A well cementing slurry back-annulus wellhead device
By designing a cement slurry return wellhead device, and utilizing the design of a sealed connection and slurry discharge space, the problem of difficulty in improving the quality of surface cementing was solved, achieving efficient delivery and return of cement slurry, and ensuring the improvement of cementing quality.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- PETROCHINA CO LTD
- Filing Date
- 2022-06-22
- Publication Date
- 2026-07-21
AI Technical Summary
Existing surface cementing methods are difficult to improve effectively, especially in low-pressure, easily leaky formations. Traditional cementing methods carry the risk of leakage, which prevents cement caps from forming effectively.
A cement slurry return wellhead device is designed, including a return wellhead pipe body, a first casing, a return pipe, and a guide pipe. Through the design of sealed connection and slurry discharge space, the device achieves efficient delivery and return of cement slurry, ensures the flowability of cement slurry within a specific space, and improves cementing quality.
The improved wellhead device enabled efficient delivery and back-extrusion of cement slurry, ensuring the sealing of the cement slurry within a specific space, improving the quality of surface cementing, preventing leakage, and enhancing the cementing effect.
Smart Images
Figure CN117307087B_ABST
Abstract
Description
Technical Field
[0001] This application belongs to the technical field of wellhead equipment, and particularly relates to a cementing slurry return wellhead device. Background Technology
[0002] With the development of technology, in order to ensure the backflow height of cement slurry in low-pressure, easily leaky formation cementing, forward injection and back-squeezing cementing technology is widely used. This technology has the advantages of low cost and good effect, and is widely used in places like Changqing Oilfield. However, this technology has limitations. Because back-squeezing cement will generate back pressure, it can only be used in wells with standard casing heads and cemented oil layer casing. Surface cementing, which has even lower pressure, higher porosity, and is more prone to leakage, usually uses a single cement slurry backflow cementing method because there is no wellhead equipment. If leakage occurs, a cement cap is passively installed at the wellhead, so it is difficult to effectively improve the quality of surface cementing. Summary of the Invention
[0003] This application provides a cement slurry return wellhead device to solve the problem that it is difficult to effectively improve the quality of existing surface cementing.
[0004] In a first aspect, embodiments of this application provide a cement slurry return wellhead device, comprising:
[0005] The return wellhead pipe body includes a first pipe and a second pipe connected to each other, the inner diameter of the second pipe being larger than the inner diameter of the first pipe; the first pipe is provided with a first hole, the second pipe is provided with a second hole, and the second hole is connected to the first hole;
[0006] The first sleeve is inserted through the first hole and the second hole; the outer wall of the first sleeve is sealed to the inner wall of the first hole; the outer wall of the first sleeve inside the second hole and the inner wall of the second hole enclose a slurry discharge space.
[0007] A return extrusion pipe is connected to the return extrusion wellhead pipe body and is disposed between the first pipe and the second pipe; the return extrusion pipe is provided with a third hole, the outlet of the third hole is connected to the slurry discharge space, and the inlet is in the external environment containing cement slurry; the return extrusion pipe allows the cement slurry to enter the slurry discharge space from the external environment through the third hole;
[0008] The conduit abuts against the end of the second tube furthest from the first tube and is sealed to the second tube; the conduit has an inner hole that communicates with the slurry discharge space and allows the first sleeve to pass through.
[0009] Optionally, a connecting portion is provided between the first tube and the second tube, the connecting portion extending from the first tube toward the second tube, and the inner diameter of the connecting portion gradually increases;
[0010] The return extrusion pipe is connected to the connecting part in the horizontal direction and communicates with the slurry discharge space.
[0011] Optionally, the connecting part is conical, and both the first tube and the second tube are cylindrical.
[0012] Optionally, a first clamp is provided between the first pipe and the first sleeve, and the first pipe and the first sleeve are locked and sealed by the first clamp.
[0013] Optionally, a second clamp is provided between the second tube and the conduit, and the second tube and the conduit are locked and sealed by the second clamp; the second tube abuts against the surface of the conduit in the up-down direction, and the lower surface of the second tube and the upper surface of the conduit are sealed together.
[0014] Optionally, a sealing ring is provided on the outer side wall of the first casing, and the sealing ring abuts against the upper surface of the first casing as the first casing passes through the return wellhead pipe body.
[0015] Optionally, the lower surface of the sealing ring is sealed to the upper surface of the first tube.
[0016] Optionally, the cement slurry return wellhead device is housed in a square well; the guide tube is sleeved on the inner wall of the square well, and the upper surface of the guide tube extends beyond the surface of the square well in the vertical direction.
[0017] Optionally, the connection between the lower surface of the second tube and the upper surface of the conduit is located above the square well.
[0018] Optionally, the back-extrusion pipe extends horizontally beyond the outer wall of the second pipe and is suspended above the square well.
[0019] This application provides a cement slurry return wellhead device. The return wellhead pipe includes a first pipe and a second pipe connected together, with the inner diameter of the second pipe being larger than that of the first pipe. The first pipe has a first hole, and the second pipe has a second hole, which are connected to the first hole, with a spatial difference between them. A first casing passes through the first hole and the second hole. The outer wall of the first casing is sealed to the inner wall of the first hole. The outer wall of the first casing within the second hole and the inner wall of the second hole enclose a slurry discharge space. This first casing fully utilizes the spatial difference between the second hole and the first hole, and the sealed connection between the outer wall of the first casing and the inner wall of the first hole ensures the slurry discharge space. The upper end of the casing is sealed to prevent the mud in the discharge space from accumulating upwards and pressing against the gap between the outer wall of the first casing and the inner wall of the first hole; the return pipe is connected to the return wellhead pipe body and is set between the first pipe and the second pipe; the return pipe has a third hole, the outlet of the third hole is connected to the discharge space, and the inlet is in the external environment containing cement slurry; the return pipe brings cement slurry from the external environment into the discharge space through the third hole, thereby realizing the flow channel transportation of cement slurry in the external environment, and the sealing of the discharge space improves the cement slurry transportation effect of the cement slurry return wellhead device, ensuring that the cement slurry is returned to the first casing in a specific space, and ensuring the cementing quality. Attached Figure Description
[0020] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0021] To gain a more complete understanding of this application and its beneficial effects, the following description will be provided in conjunction with the accompanying drawings. In the following description, the same reference numerals denote the same parts.
[0022] Figure 1 This is a simplified schematic diagram of a cement slurry return wellhead device in operation, provided in an embodiment of this application.
[0023] Figure 2 This is a schematic diagram showing the connection of the return wellhead pipe of a cement slurry return wellhead device provided in an embodiment of this application.
[0024] Figure 3 This is a schematic diagram of the first state of the return wellhead pipe of a cement slurry return wellhead device provided in an embodiment of this application.
[0025] Figure 4 This is a schematic diagram of the second state of the return wellhead pipe of a cement slurry return wellhead device provided in an embodiment of this application. Detailed Implementation
[0026] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.
[0027] This application provides a cement slurry return wellhead device 100 to solve the problem that it is difficult to effectively improve the quality of existing surface cementing.
[0028] refer to Figures 1 to 4 This application provides a cement slurry return wellhead device 100, which includes a return wellhead pipe body 10, a first casing 20, a return pipe 30, and a guide pipe 40. The return wellhead pipe body 10 is connected to the first casing 20, the return pipe 30, and the guide pipe 40.
[0029] The return wellhead pipe body 10 is a main component of the cement slurry return wellhead device 100, and is connected to the first casing 20, the return pipe 30, and the guide pipe 40 along different sides. The first casing 20 and the guide pipe 40 are located on the upper and lower sides of the return wellhead pipe body 10, and the return pipe 30 is located on the left or right side of the return wellhead pipe body 10.
[0030] The return wellhead pipe body 10 includes a first pipe 11 and a second pipe 12 connected to each other. The first pipe 11 and the second pipe 12 are arranged in sequence along the vertical direction. The first pipe 11 and the second pipe 12 share the same axis. The inner diameter of the second pipe 12 is larger than the inner diameter of the first pipe 11. The first pipe 11 is provided with a first hole, and the second pipe 12 is provided with a second hole. The second hole and the first hole are connected, and there is a spatial difference between the second hole and the first hole.
[0031] A connecting portion 13 is provided between the first pipe 11 and the second pipe 12. The connecting portion 13 extends from the first pipe 11 toward the second pipe 12, and the inner diameter of the connecting portion 13 gradually increases, while the inner diameter of the second pipe 12 is larger than the inner diameter of the first pipe 11. Optionally, the connecting portion 13 is conical, and both the first pipe 11 and the second pipe 12 are cylindrical.
[0032] The first sleeve 20 is inserted into the first hole and the second hole; the outer wall of the first sleeve 20 is sealed to the inner wall of the first hole; optionally, the outer wall of the first sleeve 20 is sealed to fit the inner wall of the first hole, or the outer wall of the first sleeve 20 is provided with a boss, and the inner wall of the first hole is provided with a groove, the boss and the groove are inserted into each other and form a stepped sealing structure, which further ensures the sealing effect between the outer wall of the first sleeve 20 and the inner wall of the first hole.
[0033] Specifically, a first clamp is provided between the first pipe 11 and the first sleeve 20, and the first pipe 11 and the first sleeve 20 are locked and sealed by the first clamp.
[0034] In addition, a sealing ring 21 protrudes from the outer wall of the first casing 20. The sealing ring 21 abuts against the upper surface of the first pipe 11 as the first casing 20 passes through the return wellhead pipe body 10. The lower surface of the sealing ring 21 is sealed to the upper surface of the first pipe 11, further improving the sealing effect between the first casing 20 and the first pipe 11.
[0035] The outer wall of the first sleeve 20 inside the second hole and the inner wall of the second hole enclose each other to form a slurry discharge space 12a. At this time, the upper end of the slurry discharge space 12a is the sealing connection between the outer wall of the first sleeve 20 and the inner wall of the first hole. The sealing connection between the outer wall of the first sleeve 20 and the inner wall of the first hole ensures the sealing of the upper end of the slurry discharge space 12a and prevents the slurry in the slurry discharge space 12a from accumulating upward and pressing the gap between the outer wall of the first sleeve 20 and the inner wall of the first hole.
[0036] The outer wall of the first sleeve 20 located inside the second hole and the inner wall of the second hole enclose each other to form a slurry discharge space 12a. The first sleeve 20 makes full use of the space difference between the second hole and the first hole and forms the slurry discharge space 12a in a sealed state. In addition, the first sleeve 20 is inserted into the second hole and the slurry discharge space 12a is naturally formed by the second hole and the first sleeve 20, which improves the convenience of forming the slurry discharge space 12a.
[0037] The return pipe 30 is connected to the return wellhead pipe body 10 and is located between the first pipe 11 and the second pipe 12. The return pipe 30 is provided with a third hole 31. The outlet of the third hole 31 is connected to the slurry discharge space 12a, and the inlet is located in the external environment containing cement slurry. The return pipe 30 brings the cement slurry from the external environment into the slurry discharge space 12a through the third hole 31, thereby realizing the flow channel transportation of cement slurry in the external environment. Furthermore, the sealing of the slurry discharge space 12a improves the cement slurry transportation effect of the cement slurry return wellhead device 100, ensuring that the cement slurry is returned to the first casing 20 in a specific space and ensuring the cementing quality.
[0038] Additionally, the return pipe 30 is connected to the connecting part 13 in a horizontal direction and communicates with the slurry discharge space 12a. The return pipe 30 extends horizontally beyond the outer wall of the second pipe 12 and is suspended above the square well.
[0039] The guide tube 40 abuts against the end of the second tube 12 away from the first tube 11 and is sealed to the second tube 12; the guide tube 40 is provided with an inner hole 41, which communicates with the slurry discharge space 12a and allows the first casing 20 to pass through, so that the inner hole 41 communicates with the slurry discharge space 12a and facilitates the improvement of cement slurry cementing quality.
[0040] A second clamp is provided between the second tube 12 and the conduit 40, and the second tube 12 and the conduit 40 are locked and sealed by the second clamp; the second tube 12 abuts against the surface of the conduit 40 in the vertical direction, and the lower surface of the second tube 12 and the upper surface of the conduit 40 are sealed together.
[0041] The cement slurry return wellhead device 100 is housed in a square well; the guide tube 40 is sleeved on the inner wall of the square well, and the upper surface of the guide tube 40 extends beyond the surface of the square well in the vertical direction. The connection between the lower surface of the second tube 12 and the upper surface of the guide tube 40 is located above the square well.
[0042] This application provides a cement slurry return wellhead device 100. The return wellhead pipe body 10 includes a first pipe 11 and a second pipe 12 connected to each other. The inner diameter of the second pipe 12 is larger than the inner diameter of the first pipe 11. The first pipe 11 has a first hole, and the second pipe 12 has a second hole. The second hole and the first hole are connected, and there is a spatial difference between the second hole and the first hole. A first casing 20 passes through the first hole and the second hole. The outer wall of the first casing 20 is sealed to the inner wall of the first hole. The outer wall of the first casing 20 located in the second hole and the inner wall of the second hole enclose a slurry discharge space 12a. The first casing 20 makes full use of the spatial difference between the second hole and the first hole, and the outer wall of the first casing 20 is sealed to the inner wall of the first hole to ensure the sealing of the upper end of the slurry discharge space 12a and to prevent the slurry in the slurry discharge space 12a from accumulating upwards and pressing against the first casing 20. The gap between the outer wall of the casing and the inner wall of the first hole; the return pipe 30 is connected to the return wellhead pipe body 10 and is set between the first pipe 11 and the second pipe 12; the return pipe 30 is provided with a third hole 31, the outlet of the third hole 31 is connected to the slurry discharge space 12a, and the inlet is in the external environment containing cement slurry; the return pipe 30 brings cement slurry from the external environment into the slurry discharge space 12a through the third hole 31, thereby realizing the flow channel transportation of cement slurry in the external environment, and the sealing of the slurry discharge space 12a improves the cement slurry transportation effect of the cement slurry return wellhead device 100, ensuring the return of cement slurry to the first casing 20 in a specific space, and ensuring the cementing quality.
[0043] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.
[0044] In the description of this application, 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. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more features.
[0045] This document uses specific examples to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the methods and core ideas of this application. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.
Claims
1. A wellhead device for returning cement slurry, characterized in that, include: The back-extrusion wellhead pipe body includes a first pipe and a second pipe connected to each other, wherein the inner diameter of the second pipe is larger than the inner diameter of the first pipe; The first tube has a first hole, and the second tube has a second hole, which is connected to the first hole; The first sleeve is inserted through the first hole and the second hole; the outer wall of the first sleeve is sealed to the inner wall of the first hole; the outer wall of the first sleeve inside the second hole and the inner wall of the second hole enclose a slurry discharge space. A return extrusion pipe is connected to the return extrusion wellhead pipe body and is disposed between the first pipe and the second pipe; the return extrusion pipe is provided with a third hole, the outlet of the third hole is connected to the slurry discharge space, and the inlet is in the external environment containing cement slurry; the return extrusion pipe allows the cement slurry to enter the slurry discharge space from the external environment through the third hole; The conduit abuts against the end of the second tube furthest from the first tube and is sealed to the second tube; the conduit has an inner hole that communicates with the slurry discharge space and allows the first sleeve to pass through.
2. The wellhead device for returning cement slurry according to claim 1, characterized in that, A connecting portion is provided between the first tube and the second tube, the connecting portion extending from the first tube toward the second tube, and the inner diameter of the connecting portion gradually increases; The return extrusion pipe is connected to the connecting part in the horizontal direction and communicates with the slurry discharge space.
3. The cement slurry return wellhead device according to claim 2, characterized in that, The connecting part is conical, and both the first tube and the second tube are cylindrical.
4. The wellhead device for returning cement slurry according to claim 3, characterized in that, A first clamp is provided between the first pipe and the first sleeve, and the first pipe and the first sleeve are locked and sealed by the first clamp.
5. The wellhead device for returning cement slurry according to claim 4, characterized in that, A second clamp is provided between the second tube and the conduit, and the second tube and the conduit are locked and sealed by the second clamp; the second tube abuts against the surface of the conduit in the up-down direction, and the lower surface of the second tube and the upper surface of the conduit are sealed together.
6. The cement slurry return wellhead device according to claim 5, characterized in that, A sealing ring is provided on the outer side wall of the first casing, and the sealing ring abuts against the upper surface of the first casing as the first casing passes through the return wellhead pipe body.
7. A cement slurry return wellhead device according to claim 6, characterized in that, The lower surface of the sealing ring is sealed to the upper surface of the first tube.
8. A cement slurry return wellhead device according to claim 7, characterized in that, The cement slurry return wellhead device is housed in a square well; the guide tube is sleeved on the inner wall of the square well, and the upper surface of the guide tube extends beyond the surface of the square well in the vertical direction.
9. A cement slurry return wellhead device according to claim 8, characterized in that, The connection between the lower surface of the second tube and the upper surface of the conduit is located above the square well.
10. A cement slurry return wellhead device according to claim 9, characterized in that, The back-extrusion tube extends horizontally beyond the outer wall of the second tube and is suspended above the square well.