Variable-diameter sleeve scraper

Abstract

The utility model relates to the technical field of oil and gas field well repair, and discloses a variable-diameter casing scraper which comprises an upper connector, and a central pipe is arranged on the inner wall of the upper connector. The variable-diameter casing scraper is provided with the scraper blade which is in a compressed state all the time when not pressed and is located in the body, the scraper blade cannot be scraped in the construction process, construction risks and equipment losses are reduced, the design of 360-degree full coverage is adopted, when scraping is needed, the inner wall of a casing can be completely covered, the scraping efficiency is improved, and the service life of the casing is prolonged. Due to the unique design of the pressure relief mechanism, when liquid in a tubular column cannot be discharged or the pressure of an oil sleeve is unbalanced, the ball seat can be directly pressed and knocked off, the balance of the oil sleeve is realized, a scraper blade of the scraper is safely withdrawn, the construction safety is effectively improved, and due to the design of the reverse circulation mechanism, a circulation system can be established during construction, and the construction efficiency is improved. The cleanness in the well can be kept, and the construction smoothness and effect can be improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to oil and gas field workover technology field, concretely is variable diameter casing scraper. BACKGROUND

[0002] Oil and gas well casing is used for a long time, due to various construction, such as fracturing, acidification and so on, or the action of ground stress, leading to casing deformation, and the deformed section needs to be lowered into packer and other tools for construction.

[0003] Such as staged fracturing, acidification, water injection and so on, before being lowered, the casing of the packer section must be scraped, facilitating packer sealing, and scraping does not affect subsequent measures of oil and gas well, and the present design is a new scraper designed for the deformation of the casing.

[0004] In the prior art, the outer diameter of the ordinary scraper body is very large, and the maximum outer diameter of the scraper is more than 10 mm larger than the inner diameter of the applicable casing under the support of the internal spring, and when the casing is deformed, the body is difficult to pass, even if the body can pass, the scraper is also easy to get stuck when passing the deformed well section, which brings great safety hazards to construction, therefore, we need a variable diameter casing scraper. TECHNICAL SOLUTION

[0005] The utility model discloses a variable diameter casing scraper, which can solve the problems in the background art.

[0006] In order to solve the above technical problems, the utility model provides the following technical scheme: a variable diameter casing scraper, comprising an upper joint, the inner wall of the upper joint is provided with a central pipe, the inner wall of the central pipe is provided with a first sealing ring, the inner wall of the upper joint is provided with a fastening pin, the outer wall of the central pipe is provided with a spring, one end of the spring is provided with a piston cylinder, the inner wall of the piston cylinder is provided with a second sealing ring, the inner wall of the central pipe is provided with a third sealing ring, the inner wall of the central pipe is slidably connected with a scraper blade, the inner wall of the scraper blade is provided with a leaf spring, the outer wall of the central pipe is provided with a lower joint, the inner wall of the lower joint is provided with a ball seat, the inner wall of the ball seat is provided with a resin ball, the inner wall of the ball seat is provided with a fourth sealing ring, the inner wall of the ball seat is provided with a constant-pressure shear pin, and the inner wall of the lower joint is provided with a limiting sleeve.

[0007] Preferably, the number of piston cylinders is two, and the upper and lower piston cylinders are slidably arranged on the central pipe.

[0008] Preferably, one end of the spring is connected with the inner wall of the upper joint, and the other end of the spring is connected with the inner wall of the piston cylinder.

[0009] Preferably, the number of springs is two, and the upper and lower ends of the central pipe are both penetrated by the springs.

[0010] Preferably, the number of leaf springs is two, and the two leaf springs are symmetrically arranged with the median line of the scraper blade as the axis of symmetry.

[0011] Preferably, the outer wall of the scraper blade and the inner wall of the center tube are matched in shape and size.

[0012] Preferably, the scraper blade is in a compressed state under the action of the upper and lower piston cylinders, and the maximum outer diameter of the scraper blade is less than or equal to the outer diameter of the body.

[0013] Compared with the prior art, the utility model has the beneficial effects that:

[0014] The scraper blade of the scraper is always in a compressed state when not pressed, and is located inside the body, so that the scraper blade is not scratched during construction, construction risks and equipment wear are reduced, a 360-degree full coverage design is adopted, the inner wall of the casing can be completely covered when scraping is needed, the scraping efficiency is improved, a unique pressure relief mechanism design can directly press and knock off the ball seat when the liquid in the pipe column cannot be discharged or the oil jacket pressure is unbalanced, the oil jacket is balanced, the scraper blade of the scraper is safely retracted, the safety of construction is effectively improved, the design of the reverse circulation mechanism can establish a circulation system during construction, which helps to keep the well clean and improve the smoothness and effect of construction. BRIEF DESCRIPTION OF DRAWINGS

[0015] Fig. 1 It is a cross-sectional structure schematic view of the utility model;

[0016] Fig. 2 It is a center tube and scraper blade structure schematic view of the utility model.

[0017] Wherein: 1, upper joint; 2, center tube; 3, first sealing ring; 4, fastening pin; 5, spring; 6, piston cylinder; 7, second sealing ring; 8, third sealing ring; 9, scraper blade; 10, leaf spring; 11, lower joint; 12, ball seat; 13, resin ball; 14, fourth sealing ring; 15, constant pressure shear pin; 16, limiting sleeve. DETAILED DESCRIPTION

[0018] The technical solutions in the embodiments of the utility model will be clearly and completely described below with reference to the drawings in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, rather than all the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the utility model.

[0019] For example, Figs. 1-2As shown, the variable diameter casing scraper includes an upper joint 1, the inner wall of the upper joint 1 is provided with a central pipe 2, and the inner wall of the central pipe 2 is provided with a first sealing ring 3, the inner wall of the upper joint 1 is provided with a fastening pin 4, the outer wall of the central pipe 2 is provided with a spring 5, and one end of the spring 5 is provided with a piston cylinder 6, the inner wall of the piston cylinder 6 is provided with a second sealing ring 7, the inner wall of the central pipe 2 is provided with a third sealing ring 8, and the inner wall of the central pipe 2 is slidably connected with a scraper blade 9, the inner wall of the scraper blade 9 is provided with a leaf spring 10, the outer wall of the central pipe 2 is provided with a lower joint 11, and the inner wall of the lower joint 11 is provided with a ball seat 12, the inner wall of the ball seat 12 is provided with a resin ball 13, and the inner wall of the ball seat 12 is provided with a fourth sealing ring 14, the inner wall of the ball seat 12 is provided with a constant pressure shear pin 15, and the inner wall of the lower joint 11 is provided with a limiting sleeve 16.

[0020] Through the above technical scheme, the scraper is provided with the scraper blade 9 which is always in a compressed state when not being pressed, and is located inside the body, so that the scraper blade 9 will not be scratched during the construction process, reducing the construction risk and equipment loss, and adopting a 360-degree full coverage design, the inner wall of the casing can be completely covered when scraping is needed, improving the scraping efficiency, and the unique pressure relief mechanism design can directly press and knock off the ball seat 12 when the liquid in the pipe string cannot be discharged or the oil jacket pressure is unbalanced, achieving oil jacket balance, making the scraper blade 9 of the scraper safely retract, and effectively improving the safety of the construction, and the design of the reverse circulation mechanism can establish a circulation system during construction, which is helpful to keep the well clean and improve the smoothness and effect of the construction.

[0021] Specifically, the number of piston cylinders 6 is two, and the upper and lower piston cylinders 6 are slidably arranged on the central pipe 2.

[0022] Through the above technical scheme, when the pipe string is being pressed, the hydraulic pressure acts on the upper and lower piston cylinders 6, the upper piston cylinder 6 moves upward, and the lower piston cylinder 6 moves downward, and this reverse movement provides a basis for the extension of the scraper blade 9.

[0023] Specifically, one end of the spring 5 is connected with the inner wall of the upper joint 1, and the other end of the spring 5 is connected with the inner wall of the piston cylinder 6.

[0024] Through the above technical scheme, the spring 5 plays a key role in elastic support and reset, and when not being pressed, the spring 5 is in a natural stretching or less compressed state, maintaining the scraper blade 9 in a compressed state in the central pipe 2, ensuring that the tool will not accidentally extend the scraper blade 9 and cause scratching during the process of lowering into the casing, and when the scraping operation is completed and the pressure is released, the spring 5 will push the piston cylinder 6 to the initial position by its own elastic potential, so that the scraper blade 9 is smoothly retracted.

[0025] Specifically, the number of springs 5 is two, and the upper and lower ends of the central pipe 2 penetrate the springs 5.

[0026] Through the technical scheme, when the upper and lower piston cylinders 6 move, the two piston cylinders 6 can apply force to the two springs 5 respectively.

[0027] Specifically, the number of leaf springs 10 is two, and the two leaf springs 10 are symmetrically arranged with the median line of the scraper blade 9 as the axis of symmetry.

[0028] Through the technical scheme, the symmetrically arranged leaf springs 10 can make the scraper blade 9 bear force evenly during the extension and retraction process. When the piston cylinder 6 moves and the two leaf springs 10 rebound from the contracted state, the scraper blade 9 is pushed to extend.

[0029] Specifically, the shape and size of the outer wall of the scraper blade 9 match the shape and size of the inner wall of the central pipe 2, and the outer wall of the scraper blade 9 is in close contact with the inner wall of the central pipe 2.

[0030] Through the technical scheme, the connection effect between the scraper blade 9 and the central pipe 2 is strengthened, and the scraper blade 9 can move in the central pipe 2.

[0031] Specifically, under the action of the upper and lower piston cylinders 6, the scraper blade 9 is in a compressed state when not pressed, and the maximum outer diameter of the scraper blade 9 is less than or equal to the outer diameter of the body.

[0032] Through the technical scheme, the scraper is more safe and smooth when running in the casing. Since the scraper blade 9 does not extend out of the body, it avoids scratching the inner wall of the casing during running in, reduces the probability of accidents such as sticking, and creates conditions for subsequent scraping operations, for example, even if the casing is slightly deformed in a complex casing environment, the scraper blade 9 that does not extend out can also follow the tool smoothly, creating conditions for subsequent scraping operations.

[0033] In use, first, when scraping a deformed casing well, the tool is connected to the lowermost end of the pipe string. At this time, the scraper blade 9 is in a compressed state under the action of the springs 5 and the upper and lower piston cylinders 6, and the maximum outer diameter thereof is less than or equal to the outer diameter of the body. During running in, the pipe string can be back circulated. When the tool reaches the designed position, the pipe string is being pressed, the springs 5 and the upper and lower piston cylinders 6 move upward and downward under the action of hydraulic pressure, the scraper blade 9 extends out of the body under the action of the leaf springs 10 and is completely in close contact with the inner wall of the casing. The pipe string is raised and lowered, the scraper blade 9 cleans the inner wall of the casing, and after scraping is completed, the pressure is released, the springs 5 compress the upper and lower piston cylinders 6, the scraper blade 9 is pressed into the body, and the outer diameter thereof is the same as or smaller than the outer diameter of the body. The well is thoroughly back washed, the pipe string and the scraper in the well are pulled out, and the construction is completed. This completes all the work. The contents not described in detail in the specification belong to the existing technology known to those skilled in the art.

[0034] Although the embodiments of the present application have been shown and described, it is to be understood that for the purpose of the present application, the embodiments can be changed, modified, replaced and varied in many ways without departing from the principles and spirit of the present application, and the scope of the present application is defined by the appended claims and their equivalents.

Claims

1. Variable diameter casing reamer comprising an upper joint (1), characterized in that: The inner wall of the upper joint (1) is provided with a center tube (2), and the inner wall of the center tube (2) is provided with a first sealing ring (3); the inner wall of the upper joint (1) is provided with a fastening pin (4); the outer wall of the center tube (2) is provided with a spring (5), and one end of the spring (5) is provided with a piston cylinder (6); the inner wall of the piston cylinder (6) is provided with a second sealing ring (7); the inner wall of the center tube (2) is provided with a third sealing ring (8), and the inner wall of the center tube (2) is slidably connected with a scraper blade (9); the inner wall of the scraper blade (9) is provided with a leaf spring (10); the outer wall of the center tube (2) is provided with a lower joint (11), and the inner wall of the lower joint (11) is provided with a ball seat (12); the inner wall of the ball seat (12) is provided with a resin ball (13), and the inner wall of the ball seat (12) is provided with a fourth sealing ring (14); the inner wall of the ball seat (12) is provided with a constant-pressure shear pin (15); and the inner wall of the lower joint (11) is provided with a limiting sleeve (16).

2. The variable diameter cannula skiving device of claim 1, wherein: The number of the piston cylinders (6) is two, and the upper and lower piston cylinders (6) are slidably arranged on the center tube (2).

3. The variable diameter cannula skiving device of claim 1, wherein: One end of the spring (5) is connected with the inner wall of the upper joint (1), and the other end of the spring (5) is connected with the inner wall of the piston cylinder (6).

4. The variable diameter cannula skiving device of claim 1, wherein: The number of the springs (5) is two, and the upper and lower ends of the center tube (2) are both penetrated by the springs (5).

5. The variable diameter cannula skiving device of claim 1, wherein: The number of the leaf springs (10) is two, and the two leaf springs (10) are symmetrically arranged with the median line of the scraper blade (9) as the axis of symmetry.

6. The variable diameter cannula skiving device of claim 1, wherein: The shape and size of the outer wall of the scraper blade (9) are matched with the shape and size of the inner wall of the center tube (2), and the outer wall of the scraper blade (9) is fitted with the inner wall of the center tube (2).

7. The variable diameter cannula skiving device of claim 1, wherein: The scraper blade (9) is in a compressed state under the action of the upper and lower piston cylinders (6) when not pressed, and the maximum outer diameter of the scraper blade (9) is less than or equal to the outer diameter of the body.

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