A union cover for wellhead equipment

Abstract

Provided is a union cap for wellhead equipment, comprising a union cap body and a lug; the connecting thread of the union cap body is a double-threaded thread, and the double-threaded thread is a 2ACME double-threaded thread. The utility model adopts a method of changing a single-threaded thread into a double-threaded thread, and designing the original 4ACME double-threaded thread into a 2ACME double-threaded thread to increase the pitch, so as to solve the technical problems that the existing union cap device for wellhead equipment is difficult to disassemble, difficult to assemble, low in assembly efficiency and poor in safety under specific pressure conditions; the utility model union cap for wellhead equipment has a simple structure, is safe and reliable, saves time, is easy to use, is more labor-saving, more humanized and has better versatility.

Description

Technical Field

[0001] The utility model belongs to the technical field of high-pressure wellhead blowout prevention devices of oil and gas well cable logging and well control equipment, and particularly relates to a union cover for wellhead equipment. Background Art

[0002] Traditional union covers, such as a union cover for wellhead equipment disclosed in announcement number CN212774208U, choose to optimize the outer circle design to add knurling, grooves, etc. to increase friction, facilitate operation, improve operating efficiency, or optimize the appearance shape to improve the difficulty of operation.

[0003] With the increase in wellhead pressure of oil and gas wells, the volume and weight of the union cover are also required to increase continuously. Simply optimizing the outer circle and adding disassembly lugs can no longer meet the operational requirements.

[0004] Therefore, it is urgent to develop a union cover with simple structure, safe and reliable, and easy operation. To this, the following improved technical solution is now proposed. Utility Model Content

[0005] The technical problem solved by the utility model is to provide a union cap for wellhead equipment, which adopts the method of changing a single-line thread into a double-line thread and designing the original 4ACME double-line thread into a 2ACME double-line thread with an increased pitch, thereby solving the technical problems that the existing union cap device for wellhead equipment is difficult to disassemble under specific pressure conditions, has great difficulty in assembly, has low assembly efficiency and poor safety.

[0006] The utility model adopts a technical solution: a union cover for wellhead equipment, comprising a union cover body and a lug; the connecting thread of the union cover body is a double-start thread, and the double-start thread is a 2ACME double-start thread.

[0007] In the above technical solution, as a further improvement of the present invention, an annular groove is provided in the middle of the inner side of the union cover body.

[0008] In the above technical solution, as a further improvement of the present invention, an annular slip is provided inside the upper end of the union cover body.

[0009] Among the above technical solutions, as the preferred technical solution of the present invention, the annular slips and the union cover body are an integrated structure.

[0010] In the above technical solution, as a further improvement of the present invention: the inner diameter of the annular slip is smaller than the inner diameter of the union cover body.

[0011] Among the above technical solutions, as the preferred technical solution of the present invention, the lugs are distributed in a ring array along the outer side of the upper end of the union cover body; and hanging holes are provided in the lugs.

[0012] Among the above technical solutions, as the preferred technical solution of the present invention, the lugs and the union cover body are integrally formed.

[0013] Among the above technical solutions, as the preferred technical solution of the present utility model: there are four lugs, and the four lugs are symmetrically distributed.

[0014] Among the above technical solutions, as the preferred technical solution of the present utility model, the upper surface of the lug, the upper surface of the union cover body and the upper surface of the annular slip are flush.

[0015] Among the above technical solutions, as the preferred technical solution of the present utility model, the lug is in the shape of a rectangular parallelepiped, and the surface of the lug is chamfered.

[0016] The advantages of this utility model compared with the prior art are:

[0017] 1. The utility model has the advantages of simple structure, safety, reliability, time saving, convenience in use, greater labor saving, higher humanization and better versatility.

[0018] 2. The utility model designs the original single-thread into a double-thread, and the original 4ACME double-thread into a 2ACME double-thread; effectively increases the pitch while ensuring the strength of the union cover body; increases the pitch, increases the thread contact surface, increases the sealing performance, improves the connection stability, enhances the load-bearing capacity, and relatively extends the service life; in addition, the double-thread connection can quickly ensure buckle-type docking and reduce the number of connection turns, so that the thread can be tightened quickly, thereby saving the time of thread screwing, thereby improving efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a longitudinal cross-sectional view of the utility model;

[0020] Figure 2 This is the main view of the utility model;

[0021] In the figure: 1-union cover body, 2-lug, 201-hanging hole, 3-annular groove, 4-annular slip, 5-double thread. DETAILED DESCRIPTION

[0022] The following is a combination of the appended examples of the present invention Figure 1-2 The technical solutions in the embodiments of the present invention are clearly and completely described. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort shall fall within the scope of protection of the present invention.

[0023] (like Figure 1(As shown) A union cover for wellhead equipment includes a union cover body 1 and a lug 2, that is, the utility model mainly protects a union cover body 1 with a lug 2.

[0024] The core improvement of the present invention lies in: the connecting threads of the union cap body 1 are improved to double-start threads 5, and the double-start threads 5 are 2ACME double-start threads. Specifically, the present invention designs the original single-start threads into double-start threads, and the original 4ACME double-start threads into 2ACME double-start threads, effectively increasing the thread pitch while ensuring the strength of the union cap body. The increased pitch increases the thread contact surface, improves sealing performance, enhances connection stability, strengthens load-bearing capacity, and relatively extends service life. In addition, the double-start thread connection can quickly ensure buckle-type docking and reduce the number of connection turns, so the threads can be tightened quickly, saving thread tightening time and improving efficiency.

[0025] It should be noted that the ACME thread, as currently used, is a thread used to transmit force and motion. It boasts advantages such as high load-bearing capacity, high transmission efficiency, good self-locking properties, and ease of manufacture and use. A double-start thread is a thread that simultaneously produces two threads in the same or different directions on the same axis. Its structural characteristic is that the two threads are concentrically arranged axially, while the pitch and helix angle of each thread differ radially. Therefore, double-start threads generate greater friction during connection, resulting in a more secure fixation. Their strong self-locking properties ensure that the connection does not loosen under vibration or load.

[0026] Regarding 4ACME, the number of threads per inch is 4, and other parameters, such as the thread angle, are determined according to the ACME standard. However, to meet certain needs, such as increasing fastening force and improving transmission efficiency, the present invention now changes the 4ACME thread design to a 2ACME thread, with the number of threads per inch being 2, but the pitch is increased compared to the original 4ACME. The increased pitch increases the distance between adjacent threads, resulting in increased friction: within the same length, the increased pitch means fewer contact points between threads, but the pressure at each contact point may increase, thereby increasing friction.

[0027] In the above embodiment, as a further improved embodiment of the present invention, an annular groove 3 is provided in the middle of the inner side of the union cover body 1. A sealing ring can be placed in the annular groove 3 to achieve a sealing effect.

[0028] In the above embodiment, as a further improved embodiment of the present invention, an annular slip 4 is provided inside the upper end of the union cover body 1. The function of the annular slip 4 is to act as a barrier when cooperating with the raised threaded portion on the outside of the sealing joint to prevent the union cover from being installed incorrectly.

[0029] In the above embodiment, as a preferred embodiment of the present invention, the annular slips 4 and the union cover body 1 are an integrated structure. The integrated structure helps to ensure the strength of the union cover body.

[0030] In the above embodiment, as a further improvement of the present invention, the inner diameter of the annular slip 4 is smaller than the inner diameter of the union cover body 1 .

[0031] It should be noted that the union cap is used as a cable wellhead blowout preventer during cable logging in oil and gas wells. As a well control device for cable logging, the cable blowout preventer can control the ejection of high-pressure fluids (oil, gas, steam, water) from the wellhead (injection well and production well) during the logging process. Existing logging blowout preventers include a blowout preventer (generally a tubing longer than 2 meters), a tubing nipple, an overflow pipe, and a blowout preventer box. The union cap is a connector used for internal sealing of the logging blowout preventer. During installation, the union cap connects the sealing joint, where the outer diameter of the sealing joint is larger than the inner diameter of the annular slip 4 and smaller than the inner diameter of the union cap body 1. This allows the sealing joint to be installed in the union cap body 1 while being blocked by the annular slip 4. However, the sealing joint connection has an outwardly protruding threaded portion, and the outer diameter of the threaded portion is compatible with the double-threaded portion 5 on the inner wall of the union cap body 1, allowing for assembly.

[0032] In the above embodiment, as a preferred technical solution of the present invention, the lugs 2 are arranged in a circular array along the outer side of the upper end of the union cover body 1; and the lugs 2 are provided with lifting holes 201. The lugs 2 are arranged in a circular array along the outer side of the upper end of the union cover body 1, which enhances structural stability, improves lifting convenience, improves installation positioning accuracy, and evens out stress distribution. The lugs 2 are provided with lifting holes 201. During use, a hook can be inserted through the lifting holes 201 to lift the entire union cover, making installation easier and avoiding the inconvenience of manual handling when the union cover is too heavy.

[0033] In the above embodiment, as a preferred technical solution of the present invention, the lug 2 is integrally formed with the union cover body 1. The integrally formed design allows for a seamless connection between the lug 2 and the union cover body 1, reducing the potential risk of loosening or breakage, thereby significantly enhancing the strength and stability of the entire structure. The integrally formed lug 2 and the union cover body 1 provide a tighter connection, reducing potential leak points and optimizing sealing performance. Because the lug 2 and the union cover body 1 are integrally formed, no additional connectors or fasteners are required during installation, simplifying the installation process and improving installation efficiency. The integrally formed design also reduces the need for repair and replacement due to connector failure, thereby reducing maintenance costs.

[0034] In the above embodiment, as the preferred technical solution of the present invention: there are four lugs 2, and the four lugs 2 are symmetrically distributed. This uniform distribution helps to reduce stress concentration, so that the union cover is more uniform when under pressure and avoids local overload. The four lugs 2 can be used as positioning points during installation. Through precise matching and fixation, it can be ensured that the union cover is in the correct position and angle during installation, and this positioning accuracy is crucial to ensuring the normal operation and sealing performance of the equipment. Lifting holes 201 are provided in the four lugs 2, which will greatly facilitate the installation and operation of the lifting equipment; through the lifting equipment, the union cover can be easily lifted to the designated position, which improves the convenience of installation and disassembly. The design of the four lugs 2 can adapt to a variety of different connection methods and application scenarios. This versatility makes the union cover more flexible and changeable, and can meet the needs of different customers.

[0035] In the above embodiment, as the preferred technical solution of the present invention: the upper surface of the lug 2, the upper surface of the union cover body 1 and the upper surface of the annular cava 4 are flush. The appearance is kept flat and beautiful, and the surface is easier to process and shape. In addition, the flush surface can reduce the friction between the lug 2, the union cover body 1 and the annular cava 4, thereby reducing the risk of wear and damage; under high-frequency operation or high-load conditions, this design can maintain the stability and reliability of the equipment and extend its service life. When the upper surfaces of the lug 2, the union cover body 1 and the annular cava 4 are flush, a closer contact can be formed between them, which helps to improve the sealing performance. In addition, the flush design makes the installation and disassembly process simpler and more convenient; operators can more easily align and fix the various components, which improves work efficiency and effectively enhances the structural strength.

[0036] In the above embodiment, as the preferred technical solution of the present invention: the lug 2 is in the shape of a rectangular parallelepiped, and the surface of the lug 2 is chamfered. The lug 2 can be quickly formed by milling and takes up less space. In addition, the rectangular lug 2 provides a larger contact area, and the contact with the connecting component is more stable, which helps to reduce looseness and vibration and enhance the stability of the overall structure. Furthermore, because the rectangular shape has a larger contact surface, the lug 2 can distribute the pressure more evenly to the connecting component when bearing a load, reducing the risk of stress concentration and local overload. As for the chamfered surface of the lug 2, it helps to reduce friction with the connecting component, reduces the wear rate, and extends the service life of the lug 2 and the connecting component. The chamfered design makes the edge of the lug 2 smoother, reduces possible sharp edges or protrusions, reduces the risk of operator injury, and improves work safety. In addition, the lug 2 with a rectangular shape and chamfered design has a neat and smooth appearance, which improves the overall aesthetics of the product.

[0037] From the above description, it can be seen that the present invention not only ensures the strength of the union, increases the pitch, and increases the thread contact surface; the double-threaded connection can quickly ensure buckle-type docking, reduce the number of connection turns, quickly tighten the threads, and save thread engagement time, thereby improving efficiency. Furthermore, the double-thread ACME thread is an optimization of the overall internal thread of the union. When the seal needs to be replaced and the threaded connection is disassembled, the large pitch design reduces the time required to tighten and loosen the threads by half for the same threaded connection length. Furthermore, the double-thread thread allows operators to quickly align and engage the threads. The optimized double-start high-pitch thread also ensures that the equipment assembly and disassembly process can be reduced by half within the same working time and space, not only improving efficiency but also saving manpower and material resources.

[0038] In summary, the utility model has the advantages of simple structure, safety and reliability, time saving, convenience in use, greater labor saving, higher humanization and better versatility.

[0039] Each embodiment in this specification is described in a related manner. The same or similar parts between the embodiments can be referred to each other. Each embodiment focuses on the differences from other embodiments.

[0040] The above description is only a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications and equivalent replacements made within the spirit and principles of the present invention are included in the scope of protection of the present invention.

Claims

1. A union cover for wellhead equipment, comprising a union cover body (1) and a lug (2); characterized in that: The connecting thread of the union cover body (1) is a double-thread thread (5), and the double-thread thread (5) is a 2ACME double-thread thread.

2. The union cover for wellhead equipment according to claim 1, characterized in that: An annular groove (3) is provided in the middle of the inner side of the union cover body (1).

3. The union cover for wellhead equipment according to claim 1, characterized in that: An annular slip (4) is arranged inside the upper end of the union cover body (1).

4. The union cover for wellhead equipment according to claim 3, characterized in that: The annular slip (4) and the union cover body (1) are an integrated structure.

5. The union cover for wellhead equipment according to claim 3 or 4, characterized in that: The inner diameter of the annular slip (4) is smaller than the inner diameter of the union cover body (1).

6. The union cover for wellhead equipment according to claim 1, characterized in that: The lugs (2) are distributed in a ring array along the outer side of the upper end of the union cover body (1); and hanging holes (201) are provided in the lugs (2).

7. The union cover for wellhead equipment according to claim 1 or 6, characterized in that: The lug (2) is integrally formed with the union cover body (1).

8. The union cover for wellhead equipment according to claim 1 or 6, characterized in that: There are four lugs (2), and the four lugs (2) are symmetrically distributed.

9. The union cover for wellhead equipment according to claim 1 or 6, characterized in that: The upper surface of the lug (2), the upper surface of the union cover body (1) and the upper surface of the annular slip (4) are flush.

10. The union cover for wellhead equipment according to claim 1 or 6, characterized in that: The lug (2) is in the shape of a rectangular parallelepiped, and the surface of the lug (2) is chamfered.

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