Rotary cutting overshot for coiled tubing of horizontal well and using method of rotary cutting overshot

Abstract

The invention provides a horizontal well coiled tubing rotary cutting overshot which comprises an overshot body, the upper end of the overshot body is connected with an upper connector, the lower end of the overshot body is connected with a guiding shoe, and the overshot body is internally and sequentially provided with an anchoring module, a cutting module, a cutting module and a cutting module from top to bottom in the axial direction, and the anchoring module is axially fixed in the overshot body through a breakable elastic shear pin assembly and used for anchoring a to-be-cut coiled tubing; the rotary cutting module axially abuts against the anchoring module through a thrust roller bearing and is used for driving a cutter assembly to cut the coiled tubing by rotating a fishing barrel; the feeding control module is used for controlling the radial feeding amount of the cutting knife assembly; and the righting mechanism is arranged at the joint of the guiding shoe and the fishing barrel and used for guiding the coiled tubing in the middle. The using method comprises the steps of coiled tubing anchoring, lifting starting cutting, rotary cutting, tool retracting protection and linkage fishing. The problems that the fishing failure rate of the coiled tubing is high and secondary accidents are easily caused due to friction resistance and lifting force transmission loss of a horizontal well section are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of downhole tools, and in particular to a horizontal well coiled tubing rotary cutting canister and a use method thereof. Background Art

[0002] With the development of the oil and gas industry and the demand for new drilling and workover technologies in oil fields, the use of coiled tubing units is becoming increasingly widespread. At the same time, the risk of stuck coiled tubing has increased significantly. Once stuck, oil and gas production will be suspended and production will be interrupted. In severe cases, wellhead pressure will increase, causing blowouts and explosions, which will have a serious impact on subsequent production operations. When a stuck pipe accident occurs during operation, the coiled tubing needs to be unstuck promptly. If unstuck is not possible, the coiled tubing must be cut, resulting in the frequent loss of coiled tubing and tool strings in the well. The recovery of lost coiled tubing tool strings has promoted the development of coiled tubing salvage tools, giving rise to various types of downhole salvage tools. These salvage tools have good salvage effects in traditional vertical wells, but are affected by various factors in horizontal wells, resulting in a low salvage success rate.

[0003] In the existing art, complex methods for recovering coiled tubing in horizontal well sections typically involve using thickened tubing outside the drill string or a lifting and cutting tool attached to the tubing. This method utilizes a longitudinal lifting force from the drill string to convert it into a transverse engaging force from the cutting tool, which then cuts and recovers the coiled tubing. While this method has a higher success rate in horizontal well sections than other tools, it still has significant drawbacks. The primary reason for this is the frictional resistance of the wellbore's deviated section. During the lifting process, a significant normal force component is generated in the deviated section, preventing the workover rig from fully transmitting some of the lifting load to the coiled tubing cutting tool, leading to salvage failure and a high probability of tool breakage. If the tool breaks, it can further complicate engineering accidents. Furthermore, in horizontal well sections, the salvage string clings closely to the bottom of the casing's inner wall, making contact with the casing at multiple points. During the lifting process, some of the lifting force is dissipated by friction between the string and the casing. This loss of lifting force increases with increasing depth and the curvature of the wellbore's deviated section. Therefore, a new type of horizontal well coiled tubing rotary cutting bucket needs to be designed to solve the above-mentioned drawbacks. Summary of the Invention

[0004] The main purpose of the present invention is to provide a horizontal well coiled tubing rotary cutting canister and its use method, so as to solve the problem that the friction resistance and pulling force transmission loss in the horizontal well section lead to a high coiled tubing fishing failure rate and easy secondary accidents.

[0005] To solve the above technical problems, the present invention adopts the following technical solutions: a horizontal well coiled tubing rotary cutting overshot, comprising a overshot body, the upper end of which is connected to an upper joint, and the lower end of which is connected to a guide shoe, wherein the overshot body is provided with the following components in order from top to bottom along the axial direction: an anchoring module, which is axially fixed in the overshot body by a breakable elastic shear pin assembly and is used to anchor the coiled tubing to be cut; The rotary cutting module is axially abutted against the anchoring module through a thrust roller bearing and is used to drive the cutter assembly to cut the coiled tubing by rotating the salvage cylinder; A feed control module, used for controlling the radial feed amount of the cutter assembly; The straightening mechanism is located at the connection between the guide shoe and the salvage cylinder and is used to center and guide the coiled tubing.

[0006] In the preferred embodiment, the anchoring module includes a slip and a slip seat. Several elastic clip petals are circumferentially provided at the end of the slip. Adjacent elastic clip petals are separated by axial gaps. The inner diameter surrounded by the several elastic clip petals is smaller than the outer diameter of the continuous oil tubing. The slip seat is fixed in the salvage barrel by an elastic shear pin assembly. The outer wall of the end of the elastic clip petal abuts against the first conical surface mating portion on the inner side of the slip seat.

[0007] In a preferred embodiment, at least two sets of elastic shear pin assemblies are provided circumferentially of the slip seat, and the elastic shear pin assemblies include shear pins and pin springs. The lower ends of the shear pins radially pass through the outer wall of the overshot shell and are inserted into the slip seat. The pin springs are sleeved on the pin springs to drive them to move radially toward the outside of the overshot shell. The pre-compression force of the pin spring is less than the static friction force between the lower end of the shear pin and the slip seat; The shear pin's breaking strength is higher than the maximum axial load required for the anchoring module to initially anchor the coiled tubing. In the preferred embodiment, the rotary cutting module includes a cutting knife frame, a cutting knife rod, a knife grain, a torsion spring, a torsion shaft, a push knife block and a cutting knife seat. Multiple cutting knife rods are rotatably connected to the end of the cutting knife frame through the torsion shaft. The knife grain is fixed to the upper end of the cutting knife rod, and its cutting edge extends radially toward the axis of the salvage cylinder. Multiple push knife blocks are fixed circumferentially on the salvage cylinder. The push knife blocks abut against the side of the cutting knife rod to drive it to move laterally. The outer wall of the end of the cutting knife rod abuts against the second conical surface matching portion on the inner side of the cutting knife seat. A torsion spring is also provided at the rotation connection between the cutting knife rod and the torsion shaft, which is used to drive the cutting knife rod to rotate radially outward and move laterally to reset.

[0008] In a preferred embodiment, a plurality of axial sliding grooves are provided on the outer wall of the cutter seat, and the cutter seat screws radially pass through the salvage cylinder and are inserted into the sliding grooves. In the preferred embodiment, the axial telescopic component of the feed control module is a compression spring, the two ends of which are respectively in contact with the end of the cutter seat and the lower end of the salvage cylinder; Alternatively, the axial telescopic assembly is at least two hydraulic cylinder buffers, including a hydraulic cylinder sleeve, a floating piston, a two-way damping valve and an energy storage compensation membrane. The hydraulic cylinder sleeve is divided into an upper hydraulic oil chamber and a lower drilling fluid chamber by the floating piston. The upper hydraulic oil chamber is connected to the energy storage compensation membrane through the two-way damping valve, and the lower drilling fluid chamber is connected to the outside of the hydraulic cylinder sleeve through a pipeline. The hydraulic cylinder sleeve is fixed to the lower end of the salvage cylinder, and the piston rod end of the floating piston is connected to the cutter seat for adjusting the cutting pressure through the two-way damping valve.

[0009] In a preferred embodiment, the centralizing mechanism comprises two centralizer rings arranged axially at intervals and a plurality of centralizer springs arranged therebetween, wherein the elastic curved surfaces of the centralizer springs protrude radially inwards.

[0010] In the preferred embodiment, the upper joint and the guide shoe are connected to both ends of the salvage cylinder through threaded structures respectively and fixed by set screws, and a spiral blade is provided at the lower end of the guide shoe.

[0011] A method for using a horizontal well coiled tubing rotary cutting canister, the method comprising: S1. Anchoring the coiled tubing: Lower the entire overshot device to the target position. Use the guide shoe to guide the coiled tubing into the overshot shell to the upper anchoring module. Push the slips to axially engage the coiled tubing and secure it. Then, lift the overshot shell to cut the shear pins. The anchoring module moves downward and pushes the rotary cutting module and feed control module downward via the thrust roller bearing. S2, cutting start: the axial telescopic component of the feed control module pushes the cutter seat to squeeze the cutter rod and rotate radially to retract, so that the cutter particles fit the coiled tubing wall; S3, rotary cutting: rotate the salvage cylinder, and the pusher block pushes the cutter rod to rotate and cut. At this time, the axial telescopic component controls the feed amount of the cutter particles; S4, cutter retraction protection: If the cutting is blocked and the cutter is stuck, the tubing string is salvaged and reversed, the cutter bar retracts and exits the cutting, and the torsion spring drives the cutter bar to lift and disengage from the coiled tubing to release the jam; S5. Salvage linkage: After the cutting is completed, the salvage cylinder is directly lifted up, and the anchoring module is anchored again under the action of the gravity of the coiled tubing, and the salvage of the cut section is completed synchronously.

[0012] In the preferred embodiment, in step S3, the method for adjusting the feed rate of the cutter grain when the axial telescopic assembly adopts a hydraulic cylinder buffer is as follows: the drilling fluid pressure in the annulus of the salvage cylinder is sensed by the floating piston, and the hydraulic oil is pushed to flow through the two-way damping valve. When the cutting resistance of the cutter grain is lower than the set threshold, the hydraulic oil flows forward through the large-aperture channel to maintain the calibrated feed speed. When the cutting resistance reaches or exceeds the set threshold, the hydraulic oil switches to the small-aperture channel to flow in the reverse direction, generating back pressure to reduce the feed speed. After penetrating the hard layer, the energy storage compensation membrane pushes the hydraulic oil back to automatically restore the calibrated feed speed.

[0013] The present invention provides a rotary cutting canister for continuous tubing in horizontal wells and a method for using the same. The integrated design of rotary cutting and anchoring salvage significantly improves the efficiency of salvaging continuous tubing in horizontal well sections. The device uses mechanical rotary cutting to replace traditional pull-up cutting, directly converting drill string torque into cutting force, effectively overcoming the loss of pull-up force transmission caused by frictional resistance in the inclination section of the horizontal well, and avoiding salvage failures caused by insufficient load transfer. The anchoring module achieves reliable anchoring of the continuous tubing through the synergistic effect of the elastic clamping flap and the conical surface mating part. Combined with a breakable elastic shear pin assembly, it can automatically release the axial constraint after initial anchoring, ensuring that the cutting module is accurately moved downward and started.

[0014] The rotary cutting module, through the mechanical linkage of the pusher block and cutter bar, directly converts the rotary motion of the salvage shell into radial feed and circumferential cutting action for the cutter. The feed control module offers two adaptive adjustment schemes: a compression spring scheme uses elastic preload to achieve basic feed control; and a hydraulic cylinder buffer scheme utilizes annular drilling fluid pressure to drive a floating piston. Combined with the intelligent switching function of a two-way damping valve, this automatically reduces the feed speed when the cutting resistance exceeds a threshold and automatically resumes the calibrated speed after penetrating the hard layer, effectively preventing tool jamming and improving cutting quality.

[0015] The device's unique cutter retraction protection mechanism utilizes a reset design with a torsion spring and conical mating surface. When cutting is blocked, simply lower the tubing and reverse the cutter bar to radially withdraw, significantly reducing the risk of secondary downhole accidents. The elastic curved spring design of the straightening mechanism ensures precise and centered insertion of the coiled tubing in the horizontal section, reducing friction between the tubing and casing. Finally, the secondary anchoring function of the anchoring module enables simultaneous cutting and salvaging, allowing the entire cutting and salvaging process to be completed in a single trip down the hole, significantly shortening the operation cycle and reducing construction costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The present invention will be further described below with reference to the accompanying drawings and embodiments: Figure 1 This is a diagram of the overall appearance of the present invention; Figure 2 It is an overall cross-sectional structural diagram of the device of the present invention; Figure 3 It is a structural diagram of the anchoring module of the present invention; Figure 4 This is a structural diagram of the rotary cutting module of the present invention; Figure 5 This is a structural diagram of the connection between the cutter bar and the cutter frame of the present invention; Figure 6 This is a diagram showing the installation structure of the pusher block and the cutter rod of the present invention; Figure 7 It is a structural diagram of the righting mechanism of the present invention; Figure 8This is a structural diagram of the feed control module in Example 1 of the present invention; Figure 9 1 is a structural diagram of a feed control module in Example 2 of the present invention; Figure 10 It is a structural schematic diagram of the hydraulic cylinder buffer of the present invention.

[0017] In the figure: salvage cylinder 1; upper joint 2; slip 3; elastic clamping petal 301; slip seat 4; first conical surface fitting portion 401; elastic shear pin assembly 5; shear pin 501; pin spring 502; cutter frame 6; cutter rod 7; cutter grain 8; torsion spring 9; torsion shaft 10; pusher block 11; cutter seat 12; second conical surface fitting portion 1201; axial sliding groove 1202; cutter seat screw 13; compression spring 14; hydraulic cylinder buffer 15; hydraulic cylinder sleeve 1501; floating piston 1502; two-way damping valve 1503; energy storage compensation membrane 1504; centralizer ring 16; centralizer spring 17; guide shoe 18; set screw 19; coiled tubing 20; thrust roller bearing 21. DETAILED DESCRIPTION

[0018] Example 1 like Figures 1 to 8 As shown, a horizontal well coiled tubing rotary cutting canister includes a canister 1, the upper end of which is connected to an upper joint 2, and the lower end is connected to a guide shoe 18. The canister 1 is provided with the following components in the following order from top to bottom along the axial direction: an anchoring module, which is axially fixed in the canister 1 by a breakable elastic shear pin assembly 5 and is used to anchor the coiled tubing 20 to be cut; The rotary cutting module is axially connected to the anchoring module through the thrust roller bearing 21 and is used to drive the cutter assembly to cut the coiled tubing 20 by rotating the salvage cylinder 1; A feed control module, used for controlling the radial feed amount of the cutter assembly; The straightening mechanism is provided at the connection between the guide shoe 18 and the salvage cylinder 1 and is used to guide the coiled tubing 20 in the center.

[0019] The cutting bucket of the present application is a hollow tubular structure with a continuous and smooth appearance. The coiled oil pipe 20 extends from the lower end guide shoe 18, is straightened by the straightening mechanism, and passes through the feed control module and the rotating cutting module in sequence until it is fixed in the anchoring module. A mechanical external cutter is used, and the cutter action is controlled by lifting and lowering the wellhead and rotating the pipe string.

[0020] In the preferred embodiment, the anchoring module includes a slip 3 and a slip seat 4. A plurality of elastic clips 301 are circumferentially provided at the end of the slip 3. Adjacent elastic clips 301 are separated by axial gaps. The inner diameter surrounded by the plurality of elastic clips 301 is smaller than the outer diameter of the coiled tubing 20. The slip seat 4 is fixed in the salvage cylinder 1 by an elastic shear pin assembly 5. The outer wall of the end of the elastic clip 301 abuts against the first conical mating portion 401 on the inner side of the slip seat 4.

[0021] The coiled tubing 20 extends into the middle portion surrounded by the plurality of elastic clips 301 of the slips 3, and after frictional contact with the inner teeth thereof, is pulled downward. Driven by the coiled tubing 20, the upper ends of the elastic clips 301 radially retract into the slip seat 4. The first conical mating portions 401 further tighten the axial gaps between adjacent elastic clips 301, thereby anchoring the coiled tubing 20.

[0022] In the preferred embodiment, at least two sets of elastic shear pin assemblies 5 are provided circumferentially on the slip seat 4. The elastic shear pin assemblies 5 include a shear pin 501 and a pin spring 502. The lower end of the shear pin 501 radially passes through the outer wall of the salvage cylinder 1 and is inserted into the slip seat 4. The pin spring 502 is sleeved on the pin spring 502 to drive it to move radially toward the outside of the salvage cylinder 1. The pre-compression force of the pin spring 502 is smaller than the static friction force between the lower end of the shear pin 501 and the slip seat 4; The breaking strength of the shear pin 501 is higher than the maximum axial load required by the anchoring module to initially anchor the coiled tubing 20 . The slip seat 4 is fixed at a certain height in the salvage cylinder 1 by an elastic shear pin assembly 5, and is used to provide a certain tightening force for the slips 3 to anchor the coiled tubing 20. When cutting is required, the salvage cylinder 1 is continuously pulled up, so that the shear pins 501 break after exceeding the maximum axial load required for anchoring the coiled tubing 20. The pin spring 502 drives the remaining shear pins 501 to pop out, preventing them from falling into the interior of the salvage cylinder 1 and affecting the cutting work.

[0023] In the preferred embodiment, the rotary cutting module includes a cutting knife frame 6, a cutting knife rod 7, a knife grain 8, a torsion spring 9, a torsion shaft 10, a pusher block 11 and a cutting knife seat 12. Multiple cutting knife rods 7 are rotatably connected to the end of the cutting knife frame 6 through the torsion shaft 10. The knife grain 8 is fixed to the upper end of the cutting knife rod 7, and its cutting edge extends radially toward the axis of the salvage cylinder 1. Multiple pusher blocks 11 are fixed circumferentially on the salvage cylinder 1. The pusher block 11 abuts against the side of the cutting knife rod 7 to drive it to move laterally. The outer wall of the end of the cutting knife rod 7 abuts against the second conical surface matching portion 1201 on the inner side of the cutting knife seat 12. A torsion spring 9 is also provided at the rotational connection between the cutting knife rod 7 and the torsion shaft 10 for driving the cutting knife rod 7 to rotate radially outward and move laterally to reset.

[0024] In a preferred embodiment, a plurality of axial sliding grooves 1202 are provided on the outer wall of the cutter seat 12 , and the cutter seat screws 13 radially pass through the salvage cylinder 1 and are inserted into the sliding grooves 1202 . When the coiled tubing 20 is anchored through the rotary cutting module, the cutter bar 7 is radially extended by the torsion spring 9, and the cutter 8 does not abut the wall of the coiled tubing 20. When cutting is required, the elastic shear pin assembly 5 releases the securing force on the slip seat 4, lifting the salvage shell 1. The anchoring module, while maintaining the coiled tubing 20 locked, moves downward relative to the cutter bar 6, which is pushed downward by the thrust roller bearing 21. The front end of the cutter bar 7 enters the inside of the cutter seat 12, radially tightening through the second conical surface engagement portion 1201. The cutter 8 cuts into the wall of the coiled tubing 20, and the salvage shell 1 is then rotated. The multiple pusher blocks 11 fixed to it, through the rotation of the sidewall, drive the already engaged cutter bar 7 to rotate and cut the pipe wall. The cutter seat 12 is restrained from rotating relative to the salvage shell 1 by the cutter seat screw 13, allowing for relative sliding.

[0025] When the cutting is blocked and the knife grain 8 is stuck, continue to pull the salvage cylinder 1 to withdraw the cutter rod 7 from the cutter seat 12, and under the drive of the torsion spring 9, radially loosen the feed of the knife grain 8 to release the jam.

[0026] In the preferred embodiment, the axial telescopic component of the feed control module is a compression spring 14 , both ends of which are respectively in contact with the end of the cutter seat 12 and the lower end of the salvage cylinder 1 .

[0027] The feed control module presses against the cutter seat 12 and the lower end of the salvage cylinder 1 through the elastic pre-tightening force of the compression spring 14. By controlling the lifting height of the salvage cylinder 1, the elastic pressing force of the compression spring 14 on the cutter seat 12 is different, thereby adjusting the tightening degree of the cutter seat 12 on the cutter rod 7, thereby realizing the control of the feed amount of the knife grain 8.

[0028] In a preferred embodiment, the centralizing mechanism includes two centralizer rings 16 spaced apart from each other in the axial direction and a plurality of centralizer springs 17 disposed therebetween. The elastic curved surfaces of the centralizer springs 17 protrude radially inward.

[0029] In the preferred embodiment, the upper connector 2 and the guide shoe 18 are connected to both ends of the salvage cylinder 1 through threaded structures and fixed by set screws 19. The lower end of the guide shoe 18 is provided with a spiral blade.

[0030] The upper joint 2 serves as the connecting part between the salvage cylinder 1 and the external control components. It needs to be reliably connected to the salvage cylinder 1 and limit the relative rotational freedom. The guide shoe 18 also needs to be reliably connected to the salvage cylinder 1 and limit the relative rotational freedom because it will generate relative rotational friction with the well. The spiral blade at its lower end facilitates lowering and feeding.

[0031] Example 2 Further illustrate with reference to Example 1, Figures 9 and 10 In the structure shown, the axial telescopic assembly is composed of at least two hydraulic cylinder buffers 15, including a hydraulic cylinder sleeve 1501, a floating piston 1502, a two-way damping valve 1503 and an energy storage compensation membrane 1504. The hydraulic cylinder sleeve 1501 is divided into an upper hydraulic oil chamber and a lower drilling fluid chamber by the floating piston 1502. The upper hydraulic oil chamber is connected to the energy storage compensation membrane 1504 through the two-way damping valve 1503, and the lower drilling fluid chamber is connected to the outside of the hydraulic cylinder sleeve 1501 through a pipeline. The hydraulic cylinder sleeve 1501 is fixed to the lower end of the salvage cylinder 1, and the piston rod end of the floating piston 1502 is connected to the cutter seat 12 for adjusting the cutting pressure through the two-way damping valve 1503.

[0032] The hydraulic cylinder buffer 15 is directly driven by drilling fluid injected into the well, utilizing annular fluid pressure as a power source. No additional hydraulic pump is required. A two-way damping valve 1503 provides coordinated control of the drilling fluid and hydraulic oil, ensuring automatic speed reduction for the cutterhead 8 during cutting of the coiled tubing 20. The end of the floating piston 1502 pushes against the tapered surface of the cutterhead 12, converting hydraulic pressure into radial thrust. Nitrogen is pre-charged into the energy storage compensation membrane 1504 to balance pressure fluctuations.

[0033] The drilling fluid path at the pressure input end is as follows: the drilling fluid freely enters the lower drilling fluid chamber and directly acts on the bottom of the floating piston 1502. A sealing ring is used on the floating piston 1502 to isolate the drilling fluid and hydraulic oil to avoid contamination.

[0034] The hydraulic oil path of the feedback control end is as follows: the upper hydraulic oil chamber is used as the main oil chamber to fill with hydraulic oil, and the top energy storage compensation membrane 1504 is pre-filled with 2MPa nitrogen to compensate for the volume change caused by temperature.

[0035] The bidirectional flow channel of the bidirectional damping valve 1503 includes a forward channel: hydraulic oil → large-aperture channel → energy storage chamber; a reverse channel: hydraulic oil → small-aperture channel → energy storage chamber.

[0036] When the axial telescopic assembly adopts the hydraulic cylinder buffer 15, the method for adjusting the feed amount of the cutter grain 8 is as follows: the drilling fluid pressure in the annulus of the salvage cylinder 1 is sensed by the floating piston 1502, and the hydraulic oil is pushed to flow through the two-way damping valve 1503. When the cutting resistance of the cutter grain 8 is lower than the set threshold, the hydraulic oil flows forward through the large-aperture channel to maintain the calibrated feed speed. When the cutting resistance reaches or exceeds the set threshold, the hydraulic oil switches to the small-aperture channel for reverse flow, generating back pressure to reduce the feed speed. After penetrating the hard layer, the energy storage compensation membrane 1504 pushes the hydraulic oil back to automatically restore the calibrated feed speed.

[0037] Example 3 Further explanation is given in conjunction with Example 1 and Example 2. Figures 1 to 10The structure shown is a method for using a rotary cutting canister for coiled tubing in a horizontal well, the method comprising: S1. Anchoring the coiled tubing 20: Lower the entire overshot assembly to the target location. The guide shoe 18 guides the coiled tubing 20 into the overshot shell 1 to the upper anchoring module. The slips 4 are pushed to axially engage the coiled tubing 20 and secure it. The overshot shell 1 is then lifted to cut the shear pin 501. The anchoring module then moves downward and pushes the rotary cutting module and feed control module downward via the thrust roller bearing 21. S2, cutting start: the axial telescopic assembly of the feed control module pushes the cutter seat 12 to squeeze the cutter rod 7 to rotate radially and retract, and the cutter particles 8 are attached to the wall of the coiled tubing 20; S3, rotary cutting: rotate the salvage cylinder 1, the pusher block 14 pushes the cutter rod 7 to rotate and cut, and the axial telescopic assembly controls the feed amount of the cutter 8; S4, cutter retraction protection: If the cutting is blocked and the cutter particle 8 is stuck, the tubular body 1 below is salvaged and reversed, the cutter bar 7 retracts and exits the cutting, and the torsion spring 9 drives the cutter bar 7 to lift and disengage from the coiled tubing 20, thus releasing the jam; S5. Salvage linkage: After the cutting is completed, the salvage cylinder 1 is directly lifted up, and the anchoring module is anchored again under the action of the gravity of the coiled tubing 20, and the salvage of the cut section is completed synchronously.

[0038] The above embodiments are merely preferred technical solutions of the present invention and should not be construed as limiting the present invention. The scope of protection of the present invention shall be the technical solutions set forth in the claims, including equivalent alternatives to the technical features of the technical solutions set forth in the claims. In other words, equivalent alternatives and improvements within this scope are also within the scope of protection of the present invention.

Claims

1. A horizontal well coiled tubing rotary cutting canister, characterized by: The invention comprises a salvage cylinder (1), the upper end of which is connected to an upper joint (2), and the lower end of which is connected to a guide shoe (18). The salvage cylinder (1) is provided with the following components in order from top to bottom along the axial direction: an anchoring module, which is axially fixed in the salvage cylinder (1) by a breakable elastic shear pin assembly (5) and is used for anchoring the continuous oil pipe (20) to be cut; A rotary cutting module is axially abutted against the anchoring module via a thrust roller bearing (21) and is used to drive a cutter assembly to cut the coiled tubing (20) by rotating the salvage cylinder (1); A feed control module, used for controlling the radial feed amount of the cutter assembly; The straightening mechanism is provided at the connection between the guide shoe (18) and the salvage cylinder (1) and is used for centering and guiding the coiled tubing (20).

2. The horizontal well coiled tubing rotary cutting canister according to claim 1, characterized in that: The anchoring module comprises a slip (3) and a slip seat (4); a plurality of elastic clips (301) are circumferentially provided at the end of the slip (3); adjacent elastic clips (301) are separated by an axial gap; the inner diameter surrounded by the plurality of elastic clips (301) is smaller than the outer diameter of the continuous oil pipe (20); the slip seat (4) is fixed in the salvage cylinder (1) through an elastic shear pin assembly (5); the outer wall of the end of the elastic clip (301) abuts against the first conical surface matching portion (401) inside the slip seat (4).

3. The horizontal well coiled tubing rotary cutting canister according to claim 1, characterized in that: At least two sets of elastic shear pin assemblies (5) are provided circumferentially on the slip seat (4), and the elastic shear pin assembly (5) includes a shear pin (501) and a pin spring (502). The lower end of the shear pin (501) radially passes through the outer wall of the salvage cylinder (1) and is inserted into the slip seat (4). The pin spring (502) is sleeved on the pin spring (502) to drive it to move radially toward the outside of the salvage cylinder (1); The pre-compression force of the pin spring (502) is smaller than the static friction force between the lower end of the shear pin (501) and the slip seat (4); The shear pin (501) has a breaking strength higher than the maximum axial load required for the anchoring module to initially anchor the coiled tubing (20).

4. The horizontal well coiled tubing rotary cutting canister according to claim 1, characterized in that: The rotary cutting module comprises a cutting knife frame (6), a cutting knife rod (7), a knife grain (8), a torsion spring (9), a torsion shaft (10), a push knife block (11) and a cutting knife seat (12). A plurality of cutting knife rods (7) are rotatably connected to the end of the cutting knife frame (6) through the torsion shaft (10). The knife grain (8) is fixed to the upper end of the cutting knife rod (7), and its cutting edge extends radially toward the axis of the salvage cylinder (1). A plurality of push knife blocks (11) are fixed circumferentially on the salvage cylinder (1). The push knife blocks (11) abut against the side of the cutting knife rod (7) to drive it to move laterally. The outer wall of the end of the cutting knife rod (7) abuts against the second conical surface matching portion (1201) on the inner side of the cutting knife seat (12). A torsion spring (9) is further provided at the rotation connection between the cutting knife rod (7) and the torsion shaft (10) for driving the cutting knife rod (7) to rotate radially outward and to move laterally to reset.

5. The horizontal well coiled tubing rotary cutting canister according to claim 4, characterized in that: The outer wall of the cutter seat (12) is provided with a plurality of axial sliding grooves (1202), and the cutter seat screw (13) radially passes through the salvage cylinder (1) and is inserted into the sliding groove (1202).

6. The horizontal well coiled tubing rotary cutting canister according to claim 1, characterized in that: The axial telescopic component of the feed control module is a compression spring (14), the two ends of which are respectively in contact with the end of the cutter seat (12) and the lower end of the salvage cylinder (1); Alternatively, the axial telescopic assembly is at least two hydraulic cylinder buffers (15), including a hydraulic cylinder sleeve (1501), a floating piston (1502), a two-way damping valve (1503) and an energy storage compensation membrane (1504). The hydraulic cylinder sleeve (1501) is divided into an upper hydraulic oil chamber and a lower drilling fluid chamber by the floating piston (1502). The upper hydraulic oil chamber is connected to the energy storage compensation membrane (1504) through the two-way damping valve (1503), and the lower drilling fluid chamber is connected to the outside of the hydraulic cylinder sleeve (1501) through a pipeline. The hydraulic cylinder sleeve (1501) is fixed to the lower end of the salvage cylinder (1). The piston rod end of the floating piston (1502) is connected to the cutter seat (12) and is used to adjust the cutting pressure through the two-way damping valve (1503).

7. The horizontal well coiled tubing rotary cutting canister according to claim 1, characterized in that: The centralizing mechanism comprises two centralizer rings (16) arranged axially at intervals and a plurality of centralizer shrapnels (17) arranged therebetween, wherein the elastic curved surfaces of the centralizer shrapnels (17) protrude radially inwards.

8. The horizontal well coiled tubing rotary cutting canister according to claim 1, characterized in that: The upper joint (2) and the guide shoe (18) are respectively connected to the two ends of the salvage cylinder (1) through a threaded structure and fixed by a set screw (19). The lower end of the guide shoe (18) is provided with a spiral blade.

9. The method for using a horizontal well coiled tubing rotary cutting canister according to any one of claims 1 to 8, characterized in that: The method includes: S1. Anchoring the continuous tubing (20): Lower the entire salvage tube device to the target position, guide the continuous tubing (20) into the salvage tube body (1) to the upper end anchoring module with the guide shoe (18), push the slips (4) to axially move and engage the continuous tubing (20) to fix it, lift the salvage tube body (1), the shear pin (501) is cut, and the anchoring module moves downward and pushes the rotary cutting module and the feed control module downward through the thrust roller bearing (21); S2, cutting start: the axial telescopic assembly of the feed control module pushes the cutter seat (12) to squeeze the cutter rod (7) to rotate and retract radially, and the cutter grain (8) is attached to the wall of the continuous oil pipe (20); S3, rotary cutting: rotating the salvage cylinder (1), the pusher block (14) pushes the cutter bar (7) to rotate and cut, at which time the axial telescopic assembly controls the feed rate of the cutter grain (8); S4, knife retraction protection: If the cutting is blocked and the knife particle (8) is stuck, the lower salvage cylinder (1) and the pipe string are reversed, the cutter rod (7) retracts and exits the cutting, and the torsion spring (9) drives the cutter rod (7) to lift and disengage from the coiled tubing (20), thereby releasing the jam; S5. Salvage linkage: After the cutting is completed, the salvage cylinder (1) is directly lifted up, and the anchoring module is anchored for the second time under the gravity of the coiled tubing (20), and the salvage of the cut section is completed synchronously.

10. The method for using a rotary cutting canister for coiled tubing in a horizontal well according to claim 9, wherein: In step S3, when the axial telescopic assembly adopts the hydraulic cylinder buffer (15), the method for adjusting the feed rate of the cutter (8) is as follows: the drilling fluid pressure in the annulus of the salvage cylinder (1) is sensed by the floating piston (1502), and the hydraulic oil is pushed to flow through the two-way damping valve (1503). When the cutting resistance of the cutter (8) is lower than the set threshold, the hydraulic oil flows forward through the large-aperture channel to maintain the calibrated feed speed. When the cutting resistance reaches or exceeds the set threshold, the hydraulic oil switches to the small-aperture channel for reverse flow, generating back pressure to reduce the feed speed. After penetrating the hard layer, the energy storage compensation membrane (1504) pushes the hydraulic oil back to automatically restore the calibrated feed speed.

Images