slides relative to the third air storage housing 715 to the pressure when the second piston disk 717 cannot slide relative to the third air storage housing 715. As the pressure in the second air storage housing 707 decreases, the first piston disk 712 drives the sliding tube 713 and the parts thereon to move to the left. After the air pump 706 pumps out the gas drawn into the second air storage housing 707, the control terminal stops the air pump 706. At this time, the state and position of a row of sliding rods 716 are as Figure 11 shown. The sliding rod 716 protruding from the third air storage housing 715 is directly below the limit groove 8092, and the position detection of the hole 102 is completed.

[0052] After the position detection of the hole 102 is completed, the hole 102 is blocked by the grouting assembly to facilitate subsequent grouting. The control terminal closes the solenoid valve in the first air duct 709 and opens the solenoid valve in the second air duct 710. At this time, the second air duct 710 is communicated with the second air storage housing 707. The control terminal starts the air pump 706 to extract the gas in the second air storage housing 707. The gas volume in the fourth air storage housing 801 decreases accordingly and the pressure drops. The third piston disk 803 drives the limit block 809 and the parts thereon to move downward through the first spline rod 802, the L-shaped rod 804, the second spline rod 805, the sliding sleeve 806 and the U-shaped frame 807. The outside gas enters the fourth air storage housing 801 through the through hole on the fourth air storage housing 801. During the downward movement of the limit block 809, since the several upper slide rods 716 do not protrude, the several upper non-protruding slide rods 716 will not block the downward movement of the limit block 809. The protruding slide rods 716 gradually enter the limit groove 8092. When the limit block 809 is blocked by the protruding slide rods 716 and cannot move downward, the protruding slide rods 716 contact the top of the limit groove 8092. Since the third piston disk 803 cannot move downward and the air pump 706 is still pumping air, the pressure in the fourth air storage housing 801 drops and the pressure in the second air storage housing 707 drops. When the pressure data detected by the pressure sensor 708 suddenly drops, the control terminal closes the air pump 706. Subsequently, the control terminal opens the solenoid valve in the first air duct 709 and closes the solenoid valve in the second air duct 710. The first air duct 709 is communicated with the second air storage housing 707. The control terminal starts the air pump 706 to inflate the second air storage housing 707. The sliding tube 713 drives the rectangular housing 714 and the third air storage housing 715 to move to the right. When the right side of the third air storage housing 715 contacts the left side of the limit block 809, the upper side of the protruding slide rod 716 and the right end of its adjacent slide rod 716 are inserted into the limit hole 8091. The third air storage housing 715 drives the limit block 809 and the parts thereon to start moving to the right, and the spring 808 is stretched. When the limit block 809 drives the sealing frame 810 to contact the inner wall of the sleeve 101, since the side of the sealing frame 810 close to the inner wall of the sleeve 101 is set as an arc surface, while the right side of the sealing frame 810 is close to the inner wall of the sleeve 101, the fitting area between the sealing frame 810 and the inner wall of the sleeve 101 is increased. Since the material of the sealing frame 810 is a high-temperature resistant elastic material, the sealing frame 810 deforms when extruded with the inner wall of the sleeve 101, increasing the extrusion force between the sealing frame 810 and the inner wall of the sleeve 101, ensuring a high sealing state between the sealing frame 810 and the inner wall of the sleeve 101 and avoiding the leakage of molten iron in the subsequent sealing frame 810.

[0053] After the sealing frame 810 is in sealing fit with the inner wall of the sleeve 101, the sealing frame 810 can no longer move to the right. The pressure sensor 708 detects that the pressure in the second gas storage housing 707 gradually increases. The control terminal stops the air pump 706 and starts an igniter 817 to ignite the adjacent magnesium strip 816. The magnesium strip 816 ignites a part of the thermite adjacent in the material storage housing 812. Since the materials of the material storage housing 812, the connecting disk 813, and the baffle 814 are all heat-insulating materials, it is avoided that the high temperature ignites the remaining thermite through the material storage housing 812, the connecting disk 813, and the baffle 814. Since the material of the blocking block 815 is a combustible material, the molten iron generated by the high-temperature reaction of the thermite melts the adjacent blocking block 815. The molten iron enters the cavity formed by the limiting block 809, the sealing frame 810, and the inner wall of the sleeve 101 through the diversion pipe 811. The molten iron gradually fills the hole 102. Since the temperature at the end of the hole 102 far from the molten iron is low, therefore, the end of the hole 102 far from the molten iron cools first, and the hole 102 cools gradually from the outside to the inside. After a period of time, the hole 102 is filled. Since the top of the limiting groove 8092 is flush with the center point of the limiting block 809, the center point of the sealing frame 810 is aligned with the hole 102, and the hole 102 is aligned with the center of the molten iron in the space formed by the limiting block 809, the sealing frame 810, and the sleeve 101, ensuring that the molten iron completely blocks the hole 102, and the filled molten iron only covers the vicinity of the hole 102, reducing the single use amount of the thermite and also facilitating the subsequent grinding of the inner wall of the sleeve 101.

[0054] Subsequently, the control terminal starts the air pump 706 to extract the gas in the second gas storage housing 707. The pressure in the second gas storage housing 707 decreases. The first piston disk 712 drives the rectangular housing 714, the third gas storage housing 715, and the parts thereon to move leftward through the sliding pipe 713. The spring 808 resets. The left side surface of the limiting block 809 closely adheres to the right side surface of the third gas storage housing 715 and moves leftward. When the first piston disk 712 contacts the limiting ring, the air pressure in the second gas storage housing 707 decreases, and the protruding sliding rod 716 starts to move leftward and reset. After the sliding rod 716 resets, the control terminal stops the air pump 706, closes the solenoid valve in the first air duct 709, and opens the solenoid valve in the second air duct 710. The control terminal starts the air pump 706 to inflate the second gas storage housing 707. The third piston disk 803 starts to move upward, and the limiting block 809 moves upward and resets. After the reset is completed, the control terminal closes the solenoid valve in the second air duct 710 and opens the solenoid valve in the third air duct 902. Embodiment 2

[0055] Based on Embodiment 1, as Figure 12As shown in the figure, the grinding mechanism includes a fifth air storage housing 901, which is welded to the rotating sleeve 703. The fifth air storage housing 901 and the first air storage housing 705 are at the same height and there is an angle between them. A third air duct 902 is connected between the fifth air storage housing 901 and the second air storage housing 707. The gas in the second air storage housing 707 enters the fifth air storage housing 901 through the third air duct 902. A solenoid valve electrically connected to the control terminal is provided in the third air duct 902. A third spline rod 903 is slidably connected to the left side of the fifth air storage housing 901. A fourth piston disk 904 welded to the third spline rod 903 is slidably connected in the fifth air storage housing 901. A through hole is provided on the left side surface of the fifth air storage housing 901. The left end of the third spline rod 903 is fixedly connected with a connecting frame 905. The connecting frame 905 is rotatably connected with an electric roller 906 electrically connected to the control terminal. A grinding housing for grinding the inner wall of the casing 101 is provided on the outer side surface of the electric roller 906. The grinding housing grinds the excess thermite reaction products. The connecting frame 905 is rotatably connected with symmetrically distributed limiting rollers 907. The outer diameter of the limiting rollers 907 is equal to the outer diameter of the grinding housing. The grinding housing only grinds the excess thermite reaction products on the casing 101 to ensure the integrity of the inner wall of the casing 101 after grinding.

[0056] After the filling of the hole 102 is completed, the excess thermite reaction products on the inner wall of the sleeve 101 are polished. The specific operation is as follows: The control terminal starts the servo motor 701, and the rotating sleeve 703 drives the fifth air storage housing 901 and the parts thereon to rotate. When the fifth air storage housing 901 rotates by a certain angle (the included angle between the fifth air storage housing 901 and the first air storage housing 705), the control terminal stops the servo motor 701. The fifth air storage housing 901 is located at the position of the first air storage housing 705 in the detection state, and the electric roller 906 is aligned with the hole 102. Subsequently, the control terminal starts the air pump 706 to fill the second air storage housing 707 with gas. The gas in the second air storage housing 707 enters the fifth air storage housing 901 through the third air duct 902. The pressure in the fifth air storage housing 901 increases, and the fourth piston disk 904 drives the electric roller 906 and the two limit rollers 907 to approach the hole 102 through the third spline rod 903 and the connecting frame 905. The gas on the left side of the fourth piston disk 904 in the fifth air storage housing 901 is discharged through the through hole of the fifth air storage housing 901. At the same time, the control terminal starts the electric roller 906 to rotate, and the control terminal starts the servo motor 701 to rotate periodically in the positive and negative directions, so that the electric roller 906 swings. When the polishing housing on the outer side of the electric roller 906 contacts the thermite reaction product, the polishing housing polishes the inner wall of the sleeve 101. During the process of polishing the inner wall of the sleeve 101, since the outer diameter of the limit roller 907 is equal to the outer diameter of the polishing housing, the polishing housing will only polish the excess thermite reaction products on the sleeve 101, ensuring the integrity of the inner wall of the sleeve 101 after polishing. After the inner wall of the sleeve 101 is polished, the control terminal stops the electric roller 906, and the control terminal starts the air pump 706 to extract the gas in the second air storage housing 707. When the electric roller 906 is reset, the control terminal stops the air pump 706 and the servo motor 701, and the filling and polishing of one hole 102 are completed.

[0057] When it is necessary to fill and polish the holes 102 at the same height, the operator does not need to remove the plugging component and continues to repeat the above steps to fill and polish the remaining holes 102. When it is necessary to fill and polish the holes 102 at other heights, the operator removes the plugging component. The specific operation is as follows: The operator releases the pressure in the fixed rod 1, and the second tension spring 1004 drives the push plate 1003 to move downward. When the push plate 1003 moves downward, the protective sand on it re-enters the upper side of the push plate 1003 in the plugging housing 1001. Since the intercepting ring 1005 is provided with an inclined surface and the diameter of the upper side of the intercepting ring 1005 is larger than that of its lower side, all the protective sand on the upper side of the intercepting ring 1005 backfills along its inner side. After the protective sand on the intercepting ring 1005 is removed, the intercepting ring 1005 resets, and there is again a gap between the intercepting ring 1005 and the inner wall of the casing 101, ensuring that the repair device moves up and down in the casing 101. When the push plate 1003 resets, as the pressure in the fixed rod 1 decreases, the pressure in the airbag 1002 begins to decrease. When the airbag 1002 loses contact with the inner wall of the casing 101 and resets, the operator stops releasing the pressure in the fixed rod 1. When the device moves to the vicinity of the holes 102 at other heights, the operator continues to repeat the above steps to fill and polish the remaining holes 102. When all the holes 102 are polished, the operator removes the plugging component and resets the repair device, and the use of the repair device is completed.

[0058] In summary, by accurately positioning the holes 102 and aligning the grouting component with the holes 102, the usage amount of the thermite agent is reduced, which is convenient for the subsequent grinding of the inner wall of the casing 101 by the grinding housing. Moreover, when the repair device is placed in the well for the first time, multiple holes 102 can be filled, avoiding frequent lowering of the repair device, reducing the complexity of the filling process of the holes 102, and being convenient for the operator to use.

[0059] Although the present disclosure has been described with respect to only a limited number of embodiments, those skilled in the art who benefit from the present disclosure will understand that various other embodiments can be designed without departing from the scope of the present invention. Therefore, the scope of the present invention should be limited only by the appended claims.

Claims

1. A repair device for damaged downhole oil casings, comprising a fixing rod (1), characterized in that, The fixed rod (1) is provided with a control terminal. The fixed rod (1) is provided with symmetrically distributed retaining discs (2). A casing (101) is arranged in the oil well. The casing (101) is provided with holes (102). The retaining disc (2) on the side away from the mouth of the casing (101) is fixedly connected to the fixed rod (1). The retaining disc (2) on the side close to the mouth of the casing (101) is slidably connected to the fixed rod (1). A first tension spring (3) is fixedly connected between the symmetrically distributed retaining discs (2). The symmetrically distributed retaining discs (2) are each hinged with connecting rods (4) that are circumferentially and equally spaced. A support frame (5) is hinged between the upper and lower adjacent connecting rods (4). Symmetrically distributed guide wheels (6) are rotatably connected inside the support frame (5). The fixed rod (1) is provided with a positioning mechanism for detecting the position of the hole (102). The positioning mechanism is located on the right side of the lower part of the fixed rod (1). A grouting assembly for plugging the hole (102) is arranged on the positioning mechanism; The fixed rod (1) is provided with a plugging assembly for plugging the casing (101). The plugging assembly is located at the lower end of the fixed rod (1). The plugging assembly includes a plugging housing (1001). The plugging housing (1001) is fixedly connected to the lower end of the fixed rod (1). An airbag (1002) is fixedly connected to the plugging housing (1001). The plugging housing (1001) is provided with a ventilation hole communicating with the airbag (1002). A push plate (1003) that is slidably connected to the fixed rod (1) is slidably connected inside the plugging housing (1001). The plugging housing (1001) is filled with protective sand on the upper side of the push plate (1003). A second tension spring (1004) is fixedly connected between the push plate (1003) and the plugging housing (1001). The fixed rod (1) is arranged as a hollow rod with a closed lower end. The fixed rod (1) is provided with an air inlet hole. The air inlet hole of the fixed rod (1) is located on the lower side of the push plate (1003); The elastic force of the first tension spring (3) makes the support frame (5), the connecting rods (4) and the retaining discs (2) coincide the central axis of the fixed rod (1) with the central axis of the casing (101); The positioning mechanism includes a servo motor (701) electrically connected to the control terminal. The servo motor (701) is fixedly connected to the fixed rod (1). A first gear (702) is fixedly connected to the output shaft of the servo motor (701). The fixed rod (1) is rotatably connected to a rotating sleeve (703) located below the retaining disc (2). A second gear (704) meshing with the first gear (702) is fixedly connected to the rotating sleeve (703). A first air storage housing (705) is fixedly connected to the rotating sleeve (703). The first air storage housing (705) is located on the right side of the rotating sleeve (703). An air pump (706) electrically connected to the control terminal is fixedly connected to the first air storage housing (705). The air pump (706) is communicated with a second air storage housing (707). A pressure sensor (708) electrically connected to the control terminal is fixedly connected inside the second air storage housing (707). A first air duct (709) and a second air duct (710) are communicated between the first air storage housing (705) and the second air storage housing (707). Solenoid valves electrically connected to the control terminal are provided in both the first air duct (709) and the second air duct (710). A detection component for detecting the position of the detection hole (102) is provided on the first air storage housing (705). A grinding mechanism for grinding the sleeve (101) is provided on the rotating sleeve (703). An adjusting mechanism for positioning the hole (102) is provided on the first air storage housing (705); The detection component includes a plugging plate (711). The plugging plate (711) is fixedly connected inside the first air storage housing (705). A first piston disk (712) is slidably connected to the side of the first air storage housing (705) far from the rotating sleeve (703). A limiting ring for limiting the first piston disk (712) is fixedly connected inside the first air storage housing (705). The plugging plate (711), the first piston disk (712) and the first air storage housing (705) cooperate to form a first cavity (7051). A second cavity (7052) is formed by the cooperation between the side of the plugging plate (711) far from the first piston disk (712) and the first air storage housing (705). A through hole is provided on the side of the first air storage housing (705) far from the plugging plate (711). A sliding tube (713) fixedly connected to the first piston disk (712) is slidably limited on the first air storage housing (705). The sliding tube (713) is communicated with the first cavity (7051). The sliding tube (713) is communicated with a rectangular housing (714). The rectangular housing (714) is communicated with equally spaced third air storage housings (715). Slide bars (716) are slidably limited in the equally spaced third air storage housings (715). Second piston disks (717) fixedly connected to the adjacent third air storage housings (715) are slidably limited on the slide bars (716). A ball is rotatably connected to the end of the slide bar (716) far from the second piston disk (717). The friction between the second piston disk (717) and the third air storage housing (715) is greater than the friction between the first piston disk (712) and the first air storage housing (705).

2. The repair device for the breakage of the downhole oil casing according to claim 1, characterized in that, The adjusting mechanism includes a fourth air storage housing (801). The fourth air storage housing (801) is fixedly connected to the first air storage housing (705) and communicates with the second cavity (7052). A first spline rod (802) is slidably connected to the fourth air storage housing (801). A third piston disc (803) fixedly connected to the first spline rod (802) is slidably connected inside the fourth air storage housing (801). A through hole is provided at one end of the fourth air storage housing (801) away from the first air storage housing (705). An L-shaped rod (804) is fixedly connected to the end of the first spline rod (802) away from the fourth air storage housing (801). A second spline rod (805) is fixedly connected to the L-shaped rod (804). A sliding sleeve (806) is slidably connected to the second spline rod (805). A U-shaped frame (807) is fixedly connected to the sliding sleeve (806). A spring (808) is fixedly connected between the U-shaped frame (807) and the second spline rod (805).

3. The repair device for the breakage of the downhole oil casing according to claim 2, characterized in that, The grouting assembly includes a limit block (809). The limit block (809) is fixedly connected to the U-shaped frame (807). The limit block (809) is provided with a limit hole (8091) and a limit groove (8092). The limit groove (8092) is located below the limit hole (8091). The distance between the limit hole (8091) and the limit groove (8092) is equal to the distance between two adjacent sliding rods (716). The diameter of the limit hole (8091) is equal to the diameter of the sliding rod (716). A sealing frame (810) is fixedly connected to the side of the limit block (809) close to the sleeve (101). A diversion pipe (811) is embedded in the limit block (809). The diversion pipe (811) communicates with a storage material housing (812). Symmetrically distributed connecting discs (813) are fixedly connected inside the storage material housing (812). Baffles (814) distributed circumferentially at equal intervals are fixedly connected between the symmetrically distributed connecting discs (813). The storage material housing (812), the connecting discs (813) and the baffles (814) are all made of heat-insulating materials. The connecting disc (813) close to the limit block (809) is provided with through holes distributed circumferentially. Blocking blocks (815) are fixedly connected in the through holes distributed circumferentially of the connecting disc (813). The blocking blocks (815) are made of combustible materials. The circumferentially equally spaced baffles (814) and the circumferentially distributed blocking blocks (815) are staggered. The connecting disc (813) away from the limit block (809) is provided with clamping holes distributed circumferentially. Magnesium strips (816) are installed in the clamping holes distributed circumferentially of the connecting disc (813). The circumferentially equally spaced baffles (814) and the circumferentially distributed magnesium strips (816) are staggered. An aluminothermic reaction agent is filled in the storage material housing (812). The connecting disc (813) away from the limit block (809) is provided with igniters (817) distributed circumferentially. The circumferentially distributed igniters (817) are respectively in contact with the adjacent magnesium strips (816).

4. A repair device for underground oil casing damage according to claim 3, characterized in that, One side of the sealing frame (810) close to the inner wall of the sleeve (101) is set as an arc surface to increase the contact area between the sealing frame (810) and the inner wall of the sleeve (101). The material of the sealing frame (810) is a high-temperature resistant elastic material to increase the sealing performance between the sealing frame (810) and the sleeve (101).

5. The repair device for damaged downhole oil casing according to claim 3, characterized in that, The top of the limiting groove (8092) is flush with the center point height of the limiting block (809) for filling the hole (102).

6. The repair device for the breakage of the downhole oil casing according to claim 1, characterized in that, The grinding mechanism includes a fifth air storage housing (901). The fifth air storage housing (901) is fixedly connected to the rotating sleeve (703). The fifth air storage housing (901) and the first air storage housing (705) are at the same height and there is an included angle between them. A third air duct (902) is connected between the fifth air storage housing (901) and the second air storage housing (707). An electromagnetic valve electrically connected to the control terminal is arranged in the third air duct (902). A third spline rod (903) is slidably connected to the fifth air storage housing (901). A fourth piston disk (904) fixedly connected to the third spline rod (903) is slidably connected in the fifth air storage housing (901). A through hole is arranged on one side of the fifth air storage housing (901) away from the rotating sleeve (703). One end of the third spline rod (903) away from the fourth piston disk (904) is fixedly connected with a connecting frame (905). An electric roller (906) electrically connected to the control terminal is rotatably connected to the connecting frame (905). A grinding housing for grinding the inner wall of the sleeve (101) is arranged on the outer side of the electric roller (906). The connecting frame (905) is rotatably connected with symmetrically distributed limiting rollers (907). The outer diameter of the limiting rollers (907) is equal to the outer diameter of the grinding housing.

7. A repair device for underground oil casing damage according to claim 1, characterized in that, The blocking housing (1001) is fixedly connected with a blocking ring (1005). The blocking ring (1005) is provided with an inclined surface. The upper diameter of the blocking ring (1005) is larger than its lower diameter. There is a gap between the outer diameter of the blocking ring (1005) and the inner wall of the sleeve (101). The material of the blocking ring (1005) is an elastic material for blocking the protective sand.

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