Coiled tubing cutting device

Abstract

The invention discloses a coiled tubing cutting device, relates to the technical field of oil field well repair, and solves the technical problems that the service life of a cutter body of an existing device is short, a slip is easy to block, and the working efficiency is reduced. The cutting device comprises an upper connector, a barrel, a guiding shoe and a cutting assembly, the two ends of the barrel are connected with the upper connector and the guiding shoe respectively, the cutting assembly is arranged in the barrel and comprises a clamping assembly, a pushing sleeve, a plurality of cutter bodies and an unclamping sleeve, the cutter bodies are rotationally connected to the inner wall of the barrel through connecting shafts respectively, and the clamping assembly is arranged on the pushing sleeve. The clamping assembly comprises a sliding sleeve and a slip, the unfreezing sleeve is movably arranged in the slip in a sleeved mode, the slip is movably arranged in the sliding sleeve in a sleeved mode, a limiting piece is connected between the sliding sleeve and the barrel, the pushing sleeve is arranged between the sliding sleeve and the cutter body, and the pushing sleeve is arranged between the sliding sleeve and the cutter body. And the inner wall of the push sleeve is in sliding fit with the outer side wall of the cutter body. The tool has the advantages that the slips can be released, and the service life is long.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of oilfield workover, and particularly relates to a coiled tubing cutting device. BACKGROUND

[0002] The tubing cutting is mainly used for handling downhole accidents in the process of oil and gas exploitation, such as sticking of drill pipe and pipe column, and the like, when the tubing or casing is stuck due to deformation, sanding, corrosion and the like, the cutting is used to segment the pipe column, so as to facilitate fishing or taking out, and reduce the operation difficulty.

[0003] In the prior art, the coiled tubing stuck is generally used for fishing operation by using an external cutter plus a fishing barrel or a cutting and fishing integrated tool, the external cutter plus the fishing barrel needs to be lowered into the well twice, and the efficiency is low; the commonly used cutting and fishing integrated tool generally comprises a joint, a fishing barrel body connected with the joint, a leading shoe connected with the fishing barrel body, the fishing barrel body is internally provided with a slip and a slip cone fixed by a shear pin, and a cutter body seat, and the cutter body is fixed on the cutter body seat by a hoop spring.

[0004] However, the coiled tubing is relatively curved when being lowered into the well, which may cause the slip to be stuck, so that the slip cannot reach the predetermined cutting position or cannot be smoothly taken out after the cutting operation is completed; in addition, the service life of the cutter used in the existing device is low, which affects the cutting efficiency. SUMMARY

[0005] Therefore, the present application discloses a coiled tubing cutting device, which aims to solve the technical problem that the service life of the cutter of the existing device is low and the slip is easily stuck, resulting in reduced operation efficiency.

[0006] To solve the above technical problems, the technical scheme adopted by the present application is as follows:

[0007] A coiled tubing cutting device comprises an upper joint, a barrel body, a leading shoe and a cutting assembly,

[0008] The barrel body is connected with the upper joint and the leading shoe at both ends, respectively, and the cutting assembly is arranged in the barrel body,

[0009] The cutting assembly comprises a clamping assembly, a pushing sleeve, a plurality of cutter bodies and a releasing sleeve, the plurality of cutter bodies are respectively rotationally connected to the inner wall of the barrel through connecting shafts and are distributed in the circumferential direction of the barrel, the clamping assembly comprises a sliding sleeve and a slip bowl, the releasing sleeve is movably sleeved in the slip bowl, the slip bowl is movably sleeved in the sliding sleeve, a limiting piece is connected between the sliding sleeve and the barrel, the pushing sleeve is arranged between the sliding sleeve and the cutter bodies, the inner wall of the pushing sleeve is in sliding fit with the outer wall of the front end of the cutter bodies, the slip bowl is clamped to the oil pipe through the sliding fit between the outer wall of the slip bowl and the inner wall of the sliding sleeve, the cutter bodies are extruded by the pushing sleeve driven by the sliding sleeve, so that the cutter bodies are inwardly retracted, and the slip bowl is expanded and the oil pipe is loosened through the sliding fit between the releasing sleeve and the inner wall of the slip bowl.

[0010] In the present application, the fish is introduced into the barrel through the guide shoe, the position of the sliding sleeve relative to the barrel is limited by the limiting piece, the upper joint drives the sliding sleeve and the barrel to move upward relative to the upper joint and the slip bowl in the process of lifting the upper joint, so that the outer wall of the slip bowl is in sliding fit with the inner wall of the sliding sleeve, the slip bowl is inwardly retracted to clamp the oil pipe, the inner wall of the slip bowl is provided with anti-skid teeth to facilitate stable clamping of the oil pipe, the limiting piece is sheared until it breaks in the process of continuously lifting the upper joint, the sliding sleeve and the barrel are released from the limiting, the sliding sleeve moves towards the cutter bodies, so that the sliding sleeve is in sliding fit with the outer side wall of the cutter bodies, the cutter bodies are inwardly retracted, the driving device is rotated to cut the oil pipe, until the oil pipe is cut off, the fishing is completed by drilling out the continuous oil pipe fish head and pulling out the oil pipe, and the inner wall of the slip bowl is provided with anti-skid teeth to stably clamp the oil pipe.

[0011] In addition, it needs to be explained that when the continuous curved oil pipe is encountered, the upper joint is pressed downward, the releasing sleeve moves downward, the slip bowl is expanded by the releasing sleeve through the sliding fit between the releasing sleeve and the inner wall of the slip bowl, so that the slip bowl can pass through the curved part more smoothly, in addition, if the oil pipe cutting is not completed or the cutter is damaged in the cutting process, the device needs to be pulled out of the wellhead to replace the cutter and then cut in the well, at this time, the oil pipe needs to be loosened and released from the clamping state, therefore, the slip bowl is expanded through the above process, so that the holding force of the oil pipe is released, and the tool can be lifted for subsequent operation.

[0012] Finally, the outer wall of the front end of the cutter body is in sliding fit with the inner wall of the pushing sleeve, the force receiving part of the cutter body is very close to the force applying part for cutting, therefore, the pushing force applied to the cutter body by the pushing sleeve can be more transmitted to the cutting part of the cutter body, and the inner wall of the pushing sleeve supports the cutter body, so that the service life is improved.

[0013] Preferably, the inner wall of the end of the slip bowl away from the releasing sleeve is provided with a sixth inclined part, the end of the releasing sleeve close to the sixth inclined part is provided with a seventh inclined part, and the seventh inclined part can be matched with the sixth inclined part.

[0014] The sixth inclined portion and the seventh inclined portion are inclined in the same direction, i.e., the direction of the axis of the barrel, and the sixth inclined portion and the seventh inclined portion form conical surfaces on the outer wall of the releasing sleeve and the inner wall of the slip, respectively, so that when the releasing sleeve moves towards the inside of the slip, the sixth inclined portion and the seventh inclined portion cooperate with each other to gradually expand the slip, thereby expanding the inner diameter of the slip and releasing the tight grip of the slip on the oil pipe.

[0015] In addition, the slip is provided with a plurality of slits in the circumferential direction, which facilitates the tightening or expansion of the slip.

[0016] Preferably, the front end of the cutter body is provided with a cutter head, the inside of the cutter head is longitudinally provided with a first inclined portion, the first inclined portion is provided with an alloy block, and the front end of the cutter head is transversely provided with a third inclined portion which is inclined upward from the first inclined portion.

[0017] The cutter head is curved towards the inside of the cutter body, so that the tip of the cutter head can contact the oil pipe, the first inclined portion facilitates the welding of a high-hardness alloy block thereon, thereby improving the overall strength of the cutter head, adapting to high-strength cutting, reducing the wear and breakage of the cutter head during cutting operation, and the third inclined portion makes the lower end of the cutter head transversely inclined from left to right, which is provided to avoid air and facilitate cutting by the cutting edge.

[0018] Preferably, the end of the cutter body away from the cutter head is provided with a connecting groove, the inside of the cutter body is provided with a limiting groove, the connecting groove is provided with a torsional spring, and the torsional arm of the torsional spring is arranged in the limiting groove.

[0019] The torsional spring provides a restoring force for the cutter body, and the limiting groove serves to fix the torsional arm of the torsional spring and relieve pressure concentration, thereby prolonging the service life of the cutter body.

[0020] Preferably, three mounting grooves are uniformly arranged on the barrel in the circumferential direction, the mounting grooves are in communication with the inside of the barrel, the side surface of one end of the cutter body is provided with a connecting hole, the side walls of the mounting grooves are each provided with a first positioning hole, one of the first positioning holes penetrates the side wall of the barrel, the other first positioning hole is provided with a through hole, the through hole penetrates the side wall of the barrel, the diameter of the through hole is smaller than the diameter of the first positioning hole, and a bolt is arranged in the first positioning hole which penetrates the side wall of the barrel.

[0021] When the cutter body is installed, the cutter body is arranged in the mounting groove, the connecting hole is aligned with the first positioning hole, the connecting shaft is inserted into the first positioning hole which penetrates the side wall of the barrel, and the bolt is screwed, thereby achieving the installation of the cutter body, and the reverse operation can achieve the disassembly.

[0022] Preferably, the sliding sleeve is provided with a fourth inclined portion on the inner wall of the end of the push sleeve, and the slip is provided with a fifth inclined portion on the outer surface of the end of the push sleeve, and the fifth inclined portion is slidably matched with the fourth inclined portion.

[0023] After the technical scheme is adopted, it should be noted that the fourth inclined portion forms a conical surface on the inner wall of the end of the push sleeve, and similarly, the fifth inclined portion forms a conical surface on the end of the push sleeve, so that when the slip slides relative to the sliding sleeve until the fourth inclined portion and the fifth inclined portion are matched, the slip gradually folds inward under the action of the fourth inclined portion, thereby cutting the oil pipe.

[0024] In addition, it should be noted that the inclination angles of the fourth inclined portion and the fifth inclined portion are both 7.3°, thereby more favorably slowly shrinking the slip and more favorably providing the slip with a better gripping force on the oil pipe.

[0025] Preferably, the cylinder is circumferentially provided with a plurality of threaded holes, the sliding sleeve is provided with a second positioning hole corresponding to the threaded hole, and one of the threaded holes and the second positioning hole is provided with one of the limiting members, and the limiting member is a shear pin.

[0026] After the technical scheme is adopted, it should be noted that the shear pin limits the sliding between the sliding sleeve and the cylinder under certain conditions, and the cylinder and the sliding sleeve are relatively stationary under the action of the shear pin during the oil pipe clamping process, and the upper joint pulls the cylinder and the sliding sleeve to move upward relative to the slip, so that the fifth inclined portion at the front end of the slip and the sixth inclined portion inside the sliding sleeve slide relative to each other to press the slip inward; and during the continuous pulling of the upper joint, the shear force received by the shear pin gradually increases until the shear pin breaks, at which time the cylinder and the sliding sleeve are released from the limiting, and the sliding sleeve can push the push sleeve to press the cutter head.

[0027] Preferably, the push sleeve is provided with an eighth inclined portion on the inner wall of the end of the cutter body, and the cutter head is provided with a second inclined portion on the outer side, and the eighth inclined portion is slidably matched with the second inclined portion.

[0028] After the technical scheme is adopted, it should be noted that the second inclined portion is provided at the cutter head part, and the eighth inclined portion on the inner wall of the push sleeve is matched with the second inclined portion to apply pressure to the cutter body, and the pressure application part is located at the cutter head part, which has the following effects: first, the force receiving part of the cutter head is very close to the force applying part for cutting, so that the pushing force applied by the push sleeve to the cutter head can be more transmitted to the cutting part of the cutter head; second, the eighth inclined portion also plays a supporting role, which acts on the cutter head part to disperse the pressure and shear force received by the cutter head, so that the cutter head can bear larger pressure and shear force during cutting, and the cutting effect is better.

[0029] Preferably, the upper joint and the inner wall of the barrel near the one end of the guide shoe are respectively provided with a plurality of first centralizing blocks and second centralizing blocks.

[0030] After the technical scheme is adopted, it is to be noted that the first centralizing blocks are circumferentially distributed on the inner wall of the upper joint, and the second centralizing blocks are axially distributed on the inner wall of the barrel near the guide shoe. When the fish enters the guide shoe and continuously enters the barrel, the second centralizing blocks can play a role of centralizing and centering the fish, so that the cutter body is uniformly stressed during cutting, and is not easy to break, thereby further improving the service life of the cutter body.

[0031] Preferably, the front end of the guide shoe is provided with a spiral opening, which facilitates the introduction of the fish.

[0032] Preferably, the length of the cutter body is 83 mm, the thickness is 19 mm, the inclination angle (rear inclination angle) of the third inclined portion is 10°, the inclination angle (secondary rear angle) of the second inclined portion is 45°, and the inclination angle of the eighth inclined portion is 30°. The reason why the inclination angle of the eighth inclined portion is set to 30° is that if the angle is less than 30°, the push sleeve will be weak, and the service life of the push sleeve will be reduced. If the eighth inclination angle is too large, excessive axial force will be applied to the cutter head, the stress of the cutter head will be increased, and the service life of the cutter head will be reduced.

[0033] In summary, since the above technical scheme is adopted, the beneficial effects of the present application are:

[0034] 1. The continuous tubing cutting device provided by the present application can prevent the slip from being stuck and facilitate the replacement of the cutter body by setting the release sleeve to move downward under the sliding cooperation between the release sleeve and the inner wall of the slip, so as to release the gripping force on the tubing by the release sleeve.

[0035] 2. The continuous tubing cutting device provided by the present application can facilitate the welding of high-hardness alloy blocks on the first inclined portion, thereby improving the overall strength of the cutter head, and the third inclined portion makes the lower end of the cutter head as a whole present a horizontal left-to-right oblique upward inclination, which is arranged to avoid emptying and facilitate the cutting of the cutting edge.

[0036] 3. The continuous tubing cutting device provided by the present application can make the pushing force applied by the push sleeve to the cutter head be more transmitted to the cutting part of the cutter head, and the eighth inclined portion also plays a supporting role, which disperses the pressure and shear force received by the cutter head, so that the cutter head can bear greater pressure and shear force during cutting, and the cutting effect is better.

[0037] 4. The coiled tubing cutting device provided by the present application, by setting the first centralizing block and the second centralizing block, when the fish enters the guide shoe and continuously enters the barrel, the second centralizing block can play a role of centralizing the fish, so that the cutter is uniformly stressed during cutting, and is not easy to break, and the service life of the cutter is further improved. BRIEF DESCRIPTION OF DRAWINGS

[0038] The present application will be described by way of example and with reference to the accompanying drawings, in which:

[0039] Figure 1 is a schematic diagram of the overall structure of the present application;

[0040] Figure 2 is a schematic diagram of the overall cross-section of the present application;

[0041] Figure 3 is an exploded view of the structure of the present application;

[0042] Figure 4 is a schematic diagram of the cutting assembly structure of the present application;

[0043] Figure 5 is a schematic diagram of the inside structure of the cutter of the present application;

[0044] Figure 6 is a schematic diagram of another perspective view of the cutter of the present application;

[0045] Figure 7 is a schematic diagram of the side view of the cutter of the present application;

[0046] Figure 8 is a schematic diagram of the sliding sleeve structure of the present application;

[0047] Figure 9 is a schematic diagram of the barrel structure of the present application;

[0048] Figure 10 is a schematic diagram of the barrel structure of the present application; Figure 2 is a schematic diagram of the barrel structure of the present application;

[0049] Reference signs

[0050] 1 - upper joint, 2 - barrel, 201 - threaded hole, 202 - mounting groove, 203 - first positioning hole, 204 - through hole, 205 - bolt, 3 - guide shoe, 4 - cutter body, 401 - cutter head, 402 - first inclined part, 403 - second inclined part, 404 - connecting groove, 405 - connecting hole, 406 - limiting groove, 407 - third inclined part, 5 - sliding sleeve, 501 - second positioning hole, 502 - fourth inclined part, 6 - slip, 601 - fifth inclined part, 602 - sixth inclined part, 7 - unblocking sleeve, 701 - seventh inclined part, 8 - pushing sleeve, 801 - eighth inclined part, 9 - shearing pin, 10 - helical opening, 11 - connecting shaft, 12 - first centralizing block, 13 - second centralizing block. DETAILED DESCRIPTION

[0051] To make the objectives, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the accompanying drawings can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the claimed present application, but merely represents selected embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0052] In the description of the embodiments of the present application, it should be noted that the terms "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the present application is usually placed during use, and are merely for the convenience of describing the present application and simplifying the description, and are not intended to indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application. In addition, the terms "first", "second", "third" and the like are only used for differentiation in description and cannot be understood as indicating or implying relative importance.

[0053] In order for those skilled in the art to better understand the technical solutions of the present application, the present application will be further described in detail below in conjunction with the accompanying drawings. It should be noted that the pitch angle refers to the rotation of the device along the Y-axis direction, the yaw angle refers to the rotation of the device along the Z-axis direction, and the roll angle refers to the rotation of the device along the X-axis direction. Here, the directions of the X-axis, Y-axis and Z-axis are based on the directions in the drawings Figure 1

[0054] Embodiment 1

[0055] ​A continuous tubing cutting device, such as Figures 1-4 As shown, it includes an upper connector 1, a cylindrical body 2, a guide shoe 3, and a cutting assembly.

[0056] The upper connector 1 and the guide shoe 3 are respectively connected to both ends of the cylindrical body 2, and the cutting assembly is located inside the cylindrical body 2.

[0057] The cutting assembly includes a clamping assembly, a push sleeve 8, multiple blades 4, and a release sleeve 7. The multiple blades 4 are rotatably connected to the inner wall of the cylinder 2 via connecting shafts 11 and are distributed circumferentially along the cylinder 2. The clamping assembly includes a sliding sleeve 5 and a slip 6. The release sleeve 7 is movably fitted inside the slip 6, and the slip 6 is movably fitted inside the sliding sleeve 5. A limiting member is connected between the sliding sleeve 5 and the cylinder 2. The push sleeve 8 is provided between the sliding sleeve 5 and the blades 4. The inner wall of the push sleeve 8 slides against the outer wall of the blades 4. The slip 6 clamps the oil pipe by sliding against the inner wall of the sliding sleeve 5. The sliding sleeve 5 drives the push sleeve 8 to squeeze the blades 4, causing the blades 4 to retract inward. The release sleeve 7 slides against the inner wall of the slip 6, causing the slip 6 to open and release the oil pipe.

[0058] The slip 6 has a sixth inclined portion 602 on its inner wall at the end away from the release sleeve 7, and the release sleeve 7 has a seventh inclined portion 701 at the end near the sixth inclined portion 602. The seventh inclined portion 701 can cooperate with the sixth inclined portion 602. The inclination directions of the sixth inclined portion 602 and the seventh inclined portion 701 are the same, both inclined towards the axis of the cylinder 2. The sixth inclined portion 602 and the seventh inclined portion 701 respectively make the outer wall of the release sleeve 7 and the inner wall of the slip 6 form a conical surface. Therefore, when the release sleeve 7 moves toward the inside of the slip 6, the sixth inclined portion 602 and the seventh inclined portion 701 cooperate with each other, so that the slip 6 is gradually opened, thereby expanding the inner diameter of the slip 6 and releasing the clamping force of the slip 6 on the oil pipe. The slip 6 has multiple slits along the circumference to facilitate the tightening or opening of the slip 6.

[0059] like Figure 5 As shown, the end of the blade body 4 away from the blade head 401 has a connecting groove 404, and the inner side of the blade body 4 has a limiting groove 406. A torsion spring is provided in the connecting groove 404, and the torsion arm of the torsion spring is placed in the limiting groove 406. The torsion spring provides a restoring force for the blade body 4.

[0060] like Figure 9 , Figure 10As shown, the barrel 2 is uniformly provided with three mounting grooves 202 in the circumferential direction, the mounting grooves 202 are in communication with the inside of the barrel 2, one end of the cutter body 4 is provided with a connecting hole 405, the two side walls of the mounting groove 202 are both provided with a first positioning hole 203, one of the first positioning holes 203 penetrates the side wall of the barrel 2, the other first positioning hole 203 is provided with a through hole 204, the through hole 204 penetrates the side wall of the barrel 2, the diameter of the through hole 204 is smaller than that of the first positioning hole 203, and the first positioning hole 203 penetrating the side wall of the barrel 2 is further provided with a bolt 205, when the cutter body 4 is installed, the cutter body 4 is placed in the mounting groove 202, the connecting hole 405 is aligned with the first positioning hole 203, the connecting shaft 11 is inserted from the first positioning hole 203 penetrating the side wall of the barrel 2, and the bolt 205 is screwed, so that the installation of the cutter body 4 is realized, and the reverse operation can be performed for disassembly.

[0061] The barrel 2 is uniformly provided with a plurality of threaded holes 201 in the circumferential direction, the sliding sleeve 5 is provided with a second positioning hole 501 corresponding to the threaded hole 201, and one of the threaded hole 201 and the second positioning hole 501 is provided with a limiting piece, the limiting piece is a shear pin 9, the sliding between the sliding sleeve 5 and the barrel 2 is limited under certain conditions through the shear pin 9, the barrel 2 and the sliding sleeve 5 are relatively stationary under the action of the shear pin 9 during the oil pipe clamping process, and the upper joint 1 pulls the barrel 2 and the sliding sleeve 5 to move upward relative to the slip 6, therefore, the fifth inclined portion 601 at the front end of the slip 6 and the sixth inclined portion 602 inside the sliding sleeve 5 are slidably matched with each other to press the slip 6 inward; and in the process of continuously pulling the upper joint 1, the shear force received by the shear pin 9 gradually increases until the shear pin 9 breaks, at this time, the barrel 2 and the sliding sleeve 5 are released from the limiting, and the sliding sleeve 5 can push the push sleeve 8 to press the cutter head 401.

[0062] In the embodiment, the fish is introduced into the barrel 2 through the guide shoe 3, the position between the sliding sleeve 5 and the barrel 2 is limited by the limiting piece, the upper joint 1 drives the sliding sleeve 5 and the barrel 2 to move upward relative to the upper joint 1 and the slip 6 in the process of lifting the upper joint 1, so that the outer wall of the slip 6 is slidably matched with the inner wall of the sliding sleeve 5, the slip 6 is retracted inward to clamp the oil pipe, and the inner wall of the slip 6 is provided with anti-skid teeth to facilitate stable clamping of the oil pipe; and in the process of continuously lifting the upper joint 1, the limiting piece is subjected to shear force until it breaks, at this time, the sliding sleeve 5 and the barrel 2 are released from the limiting, and the sliding sleeve 5 moves to the cutter body 4, so as to push the sliding sleeve 5 to be slidably matched with the outer side wall of the cutter body 4, so that the cutter body 4 is retracted inward, the driving device is rotated to cut the oil pipe, until the oil pipe is cut off, the fishing is carried out to the leaking continuous oil pipe fish head, the oil pipe is pulled out to complete the fishing, and the inner wall of the slip 6 is provided with anti-skid teeth to stably clamp the oil pipe;

[0063] In addition, when encountering a continuous curved oil pipe, the upper joint 1 is pressed down, so that the releasing sleeve 7 moves downward, and the slips 6 are expanded by the releasing sleeve 7 through the sliding fit of the releasing sleeve 7 and the inner wall of the slips 6, that is, the slips 6 are more smoothly passed through the curved part. In addition, during the cutting process, if the oil pipe cutting is not completed or the cutter is damaged, the device needs to be pulled out of the wellhead to replace the cutter body 4 and then cut into the well. At this time, the oil pipe needs to be loosened and released from the clamping state. Therefore, the slips 6 are expanded through the above process, so as to release the clamping force on the oil pipe, and then the tool is lifted for subsequent operation.

[0064] Embodiment 2

[0065] The difference between this embodiment and embodiment 1 is that, as shown in Figures 5-7 , the cutter head 401 is provided with a first inclined part 402 longitudinally arranged on the inner side of the cutter head 401, an alloy block is arranged in the first inclined part 402, and a third inclined part 407 is transversely arranged on the front end of the cutter head 401, which is inclined upward from the first inclined part 402.

[0066] In this embodiment, the cutter head 401 is partially curved towards the inner side of the cutter body 4, so as to facilitate the sharp end of the cutter head 401 to contact the oil pipe. The first inclined part 402 is arranged to facilitate the welding of a high-hardness alloy block on the first inclined part 402. The alloy block is flush with the cutting edge part of the cutter head 401, so as to improve the overall strength of the cutter head 401, adapt to high-strength cutting, and reduce the wear and breakage of the cutter head 401 during cutting operation. The third inclined part 407 makes the lower end of the cutter head 401 present a transverse left-to-right oblique upward inclination, which is arranged to avoid air and facilitate the cutting of the cutting edge.

[0067] In addition, the third inclined part 407 is Figure 6 as shown in the figure, and α is the angle of the third inclined part 407. The angle α is a backward inclination angle. In this embodiment, the angle α is 10°.

[0068] Embodiment 3

[0069] The difference between this embodiment and embodiment 2 is that, as shown in Figure 3 , Figure 8 , the sliding sleeve 5 is provided with a fourth inclined part 502 on the inner wall of one end of the sliding sleeve 5 close to the push sleeve 8, and the slips 6 are provided with a fifth inclined part 601 on the outer surface of one end of the slips 6 close to the push sleeve 8, which can be in sliding fit with the fourth inclined part 502.

[0070] In this embodiment, the fifth inclined portion 601 and the fourth inclined portion 502 are inclined in the same direction. The fourth inclined portion 502 causes the inner wall of the sliding sleeve 5 near the push sleeve 8 to form a conical surface. Similarly, the fifth inclined portion 601 causes the slip 6 near the push sleeve 8 to form a conical surface. Therefore, when the slip 6 slides relative to the sliding sleeve 5 until the fourth inclined portion 502 and the fifth inclined portion 601 are engaged, the slip 6 gradually retracts inward under the action of the fourth inclined portion 502, thereby cutting the oil pipe.

[0071] In addition, the tilt angles of the fourth inclined portion 502 and the fifth inclined portion 601 are both 7.3°, which is more conducive to the slow contraction of the slip 6 and to the slip 6 providing better clamping force to the oil pipe.

[0072] Example 4

[0073] The difference between this embodiment and embodiment 3 is that, as Figure 2 As shown, the inner wall of the push sleeve 8 near the blade body 4 is provided with an eighth inclined portion 801, and the outer side of the blade head 401 is provided with a second inclined portion 403. The eighth inclined portion 801 and the second inclined portion 403 are slidably engaged.

[0074] In this embodiment, the second inclined portion 403 is disposed on the cutter head 401, and the eighth inclined portion 801 on the inner wall of the push sleeve 8 cooperates with the second inclined portion 403 to apply pressure to the cutter body 4. This pressure application part is located on the cutter head 401, which has the following functions: First, the force-bearing part of the cutter head 401 is very close to the force-applying part of the cutting, so the pushing force applied by the push sleeve 8 to the cutter head 401 can be transmitted to the cutting part of the cutter head 401 more; Second, the eighth inclined portion 801 also plays a supporting role. It acts on the cutter head 401 and disperses the pressure and shear force on the cutter head 401, so that the cutter head 401 can bear greater pressure and shear force during cutting, and the cutting effect is better.

[0075] Furthermore, in this embodiment, the second inclined portion 403 is as follows: Figure 7 As shown, the second inclined portion 403, also known as the secondary clearance angle, denoted by γ, has an angle of 45°. The inclination angle of the eighth inclined portion 801 is 30°. The reason for setting the inclination angle of the eighth inclined portion 801 to 30° is that if this angle is less than 30°, the push sleeve 8 will become weak, reducing its service life. Conversely, if the eighth inclination angle is too large, it will apply excessive axial force to the cutter head 401, increasing the stress on the cutter head 401 and reducing its service life. Figure 2 The β angle is the tilt angle. Different α, β, and γ angles will affect the efficiency and lifespan of the cutter body 4, as shown in Table 1 below:

[0076] Table 1

[0077]

[0078]

[0079] It should be noted that the oil pipe with a wall thickness of 5 mm is taken as the cutting object, and the cutting is generally completed in 20 minutes, so that the service life less than 20 minutes indicates that a complete cutting cannot be completed, and the tool body 4 needs to be replaced, and the efficiency in the table refers to the number of times of replacing the tool body 4 after cutting the oil pipe, which can reflect the cutting efficiency, in addition, the angles of α, β and γ are related to each other and jointly affect the efficiency and service life of the tool body 4, specifically, the larger the angle of α, the easier the cutter head 401 is to be broken in the cutting process, and the smaller the angle of α, the less sharp the cutter head 401 is, so in the embodiment, the values of β and γ are 32° and 45° respectively, and the value of α is 10° under the condition; for the angle β, the larger the angle β, the larger the contact area of the cutter head 401 with the oil pipe, and the more difficult the cutter head 401 is to cut, thereby affecting the strength of the whole tool body 4, and the smaller the angle β, the smaller the strength of the cutter head 401, and the easier the cutter head 401 is to be broken, under the premise that the value of α is 10° and the value of γ is 45°, the value of β is 32°, which is the most reasonable; for the angle γ, the larger the angle γ, the more dispersed the pushing force of the pushing sleeve 8 is, and the more difficult the pushing sleeve 8 is to guide, and the smaller the angle γ, the longer the stroke of the pushing sleeve 8 is, and the weaker the cutter head 401 is and the easier the cutter head 401 is to be broken, under the premise that the value of α is 10° and the value of β is 32°, the value of γ is 45°, which is the most reasonable, and in summary, in the embodiment, the values of α, β and γ are 10°, 32° and 45° respectively, under the angles, considering the influence of errors, the overall service life of the cutter head 401 is between 24-25 minutes, taking the minimum value of the service life of the cutter head 401, the overall service life and efficiency of the cutter head 401 are as follows in Table 2:

[0080]

[0081] Example 5

[0082] The difference between the embodiment and example 4 is that, as shown in Figure 2 the upper joint 1 and the inner wall of the barrel 2 close to the one end of the guide shoe 3 are respectively provided with a plurality of first centralizing blocks 12 and second centralizing blocks 13.

[0083] In the embodiment, the first centralizing blocks 12 are circumferentially distributed on the inner wall of the upper joint 1, and the second centralizing blocks 13 are axially distributed on the inner wall of the barrel 2 close to the guide shoe 3, when the fish falls into the guide shoe 3 and continuously enters the barrel 2, the second centralizing blocks 13 can play a role of centralizing and centering the fish falling, so that the tool body 4 is uniformly stressed during cutting and is not easy to break, thereby further improving the service life of the tool body 4.

[0084] The use steps of the application are:

[0085] According to the tubing size, select the proper barrel 2, upper joint 1 and guide shoe 3, assemble the device and conduct ground inspection, stop drilling when the cutting device reaches 2m above the fish top, clean the fish top by external pump, start the drilling disc, slowly lower the cutting device, guide the fish by the guide shoe 3, after the fish is guided in, due to the bending of the tubing, there is obvious resistance when going down, rotate and go down to the predetermined position, then pull up the upper joint 1, overload 15KN, the upper joint 1 drives the sliding sleeve 5 and the barrel 2 to move upward relative to the slips 6, so that the outer wall of the slips 6 and the inner wall of the sliding sleeve 5 slide, the slips 6 stretch inwards to clamp the tubing; continue to pull up and press 5KN, the shear force on the shear pin 9 gradually increases until it breaks, at this time the barrel 2 and the sliding sleeve 5 are released from the limit, the sliding sleeve 5 and the slips 6 slide downward to push the push sleeve 8 to extrude the cutter head 401, the cutter head 401 is pressed inwards to contract, start the drilling disc to drive the barrel 2 to rotate, so that the cutter head 401 rotates to cut the tubing, until the tubing is cut, pull up the drilling tool to complete the fishing;

[0086] When encountering a continuous bending tubing, press down the upper joint 1, so that the unclamping sleeve 7 moves downward, the slips 6 are expanded by the unclamping sleeve 7 through the sliding cooperation between the unclamping sleeve 7 and the inner wall of the slips 6, so that the device can pass through the bending part more smoothly, in addition, if the tubing cutting is not completed or the cutter is damaged during the cutting process, the device needs to be pulled out of the wellhead to replace the cutter body 4 and then cut in the well, therefore, the slips 6 are expanded through the above process, so that the gripping force on the tubing is released.

[0087] The above description of disclosed embodiments enables one of ordinary skill in the art to make or use the application. Various modifications to these embodiments will be apparent to those of ordinary skill in the art, and the generic principles defined herein can be applied to other embodiments without departing from the spirit or scope of the application. Therefore, the present application is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A continuous tubing cutting device, characterized in that, Includes an upper connector (1), a cylindrical body (2), a guide shoe (3), and a cutting assembly. The upper connector (1) and the guide shoe (3) are respectively connected to both ends of the cylindrical body (2), and the cutting assembly is located inside the cylindrical body (2). The cutting assembly includes a clamping assembly, a push sleeve (8), multiple blades (4), and a release sleeve (7). The multiple blades (4) are rotatably connected to the inner wall of the cylinder (2) via connecting shafts (11) and are distributed circumferentially along the cylinder (2). The clamping assembly includes a sliding sleeve (5) and a slip (6). The release sleeve (7) is movably fitted inside the slip (6), and the slip (6) is movably fitted inside the sliding sleeve (5). The sliding sleeve (5) and the cylinder (2) are... The sliding sleeve (5) and the cutter body (4) are connected by a limiting component. The push sleeve (8) is provided between the sliding sleeve (5) and the cutter body (4). The inner wall of the push sleeve (8) slides and engages with the outer wall of the cutter body (4). The outer wall of the slip (6) slides and engages with the inner wall of the sliding sleeve (5) to clamp the oil pipe. The sliding sleeve (5) drives the push sleeve (8) to squeeze the cutter body (4) and cause the cutter body (4) to retract inward. The slip sleeve (7) slides and engages with the inner wall of the slip (6) to open and release the oil pipe.

2. The continuous tubing cutting device according to claim 1, characterized in that, The inner wall of the end of the slip (6) away from the release sleeve (7) is provided with a sixth inclined part (602), and the end of the release sleeve (7) near the sixth inclined part (602) is provided with a seventh inclined part (701), which can cooperate with the sixth inclined part (602).

3. A continuous tubing cutting device according to claim 1 or 2, characterized in that, The blade body (4) has a blade head (401) at the front end. The blade head (401) has a first inclined part (402) longitudinally arranged on the inner side. The first inclined part (402) is provided with an alloy block. The blade head (401) has a third inclined part (407) laterally arranged at the front end. The third inclined part (407) is inclined upward from the first inclined part (402).

4. The continuous tubing cutting device according to claim 3, characterized in that, The blade body (4) has a connecting groove (404) at one end away from the blade head (401), and a limiting groove (406) is opened on the inner side of the blade body (4). A torsion spring is provided in the connecting groove (404), and the torsion arm of the torsion spring is placed in the limiting groove (406).

5. A continuous tubing cutting device according to claim 2, characterized in that, The cylinder (2) has three mounting slots (202) evenly distributed around its circumference. The mounting slots (202) are connected to the interior of the cylinder (2). The blade (4) has a connecting hole (405) through one side of its end. The mounting slots (202) have first positioning holes (203) on both sides of their respective sidewalls. One of the first positioning holes (203) penetrates the sidewall of the cylinder (2), and the other first positioning hole (203) has a through hole (204) inside it. The through hole (204) penetrates the sidewall of the cylinder (2), and the diameter of the through hole (204) is smaller than the diameter of the first positioning hole (203). A bolt (205) is also provided inside the first positioning hole (203) that penetrates the sidewall of the cylinder (2).

6. A continuous tubing cutting device according to claim 4, characterized in that, The sliding sleeve (5) has a fourth inclined portion (502) on the inner wall near the push sleeve (8), and the latch (6) has a fifth inclined portion (601) on the outer surface near the push sleeve (8). The fifth inclined portion (601) can slide with the fourth inclined portion (502).

7. A continuous tubing cutting device according to claim 5, characterized in that, The cylinder (2) has a plurality of threaded holes (201) evenly distributed around its circumference. The sliding sleeve (5) is provided with a second positioning hole (501) corresponding to the threaded hole (201). A limiting member is provided in a threaded hole (201) and a second positioning hole (501) corresponding to each other. The limiting member is a shearing pin (9).

8. A continuous tubing cutting device according to claim 5, characterized in that, The push sleeve (8) has an eighth inclined portion (801) on the inner wall of one end near the blade body (4), and the blade head (401) has a second inclined portion (403) on the outer side. The eighth inclined portion (801) and the second inclined portion (403) slide together.

9. A continuous tubing cutting device according to claim 5, characterized in that, The upper connector (1) and the inner wall of the cylinder (2) near the guide shoe (3) are respectively provided with a plurality of first straightening blocks (12) and second straightening blocks (13).

10. A continuous tubing cutting device according to claim 5, characterized in that, The front end of the shoe (3) is provided with a spiral opening (10).

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