Coiled tubing anti-self-locking device

Abstract

The utility model discloses a coiled tubing anti-self-locking device. Relates to the technical field of horizontal well construction. A pushing piston is arranged in a first inner hole of the barrel, a vibration piston is arranged in a second inner hole of the barrel, an ejector rod is arranged on the upper portion of the vibration piston, a counter bore is downwards formed in the upper end face of the pushing piston, an annular groove is formed in the outer circle of the pushing piston and located on the lower side of the sealing ring, a side hole is formed between the annular groove and the counter bore, and a liquid passing channel is formed in the pipe wall of the barrel. The utility model has the beneficial effects that the propelling piston and the vibrating piston are arranged in the cylinder body, and the sequential actions of descending the propelling piston, opening the liquid passing channel, ascending the vibrating piston and closing the liquid passing channel are performed by utilizing the pressure difference between the inside and the outside of the cylinder body, so that the cylinder body moves downwards at intervals and vibrates at intervals at the same time; friction resistance between the coiled tubing and the well wall is reduced, the coiled tubing is prevented from being self-locked, and when the coiled tubing is self-locked and cannot be propelled, high-frequency and high-pressure drilling fluid is injected into the barrel body, propelling force and vibration amplitude are improved, and then the coiled tubing can be unlocked.

Description

Technical Field

[0001] This utility model relates to the field of horizontal well construction technology, and in particular to a coiled tubing anti-locking device. Background Technology

[0002] In recent years, when using coiled tubing for cement plug and bridge plug drilling in horizontal wells, a self-locking phenomenon has occurred during the drilling and running-in process. After several cycles of operation, the tubing still fails to reach the intended cement plug or bridge plug position, severely restricting the on-site construction progress and increasing downtime costs. Currently, downhole traction devices are used to solve the self-locking problem of coiled tubing. However, due to design reasons, most existing traction devices in China have defects such as complex structure, poor reliability, high downhole friction, difficulty in running in and out, and difficulty in applying drilling pressure. Utility Model Content

[0003] To address the current problem of self-locking in coiled tubing, this invention provides a device to prevent self-locking in coiled tubing.

[0004] The technical solution provided by this utility model is as follows: a continuous tubing anti-locking device, comprising a cylinder, an upper connector at the top of the cylinder and a lower connector at the bottom, the lower part of the upper connector of the cylinder being machined with a first inner hole, a second inner hole and a third inner hole respectively, the diameters of the first inner hole, the second inner hole and the third inner hole decreasing sequentially, a pushing piston being provided in the first inner hole of the cylinder, the pushing piston being fitted with the first inner hole through a sealing ring clearance, a vibrating piston being provided in the second inner hole of the cylinder, a push rod being provided on the upper part of the vibrating piston, the vibrating piston being fitted with the second inner hole through a sealing ring clearance, a countersunk hole being opened on the upper end face of the pushing piston, an annular groove being opened on the outer circle of the pushing piston below the sealing ring, a side hole being opened between the annular groove and the countersunk hole, a liquid passage being opened in the tube wall of the cylinder, the liquid passage having an outlet in the first inner hole and the third inner hole respectively, the outlet of the liquid passage in the first inner hole being located below the annular groove of the pushing piston, and a pressure relief hole communicating internally and externally being opened on the tube wall between the pushing piston and the vibrating piston of the cylinder.

[0005] The first inner bore has a compression spring at the lower part of the piston, and the lower part of the compression spring sits on the stepped annular surface between the first inner bore and the second inner bore.

[0006] The cross-sectional area of ​​the annular groove is not less than the cross-sectional area of ​​the third inner hole. There are multiple side holes, and the total cross-sectional area of ​​the multiple side holes is not less than the cross-sectional area of ​​the third inner hole. There are multiple liquid passages, and the total cross-sectional area of ​​the multiple liquid passages is not less than the cross-sectional area of ​​the third inner hole.

[0007] The beneficial effects of this utility model are as follows: By setting a propulsion piston and a vibration piston inside the cylinder, the pressure difference inside and outside the cylinder causes the propulsion piston to descend, the fluid passage to open, the vibration piston to rise, and the fluid passage to close in sequence. This causes the cylinder to move downwards at intervals while generating interval vibrations, reducing the friction between the coiled tubing and the well wall and preventing the coiled tubing from self-locking. When the coiled tubing becomes self-locked and cannot be pushed forward, high-frequency high-pressure drilling fluid is injected into the cylinder to increase the propulsion force and vibration amplitude, thereby unlocking the coiled tubing. It has the characteristics of simple structure and reliable unlocking. Attached Figure Description

[0008] Appendix Figure 1 This is a schematic diagram of the structure of this utility model;

[0009] Appendix Figure 2 This is a structural schematic diagram of the middle cylinder of the utility model;

[0010] Appendix Figure 3 This is a schematic diagram of the structure of the liquid passage opening in this utility model;

[0011] Appendix Figure 4 This is a schematic diagram of the structure of the liquid passage closure of this utility model.

[0012] In the figure, 1-cylinder, 11-upper connector, 12-lower connector, 13-first inner hole, 14-second inner hole, 15-third inner hole, 16-liquid passage, 17-pressure relief hole, 2-propulsion piston, 21-counterhead, 22-annular groove, 23-side hole, 3-vibrating piston, 31-push rod, 4-compression spring. Detailed Implementation

[0013] like Figures 1-4 As shown, a continuous tubing anti-locking device includes a cylinder 1. The cylinder 1 has an upper connector 11 at its upper part and a lower connector 12 at its lower part. The lower part of the upper connector 11 of the cylinder 1 is respectively machined with a first inner hole 13, a second inner hole 14, and a third inner hole 15, the diameters of which decrease sequentially. A push piston 2 is installed inside the first inner hole 13 of the cylinder 1, and the push piston 2 is fitted into the first inner hole 13 through a sealing ring clearance. A vibrating piston 3 is installed inside the second inner hole 14 of the cylinder 1, and a push rod 31 is provided on the upper part of the vibrating piston 3. The piston 3 is fitted with the second inner hole 14 through the gap of the sealing ring. The upper end of the push piston 2 has a countersunk hole 21 facing downward. The outer circle of the push piston 2 has an annular groove 22 on the lower side of the sealing ring. A side hole 23 is opened between the annular groove 22 and the countersunk hole 21. A liquid passage 16 is opened in the inner wall of the cylinder 1. The liquid passage 16 has an outlet in the first inner hole 13 and the third inner hole 15 respectively. The outlet of the liquid passage 16 in the first inner hole 13 is located on the lower side of the annular groove 22 of the push piston 2. A pressure relief hole 17 with internal and external communication is opened on the inner wall of the cylinder 1 between the push piston 2 and the vibrating piston 3.

[0014] The first inner hole 13 has a compression spring 4 at the lower part of the thrust piston 2, and the lower part of the compression spring 4 sits on the stepped annular surface between the first inner hole 13 and the second inner hole 14.

[0015] In actual use, the coiled tubing anti-locking device is connected between the coiled tubing and the drill string. When the drill string is lowered, the drilling fluid pressure pushes the advance piston 2 down. Before the annular groove 22 of the advance piston 2 descends to the fluid passage 16, the drilling fluid pressure pushes the entire coiled tubing and drill string downward. When the annular groove 22 of the advance piston 2 connects with the fluid passage 16, the drilling fluid flows through the annular groove 22 and the fluid passage 16 to the drill string for lubrication and cooling. At this time, since the pressure relief hole 17 connects the inside and outside of the cylinder 1, the pressure on the upper part of the vibrating piston 3 is the drilling fluid backflow pressure. The backflow drilling fluid pressure is less than the drilling fluid injection pressure, and the drilling fluid pressure pushes the vibrating piston 3 up from below. The elastic force of the push rod 31 and the compression spring 4 of the vibrating piston 3 causes the advance piston 2 to rise, and the fluid passage 16 is cut off again. This process is repeated, causing the cylinder 1 to move downward at intervals while generating interval vibration.

[0016] By setting a propulsion piston 2 and a vibration piston 3 inside the cylinder 1, the pressure difference inside and outside the cylinder 1 causes the propulsion piston 2 to descend, the fluid passage 16 to open, the vibration piston 3 to rise, and the fluid passage 16 to close in a sequential action. This causes the cylinder 1 to move downwards at intervals while generating interval vibrations, reducing the friction between the coiled tubing and the well wall and preventing the coiled tubing from self-locking. When the coiled tubing becomes self-locked and cannot be pushed forward, high-frequency high-pressure drilling fluid is injected into the cylinder 1 to increase the propulsion force and vibration amplitude, thereby unlocking the coiled tubing.

[0017] The cross-sectional area of ​​the annular groove 22 is not less than the cross-sectional area of ​​the third inner hole 15. Multiple side holes 23 are provided, and the total cross-sectional area of ​​the multiple side holes 23 is not less than the cross-sectional area of ​​the third inner hole 15. Multiple fluid passages 16 are provided, and the total cross-sectional area of ​​the multiple fluid passages 16 is not less than the cross-sectional area of ​​the third inner hole 15, so as to ensure that the drilling fluid flow rate is sufficient.

Claims

1. A coiled tubing anti-locking device, comprising a cylinder (1), characterized in that: The upper part of the cylinder (1) is provided with an upper connector (11) and the lower part is provided with a lower connector (12). The lower part of the upper connector (11) of the cylinder (1) is respectively machined with a first inner hole (13), a second inner hole (14) and a third inner hole (15). The diameters of the first inner hole (13), the second inner hole (14) and the third inner hole (15) decrease in sequence. The first inner hole (13) of the cylinder (1) is provided with a push piston (2). The push piston (2) is fitted with the first inner hole (13) through the gap of the sealing ring. The second inner hole (14) of the cylinder (1) is provided with a vibrating piston (3). The upper part of the vibrating piston (3) is provided with a push rod (31). The vibrating piston (3) is fitted with the first inner hole (13) through the gap of the sealing ring. The second inner hole (14) is fitted with a clearance fit. The upper end of the push piston (2) has a countersunk hole (21) facing downward. The outer circle of the push piston (2) has an annular groove (22) on the lower side of the sealing ring. A side hole (23) is opened between the annular groove (22) and the countersunk hole (21). A liquid passage (16) is opened in the inner wall of the cylinder (1). The liquid passage (16) has an outlet in the first inner hole (13) and the third inner hole (15) respectively. The outlet of the liquid passage (16) in the first inner hole (13) is located on the lower side of the annular groove (22) of the push piston (2). A pressure relief hole (17) with internal and external communication is opened on the inner wall of the cylinder (1) between the push piston (2) and the vibrating piston (3).

2. The anti-locking device for continuous tubing according to claim 1, characterized in that: The first inner hole (13) has a compression spring (4) at the lower part of the thrust piston (2), and the lower part of the compression spring (4) sits on the stepped annular surface between the first inner hole (13) and the second inner hole (14).

3. The anti-locking device for continuous tubing according to claim 1, characterized in that: The cross-sectional area of ​​the annular groove (22) is not less than the cross-sectional area of ​​the third inner hole (15). There are multiple side holes (23), and the total cross-sectional area of ​​the multiple side holes (23) is not less than the cross-sectional area of ​​the third inner hole (15). There are multiple liquid passages (16), and the total cross-sectional area of ​​the multiple liquid passages (16) is not less than the cross-sectional area of ​​the third inner hole (15).

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