High pressure hydraulic descaling pig

Abstract

The utility model discloses a high pressure hydraulic descaling plug, including centre axis, centre axis lower extreme connects lock shaft, pull rod and check valve in proper order, and the lower extreme of check valve is connected fixed pivot through connecting shaft, and the outer periphery of the middle section of fixed pivot is equipped with the rotary descaling sword that can rotate around it, and the outer periphery of rotary descaling sword is equipped with spiral groove sword, the top of check valve is equipped with the setting mechanism, and the top of setting mechanism is equipped with anchoring mechanism. This high pressure hydraulic descaling plug can remove or reverse the scale in the pipe, thereby protecting the plug rubber tube from being damaged. The rotary descaling sword is a hollow shell structure, and the upper end thereof is provided with a descaling sword upper seat, and the lower end thereof is gap fitted with the fixed pivot to form a rotating pair. A water throttling channel is arranged along the axis of the fixed pivot, and the middle section of the fixed pivot is provided with a plurality of bypass holes for flushing the scale after cutting. The reliability of one-time setting is ensured, the plug-in efficiency is improved, the operation efficiency is high, and the use cost generated by the multiple plug-in of the plug is reduced.

Description

Technical Field

[0001] This utility model relates to a special tool for sealing water spraying outwards from the casing of a well under high pressure, and more particularly to a high-pressure hydraulic descaling and plugging device, belonging to the technical field of downhole descaling and plugging tools. Background Technology

[0002] Currently, hydraulic plugs are used in pressurized wells. During operation, the plug is inserted into the tubing string, and a pump truck is connected to the upper end of the tubing string. The plug is then hydraulically pushed to the top of the tool string. After the pump is shut down, the high pressure inside the well causes the plug to set. When there is a lot of scale inside the tubing, it can make pushing difficult, preventing the plug from being pushed down and potentially damaging the rubber sleeve. Therefore, excessive scale can cause poor sealing of the rubber sleeve. In actual operation, long-term water injection in injection wells leads to severe scale buildup on the tubing walls.

[0003] Conventional hydraulic plugs lack a descaling blade. During hydraulic pushing, due to concerns that scale in the pipe might damage the rubber sleeve and affect the sealing effect, they are often pushed in stages. If a leak occurs, a new plug is immediately added. This repeated plugging, coupled with the rubber sleeve's inadequate seal, makes it prone to damage. Excessive scale can prevent the slips from properly supporting the pipe wall, and a poorly sealed slip body may cause the plug to shift upwards. Utility Model Content

[0004] The purpose of this section is to outline some aspects of embodiments of the present invention and to briefly describe some preferred embodiments. Simplifications or omissions may be made in this section, as well as in the abstract and title of this application, and such simplifications or omissions should not be construed as limiting the scope of the present invention.

[0005] In view of the problems existing in the above and / or prior art, this utility model is proposed.

[0006] The purpose of this invention is to overcome the problem in the existing technology that long-term water injection in water wells leads to severe scaling on the pipe walls, making it impossible to push conventional hydraulic plugs down. This invention provides a high-pressure hydraulic descaling plug that can remove or de-scale large amounts of scale inside the pipe, thereby protecting the plug's rubber sleeve from damage.

[0007] To solve the above technical problems, this utility model provides a high-pressure hydraulic descaling and clogging device, including a central shaft. The lower end of the central shaft is sequentially connected to a locking shaft, a pull rod, and a one-way valve. The lower end of the one-way valve is connected to a fixed rotating shaft via a connecting shaft. A rotary descaling blade that can rotate around the middle section of the fixed rotating shaft is fitted around its outer periphery. The rotary descaling blade has a spiral groove on its outer periphery. A setting mechanism is provided above the one-way valve, and an anchoring mechanism is provided above the setting mechanism.

[0008] Furthermore, the rotary descaling knife has a hollow shell structure, with a descaling knife upper seat at its upper end and a rotary pair formed by clearance fit between its lower end and a fixed rotating shaft.

[0009] Furthermore, a water throttling channel is provided along the axis of the fixed rotating shaft, and a plurality of bypass holes for rinsing off scale after cutting are provided in the middle section of the fixed rotating shaft.

[0010] Furthermore, the lower end of the fixed rotating shaft is provided with a spherical guide head, and the upper circumference of the spherical guide head is provided with a blade for guiding the blocker downward and initially breaking up the scale.

[0011] Furthermore, the anchoring mechanism includes a locking body and locking teeth. The locking body is fitted onto the outer periphery of the central shaft. The outer periphery of the locking body is provided with three or four cones that are narrower at the top and wider at the bottom. The cones slide in conjunction with the locking teeth to achieve unidirectional anchoring.

[0012] Furthermore, the one-way valve includes a radial water passage, a one-way ball, and a spring. The radial water passage is located at the upper end of the central channel of the one-way valve, and the spring is supported below the one-way ball to close the central channel, thereby achieving a one-way seal.

[0013] Furthermore, the setting mechanism includes two-stage rubber tubes fitted around the outer periphery of the middle part of the inner sleeve of the rubber tube, with the two rubber tubes separated by a spacer ring. The top rubber tube is embedded in the rubber tube cap, and the top of the rubber tube cap abuts against the lower part of the outer step of the upper diameter expansion section of the inner sleeve of the rubber tube.

[0014] Furthermore, an expandable leather cup and a leather cup seat are fitted around the lower outer periphery of the inner sleeve of the rubber tube. The upper end of the expandable leather cup is embedded in the lower end of the leather cup seat, and the upper end of the leather cup seat abuts against the bottom of the rubber tube. The lower end of the inner sleeve of the rubber tube is inserted into the upper port of the booster sleeve, and the lower end of the expandable leather cup is provided with a flared opening.

[0015] Furthermore, the upper outer periphery of the booster sleeve is provided with an outer conical surface for inserting into the flared opening of the expansion cup.

[0016] Furthermore, the lower end of the booster sleeve is fitted onto the outer circumference of the upper reduced-diameter section of the one-way valve and abuts against the upper outer step of the one-way valve; the lower end of the pull rod is connected to the central screw hole at the top of the one-way valve, the upper end of the pull rod is connected to the lower end of the locking shaft, and the middle section of the locking shaft is provided with one-way sawtooth spiral teeth on its outer circumference, which cooperate with the open lock nut to allow the locking shaft to move upward in one direction and prevent rebound.

[0017] Furthermore, the lower end of the slip body is connected to the upper female thread of the male-female connector via a male thread, the lower end of the male-female connector is connected to the double female connector via a male thread, and the lower end of the double female connector is connected to the upper expanded diameter section of the inner sleeve of the rubber sleeve via a conversion connector and a double male connector in sequence.

[0018] Furthermore, the upper end of the locking shaft is provided with a locking shaft expansion section, and the bottom of the locking shaft expansion section abuts against the upper part of the inner convex ring in the middle of the double female connector.

[0019] Furthermore, the top of the open lock nut abuts against the lower part of the inner convex ring in the middle of the double female connector, the lower part of the open lock nut is provided with an outer conical surface, and the top center of the adapter is provided with an inner conical surface.

[0020] Furthermore, the plug has a maximum rigid outer diameter of Φ56mm and a length of 1342mm, and is inserted into an oil pipe with an inner diameter of Φ62mm.

[0021] Compared to the prior art, the advantages or beneficial effects of the embodiments of this application include at least the following: 1. The lower end of this plug is made of high-hardness alloy steel with a rotating scraper, which can scrape off the scale inside the downhole pipe in one go. It can remove or blunt larger scale inside the pipe, thereby protecting the plug sleeve from damage, ensuring the reliability of one-time setting, and improving the plugging efficiency. 2. The rotary descaling blade has a central hole, employing a rotating method for descaling and water flushing, further enhancing the descaling ability of the plug. The rotation allows scraped scale to fall off and be flushed to the bottom of the well with water, preventing scale from damaging the rubber sleeve. Cement trucks can directly push the plug to the bottom tool. 3. The sliding block type slip is changed to a synchronous split type to ensure slip synchronization and increase the reliability of the seat seal; 4. High operating efficiency, reducing the operating costs caused by repeated plugging of the blockage device. Attached Figure Description

[0022] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. The drawings are provided for reference and illustration only and are not intended to limit this utility model. Wherein: Figure 1 This is a cross-sectional view of the high-pressure hydraulic descaling and clogging device of this utility model; Reference numerals: 1. Central shaft; 1a. Central shaft nut; 2. Collet body; 3. Collet tooth; 4. Male and female connector; 5. Double female connector; 6. Adapter connector; 7. Double male connector; 8. Inner sleeve of rubber sleeve; 9. Rubber sleeve; 10. Expanding cup; 10a. Cup seat; 11. Push sleeve; 12. Locking shaft; 13. Open lock nut; 14. Pull rod; 15. One-way valve; 15a. Radial water passage hole; 15b. One-way ball; 16. Connecting shaft; 17. Push rubber tower; 18. Rotary descaling knife; 18a. Descaling knife upper seat; 19. Fixed rotating shaft; 19a. Bypass hole. Detailed Implementation

[0023] In the following description of this utility model, the terms "upper", "lower", "front", "rear", "left", "right", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and do not mean that the device must have a specific orientation.

[0024] To make the technical means, creative features, achieved objectives and effects of this utility model easier to understand, the present utility model will be further described below with reference to specific illustrations. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments.

[0025] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

[0026] I. Structure of the High-Pressure Hydraulic Descaling and Clogging Device of this Utility Model like Figure 1 As shown, the lower end of the high-pressure hydraulic descaling and clogging device of this utility model is a descaling device and a booster device, the middle part is a sealing rubber cylinder, and the upper part is a slip. It has the characteristics of convenient downward movement, descaling, and reliable upward anchoring.

[0027] The slip body 2 is fitted onto the outer circumference of the central shaft 1. A central shaft nut 1a is screwed onto the upper end of the central shaft 1 to limit the top of the slip body 2. The lower outer circumference of the slip body 2 is symmetrically provided with three or four cones that are narrower at the top and wider at the bottom. Each cone has a slip tooth 3 that mates with it. The slip tooth 3 slides on the inclined surface of the cone to achieve one-way locking.

[0028] The lower male thread of the slip body 2 is connected to the upper female thread of the male-female connector 4. The lower male thread of the male-female connector 4 is connected to the double female connector 5. The double female connector 5 has an inwardly protruding inner ring in the middle. The lower end of the double female connector 5 is connected to the adapter 6. The lower end of the adapter 6 is connected to the double male connector 7.

[0029] Two rubber tubes 9 are fitted around the outer periphery of the inner sleeve 8. The upper end of the inner sleeve 8 has an enlarged section, and the upper end of the enlarged section is connected to the lower end of the double male connector 7. The two rubber tubes 9 are separated from each other by a spacer ring. The upper end of the top rubber tube 9 is embedded in the rubber tube cap, and the top of the rubber tube cap abuts against the lower part of the outer step of the inner sleeve 8.

[0030] The lower outer periphery of the inner sleeve 8 of the rubber tube is fitted with a leather cup seat 10a and an expandable leather cup 10. The upper end of the expandable leather cup 10 is embedded in the lower port of the leather cup seat 10a. The top of the leather cup seat 10a abuts against the lower part of the rubber tube 9 below. The lower end of the expandable leather cup 10 is provided with a flared mouth.

[0031] The lower end of the inner sleeve 8 is inserted into the upper port of the booster sleeve 11. The upper outer periphery of the booster sleeve 11 is provided with a cone that is narrow at the top and wide at the bottom, which facilitates insertion into the lower port of the expansion cup 10.

[0032] The lower end of the booster sleeve 11 is fitted and abuts against the upper outer step of the one-way valve 15. A pull rod 14 is connected to the central threaded hole at the upper end of the one-way valve 15, and the upper end of the pull rod 14 extends into the inner cavity of the double male connector 7. A locking shaft 12 is connected to the central threaded hole at the upper end of the pull rod 14. The upper end of the locking shaft has a large-diameter end, and the bottom outer step of the large-diameter end of the locking shaft abuts against the upper part of the inner convex ring step of the double female connector 5. The top central threaded hole of the large-diameter end of the locking shaft is connected to the lower end of the central shaft 1.

[0033] The middle outer periphery of the locking shaft 12 is provided with a one-way sawtooth spiral tooth, which is matched with the open lock nut 13. The top of the open lock nut 13 abuts against the inner convex ring step of the double female connector 5. The lower end of the open lock nut 13 is provided with an outer conical surface, and the upper center of the conversion connector 6 is provided with an inner conical surface, which facilitates the insertion of the outer conical surface at the lower end of the open lock nut 13.

[0034] The open lock nut 13 allows the one-way sawtooth spiral teeth of the lock shaft 12 to slide upwards, but not downwards, so that once the lock shaft 12 is on and the rubber sleeve 9 is compressed, it cannot spring back to release.

[0035] The one-way valve 15 has a radial water passage 15a at the upper end of its central channel, which communicates with the outer periphery. A one-way ball 15b is located below the step inside the central channel of the one-way valve 15. A spring supports the bottom of the one-way ball 15b, and the spring is supported on the top of the connecting shaft 16. A central channel is provided along the axis of the connecting shaft 16. Normally, under the action of the lower spring, the central channel functions as a one-way switch.

[0036] The connecting shaft 16 has a stepped structure that is narrower at the top and wider at the bottom. The male thread at the upper end of the connecting shaft 16 is connected to the central threaded hole at the lower end face of the one-way valve 15. A booster glue tower 17 is fitted around the middle section of the connecting shaft 16, and the bottom of the booster glue tower 17 abuts against the lower outer step of the connecting shaft 16.

[0037] A fixed rotating shaft 19 is connected to the central screw hole at the lower end of the connecting shaft 16. The fixed rotating shaft 19 is made of alloy material and has a spherical guide head at the lower end, which plays a guiding role during the well entry process. A knife edge is provided on the circumference above the ball head. A water throttling channel is provided along the axis of the fixed rotating shaft. Multiple bypass holes 19a are provided on the circumference of the middle section of the fixed rotating shaft for flushing dirt.

[0038] The rotary descaling blade 18 has a hollow shell structure and is fitted around the middle section of the fixed rotating shaft. The upper descaling blade seat 18a and the lower end are fitted with the fixed rotating shaft 19 with clearance, allowing the rotary descaling blade 18 to rotate around the fixed rotating shaft 19. The top of the descaling blade seat 18a rests against the lower end of the connecting shaft 16, and the bottom of the rotary descaling blade 18 is supported on the lower outer step of the fixed rotating shaft 19. The outer circumference is designed with four spiral grooves for scraping scale.

[0039] II. Technical Parameters Maximum rigid body outer diameter and length: Φ56*1342mm Applicable tubing inner diameter: Φ62mm Mechanical one-way seat seal: sealing pressure 21 MPa Unsealing method: Apply force in the opposite direction after depressurization.

[0040] III. Description of the blocking operation process: 1. Insert the high-pressure hydraulic descaling plugger (hereinafter referred to as the plugger) into the wellhead blowout preventer. In a vertical position, with the ball guide head at the bottom and the slips at the top, connect the bottom end of the blowout preventer to the top end of the wellhead tubing. Suspension valves or tubing valves must be connected to the top and bottom of the blowout preventer.

[0041] 2. Connect the upper end of the blowout preventer to the cement truck (pump truck). Slowly open the lower valve to allow the pump to push the blocker downwards. The lower booster rubber tower 17 has a one-way sawtooth rubber ring on its outer surface. When the pump truck pressurizes from above, the sawtooth rubber ring expands, generating a downward thrust that causes the blocker to move downwards.

[0042] 3. During the downward movement of the blocker, irregular scale enters the rotary descaling blade, which rotates around the fixed shaft 19 to cut away the scale. Driven by the pump pressure, the rubber tower opens, and some high-pressure water flows from the radial water passage into the middle throttling hole of the fixed shaft 19, and flows out through the bypass hole, promptly flushing away the cut-off scale and preventing scale buildup that could obstruct the downward movement of the blocker.

[0043] 4. When the pump truck experiences pressure buildup and a sudden increase in pressure, it indicates that the blocker has stopped working. This could mean the blocker has reached the top of the downhole tool string, or that excessive scale buildup has caused the blocker to become stuck. In this case, stop the pump immediately.

[0044] 5. Under downhole pressure, the water pressure applies reverse force, the one-way ball 15b closes the upper port of the intermediate throttling channel, the plug moves upward, and the slips are anchored to the inner wall of the tubing. At this time, the expansion cup 10 is pushed to expand, and the hydraulic force causes the double-stage sealing sleeve to compress and expand, blocking the inner wall of the tubing and achieving tubing sealing.

[0045] 6. This plugger operates reliably under well conditions below 21 MPa. The factory test pressure is 31.5 MPa. Failure to seal is generally due to downhole tubing deformation or damage causing harm to the rubber sleeve. Secondary plugging is possible. A small amount of overflow may occur under low pressure conditions, but this generally will not affect operations. Higher pressure results in a more reliable seal.

[0046] IV. Requirements for the use of supporting equipment: 1. Before use, well site technicians should understand the principle of the working device and formulate a reasonable operation plan. This plugger is generally not suitable for use in combined injection wells without tools at the lower end.

[0047] 2. After replacing the rubber cup of the plug, check the tightness of each connection to prevent the connecting threads from loosening.

[0048] 3. This device is suitable for operation on 2-7 / 8” oil pipes.

[0049] 4. For hydraulic delivery, since the downstream position cannot be accurately located, for safety reasons, a 10-meter-long soft floating rope is usually placed above the plug to prevent accidents caused by sudden pressure release when the plug is released.

[0050] 5. When using hydraulic pressurized plugging, it should be used in conjunction with a water tanker and pump truck. The position of the plug can be roughly calculated by estimating the water injection volume.

[0051] The above description is merely a preferred embodiment of the present utility model, showing and describing the basic principles, main features, and advantages of the present utility model. It is not intended to limit the scope of patent protection of the present utility model. Those skilled in the art should understand that the present utility model is not limited to the above embodiments. In addition to the above embodiments, the present utility model may have other implementations without departing from the spirit and scope of the present utility model. Various changes and improvements to the present utility model are also possible. All technical solutions formed by equivalent substitutions or equivalent transformations fall within the scope of protection claimed by the present utility model. The scope of protection claimed by the present utility model is defined by the appended claims and their equivalents. Technical features not described in the present utility model can be implemented by or using existing technology, and will not be elaborated here.

Claims

1. A high-pressure hydraulic descaling and clogging device, comprising a central shaft (1), characterized in that: The lower end of the central shaft (1) is connected in sequence to the locking shaft (12), the pull rod (14) and the one-way valve (15). The lower end of the one-way valve (15) is connected to the fixed rotating shaft (19) through the connecting shaft (16). The middle section of the fixed rotating shaft (19) is fitted with a rotary descaling knife (18) that can rotate around it. The rotary descaling knife (18) is provided with a spiral groove knife on its outer circumference. A setting mechanism is provided above the one-way valve (15), and an anchoring mechanism is provided above the setting mechanism.

2. The high-pressure hydraulic descaling and clogging device according to claim 1, characterized in that: The rotary descaling knife (18) has a hollow shell structure, with a descaling knife upper seat (18a) at its upper end and a rotary pair formed by clearance fit between its lower end and the fixed rotating shaft (19).

3. The high-pressure hydraulic descaling and clogging device according to claim 1, characterized in that: A water throttling channel is provided along the axis of the fixed rotating shaft (19), and a plurality of bypass holes (19a) for rinsing off scale after cutting are provided in the middle section of the fixed rotating shaft (19).

4. The high-pressure hydraulic descaling and clogging device according to claim 1, characterized in that: The fixed rotating shaft (19) is provided with a spherical guide head at its lower end, and the upper circumference of the spherical guide head is provided with a blade for guiding the blocker downward and initially breaking up the scale.

5. The high-pressure hydraulic descaling and clogging device according to claim 1, characterized in that: The anchoring mechanism includes a slip body (2) and slip teeth (3). The slip body (2) is fitted around the outer periphery of the central shaft (1). The outer periphery of the slip body (2) is provided with three or four cones that are narrow at the top and wide at the bottom. The cones slide in conjunction with the slip teeth (3) to achieve unidirectional anchoring.

6. The high-pressure hydraulic descaling and clogging device according to claim 1, characterized in that: The one-way valve (15) includes a radial water passage (15a), a one-way ball (15b) and a spring. The radial water passage (15a) is located at the upper end of the central channel of the one-way valve (15). The spring is supported below the one-way ball (15b) so that the one-way ball (15b) closes the central channel and achieves one-way sealing.

7. The high-pressure hydraulic descaling and clogging device according to claim 5, characterized in that: The sealing mechanism includes two rubber tubes (9) fitted around the outer periphery of the middle part of the inner sleeve (8) of the rubber tube. The two rubber tubes (9) are separated by a spacer ring. The top rubber tube (9) is embedded in the rubber tube cap, and the top of the rubber tube cap abuts against the lower part of the outer step of the upper diameter expansion section of the inner sleeve (8).

8. The high-pressure hydraulic descaling and clogging device according to claim 7, characterized in that: The lower outer periphery of the inner sleeve (8) of the rubber tube is also fitted with an expandable leather cup (10) and a leather cup seat (10a). The upper end of the expandable leather cup (10) is embedded in the lower end of the leather cup seat (10a). The upper end of the leather cup seat (10a) abuts against the bottom of the rubber tube (9). The lower end of the inner sleeve (8) of the rubber tube is inserted into the upper port of the booster sleeve (11). The lower end of the expandable leather cup (10) is provided with a flared mouth.

9. The high-pressure hydraulic descaling and clogging device according to claim 8, characterized in that: The upper outer periphery of the booster sleeve (11) is provided with an outer conical surface for inserting into the flared opening of the expansion cup (10).

10. The high-pressure hydraulic descaling and clogging device according to claim 8, characterized in that: The lower end of the booster sleeve (11) is fitted onto the outer periphery of the upper reduced diameter section of the one-way valve (15) and abuts against the upper outer step of the one-way valve (15); the lower end of the pull rod (14) is connected to the top center screw hole of the one-way valve (15), the upper end of the pull rod (14) is connected to the lower end of the locking shaft (12), and the middle section of the locking shaft (12) is provided with one-way sawtooth spiral teeth on the outer periphery, which cooperate with the open lock nut (13) to allow the locking shaft (12) to move upward in one direction and prevent rebound.

11. The high-pressure hydraulic descaling and clogging device according to claim 10, characterized in that: The lower end of the slip body (2) is connected to the upper end of the female thread of the male and female connector (4) through a male thread. The lower end of the male and female connector (4) is connected to the double female connector (5) through a male thread. The lower end of the double female connector (5) is connected to the upper end of the expanded diameter section of the inner sleeve (8) of the rubber tube in sequence through the conversion connector (6) and the double male connector (7).

12. The high-pressure hydraulic descaling and clogging device according to claim 11, characterized in that: The upper end of the locking shaft (12) is provided with a locking shaft expansion section, and the bottom of the locking shaft expansion section abuts against the upper part of the inner convex ring in the middle of the double female connector (5).

13. The high-pressure hydraulic descaling and clogging device according to claim 11, characterized in that: The top of the open lock nut (13) abuts against the lower part of the inner convex ring in the middle of the double female connector (5), the lower part of the open lock nut (13) is provided with an outer conical surface, and the top center of the adapter (6) is provided with an inner conical surface.

14. The high-pressure hydraulic descaling and clogging device according to any one of claims 1 to 13, characterized in that: The plug has a maximum rigid outer diameter of Φ56mm and a length of 1342mm, and is inserted into an oil pipe with an inner diameter of Φ62mm.

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