CN213684010U

CN213684010U - Flexible connector for continuous oil pipe

Info

Publication number: CN213684010U
Application number: CN202022242968.9U
Authority: CN
Inventors: 赵云刚; 江春华; 杨柳; 陆光文
Original assignee: Sichuan Kangke Petroleum Technology Co ltd
Current assignee: Sichuan Kangke Petroleum Technology Co ltd; Sinopec Southwest Petroleum Engineering Co Ltd Chongqing Drilling Branch
Priority date: 2020-10-10
Filing date: 2020-10-10
Publication date: 2021-07-13
Anticipated expiration: 2030-10-10

Abstract

The utility model relates to the field of petrochemical industry, and discloses a flexible connector for coiled tubing, which comprises a first locking component, a second locking component and at least one flexible connecting unit. The first locking component includes a first locking mandrel , a first conical cylinder and a first locking claw, the first locking claw and the first conical cylinder are sequentially sleeved on the left end of the first locking mandrel, and the left end of the first locking claw is slidably sleeved At the right end of the first conical cylinder, the second locking assembly is similar in structure to the first locking assembly, the flexible connecting unit can connect the first locking assembly and the second locking assembly, and the first locking claw is along the first cone. When the cylinder slides to the left, the first locking assembly can be clamped in the left coiled tubing. The greater the pulling force on the left coiled tubing, the greater the locking force of the first locking assembly on the left coiled tubing. Similarly The second locking assembly can also be locked in the right coiled tubing, so that the coiled tubing can be locked and the coiled tubing can be rotated at any angle in the circumferential direction.

Description

Flexible connector for continuous oil pipe

Technical Field

The utility model relates to a petrochemical technical field, in particular to flexible connector for coiled tubing.

Background

The coiled tubing is widely applied to petroleum engineering and is a pipeline which can be wound on a roller. When the coiled tubing is operated, one end of the coiled tubing is wound on the roller, and the other end of the coiled tubing penetrates through the arc gooseneck structure and then penetrates through the injection head, and then extends into the underground oil well. In order to avoid the bending fracture of the coiled tubing, when the coiled tubing passes through the circular-arc gooseneck structure, the coiled tubing needs to be divided into two sections, and then the two sections of coiled tubing are connected by using a connector. When the connector in the prior art is used for connecting two sections of coiled tubing, the coiled tubing is difficult to lock, the coiled tubing is easy to fall off from the connector when being stressed, the existing connector cannot meet the requirement of the rotation of the coiled tubing at any angle along the circumferential direction, and when the coiled tubing tends to rotate along the circumferential direction, larger acting force can be generated on the connector, the fracture of the connector is further accelerated, and the service life of the connector is greatly shortened.

SUMMERY OF THE UTILITY MODEL

The utility model aims at providing a flexible connector for coiled tubing can lock coiled tubing to can satisfy coiled tubing along the rotation of the arbitrary angle of circumference.

According to the utility model discloses flexible connector for coiled tubing, include: the first locking assembly sequentially comprises a first locking mandrel, a first conical cylinder and a first locking claw from inside to outside, the first locking claw and the first conical cylinder are sequentially sleeved at the left end of the first locking mandrel, the first locking claw is slidably sleeved at the right end of the first conical cylinder, the outer diameter of the first conical cylinder is gradually increased from the right end to the left end, and a first stop ring is sleeved at the left end of the first locking mandrel; the second locking assembly sequentially comprises a second locking mandrel, a second conical barrel and a second locking claw from inside to outside, the second locking claw and the second conical barrel are sequentially sleeved at the right end of the second locking mandrel, the second locking claw is slidably sleeved at the left end of the second conical barrel, the outer diameter of the second conical barrel is gradually increased from the left end to the right end, and a second stop ring is sleeved at the right end of the second locking mandrel; at least one flexible connection unit, flexible connection unit includes first slips, universal connecting rod and second slips from left to right in proper order, universal connecting rod's left end is equipped with flexible ball joint, the left end of first slips is connected the right-hand member of first locking dabber, the right-hand member of first slips rotates to be connected flexible ball joint, universal connecting rod's right-hand member is connected the left end of second slips, the right-hand member of second slips is connected the left end of second locking dabber.

According to the utility model discloses flexible connector for coiled tubing has following beneficial effect at least: when the flexible connector is used, the first locking component is installed in the inner hole of the left coiled tubing, and the first locking clamping claw is not clamped on the first conical barrel, so that a gap is reserved between the outer wall of the first conical barrel and the inner wall of the inner hole of the left coiled tubing, the first conical barrel and the first locking clamping claw can be smoothly installed in the inner hole of the left coiled tubing, and the left end of the first conical barrel abuts against the designated position of the inner hole of the left coiled tubing; then rotating the first locking mandrel, pushing the first locking mandrel towards the left end, and enabling the first locking clamping claw to slide leftwards along the outer wall of the first conical cylinder, wherein the outer diameter of the first conical cylinder is gradually increased from the right end to the left end, so that the outward deformation of the first locking clamping claw is gradually increased, the gap between the first locking clamping claw and the inner wall of the inner hole of the left continuous oil pipe is gradually reduced until the outer wall of the first locking clamping claw abuts against the inner wall of the inner hole of the left continuous oil pipe, and continuously screwing the first locking mandrel, so that the first locking clamping claw completely locks the left continuous oil pipe; by using the same method, the second locking assembly can be installed into the inner hole of the right coiled tubing, and the second locking claw can completely lock the right coiled tubing, so that the flexible connector can connect the left coiled tubing and the right coiled tubing; the first locking assembly and the second locking assembly are connected through the flexible connecting unit, so that the first locking assembly can rotate relative to the second locking assembly at any angle in the circumferential direction of the coiled tubing, namely the left coiled tubing can rotate relative to the right coiled tubing at any angle in the circumferential direction, and the right coiled tubing can perform downhole operation conveniently; when the left coiled tubing is subjected to pulling force, the left coiled tubing generates left pulling force on the first locking claw, so that the first locking claw continuously slides leftwards along the outer wall of the first conical cylinder, the left coiled tubing is further locked by the first locking claw, and the larger the pulling force generated by the left coiled tubing on the first locking claw is, the larger the locking force generated by the first locking claw on the left coiled tubing is; similarly, when the right coiled tubing generates larger pulling force to the second locking jaw, the larger locking force to the right coiled tubing is generated by the second locking jaw, so that the left coiled tubing and the right coiled tubing are effectively connected, smooth operation of underground operation is guaranteed, and safety guarantee is improved.

According to the utility model discloses a some embodiments, first through-hole has been seted up along the axial to first locking jack catch, first through-hole cup joints the left end of first locking dabber, the left end of first locking jack catch is equipped with a plurality of first locking pieces, and is a plurality of first locking piece centers on first through-hole distributes, and has the clearance between every two adjacent first locking pieces. The first locking blocks are connected to the outer wall of the first conical barrel in a sliding mode, a gap is reserved between every two adjacent first locking blocks, each first locking block can deform outwards when sliding leftwards along the outer wall of the first conical barrel, influence cannot be caused between the first locking blocks, and the first locking clamping claws can be clamped in inner holes of the left coiled tubing more easily.

According to some embodiments of the utility model, the left end outer wall of first locking jack catch is equipped with the first profile of tooth structure of many rings, first profile of tooth structure is followed the right-hand member to the left end downward sloping of first locking jack catch. When the first locking clamping jaw slides leftwards in the inner hole of the left coiled tubing, the first tooth-shaped structure slides along the inner hole of the left coiled tubing, sliding resistance cannot be increased for the first locking clamping jaw, and when the left coiled tubing generates pulling force for the first locking clamping jaw, the first tooth-shaped structure can generate large reaction force for the inner wall of the inner hole of the left coiled tubing, so that the first locking clamping jaw is not easy to separate from the inner hole of the left coiled tubing, and under the matching of the first conical cylinder, the first locking clamping jaw can generate large locking force for the left coiled tubing, and the left coiled tubing is further locked.

According to the utility model discloses a some embodiments, the second through-hole has been seted up along the axial to the second locking jack catch, the second through-hole cup joints the right-hand member of second locking dabber, the right-hand member of second locking jack catch is equipped with a plurality of second latch segments, and is a plurality of the second latch segment centers on the second through-hole distributes, and has the clearance between every two adjacent second latch segments. The second locking blocks are connected to the outer wall of the second conical barrel in a sliding mode, a gap is reserved between every two adjacent second locking blocks, so that each second locking block can deform outwards when sliding rightwards along the outer wall of the second conical barrel, influence cannot be caused between the second locking blocks and the inner hole of the right coiled tubing, and the second locking clamping jaw is clamped easily.

According to some embodiments of the utility model, the right-hand member outer wall of second locking jack catch is equipped with many rings of second tooth shape structure, second tooth shape structure follows the left end to the right-hand member downward sloping of second locking jack catch. When the second locking jaw slides rightwards in the inner hole of the right coiled tubing, the second tooth-shaped structure slides along the inner hole of the right coiled tubing, sliding resistance cannot be increased for sliding of the second locking jaw, and when the right coiled tubing generates pulling force for the second locking jaw, the second tooth-shaped structure can generate large reaction force for the inner wall of the inner hole of the right coiled tubing, so that the second locking jaw is not easy to separate from the inner hole of the right coiled tubing, and under the matching of the second conical barrel, the second locking jaw can generate large locking force for the right coiled tubing, and the right coiled tubing is further locked.

According to the utility model discloses a some embodiments, flexible connection unit still includes the adapter sleeve, the third through-hole has been seted up to the adapter sleeve, just the internal diameter of third through-hole is greater than universal connecting rod's external diameter, the internal diameter of third through-hole is less than flexible ball joint's external diameter, the third through-hole cup joints universal connecting rod, the left end threaded connection of adapter sleeve the right-hand member of first slips. During the installation, the third through hole of adapter sleeve cup joints on universal joint pole earlier to make the right-hand member of the left end threaded connection first slips of adapter sleeve, flexible ball joint is located between adapter sleeve and the first slips this moment, just so can make universal joint pole can be along the arbitrary angular rotation of circumference, and universal joint pole also can not follow first slips and drop simultaneously.

According to the utility model discloses a some embodiments, the right-hand member of first slips is equipped with first arc recess, the left end of adapter sleeve is equipped with second arc recess, first arc recess with second arc recess cooperation is connected flexible ball joint. The structure of first arc recess and second arc recess more is adapted to the structure of flexible ball joint, can be so that flexible ball joint at first arc recess and second arc recess internal rotation for the universal connecting rod can be followed the arbitrary angular rotation of circumference.

According to some embodiments of the utility model, universal connecting rod's right-hand member passes through radial bolted connection the second slips. After the left end of universal connecting rod connects first slips, peg graft the second slips with universal connecting rod's right-hand member to radial insert radial bolt along universal connecting rod and second slips, thereby couple together universal connecting rod and second slips.

Drawings

Fig. 1 is a schematic view of an overall structure of a flexible connector according to an embodiment of the present invention;

FIG. 2 is a cross-sectional view of the flexible connector shown in FIG. 1;

FIG. 3 is an enlarged view of a portion of FIG. 2 at A;

fig. 4 is a schematic structural diagram of a second locking assembly in an embodiment of the present invention;

FIG. 5 is a cross-sectional view of the second locking assembly in mating relationship with the right coiled tubing in an embodiment of the present invention;

fig. 6 is a schematic structural view of a second locking claw in the embodiment of the present invention;

fig. 7 is a schematic structural diagram of a second tapered drum in an embodiment of the present invention.

In the drawings: 100 first locking assembly, 110 first locking mandrel, 120 first conical barrel, 130 first locking dog, 200 second locking assembly, 210 second locking mandrel, 220 second conical barrel, 230 second locking dog, 231 second through hole, 232 second locking block, 233 second tooth structure, 240 second stop ring, 300 flexible connecting unit, 310 first slip, 311 first arc-shaped groove, 320 universal connecting rod, 321 flexible ball joint, 330 second slip, 340 connecting sleeve, 341 third through hole, 342 second arc-shaped groove, 400 left coiled tubing, 500 right coiled tubing.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are exemplary only for the purpose of explaining the present invention, and should not be construed as limiting the present invention.

In the description of the present invention, it should be understood that the orientation or positional relationship indicated with respect to the orientation description, such as up, down, front, rear, left, right, etc., is based on the orientation or positional relationship shown in the drawings, and is only for convenience of description and simplification of description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention.

In the description of the present invention, a plurality of means are one or more, a plurality of means are two or more, and the terms greater than, less than, exceeding, etc. are understood as not including the present number, and the terms greater than, less than, within, etc. are understood as including the present number. If the first and second are described for the purpose of distinguishing technical features, they are not to be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated or implicitly indicating the precedence of the technical features indicated.

In the description of the present invention, unless there is an explicit limitation, the words such as setting, installation, connection, etc. should be understood in a broad sense, and those skilled in the art can reasonably determine the specific meanings of the above words in combination with the specific contents of the technical solution.

Referring to fig. 1 to 7, the embodiment of the utility model provides a flexible connector for coiled tubing, including first locking subassembly 100, flexible connection unit 300 and second locking subassembly 200, referring to fig. 1 and 2, first locking subassembly 100 includes first locking dabber 110 from interior to exterior in proper order, first cone 120 and first locking pawl 130, first locking pawl 130 and first cone 120 cup joint the left end of first locking dabber 110 in proper order, and first locking pawl 130 slides and cup joints the right-hand member of first cone 120, the external diameter of first cone 120 is crescent by right-hand member to left end, the left end cover of first locking dabber 110 is equipped with first backstop ring.

Referring to fig. 4 and 5, the second locking assembly 200 sequentially includes a second locking core shaft 210, a second tapered barrel 220 and second locking claws 230 from inside to outside, the second locking claws 230 and the second tapered barrel 220 are sequentially sleeved on a right end of the second locking core shaft 210, and the second locking claws 230 are slidably sleeved on a left end of the second tapered barrel 220, referring to fig. 7, an outer diameter of the second tapered barrel 220 gradually increases from the left end to the right end, and a second stop ring 240 is sleeved on the right end of the second locking core shaft 210.

Referring to fig. 1, 2 and 3, at least one flexible connection unit 300 is provided, the flexible connection unit 300 sequentially includes a first slip 310, a universal connection rod 320 and a second slip 330 from left to right, the left end of the universal connection rod 320 is provided with a flexible ball joint 321, the left end of the first slip 310 is connected with the right end of the first locking mandrel 110, the right end of the first slip 310 is rotatably connected with the flexible ball joint 321, the right end of the universal connection rod 320 is connected with the left end of the second slip 330, and the right end of the second slip 330 is connected with the left end of the second locking mandrel 210.

Assuming that the left coiled tubing 400 is the section wound on the drum and the right coiled tubing 500 is the section connected with the downhole operation, when the flexible connector is used, the first locking assembly 100 is installed into the inner hole of the left coiled tubing 400, and the first locking claw 130 is not clamped on the first tapered cylinder 120, so that a gap is reserved between the outer wall of the first tapered cylinder 120 and the inner wall of the inner hole of the left coiled tubing 400, so that the first tapered cylinder 120 and the first locking claw 130 can be smoothly installed into the inner hole of the left coiled tubing 400, and the left end of the first tapered cylinder 120 abuts against the specified position of the inner hole of the left coiled tubing 400 (the specified position is set when the coiled tubing is processed and is not the structure of the flexible connector, and the flexible connector is only suitable for the coiled tubing); then, the first locking mandrel 110 is rotated, the first locking mandrel 110 is pushed towards the left end, and the first locking claw 130 slides leftwards along the outer wall of the first tapered barrel 120, the outer diameter of the first tapered barrel 120 gradually increases from the right end to the left end, so the outward deformation of the first locking claw 130 also gradually increases, the gap between the first locking claw 130 and the inner wall of the inner bore of the left coiled tubing 400 gradually decreases, until the outer wall of the first locking claw 130 abuts against the inner wall of the inner bore of the left coiled tubing 400, and the first locking mandrel 110 is continuously screwed, so that the first locking claw 130 completely locks the left coiled tubing 400.

Using the same method, the second locking assembly 200 can be installed into the inner bore of the right coiled tubing 500 and the second locking jaw 230 can completely lock the right coiled tubing 500, and the first stop ring can prevent the first tapered barrel 120 from sliding out of the first locking mandrel 110, and the second stop ring 240 can prevent the second tapered barrel 220 from sliding out of the second locking mandrel 210, so that the flexible connector can connect the left coiled tubing 400 and the right coiled tubing 500 and can lock the left coiled tubing 400 and the right coiled tubing 500, so that neither the left coiled tubing 400 nor the right coiled tubing 500 can fall off during downhole operation.

Because the first locking assembly 100 and the second locking assembly 200 are connected through the flexible connection unit 300, the first locking assembly 100 can rotate relative to the second locking assembly 200 at any angle in the circumferential direction of the coiled tubing, that is, the left coiled tubing 400 can rotate relative to the right coiled tubing 500 at any angle in the circumferential direction, so that the right coiled tubing 500 can perform downhole operation; when the left coiled tubing 400 is pulled, the left coiled tubing 400 will generate a left pulling force on the first locking jaw 130, so that the first locking jaw 130 continues to slide leftwards along the outer wall of the first tapered barrel 120, the first locking jaw 130 further locks the left coiled tubing 400, and the greater the pulling force generated by the left coiled tubing 400 on the first locking jaw 130, the greater the locking force generated by the first locking jaw 130 on the left coiled tubing 400; similarly, when the right coiled tubing 500 generates a larger pulling force to the second locking jaw 230, the second locking jaw 230 generates a larger locking force to the right coiled tubing 500, so that the left coiled tubing 400 and the right coiled tubing 500 are effectively connected, thereby ensuring smooth operation of downhole operation and improving safety guarantee.

Referring to fig. 3, in some embodiments, the flexible connection unit 300 further includes a connection sleeve 340, the connection sleeve 340 is provided with a third through hole 341, an inner diameter of the third through hole 341 is greater than an outer diameter of the universal connection rod 320, an inner diameter of the third through hole 341 is smaller than an outer diameter of the flexible ball joint 321, the third through hole 341 is sleeved on the universal connection rod 320, and a left end of the connection sleeve 340 is threadedly connected to a right end of the first slip 310. During installation, the third through hole 341 of the connecting sleeve 340 is sleeved on the universal connecting rod 320, the left end of the connecting sleeve 340 is in threaded connection with the right end of the first slip 310, and the flexible ball joint 321 is located between the connecting sleeve 340 and the first slip 310, so that the universal connecting rod 320 can rotate at any angle along the circumferential direction, and meanwhile, the universal connecting rod 320 cannot fall off from the first slip 310.

Further, in some embodiments, the right end of the first slip 310 is provided with a first arc-shaped groove 311, the left end of the connection sleeve 340 is provided with a second arc-shaped groove 342, and the first arc-shaped groove 311 and the second arc-shaped groove 342 are cooperatively connected with the flexible ball joint 321. The structures of the first arc-shaped groove 311 and the second arc-shaped groove 342 are more suitable for the structure of the flexible ball joint 321, so that the flexible ball joint 321 can rotate in the first arc-shaped groove 311 and the second arc-shaped groove 342 conveniently, and the universal connecting rod 320 can rotate at any angle in the circumferential direction. With continued reference to FIG. 3, in some embodiments, the right end of the universal connecting rod 320 is connected to the second slip 330 by a radial bolt. After the left end of the universal connecting rod 320 is connected with the first slip 310, the right end of the universal connecting rod 320 is plugged with the second slip 330, and a radial bolt is inserted along the radial direction of the universal connecting rod 320 and the second slip 330, so that the universal connecting rod 320 and the second slip 330 are connected, and the assembly and disassembly are all convenient and fast.

With further reference to fig. 2 and 3, the flexible connection unit 300 is provided in plural, and when the flexible connection unit 300 is provided in three or more, the second slip 330 of the flexible connection unit 300 at the left end and the first slip 310 of the flexible connection unit 300 at the right end are the same component for two adjacent flexible connection units 300, so that the number of components can be reduced, and the structure of the flexible connector is more compact.

Referring to fig. 4 and 5, in some embodiments, the right-end outer wall of the second locking jaw 230 is provided with a plurality of turns of the second tooth structure 233, and the second tooth structure 233 is inclined downward from the left end to the right end of the second locking jaw 230. When the second locking jaw 230 slides to the right in the inner hole of the right coiled tubing 500, the second tooth-shaped structure 233 slides along the inner hole of the right coiled tubing 500 without increasing sliding resistance to the sliding of the second locking jaw 230, and when the right coiled tubing 500 generates pulling force to the second locking jaw 230, the second tooth-shaped structure 233 will generate a large reaction force to the inner wall of the inner hole of the right coiled tubing 500, so that the second locking jaw 230 is not easily disengaged from the inner hole of the right coiled tubing 500, and under the cooperation of the second tapered barrel 220, the second locking jaw 230 will generate a larger locking force to the right coiled tubing 500, further locking the right coiled tubing 500.

Referring to fig. 6, in some embodiments, the second locking claw 230 has a second through hole 231 along the axial direction, the second through hole 231 is sleeved on the right end of the second locking core shaft 210, the right end of the second locking claw 230 is provided with a plurality of second locking blocks 232, the plurality of second locking blocks 232 are distributed around the second through hole 231, and a gap is formed between every two adjacent second locking blocks 232. The second locking blocks 232 are connected to the outer wall of the second conical barrel 220 in a sliding mode, and a gap is formed between every two adjacent second locking blocks 232, so that each second locking block 232 can deform outwards when sliding rightwards along the outer wall of the second conical barrel 220, mutual influence is avoided, and the second locking claws 230 are clamped in the inner holes of the right coiled tubing 500 more easily.

In some embodiments, the outer wall of the left end of the first locking jaw 130 is provided with a plurality of turns of a first tooth-shaped structure, which is inclined downward from the right end to the left end of the first locking jaw 130. When the first locking jaw 130 slides leftward in the inner hole of the left coiled tubing 400, the first tooth-shaped structure slides along the inner hole of the left coiled tubing 400, so that sliding resistance cannot be increased for the sliding of the first locking jaw 130, and when the left coiled tubing 400 generates pulling force for the first locking jaw 130, the first tooth-shaped structure will generate a large reaction force for the inner wall of the inner hole of the left coiled tubing 400, so that the first locking jaw 130 is not easy to disengage from the inner hole of the left coiled tubing 400, and under the cooperation of the first tapered barrel 120, the first locking jaw 130 will generate a larger locking force for the left coiled tubing 400, so as to further lock the left coiled tubing 400.

In some embodiments, the first locking claw 130 is axially provided with a first through hole, the first through hole is sleeved on the left end of the first locking mandrel 110, the left end of the first locking claw 130 is provided with a plurality of first locking blocks, the plurality of first locking blocks are distributed around the first through hole, and a gap is formed between every two adjacent first locking blocks. The plurality of first locking blocks are connected to the outer wall of the first conical barrel 120 in a sliding mode, and a gap is formed between every two adjacent first locking blocks, so that each first locking block can deform outwards when sliding leftwards along the outer wall of the first conical barrel 120, mutual influence is avoided, and the first locking claws 130 can be clamped in the inner hole of the left coiled tubing 400 more easily. While the first locking assembly 100 and the second locking assembly 200 are two sets of symmetrical structures, for the specific structure of the first locking assembly 100, reference can be made to the structure of the second locking assembly 200.

The embodiments of the present invention have been described in detail with reference to the accompanying drawings, but the present invention is not limited to the above embodiments, and various changes can be made without departing from the spirit of the present invention within the knowledge of those skilled in the art.

Claims

1. A flexible connector for coiled tubing, characterized in that, comprising:

The first locking assembly (100) includes a first locking mandrel (110), a first conical cylinder (120) and a first locking claw (130) in sequence from the inside to the outside, the first locking The claw (130) and the first conical cylinder (120) are sequentially sleeved on the left end of the first locking mandrel (110), and the first locking claw (130) is slidably sleeved over the At the right end of the first conical cylinder (120), the outer diameter of the first conical cylinder (120) gradually increases from the right end to the left end, and the left end of the first locking mandrel (110) is sleeved with a first stop ring;

The second locking assembly (200) includes a second locking mandrel (210), a second conical cylinder (220) and a second locking pawl (230) in sequence from the inside to the outside, the second locking The claw (230) and the second conical cylinder (220) are sequentially sleeved on the right end of the second locking mandrel (210), and the second locking claw (230) is slidably sleeved over the At the left end of the second conical cylinder (220), the outer diameter of the second conical cylinder (220) gradually increases from the left end to the right end, and the right end of the second locking mandrel (210) is sleeved with a second stop ring (240);

At least one flexible connecting unit (300), the flexible connecting unit (300) includes a first slip (310), a universal connecting rod (320) and a second slip (330) in sequence from left to right, the A flexible ball joint (321) is provided to the left end of the connecting rod (320), the left end of the first slip (310) is connected to the right end of the first locking mandrel (110), and the first slip (310) The right end of 310) is rotatably connected to the flexible ball joint (321), the right end of the universal connecting rod (320) is connected to the left end of the second slip (330), and the right end of the second slip (330) Connect the left end of the second locking mandrel (210).

2 . The flexible connector for coiled tubing according to claim 1 , wherein the first locking claw ( 130 ) is provided with a first through hole in the axial direction, and the first through hole is sleeved. 3 . Connected to the left end of the first locking mandrel (110), the left end of the first locking claw (130) is provided with a plurality of first locking blocks, and a plurality of the first locking blocks surround the The first through holes are distributed, and there is a gap between every two adjacent first locking blocks.

3. The flexible connector for coiled tubing according to claim 1 or 2, characterized in that, the outer wall of the left end of the first locking claw (130) is provided with a plurality of first tooth structures, and the The first tooth structure is inclined downward along the right end to the left end of the first locking claw (130).

4 . The flexible connector for coiled tubing according to claim 1 , wherein the second locking claw ( 230 ) is provided with a second through hole ( 231 ) in the axial direction, and the second The through hole (231) is sleeved on the right end of the second locking mandrel (210), and the right end of the second locking claw (230) is provided with a plurality of second locking blocks (232), a plurality of which are The second locking blocks (232) are distributed around the second through holes (231), and there is a gap between every two adjacent second locking blocks (232).

5. The flexible connector for coiled tubing according to claim 1 or 4, characterized in that, the outer wall of the right end of the second locking claw (230) is provided with multiple rings of second tooth structures (233) , the second tooth structure (233) is inclined downward along the left end to the right end of the second locking claw (230).

6 . The flexible connector for coiled tubing according to claim 1 , wherein the flexible connecting unit ( 300 ) further comprises a connecting sleeve ( 340 ), and the connecting sleeve ( 340 ) is provided with a third channel. 7 . A hole (341), and the inner diameter of the third through hole (341) is larger than the outer diameter of the universal connecting rod (320), and the inner diameter of the third through hole (341) is smaller than the flexible ball joint (321) ), the third through hole (341) is sleeved with the universal connecting rod (320), and the left end of the connecting sleeve (340) is threadedly connected to the right end of the first slip (310).

7 . The flexible connector for coiled tubing according to claim 6 , wherein the right end of the first slip ( 310 ) is provided with a first arc-shaped groove ( 311 ), and the connecting sleeve ( The left end of 340) is provided with a second arc-shaped groove (342), and the first arc-shaped groove (311) and the second arc-shaped groove (342) cooperate to connect the flexible ball joint (321).

8 . The flexible connector for coiled tubing according to claim 1 , wherein the right end of the universal connecting rod ( 320 ) is connected to the second slip ( 330 ) through radial bolts. 9 .