Flow limiting tool for continuous pipe

Abstract

The utility model discloses a flow limiting tool for a continuous pipe, and aims to solve the problem that the flow of an existing continuous pipe tool exceeds a rated value of a screw motor during rotating operation, so that excessive abrasion or damage of a screw is reduced, and the service life of a power drilling tool is prolonged. When fluid is pumped, pressure difference is formed through the throttling effect of the overflowing nozzle, and the piston is pushed to compress the spring. And when the fluid amount reaches a limit value, the piston moves to a specific position, so that the inclined hole is communicated with the outer cylinder hole to form a bypass path. A part of fluid flows out from the bypass, the situation that the flow in the tool is too large is avoided, the screw motor is protected, meanwhile, the bypass fluid can flush the inner wall of a sleeve and promote circulation of annular fluid, and therefore operation efficiency and safety are improved.

Description

Technical Field

[0001] The utility model belongs to the technical field of petroleum machinery and equipment, and relates to a flow limiting tool for continuous pipes. Background Art

[0002] In conventional coiled tubing operations, screw motors and other powered drilling tools are often used for cutting, milling, rotary cleaning, and other operations. The operation method is to pump fluid through the coiled tubing into the screw motor. The screw motor rotates under the action of the fluid, thereby driving the lower tool to rotate.

[0003] Due to the complex downhole environment, the circulating fluid that drives the motor during rotary operation is supplied by a surface pump. Human errors or data delays may occur during the adjustment of the pump flow. If the flow through the screw motor is too large, it will cause excessive wear or damage to the screw, greatly reducing the service life of the screw motor and other power drilling tools.

[0004] Therefore, there is an urgent need for a continuous pipe flow limiting tool that can prevent the flow to the screw motor from exceeding the limit value, thereby ensuring the safe use of the screw motor and extending its service life. Summary of the Invention

[0005] The purpose of the utility model is to provide a flow limiting tool for continuous pipes, which solves the problem in the prior art that when a screw motor is in operation and pumps an excessive flow through the screw motor, the screw motor product is damaged.

[0006] The technical solution adopted by the present utility model is that the upper end of the tool is a joint, which is threadedly connected to the connecting outer tube. A core shaft is mounted on the inner wall of the connecting outer tube, and a piston is mounted on the core shaft. The piston can slide on the core shaft. A seal with a retaining ring is provided between the core shaft and the connecting outer tube. A limit pin is installed on the connecting outer tube to limit the movement of the piston. The retaining ring is mounted on the piston and supported by a spring mounted on the core shaft. The rear end of the spring is mounted with a backing ring and an adjustment sleeve. The adjustment sleeve is threadedly connected to the core shaft to compress the spring. The end of the core shaft is directly connected to the axial hole of the water eye seat, with an O-ring C disposed therebetween. The water eye seat is threadedly tightened with a water eye. The end of the connecting outer tube is threadedly connected to the lower joint.

[0007] The beneficial effect of this utility model is that when pumping fluid, the throttling effect of the flow nozzle generates a certain pressure differential, which pushes the piston and compresses the spring. When the pumped fluid increases to a limited value, the generated pressure differential reaches a certain value, causing the piston to compress the spring and move. The inclined hole in the piston connects with the hole in the connecting outer cylinder, forming a bypass passage to the outside. At this time, some fluid flows out through the bypass, and the flow rate entering the tool center does not increase, thereby protecting the screw motor. This significantly increases the life of the lower tool and prevents safety accidents.

[0008] When the fluid flow rate of the utility model tool is too large and exceeds the limit value during operation, the fluid is discharged from the bypass, which promotes the upward circulation of the fluid in the annulus, especially in the milling operation, which promotes the upward return of the debris generated by the milling to avoid blocking the wellbore.

[0009] The utility model adopts an adaptable design, and can meet the use requirements by replacing water holes and adjusting different flow limiting parameters according to different operation contents and well conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is a structural principle diagram of the utility model;

[0011] In the figure, 1. upper joint, 2. connecting outer cylinder, 3. core shaft, 4. piston, 5. limit pin, 6. retaining ring, 7. spring, 8. gasket, 9. adjustment sleeve, 10. water eye seat, 11. water eye, 12. lower joint, 13. O-ring A, 14. retaining ring, 15. O-ring B, 16. O-ring C, 17. O-ring D, 18. O-ring E. DETAILED DESCRIPTION

[0012] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0013] Reference Figure 1 The upper end of the tool is the upper joint 1, which is connected to the connecting outer tube 2 by a threaded connection, with an O-ring A13 provided between the two. A core shaft 3 is installed on the inner wall of the connecting outer tube 2, and an O-ring A13 is provided between the core shaft 3 and the connecting outer tube 2. A piston 4 is installed on the core shaft 3, and an inclined hole is machined on the piston 4, which can slide on the core shaft 3. There are two groups of seals on the core shaft 3 and the connecting outer tube 2. The seals between the two groups of seals include O-ring A13 and retaining ring 14. O-ring B 15 is provided on the piston 4 and the core shaft 3. A limit pin 5 is installed on the connecting outer tube 2 for limiting the position of the piston 4 during movement. The retaining ring is installed on the piston 4 and is supported by a spring 7 installed on the core shaft 3. A gasket 8 and an adjusting sleeve 9 are installed at the rear end of the spring 7. The adjusting sleeve 9 is threadedly connected to the core shaft 3 to compress the spring 7. The end of the core shaft 3 is directly connected to the axial hole of the water hole seat 10, with an O-ring C16 installed between the two. The water hole 11 is tightened on the water hole seat 10 through a thread. The end of the connecting outer tube 2 is threadedly connected to the lower joint 12. At the same time, an O-ring D17 is installed between the connecting outer tube 2 and the lower joint 12. The end face of the threaded end of the lower joint 12 is equipped with an O-ring E18 to seal between the product and the lower connection tool.

[0014] The working mode of the utility model is:

[0015] When pumped fluid enters the tool's fluid circulation system, the throttling and pressurizing effect of the small orifice 11 generates fluid pressure at the tool's center. This pressure, through the flow hole at the front end of the core shaft 3, pushes piston 4, compressing spring 7 to the right, until the thrust generated by the fluid pressure within the cavity area balances the elastic force of spring 7. When the flow rate reaches a specified value, the pressure at this point compresses the spring to a certain distance, moving piston 4 to a position that connects it to the inclined hole in the connecting outer cylinder 2, forming a fluid bypass path. Fluid flows out through this branch path, and the flow rate through the tool's center no longer increases, thus achieving the desired flow limiting effect.

[0016] When the fluid flow entering the tool is too large and the flow limiting effect is activated, the upward impact fluid flowing out of the bypass passage will flush the casing, which will also promote the upward circulation of the annular fluid and improve operating efficiency.

Claims

1. A flow limiting tool for continuous tubing, characterized by: The upper end of the tool is an upper joint (1), which is connected to the connecting outer tube (2) by a thread, and an O-ring A (13) is provided between the two. A core shaft (3) is installed on the inner wall of the connecting outer tube (2), and an O-ring A (13) is provided between the core shaft (3) and the connecting outer tube (2). A piston (4) is installed on the core shaft (3), and an inclined hole is machined on the piston (4) so ​​that it can slide on the core shaft (3). Two groups of seals are provided on the core shaft (3) and the connecting outer tube (2), and the seal between the two groups of seals includes an O-ring A (13) and a retaining ring (14). An O-ring B is provided on the piston (4) and the core shaft (3). (15), a limit pin (5) is installed on the connecting outer cylinder (2) for limiting the position of the piston (4) during movement, a retaining ring is installed on the piston (4) and is supported by a spring (7) installed on the core shaft (3), a backing ring (8) and an adjusting sleeve (9) are installed at the rear end of the spring (7), and the adjusting sleeve (9) is threadedly connected to the core shaft (3) to play the role of compressing the spring (7).

2. A flow limiting tool for a continuous tube according to claim 1, wherein the end of the core shaft (3) is directly connected to the axial hole of the water eye seat (10), an O-ring C (16) is provided between the two, a water eye (11) is tightened on the water eye seat (10) through a thread, the end of the connecting outer tube (2) is threadedly connected to the lower joint (12), and an O-ring D (17) is provided between the connecting outer tube (2) and the lower joint (12), and an O-ring E (18) is provided on the threaded tail end face of the lower joint (12) for sealing between the product and the lower connection tool.

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