Well hole sealing device

Abstract

The invention provides a well hole sealing device which comprises a sealing inner pipe column string, an outer pipe column string arranged on the periphery of the sealing inner pipe column string in a sleeving mode, a split ring, a shearing ring and a fixing piece, and the shearing ring is arranged on the periphery of the sealing inner pipe column string in a sleeving mode and connected with the outer pipe column string through the fixing piece. The split ring is fixedly arranged on the periphery of the sealing inner pipe column string in a sleeving mode and abuts against the upper surface of the shearing ring, the split ring can abut against the shearing ring so that the shearing ring can shear off the fixing piece, and the sealing inner pipe column string is separated from the outer pipe column string and moves downwards into the branch well hole for mechanical sealing. The sealing assembly at the tail end of the pipe column can be effectively protected, and meanwhile the sealing assembly is inserted into a sealing cylinder in a branch well hole so as to achieve mechanical sealing.

Description

Technical Field

[0001] The invention relates to the field of drilling engineering, and in particular to a wellbore sealing device. Background Art

[0002] Branch well technology is a further extension and expansion of horizontal well technology. It can increase the oil leakage area of ​​a single well, effectively tap the potential of remaining oil, improve the recovery rate and improve the effect of oilfield development. The key to branch well technology lies in the connection of each branch wellbore with the main wellbore at the branch point. In the five-level branch well construction technology, casing is lowered into the main wellbore and the branch wellbore for cementing. The connection between the main wellbore and the branch wellbore has mechanical support and sealing capabilities, and both the main wellbore and the branch wellbore can be re-entered. In order to achieve the sealing of the wellbore connection, a pipe lowering device can be used to achieve the main wellbore oil pipe entering the main wellbore and forming an inserted seal, and the branch wellbore oil pipe entering the branch wellbore and forming an inserted seal. However, in actual applications, the following problems are often encountered: First, during the lowering of the branch wellbore oil pipe, its end sealing component is easily damaged; second, the sealing component at the end of the branch wellbore oil pipe cannot be inserted into the sealing cylinder in the branch wellbore, which leads to unsuccessful sealing. How to effectively protect the end sealing component while ensuring that the sealing component is inserted into the sealing tube in the branch wellbore to achieve insertion sealing between the branch wellbore oil pipe and the branch wellbore is a key technical problem for the successful implementation of the double-tube running device. Summary of the invention

[0003] One object of the present invention is to provide a wellbore sealing device to effectively protect the sealing component at the end of the pipe string during the process of running the pipe string into the branch wellbore, and at the same time allow the sealing component to be inserted into the sealing tube in the branch wellbore to achieve mechanical sealing.

[0004] According to the present invention, a wellbore sealing device is provided, comprising a sealing inner tubing string, an outer tubing string sleeved on the outer periphery of the sealing inner tubing string, an open ring, a shear ring and a fixing piece, wherein the shear ring is sleeved on the outer periphery of the sealing inner tubing string and connected to the outer tubing string through the fixing piece, the open ring fixing sleeve is placed on the outer periphery of the sealing inner tubing string and abuts against the upper surface of the shear ring, the open ring can press against the shear ring so that the shear ring cuts off the fixing piece, and the sealing inner tubing string is then separated from the outer tubing string and moves downward to the branch wellbore for mechanical sealing.

[0005] In a preferred embodiment, it also includes an elastic retaining ring and a fixing ring, the fixing ring abuts against the lower surface of the shear ring, the inner wall of the outer pipe string is provided with a groove below the fixing ring, the elastic retaining ring is arranged in the groove and abuts against the lower surface of the fixing ring.

[0006] In a preferred embodiment, the open ring is provided with a plurality of cutouts along the outer circumference.

[0007] In a preferred embodiment, the sealed inner tubing string includes a tubing nipple, an upper joint, a sealed connecting pipe, a lower joint, and a sealing assembly sleeved on the outer surface of the sealed connecting pipe, which are sequentially connected from top to bottom.

[0008] In a preferred embodiment, the sealing assembly includes a support frame and a first sealing ring and a second sealing ring both arranged on the support frame, the first sealing ring being able to tightly engage with the inner wall of the polishing cylinder in the branch wellbore, and the second sealing ring enabling the upper joint to be sealed with the sealing connecting pipe at the connection point.

[0009] In a preferred embodiment, the first sealing ring is configured in a U shape, and the second sealing ring is configured in an O shape.

[0010] In a preferred embodiment, the outer tubular string includes an upper suspension tube, a lower suspension tube and a shell connected in sequence from top to bottom, the lower suspension tube is connected to the shear ring via the fixing member, and the inner wall of the lower suspension tube is provided with the groove.

[0011] In a preferred embodiment, the open ring is located between the lower suspension tube, the shear ring and the upper joint.

[0012] In a preferred embodiment, the upper suspension tube has an axial cutout.

[0013] In a preferred embodiment, the bottom end of the outer tubing string is closer to the inside of the branch well than the bottom end of the sealed inner tubing string.

[0014] The present invention has the following beneficial effects:

[0015] The present invention comprises a sealed inner tubular string, an outer tubular string sleeved on the outer periphery of the sealed inner tubular string, an open ring, a shear ring and a fixing piece. The shear ring is sleeved on the outer periphery of the sealed inner tubular string and connected to the outer tubular string through the fixing piece. The open ring fixing sleeve is placed on the outer periphery of the sealed inner tubular string and abuts against the upper surface of the shear ring. The open ring can press the shear ring so that the shear ring shears off the fixing piece, the sealed inner tubular string is separated from the outer tubular string and moves down to the branch wellbore for mechanical sealing. During the process of lowering the tubular string into the branch wellbore, the present invention sleeves the outer tubular string on the outer periphery of the sealed inner tubular string, and surrounds and protects the sealed inner tubular string through the outer tubular string, so as to prevent the sealed inner tubular string from hitting other facilities in the wellbore during the lowering process, thereby preventing the sealing failure due to collision and effectively protecting the tubular end sealing component.

[0016] The present invention has a fixing ring abutting against the lower surface of the shear ring, an inner wall of the outer pipe string is provided with a groove below the fixing ring, and an elastic retaining ring is arranged in the groove and abuts against the lower surface of the fixing ring. In the process of the sealed inner pipe string being separated from the outer pipe string and continuing to descend, the fixing ring together with the elastic retaining ring can limit the shear ring, thereby making the open ring separate from the sealed inner pipe string, and preventing the shear ring and the open ring from continuing to descend with the sealed inner pipe string. On the one hand, it can avoid the impact on the moving trajectory of the sealed inner pipe string due to collision. On the other hand, it can prevent the shear ring and the open ring from falling freely and colliding with the sealing assembly at the lower end thereof, resulting in the failure of its sealing, and at the same time, it can also avoid adverse effects on the construction in the well.

[0017] The wellbore sealing device of the present invention can center the wellbore sealing device in the casing in the branch wellbore by setting the maximum outer diameter of the outer pipe string to be the same or similar to the inner diameter of the casing in the branch wellbore, thereby increasing the success rate of the inserted sealing.

[0018] The first sealing ring of the present invention is configured in a U shape, which can be tightly engaged with the inner wall of the polishing tube in the branch wellbore, and the second sealing ring is configured in an O shape, which can seal the upper joint and the sealing connecting pipe at the connection.

[0019] The upper suspension tube of the present invention has an axial cutout, which can increase the elasticity of the upper suspension tube, thereby facilitating the assembly of the wellbore sealing device.

[0020] The open ring of the present invention has multiple cutouts along the outer circumference, so that when the sealed inner pipe string separates from the outer pipe string and continues to descend, the open ring is easily squeezed out of the sealed inner pipe string by the shear ring and separated from the sealed inner pipe string. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 The overall structure of the wellbore sealing device according to the present invention is schematically shown;

[0022] Figure 2 The structural schematic diagram of the sealing assembly of the wellbore sealing device according to the present invention is schematically shown;

[0023] Figure 3 A schematic diagram of the structure of the sealing assembly according to the present invention cooperating with the upper joint is shown;

[0024] Figure 4 The schematic diagram of the wellbore sealing device according to the present invention and other structures in the well is schematically shown.

[0025] In the present application, all drawings are schematic drawings, which are only used to illustrate the principles of the present invention and are not drawn according to the actual scale. DETAILED DESCRIPTION

[0026] The technical solution of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present invention. It should be noted that, in the absence of conflict, the embodiments in this application and the features in the embodiments can be combined with each other arbitrarily.

[0027] In the description of the present invention, it should be understood that the terms "inner", "upper", "lower", "outer", "axial", "radial", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In the description of the present invention, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0028] In the present invention, unless otherwise clearly specified and limited, the term "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0029] like Figures 1 to 4 As shown, the wellbore sealing device 100 of the present invention comprises a sealing inner tubular string a having a sealing assembly, an outer tubular string b sleeved on the outer periphery of the sealing inner tubular string a, an open ring 4, a shear ring 5 and a fixing member 12. The open ring 4 and the shear ring 5 are both constructed as cylindrical bodies and are both located between the sealing inner tubular string a and the outer tubular string b. The shear ring 5 is sleeved on the outer periphery of the sealing inner tubular string a and connected to the outer tubular string b through the fixing member 12. The fixing member 12 enters the outer tubular string b and the shear ring 5 radially from the outer surface of the outer tubular string b, thereby fixing the shear ring 5 to the outer tubular string b. The open ring 4 is fixedly sleeved on the outer periphery of the sealing inner tubular string a by a tight hoop. The open ring 4 is arranged above the shear ring 5, and its lower surface abuts against the upper surface of the shear ring 5, so that pressure can be applied to the shear ring 5. The open ring 4 presses the shear ring 5, so that the shear ring 5 cuts off the fixing member 12, thereby separating the sealing inner tubular string a from the outer tubular string b. The fixing member 12 may be a shear nail.

[0030] There is a certain height difference between the bottom end of the sealed inner tubular string a and the bottom end of the outer tubular string b. Compared with the bottom end of the sealed inner tubular string a, the bottom end of the outer tubular string b is closer to the well, so that after being lowered into the branch wellbore, the outer tubular string b contacts the branch wellbore anchoring seal assembly 23 in the branch wellbore before the sealed inner tubular string a. When the outer tubular string b contacts the branch wellbore anchoring seal assembly 23 in the branch wellbore, the outer tubular string b stops, and the sealed inner tubular string a has a tendency to continue to descend, thereby driving the open ring 4 to press against the shear ring 5, and the shear ring 5 can then cut the fixing part 12, so that the sealed inner tubular string a breaks away from the outer tubular string b and continues to descend until it reaches the polishing cylinder in the branch wellbore and is mechanically sealed with it.

[0031] The present invention comprises a sealed inner tubular string a, an outer tubular string b sleeved on the outer periphery of the sealed inner tubular string a, an open ring 4, a shear ring 5 and a fixing member 12. The shear ring 5 is sleeved on the outer periphery of the sealed inner tubular string b and connected to the outer tubular string b through the fixing member 12. The open ring 4 is fixedly sleeved on the outer periphery of the sealed inner tubular string b and abuts against the upper surface of the shear ring 5. The open ring 4 can press the shear ring 5 so that the shear ring 5 cuts off the fixing member 12, the sealed inner tubular string a is separated from the outer tubular string b and moves down to the branch wellbore for mechanical sealing. On the one hand, during the process of lowering the tubular string into the branch wellbore, the present invention sleeves the outer tubular string b on the outer periphery of the sealed inner tubular string a, and surrounds and protects the sealed inner tubular string a through the outer tubular string b, so as to prevent the sealed inner tubular string a from hitting other facilities in the wellbore during the lowering process, thereby preventing the sealing failure due to collision and effectively protecting the tubular end sealing component.

[0032] In addition, the present invention can also center the wellbore sealing device 100 in the casing in the branch wellbore by setting the maximum outer diameter of the outer tubing string b to be the same or similar to the inner diameter of the casing in the branch wellbore, thereby increasing the success rate of the inserted seal.

[0033] In one or more embodiments, the wellbore sealing device 100 described in the present invention also includes an elastic retaining ring 11 and a fixing ring 6, the fixing ring 6 abuts against the lower surface of the shear ring 5 to avoid displacement of the shear ring 5 along the axial direction, and the inner wall of the outer tubing string b is provided with a groove below the fixing ring 6, and the elastic retaining ring 11 is arranged in the groove 11 and abuts against the lower surface of the fixing ring 6.

[0034] The present invention has a fixing ring 6 abutting against the lower surface of the shear ring 5, an inner wall of the outer pipe string b is provided with a groove below the fixing ring 6, and an elastic retaining ring 11 is arranged in the groove 11 and abuts against the lower surface of the fixing ring 6. In the process of the sealed inner pipe string a being separated from the outer pipe string b and continuing to descend, the fixing ring 6 together with the elastic retaining ring 11 can limit the shear ring 5, thereby making the open ring 4 separate from the sealed inner pipe string a, and preventing the shear ring 5 and the open ring 4 from continuing to descend with the sealed inner pipe string a. On the one hand, it can avoid the impact on the moving trajectory of the sealed inner pipe string a due to collision. On the other hand, it can prevent the shear ring 5 and the open ring 4 from falling freely and colliding with the sealing assembly 7 at the lower end thereof, resulting in the failure of its sealing, and at the same time, it can also avoid adverse effects on the well construction.

[0035] In one or more embodiments, the open ring 4 is provided with a plurality of cutouts along the outer circumference, so that when the sealed inner tubular string a separates from the outer tubular string b and continues to descend, the open ring 4 is conveniently squeezed out of the sealed inner tubular string a by the shear ring 5 and separates from the sealed inner tubular string a.

[0036] In one or more embodiments, the sealed inner tubing string a includes a tubing nipple 1, an upper joint 13, a sealing connection pipe 8, a lower joint 9, and a sealing assembly 7 sleeved on the outer surface of the sealing connection pipe 8, which are sequentially connected from top to bottom. On the one hand, the sealing assembly 7 can be mechanically sealed with the polishing tube when the sealed inner tubing string a is separated from the outer tubing string b and continues to descend to the polishing tube inside the branch wellbore. On the other hand, the sealing assembly 7 can seal and connect the sealing connection pipe 8 with the lower joint 9 and the upper joint 13, respectively. Optionally, the tubing nipple 1 is threadedly connected to the upper joint 13, the upper joint 13 is threadedly connected to the first end of the sealing connection pipe 8, and the second end of the sealing connection pipe 8 is threadedly connected to the lower joint 9. The lower joint 9 is used for the sealing assembly 7 sleeved on the sealing connection pipe 8 to prevent the sealing assembly 7 from failing due to collision during the process of being lowered into the well.

[0037] In one or more embodiments, the sealing assembly 7 includes a support frame 71 and a first sealing ring 72 and a second sealing ring 73 arranged on the support frame 71, wherein the first sealing ring 72 is configured to be U-shaped and can be tightly engaged with the inner wall of the polishing cylinder in the branch wellbore, and the second sealing ring 73 is configured to be O-shaped and can enable the upper joint 13 to be sealed and engaged with the sealing connecting pipe 8 at the connection.

[0038] In one or more embodiments, the outer tubular string b includes an upper suspension tube 2, a lower suspension tube 3 and a housing 10 connected in sequence from top to bottom, the lower suspension tube 3 is connected to the shear ring 5 by a fixing member 12, and a groove is provided on the inner wall of the lower suspension tube 3, and an elastic retaining ring 11 is fixedly arranged in the groove. Optionally, the upper suspension tube 2 is connected to the lower suspension tube 3 by threads, and the lower suspension tube 3 is connected to the housing 10 by threads. The housing 10 can effectively protect the sealing assembly 7 during the lowering process, and prevent the sealing assembly 7 from failing due to collision during the lowering process into the well.

[0039] In one or more embodiments, the split ring 4 is located between the lower suspension tube 3 , the shear ring 5 and the upper joint 9 .

[0040] In one or more embodiments, the upper suspension tube 2 has an axial cutout, which can increase the elasticity of the upper suspension tube 2 , thereby facilitating the assembly of the wellbore sealing device 100 .

[0041] During the construction process, the wellbore sealing device 100 described in the present invention is lowered into the branch well. When the shell 10 of the wellbore sealing device 100 hits the branch wellbore anchoring seal assembly 23, the shell 10 is blocked by the branch wellbore anchoring seal assembly 23, so that the outer tubing string b cannot continue to descend, and the sealed inner tubing string a has a tendency to continue to descend, so that the open ring 4 applies pressure to the shear ring 5, and the shear ring 5 cuts off the fixing piece 12, so that the sealed inner tubing string a is separated from the outer tubing string b, and the sealed inner tubing string a continues to descend. The fixing ring 6 is connected to the elastic retaining ring 11 to limit the axial displacement of the shear ring 5, and the open ring 4 is squeezed out of the upper joint 13 of the sealed inner tubing string a, and the sealed inner tubing string a is lowered into the polishing cylinder of the branch wellbore anchoring seal assembly 23, and the sealing component 7 takes effect to achieve mechanical sealing.

[0042] Although the present invention has been described with reference to preferred embodiments, various modifications may be made thereto and parts thereof may be replaced by equivalents without departing from the scope of the present invention. In particular, the various technical features mentioned in the various embodiments may be combined in any manner as long as there are no structural conflicts. 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. A wellbore sealing device, comprising a sealing inner tubing string, an outer tubing string sleeved on the outer periphery of the sealing inner tubing string, an open ring, a shear ring and a fixing piece, wherein the shear ring is sleeved on the outer periphery of the sealing inner tubing string and connected to the outer tubing string through the fixing piece, the open ring fixing sleeve is placed on the outer periphery of the sealing inner tubing string and abuts against the upper surface of the shear ring, the open ring can press against the shear ring so that the shear ring cuts off the fixing piece, and the sealing inner tubing string is then separated from the outer tubing string and moves downward to the branch wellbore for mechanical sealing.

2. The wellbore sealing device according to claim 1, characterized in that: It also includes an elastic retaining ring and a fixing ring, wherein the fixing ring abuts against the lower surface of the shear ring, the inner wall of the outer pipe string is provided with a groove below the fixing ring, and the elastic retaining ring is arranged in the groove and abuts against the lower surface of the fixing ring.

3. The wellbore sealing device according to claim 2, characterized in that: The open ring is provided with a plurality of cutouts along the outer circumference.

4. The wellbore sealing device according to claim 3, characterized in that: The sealed inner pipe string comprises a tubing nipple, an upper joint, a sealed connecting pipe, a lower joint, and a sealing assembly sleeved on the outer surface of the sealed connecting pipe, which are sequentially connected from top to bottom.

5. The wellbore sealing device according to claim 4, characterized in that: The sealing assembly includes a support frame and a first sealing ring and a second sealing ring both arranged on the support frame. The first sealing ring can be tightly engaged with the inner wall of the polishing cylinder in the branch wellbore, and the second sealing ring enables the upper joint and the sealing connecting pipe to be sealed at the connection.

6. The wellbore sealing device according to claim 5, characterized in that: The first sealing ring is configured in a U shape, and the second sealing ring is configured in an O shape.

7. The wellbore sealing device according to claim 4, characterized in that: The outer pipe string includes an upper suspension tube, a lower suspension tube and a shell which are sequentially connected from top to bottom. The lower suspension tube is connected to the shear ring via the fixing member, and the inner wall of the lower suspension tube is provided with the groove.

8. The wellbore sealing device according to claim 7, characterized in that: The open ring is located between the lower suspension tube, the shear ring and the upper joint.

9. The wellbore sealing device according to claim 7, characterized in that: The upper suspension tube has an axial cutout.

10. The wellbore sealing device according to claim 1, characterized in that: The bottom end of the outer tubing string is closer to the inside of the branch well than the bottom end of the sealed inner tubing string.

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