Self-locking sealing valve for producing well casing

Abstract

The utility model relates to the technical field of wellhead pollution prevention, in particular to a self-locking sealing valve for a producing well casing. The self-locking sealing valve comprises a steel ring of a hollow cylindrical structure, a check ring is arranged at one end of the steel ring, a barrel is arranged on the outer side of the steel ring in a sleeving mode, a check valve mechanism composed of a baffle, a hinge and a reset spring is integrated on the inner wall of the barrel, and a check block for limiting the baffle is arranged. During working, the pressure difference generated by crude oil leakage pushes the baffle to rotate around the hinge, and the baffle is in sealing fit with the steel ring check ring, so that a leakage channel is blocked; when the pressure is balanced, the reset spring pulls the baffle to reset and open, and the stop block limits the maximum opening and closing angle so as to guarantee smooth well washing, testing and other operations. According to the device, through the sleeving structure of the barrel and the steel ring, a special anti-theft tool is omitted, a differential pressure driving sealing and spring reset mechanism is utilized, the integrated function of anti-theft sealing, automatic reset and tool-free maintenance is achieved, the leakage problem caused by oil stealing is solved, the equipment maintenance complexity is reduced, and the safety and convenience of oil extraction operation are guaranteed.

Description

Technical Field

[0001] This utility model relates to the field of wellhead pollution prevention technology, and in particular to a self-locking sealing valve for oil well casing. Background Technology

[0002] In the oil and gas development sector, the theft of crude oil from production wells has always been a significant challenge affecting the safety and economic benefits of oilfields. Oil thieves often target wells with dynamic fluid levels near the wellhead, connecting pipelines at the casing valves and then using downhole pressure to allow crude oil to leak out, thus stealing oil. This behavior not only severely impacts normal well production but also causes huge economic losses to oilfield companies. Furthermore, crude oil leaks can lead to environmental pollution and other safety and environmental problems.

[0003] Current anti-theft technologies for oil well casing valves typically involve altering the valve structure, such as designing special interfaces or operating mechanisms that require specialized tools like anti-theft wrenches of matching size and shape to open. However, this type of technology has significant drawbacks: firstly, the use of specialized tools increases the burden of carrying tools during daily operations and production maintenance for oilfield workers, significantly increasing their workload; secondly, this technology only prevents theft through mechanical locking, and is still difficult to effectively prevent crude oil theft when oil thieves use destructive methods, and it cannot solve the environmental pollution problems caused by crude oil leaks.

[0004] Existing technologies do not fully consider the convenience and safety of on-site operations at oil wells during their design. For example, when routine operations such as testing and well washing are required, the frequent use of specialized tools will reduce operational efficiency. On the other hand, simplifying the anti-theft structure for ease of operation may weaken the anti-theft effect. Summary of the Invention

[0005] (a) Technical problems to be solved

[0006] This utility model provides a self-locking sealing valve for oil well casing to overcome the problems of complex anti-theft operation and inability to automatically seal and prevent leakage in existing casing valves.

[0007] (II) Technical Solution

[0008] To achieve the above objectives, this utility model provides a self-locking sealing valve for oil well casing, comprising: a steel ring;

[0009] The steel ring has a hollow cylindrical structure, and a retaining ring is provided at one end of the steel ring;

[0010] A cylindrical body is provided on the right side of the steel ring, and the cylindrical body is fitted onto the outer wall of the steel ring;

[0011] The cylinder is equipped with a check valve mechanism, which is connected to the inner wall of the cylinder.

[0012] The check valve mechanism includes: a baffle, a hinge, and a return spring. The hinge is located on the inner wall of the cylinder. The baffle is rotatably connected to the hinge. One end of the return spring is connected to the baffle and the other end is connected to the inner wall of the cylinder.

[0013] The inner wall of the cylinder is provided with a stop block, which is located at the right end of the hinge and limits the position of the baffle.

[0014] Preferably, the retaining ring is an annular structure and is embedded in the right end face of the steel ring.

[0015] Preferably, the baffle includes a base and a sealing body. The base is the lower end of the baffle and has a cylindrical structure. The upper end of the base is provided with a sealing body. The outer diameter of the lower end of the sealing body matches the inner diameter of the cylinder. The baffle can completely seal the cylinder.

[0016] Preferably, the sealing body has a frustum structure and the cone angle of the sealing body is 15°-30°.

[0017] Preferably, the inner wall of the cylinder and the back of the baffle are respectively provided with spring retaining rings, and the two ends of the reset spring are respectively hooked on the two spring retaining rings.

[0018] Preferably, the outer wall of the right end of the steel ring is threaded, the inner wall of the left end of the cylinder is threaded, and the steel ring is threadedly connected to the cylinder.

[0019] Preferably, the left end of the steel ring is provided with a flange connection part, and the flange connection part is provided with a clamp groove.

[0020] (III) Beneficial Effects

[0021] This utility model provides a self-locking sealing valve for oil well casing, which can realize the function of sleeved on the outer wall of steel ring, with internal integrated check valve mechanism and limit block, eliminating the need for special anti-theft tools and reducing maintenance complexity.

[0022] Under the action of pressure difference, the baffle rotates and closes around the hinge, forming a sealing fit with the retaining ring of the steel ring to block the crude oil leakage channel and solve the leakage problem caused by oil theft. When the pressure is balanced, the return spring pulls the baffle to open, and at the same time the stop block limits its maximum opening and closing angle to ensure that the valve is normally unobstructed and reset reliably, maintaining normal well washing and testing operations, thereby achieving the purpose of simultaneously realizing anti-theft sealing, automatic reset and tool-free maintenance. Attached Figure Description

[0023] Figure 1 This diagram illustrates the structure of a self-locking sealing valve for oil well casing according to the present invention.

[0024] Wherein: 1: steel ring; 2: cylinder; 3: baffle; 4: hinge; 5: return spring; 6: retaining ring. Detailed Implementation

[0025] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0026] In the description of this utility model, it is necessary to understand that the orientation or positional relationship indicated by terms such as "upper", "lower", "left", "right", "inner", "outer", "top", and "bottom" are all based on the orientation or positional relationship shown in the accompanying drawings. The purpose is only to facilitate the description of this utility model and simplify the description, and is not intended to indicate or imply that the indicated component must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of this utility model.

[0027] like Figure 1 As shown, the present invention provides a self-locking sealing valve for oil well casing, comprising: a steel ring 1;

[0028] The steel ring 1 is a hollow cylindrical structure with a through-type fluid channel inside. The left end of the steel ring 1 is provided with a flange connection part, and the flange connection part is provided with a clamp groove. The clamp groove is used to axially lock the connection with the oil well casing four-way through the clamp. The right end of the steel ring 1 is provided with a retaining ring 6. The retaining ring 6 is an annular structure. The retaining ring 6 is embedded in the right end face of the steel ring 1 to form a sealing boss that protrudes from the end face.

[0029] The steel ring 1 has a cylinder 2 on its right side. The inner diameter of the cylinder 2 is larger than the outer diameter of the steel ring 1. The cylinder 2 is fitted onto the outer wall of the steel ring 1. The outer wall of the right end of the steel ring 1 is threaded, and the inner wall of the left end of the cylinder 2 is threaded. The steel ring 1 and the cylinder 2 are threaded together, so that the check valve mechanism in the cylinder 2 can be detachably encapsulated, which is convenient for maintenance and replacement.

[0030] The cylinder 2 is equipped with a check valve mechanism, which is connected to the inner wall of the cylinder 2. The check valve mechanism includes a baffle 3, a hinge 4, and a return spring 5. The hinge 4 is located on the inner wall of the cylinder 2, and the baffle 3 and the hinge 4 are rotatably connected.

[0031] The baffle 3 includes a base and a sealing body. The base is the lower end of the baffle 3 and is a cylindrical structure that serves as a load-bearing support. A rotating shaft is provided on one side of the cylindrical structure. The sealing body is a frustum structure with a cone angle of 15°-30°. The outer diameter of the lower end of the sealing body matches the inner diameter of the cylinder 2 to achieve zero-gap closure. The baffle 3 can completely seal the cylinder 2. When the baffle 3 is closed, the cone surface of the sealing body can form a full circumferential surface contact seal with the retaining ring 6 of the steel ring 1.

[0032] The hinge 4 is welded to the cylinder 2, and the rotating shaft of the baffle 3 is embedded in the hinge 4 so that the baffle 3 and the hinge 4 are rotatably connected.

[0033] The inner wall of the cylinder 2 and the back of the baffle 3 are respectively provided with spring retaining rings. The two ends of the return spring 5 are respectively hooked and fixed in the two spring retaining rings. The return spring 5 is used to pull the baffle 3 to open when the pressure is balanced.

[0034] The inner wall of the cylinder 2 is provided with a stop block, which is located at the right end of the hinge 4. The stop block is used to limit the maximum opening angle of the baffle 3 and prevent the baffle 3 from hitting the cylinder wall.

[0035] The following is a detailed description of the actual working scenario of a self-locking sealing valve for oil well casing.

[0036] When the vent valve of the oil well casing is closed: the internal and external pressures of the cylinder 2 are balanced, the return spring 5 is in a naturally stretched state, the baffle 3 is opened to the mechanical limit position of the stop block, the fluid passage is unobstructed, and well washing, testing and other operations can be carried out normally.

[0037] When oil thieves open the casing vent valve in an attempt to steal oil: the casing annular pressure rises sharply and a pressure differential is generated. The high-pressure fluid pushes the back of the baffle 3, and the baffle 3 rotates counterclockwise around the hinge 4. The frustum sealing body of the baffle 3 fits tightly with the retaining ring 6 of the steel ring 1. The two form a full circumferential metal hard seal, which completely blocks the crude oil leakage channel. Thus, the oil theft fails and there is no crude oil spray leakage that pollutes the environment.

[0038] When oil theft stops or normal operation is required: close the casing vent valve → the annular pressure and the external pressure of the valve are restored to balance, the return spring 5 releases the stored elastic potential energy, the return spring 5 contracts and pulls the back of the baffle 3 to rotate clockwise around the hinge 4, when the baffle opens to the set angle it is blocked by the block on the inner wall of the cylinder 2, the baffle is stably suspended and the fluid channel is restored to unobstructed flow, the well washing fluid flows freely, and the testing instrument can also pass through without obstruction.

[0039] It is understood that the above-mentioned embodiments mentioned in this utility model can be combined with each other to form combined embodiments without violating the principle and logic. Due to space limitations, this utility model will not elaborate further.

[0040] Those skilled in the art will understand that, in the above-described method of the specific implementation, the order in which each step is written does not imply a strict execution order and does not constitute any limitation on the implementation process. The specific execution order of each step should be determined by its function and possible internal logic.

[0041] The present invention provides a self-locking sealing valve for oil well casing by fitting the cylinder 2 onto the outer wall of the steel ring 1, and integrating a check valve mechanism and a limit block inside, eliminating the need for special anti-theft tools and reducing maintenance complexity.

[0042] Under the action of pressure difference, the baffle 3 rotates and closes around the hinge 4, forming a sealing fit with the retaining ring 6 of the steel ring 1, blocking the crude oil leakage channel and solving the leakage problem caused by oil theft. When the pressure is balanced, the return spring 5 pulls the baffle 3 to open, and at the same time the stop block limits its maximum opening and closing angle, ensuring that the valve is normally unobstructed and reset reliably, maintaining normal well washing and testing operations, thereby achieving the purpose of simultaneously realizing anti-theft sealing, automatic reset and tool-free maintenance.

[0043] The various embodiments of the present invention have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical applications, or technical improvements to the embodiments in the market, or to enable others skilled in the art to understand the embodiments disclosed herein.

Claims

1. A self-locking sealing valve for oil well casing, characterized in that, include: Steel ring (1); The steel ring (1) is a hollow cylindrical structure, and a retaining ring (6) is provided at one end of the steel ring (1). A cylindrical body (2) is provided on the right side of the steel ring (1), and the cylindrical body (2) is fitted onto the outer wall of the steel ring (1); The cylinder (2) is provided with a check valve mechanism, which is connected to the inner wall of the cylinder (2); The check valve mechanism includes: a baffle (3), a hinge (4) and a return spring (5). The hinge (4) is located on the inner wall of the cylinder (2). The baffle (3) is rotatably connected to the hinge (4). One end of the return spring (5) is connected to the baffle (3) and the other end is connected to the inner wall of the cylinder (2). The inner wall of the cylinder (2) is provided with a stop block, which is located at the right end of the hinge (4) and limits the position of the baffle (3).

2. The self-locking sealing valve for oil well casing according to claim 1, characterized in that, The retaining ring (6) is a ring structure and is embedded in the right end face of the steel ring (1).

3. The self-locking sealing valve for oil well casing according to claim 1, characterized in that, The baffle (3) includes a base and a sealing body. The base is the lower end of the baffle (3) and is a cylindrical structure. The upper end of the base is provided with a sealing body. The outer diameter of the lower end of the sealing body matches the inner diameter of the cylinder (2). The baffle (3) can completely seal the cylinder (2).

4. The self-locking sealing valve for oil well casing according to claim 3, characterized in that, The sealing body has a frustum structure, and the cone angle of the sealing body is 15°-30°.

5. The self-locking sealing valve for oil well casing according to claim 1, characterized in that, The inner wall of the cylinder (2) and the back of the baffle (3) are respectively provided with spring fixing rings, and the two ends of the reset spring (5) are respectively hooked on the two spring fixing rings.

6. The self-locking sealing valve for oil well casing according to claim 1, characterized in that, The steel ring (1) has a thread on the outer wall of the right end, and the cylinder (2) has a thread on the inner wall of the left end. The steel ring (1) and the cylinder (2) are threaded together.

7. The self-locking sealing valve for oil well casing according to claim 1, characterized in that, The steel ring (1) has a flange connection at its left end, and the flange connection has a clamp groove.

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