Soluble bridge plug

Abstract

The utility model provides a soluble bridge plug, and belongs to the technical field of bridge plugs. The soluble bridge plug comprises a taper sleeve, a slip and a guide shoe which are arranged from top to bottom, the guide shoe is provided with a lower outer conical surface, and the slip is provided with a lower inner conical surface which is matched with the lower outer conical surface and used for expanding the slip after the slip and the guide shoe move oppositely. The lower outer conical surface is arranged on the guide shoe, and the lower inner conical surface is arranged on the slip, so that the lower end of the slip can be expanded by the guide shoe under the condition that the upper end of the slip cannot be expanded by the conical sleeve, and the anchoring reliability of the bridge plug is ensured.

Description

Technical Field

[0001] The utility model belongs to the field of bridge plugs, in particular to a soluble bridge plug. Background Art

[0002] The post-completion fracturing and transformation of horizontal wells generally adopts the staged fracturing process of pumping bridge plugs and perforating. The bridge plugs are mainly used to seal the lower transformed reservoir and force the fracturing fluid into the target layer. In the early stage of this process, drillable materials are used to process the bridge plugs. After the fracturing and transformation operation is completed, the bridge plugs are destroyed by drilling, grinding and milling to open the production channel. In recent years, soluble bridge plugs have appeared, which can dissolve in the chloride ion solution in the well, reducing construction costs and construction risks.

[0003] The existing Chinese utility model patent with authorization announcement number CN215889971U and authorization announcement date February 22, 2022 discloses an internally locked all-metal soluble bridge plug, which includes a pull rod, the lower end of the pull rod is inserted into the guide shoe, the pull rod and the guide shoe are fixedly connected by multiple shear nails, and a slip is provided on the pull rod above the guide shoe, and the lower end of the slip is processed with a lower inner edge conical surface, and the upper end of the guide shoe is processed with a lower outer edge conical surface, and the lower inner edge conical surface is fit with the lower outer edge conical surface; the pull rod is also provided with a cone sleeve, the lower end of the cone sleeve is processed with a middle outer edge conical surface, and the upper end of the slip is processed with a middle inner edge conical surface, and the middle outer edge conical surface is fit with the middle inner edge conical surface; a metal expansion ring is provided on the middle outer edge conical surface, and the lower end of the metal expansion ring contacts the upper end of the slip, the upper end of the cone sleeve is processed with an upper inner edge conical surface, and the upper part of the pull rod is processed with an upper outer edge conical surface, and the upper outer edge conical surface is fit with the upper inner edge conical surface. When in use, the pull rod is used to move the cone sleeve and the guide shoe toward each other, and the guide shoe pushes the slip and the metal expansion ring to move upward relative to the cone sleeve. The cone sleeve opens the metal expansion ring and fits it to the inner wall of the casing to play a sealing role. At the same time, the cone sleeve opens the slip, and the anchoring teeth embedded on the outer wall of the slip bite into the inner wall of the casing, so that the bridge plug is anchored into the casing.

[0004] However, in actual use, once the metal expansion ring (i.e., sealing ring) fits against the inner wall of the casing, the metal expansion ring will be squeezed by the inner wall of the casing and the cone sleeve, making it difficult for the metal expansion ring to continue to move relative to the cone sleeve, and the metal expansion ring will also hinder the movement of the slip relative to the cone sleeve. The slip is difficult to move relative to the cone sleeve, that is, the slip is difficult to continue to be opened, but if the anchor teeth on the slip are not engaged at this time, the anchoring reliability of the bridge plug will be reduced, and the bridge plug will easily shift during the fracturing construction and cause accidents. Utility Model Content

[0005] The utility model aims to provide a soluble bridge plug to solve the technical problem that the sealing ring of the prior art bridge plug easily hinders the movement of the slip relative to the cone sleeve during the setting process, so that the slip cannot be opened into place and finally affects the reliability of the bridge plug anchoring.

[0006] In order to achieve the above-mentioned purpose, the technical solution of the soluble bridge plug provided by the utility model is:

[0007] A soluble bridge plug comprises a cone sleeve, a slip and a guide shoe arranged from top to bottom. The guide shoe is provided with a lower outer cone surface, and the slip is provided with a lower inner cone surface which cooperates with the lower outer cone surface and is used to expand the slip after the slip and the guide shoe move toward each other.

[0008] As a further improvement, an upper outer cone surface is provided on the cone sleeve, an upper inner cone surface for cooperating with the upper outer cone surface is provided on the slip, and the soluble bridge plug also includes a sealing ring sleeved on the outside of the slip.

[0009] As a further improvement, an open groove is provided on the cava which penetrates the cava radially. The length direction of the open groove is in the same direction as the axial extension direction of the cava. The lower end of the open groove penetrates the lower end wall of the cava, and the sealing ring is located between the upper end of the cava and the upper end of the open groove.

[0010] As a further improvement, a deformation groove extending along the circumferential direction of the slip is opened on the outer peripheral wall of the slip, and the deformation groove is located at the upper end of the opening groove and intersects with the opening groove.

[0011] As a further improvement, the slip is provided with an annular mounting groove for mounting a sealing ring.

[0012] As a further improvement, the cava includes a cava body and a limit sleeve, the cava body includes a small diameter section located at the upper end of the cava body and a large diameter section adjacent to the small diameter section, and the outer diameter of the small diameter section is smaller than the outer diameter of the large diameter section, the limit sleeve can be removably installed outside the small diameter section, and the area surrounded by the axial end wall of the limit sleeve, the axial end wall of the large diameter section and the outer peripheral wall of the small diameter section constitutes an installation groove.

[0013] As a further improvement, a sealing ring groove is formed on a side of the sealing ring away from the slip.

[0014] As a further improvement, the sealing ring is a metal sealing ring.

[0015] As a further improvement, the slip has an anchoring fitting section for fitting with the inner wall of the casing so as to anchor the soluble bridge plug, and the anchoring fitting section is located at the lower end of the slip.

[0016] As a further improvement, the axial length of the anchoring fitting section is less than or equal to the axial length of the opening groove in the slip.

[0017] The beneficial effect is that the soluble bridge plug provided by the utility model is an improvement on the prior art. The soluble bridge plug is provided with a lower outer cone surface on the guide shoe and a lower inner cone surface matched with the lower outer cone surface on the slip, so that when the upper end of the slip cannot move relative to the cone sleeve and is stretched open, the lower end of the slip can be stretched open by the guide shoe, ensuring that the slip can be anchored in place on the inner wall of the casing, improving the anchoring reliability of the bridge plug, and preventing the bridge plug from shifting during the fracturing construction process to cause an accident. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a structural schematic diagram of an embodiment of the soluble bridge plug in the utility model in a setting state;

[0019] Figure 2 It is a schematic structural diagram of the embodiment of the soluble bridge plug in the utility model after setting;

[0020] Figure 3 It is a schematic diagram of the local structure of the soluble bridge plug in the utility model.

[0021] Description of reference numerals:

[0022] 1. Cone sleeve; 2. Slip; 21. Slip body; 211. Large diameter section; 212. Small diameter section; 213. Anchoring matching section; 22. Limit sleeve; 3. Guide shoe; 4. Sealing ring; 5. Shear ring; 6. Connecting rod; 7. Connecting tube; 8. Upper outer cone surface; 9. Upper inner cone surface; 10. Lower outer cone surface; 11. Lower inner cone surface; 12. Opening groove; 13. Deformation groove; 14. Sealing ring groove; 15. Fracturing ball; 16. Pressure cap. DETAILED DESCRIPTION

[0023] The present invention is further described in detail below in conjunction with the embodiments.

[0024] In order to solve the problems in the prior art, the basic concept of the utility model is to set a lower outer cone surface on the guide shoe and a lower inner cone surface on the slip, so that when the upper end of the slip cannot be supported by the cone sleeve, the lower end of the slip can be supported by the guide shoe, thereby ensuring the anchoring reliability of the bridge plug.

[0025] Specific embodiments of the soluble bridge plug provided by the utility model:

[0026] See attached Figure 1 and attached Figure 2 A soluble bridge plug comprises a cone sleeve 1, a slip 2 and a guide shoe 3 arranged from top to bottom.

[0027] The cone sleeve 1 is provided with an upper outer cone surface 8, and the slip 2 is provided with an upper inner cone surface 9 for matching with the upper outer cone surface 8. The guide shoe 3 is provided with a lower outer cone surface 10, and the slip 2 is provided with a lower inner cone surface 11 matching with the lower outer cone surface 10.

[0028] See attached Figure 3 An annular mounting groove is provided on the upper part of the outer wall of the slip 2, and a sealing ring 4 is provided in the mounting groove. The sealing ring 4 is a metal sealing ring 4 made of a relatively soft metal, and after the fracturing construction is completed, the metal sealing ring 4 can also be dissolved, thereby reducing the residual amount of the soluble bridge plug after dissolution. A sealing ring groove 14 is formed on the side of the sealing ring 4 away from the slip 2. The sealing ring groove 14 can make the surface of the sealing ring 4 more easily deform adaptively when the sealing ring 4 contacts the inner wall of the sleeve, thereby improving the sealing effect of the sealing ring 4. The number of sealing ring grooves 14 can be one, two or three.

[0029] The mounting groove can keep the sealing ring 4 stable. In order to facilitate the installation of the sealing ring 4 into the mounting groove, the present embodiment divides the cava 2 into a cava body 21 and a limiting sleeve 22. The cava body 21 includes a small diameter section 212 located at the upper end of the cava body 21 and a large diameter section 211 adjacent to the small diameter section 212. The outer diameter of the small diameter section 212 is smaller than the outer diameter of the large diameter section 211, so that a step structure is formed between the small diameter section 212 and the large diameter section 211. The limiting sleeve 22 is detachably installed on the outside of the small diameter section 212 by means of threads. After installation, the upper end of the limiting sleeve 22 is aligned with the upper end of the cava body 21. The area surrounded by the lower end wall of the limiting sleeve 22, the upper end wall of the large diameter section 211 and the outer peripheral wall of the small diameter section 212 constitutes the mounting groove.

[0030] The slip 2 is provided with a plurality of open grooves 12 which penetrate the slip 2 in the radial direction, the length direction of the open grooves 12 is in the same direction as the axial extension direction of the slip 2, the lower end of the open grooves 12 penetrates the lower end wall of the slip 2, and the sealing ring 4 is located between the upper end of the slip 2 and the upper end of the open grooves 12. The open grooves 12 are provided to facilitate the opening of the slip 2, and the open grooves 12 are not provided at the position where the sealing ring 4 is provided, in order to prevent the open grooves 12 from affecting the sealing of the sealing ring 4.

[0031] A deformation groove 13 extending along the circumferential direction of the slip 2 is provided on the outer peripheral wall of the slip 2. In this embodiment, the deformation groove 13 is an annular groove, and the deformation groove 13 is located at the upper end of the opening groove 12 and intersects with the opening groove 12. The opening groove 12 further improves the deformation ability of the slip 2, making it easier for the slip 2 to be opened. In other embodiments, the deformation groove 13 may also be an arc groove arranged in sections, and if the deformation ability of the slip 2 is sufficient, the deformation groove 13 may not be provided.

[0032] The main body 21 of the slip 2 also includes an anchoring section 213 located at the lower end of the main body. After the anchoring section 213 is stretched, its outer portion contacts the inner wall of the casing. The outer wall of the anchoring section 213 is processed to have a strong hardness, such as inlaying ceramic particles or hard alloy particles, so that the anchoring section 213 bites the casing under pressure, so that the soluble bridge plug is anchored. However, since the open groove 12 is not fully distributed along the axial direction of the slip 2, the lower end of the slip 2 is stretched to a greater extent. At the same time, the processing cost of the anchoring section 213 is relatively high, so that the axial length of the anchoring section 213 is smaller than the length of the open groove 12 in the circumferential direction of the slip 2, which can avoid the waste of materials caused by the part of the anchoring section 213 not being matched with the inner wall of the casing after the bridge plug is anchored.

[0033] When using, see the attached Figure 1 , the soluble bridge plug is connected to the sealing tool by using the connecting rod 6 and the connecting tube 7. After the soluble bridge plug is lowered into place, the sealing tool is used to move the guide shoe 3 and the cone sleeve 1 toward each other. In this process, the upper end of the guide shoe 3 will be inserted into the slip 2, and the guide shoe 3 and the slip 2 will move toward each other; the lower end of the cone sleeve 1 will also be inserted into the slip 2, and the cone sleeve 1 and the slip 2 will move toward each other. The lower end of the slip 2 is stretched open by the guide shoe 3, so that the anchoring matching part cooperates with the inner wall of the casing; the upper end of the slip 2 expands due to its own ductility under the action of the cone sleeve 1, so that the sealing ring 4 cooperates with the inner wall of the casing. At this time, the slip 2 can no longer produce axial movement, but the guide shoe 3 and the cone sleeve 1 can still continue to move toward each other, strengthening the cooperation between the anchoring matching part and the casing and the cooperation between the sealing ring 4 and the casing, effectively ensuring the reliability of the bridge plug anchoring and the reliability of the seal.

[0034] The guide shoe 3 is provided with a shear ring 5, and the lower end of the connecting rod 6 is connected with a pressure cap 16 through a thread, and the pressure cap 16 cooperates with the shear ring 5 to stop. After the bridge plug is anchored, continue to apply force to the connecting rod 6 to cut the shear ring 5, and finally remove the connecting rod 6 and the connecting tube 7, and put in a soluble fracturing ball 15, see the attached Figure 2 The fracturing ball 15 will be stuck in the step structure inside the cone sleeve 1, and the inside of the soluble bridge plug will be sealed. The shear ring 5 is also made of soluble material to reduce the residue after the soluble bridge plug is dissolved.

[0035] In other embodiments, the axial length of the anchoring section can also be equal to the axial length of the opening slot in the slip. If the slip has good ductility and can achieve a greater degree of expansion and deformation, the axial length of the anchoring section can also be greater than the axial length of the opening slot in the slip.

[0036] In other embodiments, the sealing ring may also be a soluble rubber ring. Since the soluble rubber ring has good deformation ability, the slip may not be divided into a slip body and a limit sleeve in this embodiment, and the mounting groove is directly processed on the slip.

[0037] In other embodiments, the sealing ring may also be fixed to the slip by bonding with an adhesive, in which case the sealing ring may also remain stable and no mounting groove may be provided.

[0038] In other embodiments, the sealing ring has a strong deformation ability, which can form a better sealing effect, and the sealing ring groove may not be provided on the sealing ring.

[0039] In other embodiments, the sealing ring may not be arranged on the slip, but may be arranged on the upper outer conical surface of the cone sleeve independently of the slip. In this embodiment, since the structure of the slip has no effect on the sealing, an open groove may be arranged on the upper end of the slip so that the entire section of the slip can have a larger deformation in the radial direction. In this embodiment, the axial length of the anchoring fitting section may also be equal to the entire axial length of the slip. In this embodiment, when the sealing ring is attached to the inner wall of the casing and is squeezed internally and externally by the inner wall of the casing and the cone sleeve so that it is difficult to continue to move relative to the cone sleeve, the slip is also difficult to move relative to the cone sleeve axially, but because the lower inner conical surface of the slip cooperates with the lower outer conical surface of the guide shoe, the guide shoe can also move axially relative to the slip, further stretching the lower end of the slip, thereby ensuring the anchoring reliability of the soluble bridge plug.

[0040] Finally, it should be noted that the above is only a preferred embodiment of the utility model and is not intended to limit the utility model. Although the utility model is described in detail with reference to the above embodiments, those skilled in the art can still modify the technical solutions recorded in the above embodiments without creative work, or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the utility model shall be included in the protection scope of the utility model.

Claims

1. A soluble bridge plug, comprising a cone sleeve, a slip and a guide shoe arranged from top to bottom, characterized in that: The guide shoe is provided with a lower outer conical surface, and the slip is provided with a lower inner conical surface which cooperates with the lower outer conical surface and is used for expanding the slip after the slip and the guide shoe move toward each other.

2. The soluble bridge plug according to claim 1, characterized in that: An upper outer cone surface is arranged on the cone sleeve, an upper inner cone surface for cooperating with the upper outer cone surface is arranged on the slip, and the soluble bridge plug also includes a sealing ring sleeved on the outside of the slip.

3. The soluble bridge plug according to claim 2, characterized in that: An open groove is provided on the slip which penetrates the slip radially. The length direction of the open groove is in the same direction as the axial extension direction of the slip. The lower end of the open groove penetrates the lower end wall of the slip. The sealing ring is located between the upper end of the slip and the upper end of the open groove.

4. The soluble bridge plug according to claim 3, characterized in that: A deformation groove extending along the circumferential direction of the slip is provided on the outer peripheral wall of the slip, and the deformation groove is located at the upper end of the opening groove and intersects with the opening groove.

5. The soluble bridge plug according to any one of claims 2 to 4, characterized in that: The slip is provided with an annular mounting groove for mounting a sealing ring.

6. The soluble bridge plug according to claim 5, characterized in that: The cava includes a cava body and a limit sleeve. The cava body includes a small diameter section located at the upper end of the cava body and a large diameter section adjacent to the small diameter section. The outer diameter of the small diameter section is smaller than the outer diameter of the large diameter section. The limit sleeve can be detachably installed outside the small diameter section. The area surrounded by the axial end wall of the limit sleeve, the axial end wall of the large diameter section and the outer peripheral wall of the small diameter section constitutes a mounting groove.

7. The soluble bridge plug according to any one of claims 2 to 4, characterized in that: A sealing ring groove is formed on the side of the sealing ring away from the slip.

8. The soluble bridge plug according to any one of claims 2 to 4, characterized in that: The sealing ring is a metal sealing ring.

9. The soluble bridge plug according to claim 3 or 4, characterized in that: The slip has an anchoring section for cooperating with the inner wall of the casing to anchor the soluble bridge plug, and the anchoring section is located at the lower end of the slip.

10. The soluble bridge plug according to claim 9, characterized in that: The axial length of the anchoring matching section is less than or equal to the axial length of the opening groove of the slip.

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