Auxiliary sealing device for expansion casing

Abstract

The utility model provides an auxiliary sealing device for an expansion casing pipe, which comprises an auxiliary sealing casing pipe, a bulge is arranged on the inner wall of the auxiliary sealing casing pipe, and after a casing pipe male joint is connected with a casing pipe female joint, the bulge is propped against a gap between the end face of the casing pipe female joint and the end face of the casing pipe male joint. A plurality of sealing ring grooves are further formed in the inner wall of the auxiliary sealing sleeve, sealing rings are arranged in the sealing ring grooves, and the inner wall of the auxiliary sealing sleeve makes contact with the outer wall of the sleeve male connector and the outer wall of the sleeve female connector and is sealed through the sealing rings. According to the auxiliary sealing sleeve, pressure generated in the expansion process can be effectively sealed, when the pressure generated after expansion leaks from the connecting position of the sleeve male connector and the sleeve female connector, the pressure can still be sealed in the auxiliary sealing sleeve, the pressure bearing performance of the connecting position of the sleeve male connector and the sleeve female connector is improved, and then the pressure bearing performance of a whole shaft is improved.

Description

Technical Field

[0001] This utility model relates to the field of well completion tools, specifically to an auxiliary sealing device for expansion casing. Background Technology

[0002] Shale oil well casing damage, repeated fracturing, and fracturing of old formations place extremely high demands on wellbore integrity. Using expansion casing can precisely control the flow of fracturing fluid, which can greatly improve the success rate of subsequent fracturing operations.

[0003] Chinese utility model patent CN203081336U discloses a couplingless expansion external thread joint and an internal thread joint for expansion sleeves. The joints are formed by male and female threads machined on the expansion sleeve and mating with each other through expandable threads. The threads employ a modified trapezoidal thread with a hooked tooth profile, providing good load-bearing capacity. The secondary seal is a reverse shoulder seal, with reverse shoulders machined at both ends of the male and female threads. However, the sealing performance of the expanded threads is significantly reduced, and the pressure resistance generally does not exceed 40 MPa.

[0004] The existing expansion casing is formed by connecting the male and female ends through threads without auxiliary sealing measures, resulting in insufficient pressure bearing capacity at the threaded connection. After oil and gas expansion, the sealing performance at the threaded connection is difficult to meet the requirements of fracturing wellbore subsidies. Utility Model Content

[0005] One objective of this invention is to provide an auxiliary sealing device for expansion casing, which can effectively seal the pressure generated during the expansion process. When the pressure generated after expansion leaks from the connection between the male and female casing joints, it can still be sealed inside the auxiliary sealing casing, thereby improving the pressure bearing capacity of the male and female casing joints at the connection and thus improving the pressure bearing capacity of the entire wellbore.

[0006] According to this utility model, an auxiliary sealing device for an expansion sleeve is provided, comprising: an auxiliary sealing sleeve, wherein the inner wall of the auxiliary sealing sleeve is provided with a protrusion, and after the male sleeve connector and the female sleeve connector are connected, the protrusion abuts against the gap between the end face of the female sleeve connector and the end face of the male sleeve connector; the inner wall of the auxiliary sealing sleeve is also provided with a plurality of sealing ring grooves, and sealing rings are disposed inside the sealing ring grooves; the inner wall of the auxiliary sealing sleeve contacts the outer walls of both the male sleeve connector and the female sleeve connector and is sealed by the sealing rings.

[0007] In a preferred embodiment, the auxiliary sealing tool is made of a soft metal.

[0008] In a preferred embodiment, the auxiliary sealing tool is made of copper alloy or aluminum alloy.

[0009] In a preferred embodiment, the sealing ring groove is configured in a cubic shape.

[0010] In a preferred embodiment, the male sleeve connector includes a first connector portion configured as a protrusion, and the female sleeve connector includes a second connector portion configured as a recess, the first connector portion being insertable into the second connector portion and being threadedly connected.

[0011] In a preferred embodiment, the male sleeve connector has a step integrally connected to the end of the first connector portion away from the second connector portion, and the step is opposite to the end face of the female sleeve connector forming the second connector portion.

[0012] In a preferred embodiment, the protrusion is located between the step and the end face of the sleeve female connector forming the second joint portion.

[0013] In a preferred embodiment, the inner wall of the auxiliary sealing sleeve is provided with a sealing ring groove at the contact point with the outer wall of the step.

[0014] In a preferred embodiment, the sleeve female connector has a body on the side of the second connector portion away from the first connector portion, and the inner wall of the auxiliary sealing sleeve is provided with the sealing ring groove at the contact point with the outer wall of the body portion.

[0015] In a preferred embodiment, the protrusion extends circumferentially along the inner wall of the auxiliary sealing sleeve.

[0016] This utility model has at least the following technical effects:

[0017] According to this utility model, an auxiliary sealing sleeve is provided, and the inner wall of the auxiliary sealing sleeve is provided with a protrusion. After the male sleeve connector and the female sleeve connector are connected, the protrusion abuts against the gap between the end face of the female sleeve connector and the end face of the male sleeve connector. Thus, on the one hand, the protrusion can serve as an indicator after the male sleeve connector and the female sleeve connector are connected in place, and on the other hand, the auxiliary sealing sleeve is connected to the male sleeve connector and the female sleeve connector through the protrusion.

[0018] Furthermore, the inner wall of the auxiliary sealing casing is also provided with a sealing ring groove, and a sealing ring is installed inside the sealing ring groove. The inner wall of the auxiliary sealing casing is in contact with the outer walls of both the male and female casing joints, and auxiliary sealing is achieved through the sealing ring. On the one hand, it can seal the pressure generated during expansion; on the other hand, when the pressure generated after expansion leaks from the connection between the male and female casing joints, it can still be sealed within the auxiliary sealing casing, allowing the pressure resistance at the connection between the male and female casing joints to reach over 90MPa, thereby improving the pressure resistance performance of the entire wellbore. In addition, it can effectively protect the connection between the male and female casing joints, preventing damage to the connection during running and expansion. Attached Figure Description

[0019] Figure 1 A schematic diagram of the structure of an auxiliary sealing device for an expansion sleeve according to the present invention is shown.

[0020] Figure 2 The diagram schematically illustrates the structure of the auxiliary sealing device for expansion sleeve according to the present invention after being connected with the sleeve female connector and the sleeve female connector.

[0021] Figure 3 The schematic diagram shows the structure of the auxiliary sealing device for the expansion sleeve according to the present invention after expansion.

[0022] In this application, all the accompanying drawings are schematic drawings, used only to illustrate the principle of the present invention, and are not drawn to scale. Detailed Implementation

[0023] The technical solution of this utility model will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0024] In this utility model, unless otherwise explicitly specified and limited, the terms "connection," "fixed," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a communication connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal connection of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances. In this utility model, "multiple" refers to two or more.

[0025] In the description of this utility model, it should be understood that the terms "inner," "outer," etc., indicating the orientation or positional relationship are 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 indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated.

[0026] like Figure 1 and Figure 2 As shown, the auxiliary sealing device 100 for expansion sleeves of this utility model includes: an auxiliary sealing sleeve 5, the inner wall of which is provided with a protrusion 4, optionally extending circumferentially along the inner wall of the auxiliary sealing sleeve 5. The inner wall of the auxiliary sealing sleeve 5 also has multiple sealing ring grooves 2, and sealing rings 3 are disposed inside the sealing ring grooves 2. A male sleeve connector 1 and a female sleeve connector 6 are connected inside the auxiliary sealing sleeve 5. After the male sleeve connector 1 and the female sleeve connector 6 are connected, the end face of the male sleeve connector 1 faces the end face of the female sleeve connector 6, and a gap S is formed between the two end faces. The protrusion 4 is located within this gap S, thereby allowing the auxiliary sealing sleeve 5 to be connected to the male sleeve connector 1 and the female sleeve connector 6 through the protrusion 4. The outer walls of the male sleeve connector 1 and the female sleeve connector 6 are in contact with the inner wall of the auxiliary sealing sleeve 5, and sealing is achieved through the sealing rings 3.

[0027] The assembly process of the auxiliary sealing device 100 for expansion sleeves described in this utility model is briefly described below. First, clean the processed male sleeve connector 1 and female sleeve connector 6, and apply grease to the inner wall of the auxiliary sealing device 5 with the sealing ring 3 installed. Place the auxiliary sealing device 5 onto the male sleeve connector 1 until the protrusion 4 contacts the end face of the male sleeve connector 1. Slowly insert the female sleeve connector 6 into the threaded auxiliary sealing device 5, and engage and tighten it with the male sleeve connector 1 until the end face of the female sleeve connector 6 contacts and presses against the protrusion 4, so that the auxiliary sealing sleeve 5 is connected to the male sleeve connector 1 and the female sleeve connector 6 through the protrusion 4.

[0028] The working process of the auxiliary sealing device 100 for expansion sleeves described in this utility model is briefly described below. For example... Figure 3As shown, the expansion casing body is installed inside the wellbore (not shown in the figure), including the casing male connector 1 and the casing female connector 6 connected to the casing male connector 1. The expansion cone 7 moves axially along the expansion casing body so that the casing male connector 1 and the casing female connector 6 undergo radial plastic expansion. At this time, the expansion casing body squeezes the auxiliary sealing device 5 and causes it to expand radially. During the expansion process, the sealing groove 2 and the sealing ring 3 will not be damaged. The auxiliary sealing device 5 and the casing male connector 1 and the casing female connector 6 always maintain a sealed state, ensuring a high-strength seal after expansion, which meets the requirements for repair of fracturing wellbore casing damage and reconstruction of repeated fracturing wellbore.

[0029] According to this utility model, an auxiliary sealing sleeve 5 is provided, and the inner wall of the auxiliary sealing sleeve 5 is provided with a protrusion 4. After the male sleeve connector 1 and the female sleeve connector 6 are connected, the protrusion 4 abuts against the gap between the end face of the female sleeve connector 6 and the end face of the male sleeve connector 1. Thus, on the one hand, the protrusion 4 can serve as an indicator after the male sleeve connector 1 and the female sleeve connector 6 are connected in place, and on the other hand, the auxiliary sealing sleeve is connected to the male sleeve connector 1 and the female sleeve connector 6 through the protrusion 4.

[0030] Furthermore, the inner wall of the auxiliary sealing sleeve 5 is also provided with a sealing ring groove 2, and a sealing ring 3 is installed inside the sealing ring groove 2. The inner wall of the auxiliary sealing sleeve 5 is in contact with the outer walls of the casing male connector 1 and the casing female connector 6, and auxiliary sealing is achieved through the sealing ring 3. On the one hand, it can seal the pressure generated during expansion. On the other hand, when the pressure generated after expansion leaks from the connection between the casing male connector 1 and the casing female connector 6, it can still be sealed inside the auxiliary sealing sleeve 5, so that the pressure resistance at the connection between the casing male connector 1 and the casing female connector 6 can reach more than 90MPa, thereby improving the pressure resistance performance of the entire wellbore. In addition, it can effectively protect the connection between the casing male connector 1 and the casing female connector 6, preventing damage to the connection during running and expansion.

[0031] In one or more embodiments, the auxiliary sealing tool 5 is made of a soft metal to avoid affecting the expansion of the expansion sleeve body. Optionally, the auxiliary sealing tool 5 is made of copper alloy or aluminum alloy.

[0032] In one or more embodiments, the sealing groove 2 is configured as a cube.

[0033] In one or more embodiments, the male sleeve connector 1 includes a first connector portion 11 configured as a protrusion, and the female sleeve connector 6 includes a second connector portion 61 configured as a recess, wherein the first connector portion 11 is insertable into the second connector portion 61 and is fixedly connected by threads.

[0034] In one or more embodiments, the male sleeve connector 1 has a step 12 integrally connected to the end of the first connector portion 11 away from the second connector portion 61, and the step 12 is opposite to the end face of the female sleeve connector 6 forming the second connector portion 61.

[0035] In one or more embodiments, the protrusion 4 is located between the step 12 and the end face of the sleeve female connector 6 forming the second connector portion 61.

[0036] In one or more embodiments, the inner wall of the auxiliary sealing sleeve 5 is provided with a sealing ring groove 2 at the contact point with the outer wall of the step 12.

[0037] In one or more embodiments, the sleeve female connector 6 has a body 62 on the side of the second connector 61 away from the first connector 11, and the inner wall of the auxiliary sealing sleeve 5 is provided with a sealing ring groove 2 at the contact point with the outer wall of the body 62.

[0038] Although the present invention has been described with reference to preferred embodiments, various modifications can be made thereto and components can be replaced with equivalents without departing from the scope of the invention. In particular, the technical features mentioned in the various embodiments can be combined in any manner, provided there is no structural conflict. The present invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. An auxiliary sealing device for an expansion sleeve, characterized in that, include: An auxiliary sealing sleeve has a protrusion on its inner wall. After the male and female sleeve connectors are connected, the protrusion abuts against the gap between the end face of the female and male sleeve connectors. The inner wall of the auxiliary sealing sleeve also has multiple sealing ring grooves, and sealing rings are installed inside the sealing ring grooves. The inner wall of the auxiliary sealing sleeve contacts the outer walls of both the male and female sleeve connectors and is sealed by the sealing rings.

2. The auxiliary sealing device for expansion sleeves according to claim 1, characterized in that, The auxiliary sealing sleeve is made of soft metal.

3. The auxiliary sealing device for expansion sleeves according to claim 2, characterized in that, The auxiliary sealing sleeve is made of copper alloy or aluminum alloy.

4. The auxiliary sealing device for expansion sleeves according to claim 1 or 2, characterized in that, The sealing ring groove is constructed in a cubic shape.

5. The auxiliary sealing device for expansion sleeves according to claim 1 or 2, characterized in that, The male sleeve connector includes a first connector portion configured as a protrusion, and the female sleeve connector includes a second connector portion configured as a recess. The first connector portion can be inserted into the second connector portion and fixedly connected by threads.

6. The auxiliary sealing device for expansion sleeve according to claim 5, characterized in that, The male sleeve connector has a step integrally connected to the end of the first connector portion away from the second connector portion, and the step is opposite to the end face of the female sleeve connector forming the second connector portion.

7. The auxiliary sealing device for expansion sleeves according to claim 6, characterized in that, The protrusion is located between the step and the end face of the sleeve female joint forming the second joint portion.

8. The auxiliary sealing device for expansion sleeve according to claim 6, characterized in that, The inner wall of the auxiliary sealing sleeve has a sealing ring groove at the contact point with the outer wall of the step.

9. The auxiliary sealing device for expansion sleeve according to claim 8, characterized in that, The sleeve female connector has a main body on the side of the second connector that is away from the first connector, and the inner wall of the auxiliary sealing sleeve has the sealing ring groove at the contact point with the outer wall of the main body.

10. The auxiliary sealing device for an expansion sleeve according to claim 1, characterized in that, The protrusion extends circumferentially along the inner wall of the auxiliary sealing sleeve.

Images