Sleeve scraper for well repair

Abstract

The utility model discloses a casing scraper for well repair, and relates to the technical field of oil field downhole tools. The lower portion of the connector is in threaded connection with a central pipe through a sealing ring, the lower portion of the central pipe is in threaded connection with a supporting seat through a sealing ring, a piston is installed between the supporting seat and the central pipe and connected with the supporting seat and the central pipe in a clearance fit mode through a sealing ring, and the central pipe is provided with a liquid inlet hole. The conical surface of the upper portion of the piston is connected with four cutting edges through dovetail groove guide rails, the cutting edges are circumferentially and evenly distributed, and compression springs are arranged between the tops of the cutting edges and the upper connector. A ball seat hole is machined in the lower portion of the center pipe. The utility model has the beneficial effects that the piston is connected with the cutting edge through the dovetail groove guide rail on the conical surface, the cutting diameter of the cutting edge after entering a well is changed by pitching and pressing in the tubular column, the device can adapt to most casings with different diameters, the application range is wide, the pressure value in the tubular column can be adjusted, the cutting force of the cutting edge can be changed according to the situation, and the working efficiency is improved. The pretreatment and backwashing functions are also realized.

Description

Technical Field

[0001] The utility model relates to the technical field of downhole tools in oil fields, in particular to a casing scraper for well repair. Background Art

[0002] Casing scrapers are used to scrape the inner wall of casing and remove cement, hard wax, salt scale and blasthole burrs on the inner wall of casing. It is an important process for well repair operations and normal downhole operations, and is necessary for the lowering of downhole tools and normal work. However, casing has various diameters, and the existing technology uses replacement of scrapers to deal with it, which has very low working efficiency. Utility Model Content

[0003] In order to solve the problems that the current casing scrapers for well repair have fixed sizes, are not suitable for casings of various diameters, and have a narrow application range, the utility model provides a casing scraper for well repair.

[0004] The technical scheme provided by the utility model is: a casing scraper for well repair, comprising an upper joint, a female threaded hole is processed on the upper joint, the lower part of the upper joint is threadedly connected to a center pipe through a sealing ring, the inner wall of the center pipe is flush with the inner wall of the upper joint, the lower part of the center pipe is threadedly connected to a support seat through a sealing ring, a piston is installed between the support seat and the center pipe, the piston is connected with the support seat and the center pipe through a sealing ring, a liquid inlet hole is opened at the part below the sealing ring of the piston, the upper part of the piston is a conical surface with a reduced diameter, the conical surface of the upper part of the piston is connected to four cutting edges through a dovetail groove guide rail, the cutting edges are evenly distributed around the circumference, and a compression spring is arranged between the top of the cutting edge and the upper joint;

[0005] The center tube is machined with a ball seat hole at the lower part of the liquid inlet hole.

[0006] The outer circle of the lower part of the support seat is processed into a guide head with a smaller diameter, a hard alloy block is welded on the guide head, and a center hole is opened at the position below the center tube of the support seat.

[0007] The beneficial effects of the utility model are as follows: a piston is arranged to connect the cutting edge through a dovetail groove guide rail on a conical surface, and a ball is thrown into the pipe column to pressurize the cutting edge to change the cutting diameter after the cutting edge enters the well. The utility model can adapt to most casings of different diameters and has a wide range of applications. At the same time, the pressure value in the pipe column can be adjusted to change the cutting force of the cutting edge according to the situation, and the utility model also has pretreatment and backwashing functions. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Attached Figure 1 It is a structural schematic diagram of the utility model;

[0009] Attached Figure 2 Attached Figure 1 AA cross-section diagram.

[0010] In the figure, 1-upper joint, 2-center tube, 3-cutting edge, 4-support seat, 5-piston, 6-dovetail groove guide rail, 7-liquid inlet hole, 8-ball seat hole, 9-guide head, 10-carbide block, 11-compression spring, 12-center hole. DETAILED DESCRIPTION

[0011] like Figures 1-2 As shown, a casing scraper for well repair comprises an upper joint 1, on which a female threaded hole is processed, the lower part of the upper joint 1 is threadedly connected to a center pipe 2 through a sealing ring, the inner wall of the center pipe 2 is flush with the inner wall of the upper joint 1, the lower part of the center pipe 2 is threadedly connected to a support seat 4 through a sealing ring, a piston 5 is installed between the support seat 4 and the center pipe 2, the piston 5 is connected with the support seat 4 and the center pipe 2 through a sealing ring, a liquid inlet hole 7 is opened at the part below the sealing ring of the piston 5, the upper part of the piston 5 is a conical surface with a reduced diameter, the conical surface of the upper part of the piston 5 is connected to four cutting edges 3 through a dovetail groove guide rail 6, the cutting edges 3 are evenly distributed around the circumference, and a compression spring 11 is provided between the top of the cutting edge 3 and the upper joint 1;

[0012] The center tube 2 is processed with a ball seat hole 8 at the lower part of the liquid inlet hole 7 .

[0013] When in use, the casing cutter is connected to the lower part of the pipe string, and a soluble ball is put in when it reaches the working position. The soluble ball falls on the ball seat hole 8 and seals it, pressurizing the inside of the pipe string, causing the piston 5 to rise, and the cutting edge 3 to expand outward under the action of the dovetail groove guide 6. When the pressure in the pipe string rises, it means that the cutting edge 3 has been against the inner wall of the casing, and the pressure value in the pipe string determines the cutting force of the cutting edge 3 on the inner wall of the casing.

[0014] The outer circle of the lower part of the support seat 4 is processed into a guide head 9 with a smaller diameter. A hard alloy block 10 is welded on the guide head 9 to pre-treat the inner wall of the casing. The support seat 4 is provided with a center hole 12 below the center pipe 2. After the operation is completed, the soluble ball is dissolved and backwash water is introduced into the pipe column to wash out the cut cement, hard wax, salt scale and other debris.

[0015] The piston 5 is arranged to connect the cutting edge 3 through the dovetail groove guide rail 6 on the conical surface, and the cutting diameter of the cutting edge 3 after entering the well is changed by using a ball thrown into the pipe string to pressurize it. It can adapt to most casings with different diameters and has a wide range of applications. At the same time, the adjustable pressure value in the pipe string can change the cutting force of the cutting edge 3 according to the situation, and it also has pretreatment and backwashing functions.

Claims

1. A casing scraper for well repair, comprising an upper joint (1), characterized in that: A female threaded hole is processed on the upper joint (1), the lower part of the upper joint (1) is threadedly connected to the center tube (2) through a sealing ring, the inner wall of the center tube (2) is flush with the inner wall of the upper joint (1), the lower part of the center tube (2) is threadedly connected to the support seat (4) through a sealing ring, a piston (5) is installed between the support seat (4) and the center tube (2), the piston (5) is connected to the support seat (4) and the center tube (2) through a sealing ring, a liquid inlet hole (7) is opened at the part below the sealing ring of the piston (5), the upper part of the piston (5) is a conical surface with a reduced diameter, the conical surface of the upper part of the piston (5) is connected to four cutting edges (3) through a dovetail groove guide rail (6), the cutting edges (3) are evenly distributed around the circumference, and a compression spring (11) is provided between the top of the cutting edge (3) and the upper joint (1); The center tube (2) is processed with a ball seat hole (8) at the lower part of the liquid inlet hole (7).

2. The casing scraper for well repair according to claim 1, characterized in that: The outer circle of the lower part of the support seat (4) is processed into a guide head (9) with a smaller diameter, a hard alloy block (10) is welded on the guide head (9), and a center hole (12) is opened in the support seat (4) below the center tube (2).

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