A fish head repair rotating device and its usage method

Abstract

The present invention discloses a fish top rotating device and its usage method, which relates to the technical field of downhole fish top repair tools. It includes a lifting and rotating assembly and a hydraulic anchor. An axial limiting groove is provided on the outer wall of the upper part of the lifting sleeve, and a lifting sleeve is provided at the bottom. Two radially and coaxially arranged fixing ears are provided on the bottom wall of the lifting sleeve, and a lifting pin shaft is inserted into the fixing ears. The upper part of the direction-changing shaft is the upper shaft of the direction-changing shaft, and the lower part is the lower shaft of the direction-changing shaft. A direction-changing track adapted to the lifting pin shaft is provided on the outer wall of the upper shaft of the direction-changing shaft. The direction-changing track is a 360-degree surrounding wavy track, and a lower joint is provided at the lower end of the lower shaft of the direction-changing shaft. Both the lifting sleeve and the direction-changing shaft are hollow tubular structures. The lifting sleeve is slidably sleeved on the outside of the upper shaft of the direction-changing shaft, and the two lifting pin shafts are slidably arranged in the direction-changing track. When this device is in use, there is no need to rotate the fishing and workover pipe string. By lifting and lowering the pipe string, only the fish top device is driven to rotate to repair the fish top, improving the efficiency of repairing the fish top.

Description

Technical Field

[0001] The present invention relates to the technical field of downhole fish top repair tools, and particularly relates to a fish top repair rotating device and a using method thereof. Background Art

[0002] As the oilfield development continuously enters the middle and late stages, the number of oil and gas wells that need repair operations, such as those with deep depths and special structural wells, increases year by year. Due to complex formation structures and other reasons, the fishing operations in oilfield oil and gas wells are increasing, and the fishing complexity is also increasing. Some cause the drill string to fracture and fail, forming a fish in the well, and some cause the original well string to fracture, resulting in a fish with an irregular fish top. This not only increases the operation cost caused by fishing for the fish, but may also lead to the abandonment of the wellbore in severe cases, greatly affecting the operation cost. To eliminate the failure, tools often need to be lowered to fish for the fish in the well.

[0003] Since the shapes and structures of the fish tops of the fish in the well are different, generally, there are two common ways to repair the fish top: One is to use a milling shoe to mill or a female taper tool to repair the fish top with an outwardly deformed shape. The milling shoe or female taper rotates by driving the downhole pipe string to rotate through the rotary table on the wellhead drill floor to repair the fish top; the other is to use a male taper, a pointed rotary threading fishing tool to repair the fish top. These two methods have the following disadvantages in repairing the fish top;

[0004] 1. When used in horizontal wells, high-angle wells, etc., it is easy to tighten the connection buckle types of the fishing drill pipe and tubing string, and it is not easy to release the buckle when pulling out the drill, resulting in a reduction in operation efficiency;

[0005] 2. Since the workover operation equipment does not have a rotary table, this tool cannot be used for repair, and it is necessary to move the heavy workover equipment to carry out the operation, resulting in great waste;

[0006] 3. When used in horizontal wells and high-angle wells, it is easy to cause serious wear of the fishing string, resulting in increased fatigue of the fishing string and reduced service life of the fishing string;

[0007] Chinese Patent CN2651424 discloses a retrievable fish top repair milling and fishing composite tool for oil, gas, and water well workovers, which consists of an upper sub, an outer fishing barrel, a Lan type slip, a control ring, a sealing ring, a fastening sleeve, a conversion joint, a mill shoe body, milling teeth, a spear rod, a back-off ring, a piston sealing ring, a hydraulic piston, a limit pin, a tapered slip, a cone, a gauge protection tooth, and a spring; when using this tool, it is necessary to combine with a rotary fishing workover pipe string, and the structure is complex and not suitable for workover operations.

[0008] For the above various methods, basically, the fishing string is rotated to drive the repair tool to rotate and repair the fish top. The existing disadvantages include increased production costs, reduced operation efficiency, and reduced service life of the equipment. Therefore, there is an urgent need for a special device on site to change this situation. Summary of the Invention

[0009] The object of the present invention is to provide a fish top rotating device and its using method in view of the defects existing in the prior art.

[0010] The technical solution of the present invention is: a fish top rotating device, including a lifting and rotating assembly and a hydraulic anchor. The lifting and rotating assembly includes a lifting sleeve, a deflecting shaft, a pin shaft limiting plug, a housing and a limiting block. The top of the lifting sleeve is provided with an upper joint, the upper outer wall is provided with an axial limiting groove, and the bottom is provided with a lifting sleeve barrel. Two radially and coaxially arranged fixing ears are provided on the bottom barrel wall of the lifting sleeve barrel, and a lifting pin shaft is inserted in the fixing ears. The upper part of the deflecting shaft is the upper shaft of the deflecting shaft, and the lower part is the lower shaft of the deflecting shaft. The outer diameter of the upper shaft of the deflecting shaft is larger than that of the lower shaft of the deflecting shaft. A deflecting track adapted to the lifting pin shaft is provided on the outer wall of the upper shaft of the deflecting shaft. The deflecting track is a 360-degree surrounding wavy track, and the lower end of the lower shaft of the deflecting shaft is provided with a lower joint. Both the lifting sleeve and the deflecting shaft are hollow tubular structures. The lifting sleeve barrel is slidably sleeved on the outside of the upper shaft of the deflecting shaft, and the two lifting pin shafts are slidably arranged in the deflecting track.

[0011] The housing is sleeved on the lifting sleeve and the deflecting shaft. The pin shaft limiting plug is installed at the upper end of the housing. The pin shaft limiting plug is provided with an inner hole adapted to the upper part of the lifting sleeve, and a boss adapted to the limiting groove is provided in the inner hole. The upper part of the lifting sleeve is vertically slidably arranged in the inner hole. The hydraulic anchor includes a special-shaped joint, and the special-shaped joint is installed at the lower end of the housing, and a through hole is provided at the central axis position. The lower shaft of the deflecting shaft penetrates through the through hole. The limiting block is fixedly installed in the limiting groove on the upper side of the boss, and the length of the limiting groove below the limiting block is equal to the axial length of the deflecting track.

[0012] Preferably, the hydraulic anchor further includes a hydraulic anchor barrel, an anchor barrel lower plug, a slip, a slip seat, a locking shear pin, a pin spring and a tooth block support spring. The hydraulic anchor barrel is a cylindrical structure. The lower end of the special-shaped joint is detachably connected to the upper end of the hydraulic anchor barrel. The anchor barrel lower plug is installed at the lower end of the hydraulic anchor barrel, and a central hole adapted to the lower shaft of the deflecting shaft is provided on the anchor barrel lower plug. The lower shaft of the deflecting shaft is rotatably and sealedly installed in the central hole of the anchor barrel lower plug.

[0013] A plurality of groups of slot holes are formed in the outer wall of the hydraulic anchor cylinder. The lower part of the slot hole is a slip groove adapted to the slips, and the upper part is a slip seat groove adapted to the slip seat. The slips are radially slidably arranged in the slip groove, and the slip seat is fixedly installed in the slip seat groove. A plurality of slip teeth are provided on the slips, and shear pin holes are provided at the bottom of the side walls of the slip teeth. A plurality of slip holes corresponding to the slip teeth are provided on the slip seat, and locking holes are provided on the inner walls of the slip holes. The locking shear pin and the pin spring are installed in the locking holes, and the locking shear pin is adapted to the shear pin holes. A plurality of spring hole seats are provided at the bottom of the slip seat. The upper end of the tooth block support spring is located in the spring hole seat, and the lower end abuts against the slips. When the slips are located at the bottom of the slip groove, the locking shear pin abuts against the side surface of the slip teeth. When the slips extend out, the shear pin holes and the locking holes are located on the same straight line, and the locking shear pin enters the shear pin holes. A seat sealing liquid inlet hole communicating with the inner cavity of the hydraulic anchor cylinder is provided at the bottom of the slip groove, and a liquid inlet hole communicating with the inner cavity of the anchor cylinder is provided on the lower plug of the anchor cylinder.

[0014] Preferably, the pin shaft limiting plug is of a split structure, including a pin shaft limiting outer sleeve and a pin shaft limiting inner sleeve. A square hole is provided on the pin shaft limiting outer sleeve, the pin shaft limiting inner sleeve is fixedly nested in the square hole, and the inner hole and the boss are provided on the pin shaft limiting inner sleeve.

[0015] Preferably, a special-shaped groove is provided on the special-shaped joint. The special-shaped groove is a square groove, and a lower pin shaft limiting sleeve is embedded in the special-shaped groove. A central hole adapted to the outer diameter of the lower shaft of the steering shaft is provided on the lower pin shaft limiting sleeve, and the lower shaft of the steering shaft is rotationally and sealingly connected to the central hole of the lower pin shaft limiting sleeve. An isolation retaining ring is sleeved on the upper shaft of the steering shaft between the lower pin shaft limiting sleeve and the lower end of the upper shaft of the steering shaft.

[0016] Preferably, the maximum gap between the slips and the slip seat is equal to the maximum anchoring height of the slips, and the height difference between the locking holes and the shear pin holes is equal to the maximum anchoring height of the slips.

[0017] Preferably, two liquid inlet holes are provided on the lower plug of the anchor cylinder, and the cross-sectional area of the liquid inlet holes is smaller than the cross-sectional area of the slip teeth.

[0018] A usage method of a fish top rotating device includes the following steps:

[0019] 1) Connect this device to the lower end of the fishing and workover string, install a fish top repair tool, such as a milling and repairing female taper head or a male taper with a through pipe milling, on the lower joint of the steering shaft, and then lower it into the well.

[0020] 2) After detecting the fish top, perform a normal circulation to flush the fish top.

[0021] 3) After cleaning the fish head, stop the pump. Lower the drill string until the fish head repair tool touches the fish head, then stop lowering. Next, start the pump and reverse the pressure to circulate. The liquid enters the inner cavity of the hydraulic anchor cylinder through the liquid inlet hole, and then pushes the slips upward to anchor. When the locking shear pin in the locking hole enters the shear pin hole under the elastic force of the pin spring, the anchoring self-locking is completed. When the pump stops, the slips will not reset.

[0022] 4) After the hydraulic anchor is anchored, lift and lower the fishing and workover pipe string to drive the lifting and lowering sleeve to move up and down in a reciprocating linear motion. Under the action of the lifting and lowering pin shaft moving along the deflection track, the reciprocating linear motion of the lifting and lowering sleeve is converted into the rotational motion of the deflection shaft. The deflection shaft drives the fish head repair tool at the lower part to rotate, and repair processes such as milling the fish head or expanding the pipe hole are carried out on the fish head.

[0023] 5) When a certain degree of repair is completed or the repair is finished, start the pump and reverse the pressure to circulate. Since the cross-sectional area of multiple slip teeth is much larger than the cross-sectional area of the liquid inlet hole of the lower plug of the anchor cylinder, when the pressure reaches a certain value, the liquid pushes the slips downward to cut the locking shear pin, and the slips reset to complete the unsealing.

[0024] 6) When the fish head cannot be repaired in one operation after the hydraulic anchor is anchored, and it is necessary to lower the tubing to change the anchoring position and continue the repair, then lift out this pipe string, replace the locking shear pin, and then lower the well to repeat steps 3 - 4 to continue repairing the fish head until the fish head repair is completed.

[0025] Compared with the prior art, the present invention has the following advantages:

[0026] When this device is in use, there is no need to rotate the fishing and workover pipe string. By lifting and lowering the pipe string, only the fish head repair device is driven to rotate to repair the fish head, which improves the efficiency of repairing the fish head and provides technical support for improving the quality and efficiency of workover operations. Since this device does not require rotating the pipe string, when used in horizontal wells, highly deviated wells, etc., problems such as the tight connection of the fishing drill pipe and tubing pipe string can be avoided, making it easier to release the connection when pulling out the drill string and improving the operation efficiency. This device is suitable for minor workover operations, overcomes the problem that the minor workover equipment cannot rotate to repair the fish head due to the absence of a rotary table, and reduces the operation cost. When this device is used in horizontal wells and highly deviated wells, the wear problem of the fishing pipe string is alleviated, and the service life of the fishing pipe string is extended. The hydraulic anchor in this device changes the traditional locking method of the hydraulic anchor, has a built-in self-locking mechanism, does not require the use of other cooperating packers, and changes the situation where anchoring can only be achieved by maintaining hydrodynamic force. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 is the overall structural schematic diagram of the present invention;

[0028] Figure 2 is the cross-sectional schematic diagram of the lifting and lowering and rotating assembly;

[0029] Figure 3Isometric view of the lifting and lowering sleeve;

[0030] Figure 4 Isometric view of the direction-changing shaft;

[0031] Figure 5 Isometric view of the pin shaft limit outer sleeve, pin shaft limit inner sleeve and lower pin shaft limit sleeve;

[0032] Figure 6 Structural schematic diagram of the hydraulic anchor;

[0033] Figure 7 Is Figure 6 Cross-sectional schematic view of;

[0034] Figure 8 Is Figure 7 Enlarged view of part A in;

[0035] Figure 9 Structural schematic diagram of the slip;

[0036] Figure 10 Structural schematic diagram of the slip seat.

[0037] In the figure: 1. Lifting and lowering sleeve, 101. Limit groove, 102. Lifting and lowering sleeve tube, 103. Fixed ear, 104. Lifting and lowering pin shaft, 2. Direction-changing shaft, 201. Upper direction-changing shaft, 202. Lower direction-changing shaft, 203. Direction-changing track, 3. Outer housing, 4. Pin shaft limit outer sleeve, 401. Square hole, 5. Pin shaft limit inner sleeve, 501. Boss, 6. Special-shaped joint, 601. Special-shaped groove, 7. Limit block, 8. Hydraulic anchor cylinder, 801. Slip groove, 802. Slip seat groove, 803. Sealing liquid inlet hole, 9. Lower plug of the anchor cylinder, 901. Liquid inlet hole, 10. Slip, 1001. Slip teeth, 1002. Shearing pin hole, 11. Slip seat, 1101. Slip hole, 1102. Locking hole, 1103. Spring hole seat, 12. Locking shear pin, 13. Pin spring, 14. Tooth block support spring, 15. Lower pin shaft limit sleeve, 16. Isolation retaining ring. Detailed implementation mode

[0038] The following further describes the present invention in conjunction with the drawings and embodiments.

[0039] Embodiment 1

[0040] Refer to Figure 1-4As shown in the figure, a fish top rotating device includes a lifting and rotating assembly and a hydraulic anchor. The lifting and rotating assembly includes a lifting sleeve 1, a deflecting shaft 2, a pin shaft limit plug, a housing 3, and a limit block 7. The top of the lifting sleeve 1 is provided with an upper joint, the outer wall of the upper part is provided with an axial limit groove 101, and the bottom is provided with a lifting sleeve 102. On the bottom wall of the lifting sleeve 102, two radially and coaxially arranged fixing ears 103 are provided, and a lifting pin shaft 104 is inserted into the fixing ear 103. The upper part of the deflecting shaft 2 is the upper deflecting shaft 201, and the lower part is the lower deflecting shaft 202. The outer diameter of the upper deflecting shaft 201 is larger than that of the lower deflecting shaft 202. On the outer wall of the upper deflecting shaft 201, a deflecting track 203 adapted to the lifting pin shaft 104 is provided. The deflecting track 203 is a 360-degree circular wave track. The lower end of the lower deflecting shaft 202 is provided with a lower joint. Both the lifting sleeve 1 and the deflecting shaft 2 are hollow tubular structures. The lifting sleeve 102 is slidably sleeved outside the upper deflecting shaft 201, and the two lifting pin shafts 104 are slidably arranged in the deflecting track 203.

[0041] The housing 3 is sleeved on the lifting sleeve 1 and the deflecting shaft 2. The pin shaft limit plug is installed at the upper end of the housing 3. The pin shaft limit plug is provided with an inner hole adapted to the upper part of the lifting sleeve 1, and a boss 501 adapted to the limit groove 101 is provided in the inner hole. The upper part of the lifting sleeve 1 is vertically slidably arranged in the inner hole. The hydraulic anchor includes a special-shaped joint 6. The special-shaped joint 6 is installed at the lower end of the housing 3, and a through hole is provided at the central axis position. The lower deflecting shaft 202 penetrates through the through hole. The limit block 7 is fixedly installed in the limit groove 101 above the boss 501. The length of the limit groove 101 below the limit block 7 is equal to the axial length of the deflecting track 203. The limit block 7 is used to limit the downward distance of the lifting sleeve 1.

[0042] Refer to Figure 6 As shown in the figure, the hydraulic anchor further includes a hydraulic anchor cylinder 8, an anchor cylinder lower plug 9, a slip 10, a slip seat 11, a locking shear pin 12, a pin spring 13, and a tooth block support spring 14. The hydraulic anchor cylinder 8 is a cylindrical structure. The lower end of the special-shaped joint 6 is detachably connected to the upper end of the hydraulic anchor cylinder 8. The anchor cylinder lower plug 9 is installed at the lower end of the hydraulic anchor cylinder 8, and the anchor cylinder lower plug 9 is provided with a central hole adapted to the lower deflecting shaft 202. The lower deflecting shaft 202 is rotationally and sealingly installed in the central hole of the anchor cylinder lower plug 9.

[0043] Refer to Figures 7-10As shown in the figure, multiple groups of slots are provided on the outer wall of the hydraulic anchor barrel 8. The lower part of the slot is a slip groove 801 adapted to the slips 10, and the upper part is a slip seat groove 802 adapted to the slip seat 11; the slips 10 are radially slidably arranged in the slip groove 801, and the slip seat 11 is fixedly installed in the slip seat groove 802; multiple slip teeth 1001 are provided on the slips 10, and shear pin holes 1002 are provided at the bottom of the side wall of the slip teeth 1001; multiple slip holes 1101 corresponding to the slip teeth 1001 are provided on the slip seat 11, and locking holes 1102 are provided on the inner wall of the slip holes 1101; the locking shear pin 12 and the pin spring 13 are installed in the locking holes 1102, and the locking shear pin 12 is adapted to the shear pin holes 1002; multiple spring hole seats 1103 are provided at the bottom of the slip seat 11, the upper end of the tooth block support spring 14 is located in the spring hole seats 1103, and the lower end abuts against the slips 10; when the slips 10 are located at the bottom of the slip groove 801, the locking shear pin 12 abuts against the side of the slip teeth 1001; when the slips 10 extend out, the shear pin holes 1002 and the locking holes 1102 are located on the same straight line, and the locking shear pin 12 enters the shear pin holes 1002; a setting fluid inlet hole 803 communicating with the inner cavity of the hydraulic anchor barrel 8 is provided at the bottom of the slip groove 801, and a fluid inlet hole 901 communicating with the inner cavity of the hydraulic anchor barrel 8 is provided on the lower plug 9 of the anchor barrel.

[0044] When this device is in use, it includes the following steps:

[0045] 1) Connect this device to the lower end of the fishing and workover string, install a fish top repair tool on the lower joint of the deflecting shaft 2, and then lower it into the well; the fish top repair tool can be selected as a milling and repairing female taper head according to the fish top situation, or a male taper with a through-tube milling, or other special tools for repairing the fish top;

[0046] 2) After detecting the fish top, make the fish top repair tool about 5 meters away from the fish top, and then start the pump to conduct a positive circulation flush of the fish top through the hollow lifting sleeve 1 and the deflecting shaft 2;

[0047] 3) Stop the pump after cleaning the fish top. After the fish top repair tool touches the fish top, stop lowering the drill string, and then start the pump to conduct a reverse pressure circulation; since the fish top is in contact with the repair tool, the positive circulation outlet is closed. Therefore, during the reverse pressure circulation, the liquid can only enter the inner cavity of the hydraulic anchor barrel 8 through the fluid inlet hole 901, and then push the slips 10 to move upward for anchoring; when the locking shear pin 12 in the locking hole 1102 enters the shear pin holes 1002 under the elastic force of the pin spring 13, the anchoring self-locking is completed; when the pump is stopped, the slips 10 will not reset;

[0048] 4) After the hydraulic anchor is anchored, the fishing and workover string is lifted and lowered to drive the lifting and lowering sleeve 1 to move up and down in a reciprocating linear motion. Under the action of the lifting and lowering pin shaft 104 moving along the 360-degree circumferential wave-shaped deformation track 203, the reciprocating linear motion of the lifting and lowering sleeve 1 is converted into the rotational motion of the deflecting shaft 2; the deflecting shaft 2 drives the fish head repair tool at the lower part to rotate, and repair processes such as milling the fish head or expanding the pipe hole are carried out on the fish head.

[0049] 5) When a certain degree of repair is completed or after completion, the pump is started to reverse the pressure and circulate; since the cross-sectional area of multiple slip teeth 1001 is much larger than the cross-sectional area of the liquid inlet hole 901 of the lower plug 9 of the anchor barrel, when the pressure reaches a certain value, the liquid pushes the slips 10 downward to cut off the locking shear pin 12, and the slips 10 are reset to complete the unsealing.

[0050] 6) When the fish head cannot be repaired in one time after the hydraulic anchor is anchored and it is necessary to lower the tubing to change the anchoring position and continue the repair, then lift out the string, replace the locking shear pin 12, and then lower the well to repeat steps 3-4 to continue repairing the fish head until the fish head repair is completed.

[0051] When this device is in use, there is no need to rotate the fishing and workover string. By lifting and lowering the string, only the fish head repair device is driven to rotate to repair the fish head, which improves the efficiency of repairing the fish head and provides technical guarantee for improving the quality and efficiency of workover operations; since this device does not require rotating the string, when used in horizontal wells, highly deviated wells, etc., problems such as the connection buckle type of the fishing drill pipe and tubing string being tightened can be avoided, making it easy to release the buckle when pulling out the drill string and improving the operation efficiency; this device is suitable for minor workover operations, overcomes the problem that the minor workover equipment cannot rotate to repair the fish head due to the absence of a rotary table, and reduces the operation cost; when this device is used in horizontal wells and highly deviated wells, the wear problem of the fishing string is alleviated and the service life of the fishing string is extended; the hydraulic anchor in this device changes the traditional hydraulic anchor locking method, is internally provided with a self-locking mechanism, does not require the use of other cooperating packers, and changes the situation that it can only be anchored by maintaining hydrodynamic force.

[0052] Embodiment 2

[0053] As a preferred embodiment of the present invention, the structure of the pin shaft limit plug is optimized on the basis of Embodiment 1, specifically as follows:

[0054] Refer to Figure 5 As shown, for the convenience of assembly, the pin shaft limit plug of this embodiment adopts a split structure, including a pin shaft limit outer sleeve 4 and a pin shaft limit inner sleeve 5; a square hole 401 is provided on the pin shaft limit outer sleeve 4, and the pin shaft limit inner sleeve 5 is fixedly nested in the square hole 401, and an inner hole and a boss 501 are provided on the pin shaft limit inner sleeve 5.

[0055] After the lifting and lowering sleeve 1 and the deflecting shaft 2 are connected, they are installed in the outer housing 3, and the upper joint of the lifting and lowering sleeve 1 exposes from the top of the outer housing 3; the pin shaft limiting outer sleeve 4 is installed at the upper end of the outer housing 3 through threads, and then the boss 501 is sleeved on the pin shaft limiting inner sleeve 5 along the limiting groove 101 of the lifting and lowering sleeve 1, and the pin shaft limiting inner sleeve 5 is nested in the pin shaft limiting outer sleeve 4, and the two are assembled with an interference fit; finally, the limiting block 7 is fixed by screws to limit the downward distance of the lifting and lowering sleeve 1.

[0056] Embodiment III

[0057] As a preferred embodiment of the present invention, on the basis of Embodiment II, the bottom structure of the lifting and rotating assembly is optimized, specifically:

[0058] Refer to Figure 2 、 Figure 5 and Figure 6 As shown, the special-shaped joint 6 is provided with a special-shaped groove 601, the special-shaped groove 601 is a square groove, and a lower pin shaft limiting sleeve 15 is embedded in the special-shaped groove 601. The lower pin shaft limiting sleeve 15 is provided with a central hole adapted to the outer diameter of the lower shaft 202 of the deflecting shaft. The lower shaft 202 of the deflecting shaft is rotationally and hermetically connected to the central hole of the lower pin shaft limiting sleeve 15; an isolation retaining ring 16 is sleeved on the upper shaft 201 of the deflecting shaft between the lower pin shaft limiting sleeve 15 and the lower end of the upper shaft 201 of the deflecting shaft.

[0059] The lower pin shaft limiting sleeve 15 in this embodiment adds a support for the rotation of the deflecting shaft 2, making the operation of the device more stable and reliable.

[0060] Embodiment IV

[0061] As a preferred embodiment of the present invention, on the basis of Embodiment I, the settings of the locking hole 1102 and the shear pin hole 1002 in the hydraulic anchor are optimized, specifically:

[0062] Refer to Figure 8 As shown, the maximum clearance between the slip 10 and the slip seat 11 is equal to the maximum anchoring height of the slip 10, and the height difference between the locking hole 1102 and the shear pin hole 1002 is equal to the maximum anchoring height of the slip 10; this setting can lock the slip 10 at the maximum anchoring height of the slip 10, effectively improving the reliability of the hydraulic anchor setting.

[0063] Embodiment V

[0064] As a preferred embodiment of the present invention, on the basis of Embodiment IV, the liquid inlet hole 901 on the lower plug 9 of the anchor barrel is optimized, specifically:

[0065] Two liquid inlet holes 901 are provided on the anchor tube lower plug 9, and the cross-sectional area of ​​the liquid inlet hole 901 is smaller than the cross-sectional area of ​​the slip tooth 1001; this arrangement helps to smoothly unseal the hydraulic anchor and improves the reliability of the operation of the device.

[0066] The present invention is not limited to the above-mentioned embodiments. Various changes can be made within the knowledge scope of those skilled in the art without departing from the spirit of the present invention. The changed contents still fall within the protection scope of the present invention.

Claims

1. A fish top rotating device, characterized in that: It includes a hoisting and rotating assembly and a hydraulic anchor. The hoisting and rotating assembly includes a hoisting sleeve, a deflecting shaft, a pin shaft limit plug, a housing, and a limit block. The top of the hoisting sleeve is provided with an upper joint, the upper outer wall is provided with an axial limit groove, and the bottom is provided with a hoisting sleeve barrel. Two radially and coaxially arranged fixing ears are provided on the bottom wall of the hoisting sleeve barrel, and a hoisting pin shaft is inserted into the fixing ears. The upper part of the deflecting shaft is the upper shaft of the deflecting shaft, and the lower part is the lower shaft of the deflecting shaft. The outer diameter of the upper shaft of the deflecting shaft is larger than that of the lower shaft of the deflecting shaft. A deflecting track adapted to the hoisting pin shaft is provided on the outer wall of the upper shaft of the deflecting shaft. The deflecting track is a 360-degree circular wave-shaped track. The lower end of the lower shaft of the deflecting shaft is provided with a lower joint. Both the hoisting sleeve and the deflecting shaft are hollow tubular structures. The hoisting sleeve barrel is slidably sleeved on the outside of the upper shaft of the deflecting shaft, and the two hoisting pin shafts are slidably arranged in the deflecting track. The housing is sleeved on the hoisting sleeve and the deflecting shaft. The pin shaft limit plug is installed at the upper end of the housing. The pin shaft limit plug is provided with an inner hole adapted to the upper part of the hoisting sleeve, and a convex platform adapted to the limit groove is provided in the inner hole. The upper part of the hoisting sleeve is vertically slidably arranged in the inner hole. The hydraulic anchor includes a special-shaped joint, and the special-shaped joint is installed at the lower end of the housing. A through hole is provided at the central axis position. The lower shaft of the deflecting shaft passes through the through hole. The limit block is fixedly installed in the limit groove on the upper side of the convex platform. The length of the limit groove below the limit block is equal to the axial length of the deflecting track. The hydraulic anchor further includes a hydraulic anchor barrel, an anchor barrel lower plug, slips, a slips seat, a locking shear pin, a pin spring, and a tooth block support spring. The hydraulic anchor barrel is a cylindrical structure. The lower end of the special-shaped joint is detachably connected to the upper end of the hydraulic anchor barrel. The anchor barrel lower plug is installed at the lower end of the hydraulic anchor barrel, and a central hole adapted to the lower shaft of the deflecting shaft is provided on the anchor barrel lower plug. The lower shaft of the deflecting shaft is rotationally and sealingly installed in the central hole of the anchor barrel lower plug. Multiple groups of slot holes are provided on the outer wall of the hydraulic anchor barrel. The lower part of the slot hole is a slips groove adapted to the slips, and the upper part is a slips seat groove adapted to the slips seat. The slips are radially slidably arranged in the slips groove, and the slips seat is fixedly installed in the slips seat groove. Multiple slips teeth are provided on the slips, and shear pin holes are provided at the bottom of the side wall of the slips teeth. Multiple slips holes corresponding to the slips teeth are provided on the slips seat, and locking holes are provided on the inner wall of the slips holes. The locking shear pin and the pin spring are installed in the locking holes, and the locking shear pin is adapted to the shear pin holes. Multiple spring hole seats are provided at the bottom of the slips seat. The upper end of the tooth block support spring is located in the spring hole seats, and the lower end abuts against the slips. When the slips are located at the bottom of the slips groove, the locking shear pin abuts against the side of the slips teeth. When the slips extend, the shear pin holes and the locking holes are located on the same straight line, and the locking shear pin enters the shear pin holes. A seat sealing liquid inlet hole communicating with the inner cavity of the hydraulic anchor barrel is provided at the bottom of the slips groove, and a liquid inlet hole communicating with the inner cavity of the hydraulic anchor barrel is provided on the anchor barrel lower plug. The maximum gap between the slip and the slip seat is equal to the maximum anchoring height of the slip, and the height difference between the locking hole and the shear pin hole is equal to the maximum anchoring height of the slip.

2. The rotary device for repairing fish head according to claim 1, wherein: The pin limiting plug is a split structure, including a pin limiting outer sleeve and a pin limiting inner sleeve; the pin limiting outer sleeve is provided with a square hole, the pin limiting inner sleeve is fixedly nested in the square hole, and the inner hole and the boss are arranged on the pin limiting inner sleeve.

3. The rotary device for repairing fish head according to claim 1, wherein: The special-shaped joint is provided with a special-shaped groove, which is a square groove. A lower pin shaft limiting sleeve is embedded in the special-shaped groove. The lower pin shaft limiting sleeve is provided with a center hole that is adapted to the outer diameter of the lower shaft of the changing shaft. The lower shaft of the changing shaft is rotatably sealed with the center hole of the lower pin shaft limiting sleeve; an isolation retaining ring is mounted on the upper shaft of the changing shaft between the lower pin shaft limiting sleeve and the lower end of the upper shaft of the changing shaft.

4. A fish top rotating device according to claim 1, characterized in that: Two liquid inlet holes are arranged on the lower plug of the anchor cylinder, and the cross-sectional area of ​​the liquid inlet holes is smaller than the cross-sectional area of ​​the slip teeth.

5. A method for using a fish top rotating device according to any one of claims 1-4, characterized in that, The following steps are involved: 1) Connect the device to the lower end of the salvage and workover pipe string, install the fish top repair tool on the lower joint of the change-direction shaft. The fish top repair tool is a sleeve milling repair female cone head or a male cone with through pipe milling, and then lower it into the well; 2) After finding the top of the fish, perform positive circulation to flush the top of the fish; 3) After cleaning the fish top, stop the pump, make the fish top repair tool stop drilling after touching the fish top, and then start the pump to reverse the pressure cycle; the liquid enters the inner cavity of the hydraulic anchor cylinder through the liquid inlet hole, and then pushes the slips upward for anchoring; when the locking shear pin in the locking hole enters the shear pin hole under the elastic force of the pin spring, the anchoring self-locking is completed; when the pump is stopped, the slips will not reset; 4) After the hydraulic anchor is anchored, the lifting and lowering of the salvage and repair pipe string drives the lifting and releasing sleeve to make up and down reciprocating linear motion. Under the action of the lifting and releasing pin shaft moving along the direction-changing track, the up and down reciprocating linear motion of the lifting and releasing sleeve is converted into the rotational motion of the direction-changing shaft; the direction-changing shaft drives the lower fish top repair tool to rotate, and the fish top is milled or the pipe is expanded; 5) When the repair reaches a certain level or is completed, start the pump to reverse the pressure cycle; because the cross-sectional area of ​​the multiple slip teeth is much larger than the cross-sectional area of ​​the liquid inlet hole of the plug under the anchor barrel, when the pressure reaches a certain value, the liquid pushes the slip downward to shear off the locking shear pin, and the slip is reset to complete the unsealing; 6) When the fish top repair cannot be completed after the hydraulic anchor is anchored, and the oil pipe needs to be lowered to change the anchor position to continue the repair, the pipe string is pulled out, the locking shear pin is replaced, and then the well is lowered to repeat steps 3-4 to continue repairing the fish top until the fish top repair is completed.

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