Decomposable slip

Abstract

A detachable slip relates to the technical field of downhole tools, and is characterized in that the lower part of a slip body is in interference fit with a bearing sleeve, the upper part of the slip body is provided with a section of guide pipe, the guide pipe is transited to an inner hole through a conical hole, the guide pipe is connected with a propelling sleeve, the lower part of the propelling sleeve is provided with a conical head, and the conical head and the conical hole have the same taper; the upper excircle of the propelling sleeve is in clearance fit with the guide pipe. The slip has the beneficial effects that the propelling sleeve and the bearing sleeve which are high in strength are adopted, the slip body with the high plastic deformation degree is subjected to complete plastic deformation under the action of the propelling sleeve, the outer circle of the slip body is expanded to be in interference fit with the sleeve for anchoring, retraction caused by elastic deformation is avoided, the propelling sleeve does not ascend after descending, and the slip is prevented from falling off. The fully-soluble slip body serves as a framework of the slip body to provide powerful support, the anchoring effect is further improved, and when liquid in a casing pipe chemically reacts with the fully-soluble slip body, the propelling sleeve and the force bearing sleeve, automatic unblocking is achieved after the dissolvable slip is dissolved.

Description

Technical Field

[0001] The invention relates to the technical field of downhole tools, and in particular to a decomposable slip. Background Art

[0002] A wide variety of downhole tools are required in the process of oil and gas development, some of which require unsealed anchoring structures, including packer tools required for special operations such as testing, well repair, and stratified injection and production; bridge plug tools for temporary plugging of wellbores in oil and gas well fracturing and transformation operations. The slips in the traditional anchoring structure adopt a conical hole structure, and special tools are used to push the conical hole to expand so that the slips are anchored in the casing. This method causes plastic deformation of the slips, and other mechanisms are required to prevent the slips from rebounding and reducing the anchoring effect; The slips in the traditional anchoring structure use hardened surface teeth or inlaid carbide teeth, ceramic teeth, etc. This traditional slip will not only damage the casing wall and cause casing deformation and damage, but may also leave fragments of the slip teeth in the well, causing accidents. Summary of the invention

[0003] In order to solve the problem that traditional slips rebound after elastic deformation resulting in poor anchoring effect, the present invention provides a decomposable slip.

[0004] The technical solution provided by the present invention is: a decomposable slip, comprising a slip body, the lower part of the slip body is connected to a bearing sleeve by interference fit, a guide tube is provided on the upper part of the slip body, the guide tube transitions to the inner hole through a tapered hole, the guide tube is connected to a propulsion sleeve, a tapered head is provided on the lower part of the propulsion sleeve, the tapered head has the same taper as the tapered hole, and a support column on the upper part of the propulsion sleeve is in clearance fit with the guide tube; The bearing sleeve and propulsion sleeve are made of water-soluble magnesium-aluminum alloy, and the material formula is: magnesium 65-75%, aluminum 32-22%, and other materials 3%; The slip body is made of water-soluble magnesium-aluminum alloy, and its material formula is: magnesium 50-55%, aluminum 47-52%, and other materials 3%; When the propulsion sleeve descends, the slip body undergoes plastic deformation, and the slip body after plastic deformation is connected with the sleeve by interference fit.

[0005] The taper angle of the tapered hole and the tapered head is smaller than the friction self-locking angle of the two materials.

[0006] The pipe section of the outer circle of the slip body that is completely plastically deformed is set as the anchoring section. The slip body is provided with buffer ring grooves on both sides of the anchoring section, and the slip body is provided with a transition ring groove between the anchoring section and the guide pipe.

[0007] The beneficial effects of the present invention are as follows: a high-strength propulsion sleeve and a bearing sleeve are adopted, and a special tool is used to hold the bearing sleeve and press the propulsion sleeve downward. The cava body with a high degree of plastic deformation is completely plastically deformed under the action of the propulsion sleeve, and the outer circle of the cava body is expanded and anchored with an interference fit with the casing, and will not shrink due to elastic deformation. The taper angle of the conical hole and the conical head is smaller than the friction self-locking angle of the two materials, that is, the propulsion sleeve will not rise again after it is lowered, and it provides strong support as the skeleton of the cava body, further improving the anchoring effect. When the liquid in the casing reacts chemically with the fully soluble cava body, the propulsion sleeve and the bearing sleeve, the decomposable cava is dissolved and automatically unsealed. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Attached Figure 1 It is a schematic diagram of the structure of the present invention; Attached Figure 2 It is a schematic diagram of the structure after the slip is anchored; Attached Figure 3 It is a schematic diagram of the structure of the slip body in the present invention; Attached Figure 4 It is a structural schematic diagram of the propulsion sleeve in the present invention.

[0009] In the figure, 1-slip body, 101-guide tube, 102-conical hole, 103-inner hole, 104-transition ring groove, 105-buffer ring groove, 106-anchor section, 2-load bearing sleeve, 3-propulsion sleeve, 301-support column, 302-conical head, 4-casing. DETAILED DESCRIPTION

[0010] like Figures 1 to 4 As shown, a decomposable slip comprises a slip body 1, the lower part of the slip body 1 is connected to a bearing sleeve 2 by interference fit, a guide tube 101 is arranged on the upper part of the slip body 1, the guide tube 101 transitions to an inner hole 103 through a tapered hole 102, the guide tube 101 is connected to a propulsion sleeve 3, a tapered head 302 is arranged on the lower part of the propulsion sleeve 3, the tapered angle of the tapered head 302 is the same as that of the tapered hole 102, and a support column 301 on the upper part of the propulsion sleeve 3 is clearance-matched with the guide tube 101; The bearing sleeve 2 and the propulsion sleeve 3 are made of a water-soluble magnesium-aluminum alloy, and the material formula is: magnesium 65-75%, aluminum 32-22%, and other materials 3%; The slip body 1 is made of a water-soluble magnesium-aluminum alloy, and its material formula is: 50-55% magnesium, 47-52% aluminum, and 3% other materials; The material formula makes the strength of the bearing sleeve 2 and the propulsion sleeve 3 higher than that of the slip body 1 , and the plastic deformation degree of the slip body 1 is higher than that of the bearing sleeve 2 and the propulsion sleeve 3 .

[0011] When the propulsion sleeve 3 descends, the slip body 1 undergoes plastic deformation, and the slip body 1 after plastic deformation is connected with the sleeve 4 by interference fit.

[0012] A high-strength propulsion sleeve 3 and a bearing sleeve 2 are used, and a special tool is used to hold the bearing sleeve 2 and press the propulsion sleeve 3 downward. The slip body 1 is completely plastically deformed under the action of the propulsion sleeve 3, and the outer circle of the slip body 1 is expanded and anchored with the sleeve 4 by interference fit, and will not shrink due to elastic deformation.

[0013] The taper angles of the conical hole 102 and the conical head 302 are smaller than the friction self-locking angles of the two materials, that is, the propulsion sleeve 3 will not rise again after it descends, providing strong support as the skeleton of the slip body 1, further improving the anchoring effect.

[0014] The pipe section of the outer circle of the slip body 1 that is completely plastically deformed is set as the anchor section 106. The slip body 1 is provided with buffer annular grooves 105 on both sides of the anchor section 106. When the slip body 1 is interference fit connected to the sleeve 4, the interference may be too large due to the size error. The buffer annular groove 105 can buffer this part of the metal deformation body. The slip body 1 is provided with a transition annular groove 104 between the anchor section 106 and the guide tube 101.

Claims

1. A decomposable slip, comprising a slip body (1), characterized in that: The lower part of the slip body (1) is connected to the bearing sleeve (2) by interference fit, the upper part of the slip body (1) is provided with a guide tube (101), the guide tube (101) transitions to the inner hole (103) through the tapered hole (102), the guide tube (101) is connected to the propulsion sleeve (3), the lower part of the propulsion sleeve (3) is provided with a tapered head (302), the tapered angle of the tapered head (302) and the tapered hole (102) are the same, and the support column (301) on the upper part of the propulsion sleeve (3) is clearance-fitted with the guide tube (101); The bearing sleeve (2) and the propulsion sleeve (3) are made of a water-soluble magnesium-aluminum alloy, and the material formula thereof is: 65-75% magnesium, 32-22% aluminum, and 3% other materials; The slip body (1) is made of a water-soluble magnesium-aluminum alloy, and its material formula is: 50-55% magnesium, 47-52% aluminum, and 3% other materials; When the propulsion sleeve (3) descends, the slip body (1) undergoes plastic deformation, and the slip body (1) after plastic deformation is connected to the sleeve (4) by interference fit.

2. A decomposable slip according to claim 1, characterized in that: The taper angles of the conical hole (102) and the conical head (302) are smaller than the friction self-locking angles of the materials of the two.

3. The decomposable slips according to claim 1, characterized in that: The outer circumferential pipe section of the slip body (1) that is completely plastically deformed is set as an anchoring section (106), the slip body (1) is provided with buffer annular grooves (105) on both sides of the anchoring section (106), and the slip body (1) is provided with a transition annular groove (104) between the anchoring section (106) and the guide tube (101).

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