Double-acting valve

Abstract

The utility model discloses a double-acting valve, and relates to the technical field of oil field injection and production equipment. The double-acting valve comprises an upper connector, a pressing cap assembly, a steel ball, a ball seat, a piston rod, a release pin, a reverse pressure-bearing valve, a lower connector and a sealing assembly. The upper connector is connected with the pressing cap assembly, the steel ball is arranged in the pressing cap assembly, the ball seat is arranged below the steel ball, a through hole for the piston rod to penetrate through is formed in the middle of the ball seat, one end of the piston rod is connected with the pressing cap assembly, and the other end of the piston rod extends downwards and is connected with the reverse pressure-bearing valve in a matched mode. The lower connector is used for limiting the position of the reverse pressure-bearing valve and connected with the ball seat, and the sealing assembly is arranged at the matched position of all connecting parts. The double-acting valve provided by the utility model is used for realizing a blowout prevention function when a pipe column descends into a well and a pressure bearing function when the pipe column is set, so that the safety and the efficiency of the operation of the pipe column of a water injection well are improved.

Description

Technical Field

[0001] This utility model relates to the field of oilfield injection and production equipment technology, and in particular to a dual-acting valve. Background Technology

[0002] In oilfield development, tubing operations for water injection wells are a crucial task. In high-pressure water injection well tubing installation, challenges arise regarding tubing setting pressure and preventing high-pressure fluid from gushing out of the wellhead during tubing running. Traditional well-washing valves primarily function as well-washing valves, but they are significantly inadequate in reverse pressure resistance. During tubing running, high-pressure fluid from the casing may gushing out of the wellhead through the tubing, posing a safety hazard and hindering successful tubing run. Furthermore, traditional well-washing valves cannot effectively switch functions to meet the pressure requirements during tubing setting, resulting in complex and inefficient operations. While some improved devices have emerged, these often have complex structures and poorly coordinated components, leading to low reliability, susceptibility to failure, and high installation and maintenance costs. Summary of the Invention

[0003] The purpose of this invention is to provide a dual-acting valve for achieving both blowout prevention during tubing string installation and pressure bearing during setting, thereby improving the safety and efficiency of water injection well tubing string operations.

[0004] To achieve the above objectives, this utility model provides the following technical solution: a double-acting valve, comprising an upper connector, a pressure cap assembly, a steel ball, a ball seat, a piston rod, a release pin, a reverse pressure valve, a lower connector, and a sealing assembly; the upper connector is connected to the pressure cap assembly, the steel ball is disposed within the pressure cap assembly, the ball seat is disposed below the steel ball, the ball seat has a through hole in the middle for the piston rod to pass through, one end of the piston rod is connected to the pressure cap assembly, and the other end extends downward and is connected to the reverse pressure valve, the release pin is disposed between the reverse pressure valve and the ball seat to limit the position of the reverse pressure valve, the lower connector is connected to the ball seat, and the sealing assembly is disposed at the mating points of the connecting components.

[0005] Optionally, the upper connector is connected to the pressure cap assembly via a threaded structure, and the sealing component is provided on the threaded structure.

[0006] Optionally, a reduced-diameter step is provided above the ball seat, and the reverse pressure valve is located below the reduced-diameter step. The reduced-diameter step is used to limit the upward movement of the reverse pressure valve.

[0007] Optionally, the piston rod passes through the through hole of the ball seat and extends below the ball seat, with the lower end of the piston rod connected to the reverse pressure valve to support the steel ball so that it cannot sit directly on the ball seat.

[0008] Optionally, the release pin is disposed between the outer peripheral wall of the reverse pressure valve and the inner peripheral wall of the ball seat. When the reverse pressure valve is subjected to a downward force that reaches a predetermined value, the release pin is sheared off.

[0009] Optionally, the sealing assembly includes an O-ring, which is disposed at the connection between the upper connector and the pressure cap assembly, the connection between the ball seat and the lower connector, and the mating point between the piston rod and the through hole of the ball seat.

[0010] Optionally, the pressure cap assembly includes a pressure cap body and a limiting structure disposed within the pressure cap body. The limiting structure is used to limit the steel ball so that the steel ball is kept in a predetermined position within the pressure cap body.

[0011] Optionally, both the upper connector and the lower connector are key components with predetermined threaded structures at both ends, and the upper end of the upper connector and the lower end of the lower connector are used to connect to an external tubing column.

[0012] Compared with the prior art, the double-acting valve provided by this utility model, after replacing the original well-washing valve and installed in the tubing string, allows the high-pressure liquid inside the casing to act on the reverse pressure-bearing valve. Because the reverse pressure-bearing valve is limited by the reduced-diameter step and the piston rod supports the steel ball, liquid cannot enter the tubing, effectively preventing the high-pressure liquid inside the well from spraying out of the wellhead through the tubing, ensuring the safety of the tubing string running operation; after the tubing string is in place, when the pressure inside the tubing is higher than the casing pressure by a certain value, the release pin shears off, the reverse pressure-bearing valve falls, and the steel ball sits on the ball seat and begins to bear pressure. At this time, the double-acting valve transforms into an ordinary well-washing valve. It can continue to pressurize and set the packer, and can meet the normal well washing requirements during backwashing. The steel ball bears pressure during water injection to ensure water injection operation. Through the design of the release pin, when the pressure inside the tubing and the pressure in the casing reach the predetermined pressure difference, the release pin shears off, realizing the automatic conversion from blowout preventer state to pressurized well washing state without complicated operation, thus improving operation efficiency. The water injection frequency during tubing string running is specified for pressurized wells and non-pressurized wells respectively, which can prevent the tubing string from being damaged by negative pressure, thus reducing equipment damage and operation interruption caused by negative pressure problems. Attached Figure Description

[0013] Figure 1 A schematic diagram of the structure of a double-acting valve provided in an embodiment of this utility model.

[0014] Reference numerals: 100-Double-acting valve; 1-Upper connector; 2-Pressure cap assembly; 3-Steel ball; 4-Ball seat; 5-Piston rod; 6-Release pin; 7-Reverse pressure valve; 8-Lower connector; 9-Sealing ring. Detailed Implementation

[0015] To make the technical problems, technical solutions, and beneficial effects of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the present utility model.

[0016] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as being "connected to" another component, it can be directly connected to or indirectly connected to that other component.

[0017] 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 indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified. "Several" means one or more, unless otherwise explicitly specified.

[0018] In the description of this utility model, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They 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. Therefore, they should not be construed as limitations on this utility model.

[0019] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication 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.

[0020] Please see Figure 1The double-acting valve 100 provided in this embodiment includes an upper connector 1, a pressure cap assembly 2, a steel ball 3, a ball seat 4, a piston rod 5, a release pin 6, a reverse pressure valve 7, a lower connector 8, and a sealing assembly. The upper connector 1 and the pressure cap assembly 2 are connected by a threaded structure, which facilitates installation and disassembly. A sealing assembly is provided on the threaded structure to ensure the sealing of the connection and prevent liquid leakage. The steel ball 3 is provided inside the pressure cap assembly 2, and the ball seat 4 is provided below the steel ball 3. The ball seat 4 has a through hole in the middle for the piston rod 5 to pass through. One end of the piston rod 5 is connected to the pressure cap assembly 2, and the other end extends downward and is connected to the reverse pressure valve 7. The release pin 6 is provided between the reverse pressure valve 7 and the ball seat 4 to limit the position of the reverse pressure valve 7. The lower connector 8 is connected to the ball seat 4, and the sealing assembly is provided at the mating points of each connecting component.

[0021] In this application, the upper connector 1 and the pressure cap assembly 2 are connected by a threaded structure, and a sealing component is provided on the threaded structure.

[0022] In one embodiment provided in this application, a reduced-diameter step is provided above the ball seat 4, and the reverse pressure valve 7 is disposed below the reduced-diameter step. The reduced-diameter step is used to limit the upward movement of the reverse pressure valve 7, thereby determining the position range of the reverse pressure valve 7 during normal operation.

[0023] In this application, the piston rod 5 passes through the through hole of the ball seat 4 and extends to the bottom of the ball seat 4. The lower end of the piston rod 5 is connected to the reverse pressure valve 7 to support the steel ball 3 so that it cannot sit directly on the ball seat 4. This structural design makes the steel ball 3 supported by the piston rod 5 in the initial state, with a certain gap between it and the ball seat 4, which facilitates the flow of liquid.

[0024] In one embodiment provided in this application, the release pin 6 is disposed between the outer peripheral wall of the reverse pressure valve 7 and the inner peripheral wall of the ball seat 4. When the reverse pressure valve 7 is subjected to a downward force that reaches a predetermined value, the release pin 6 is sheared, thereby enabling the reverse pressure valve 7 to move downward.

[0025] In this application, the sealing assembly includes an O-ring 9, which is disposed at the connection between the upper connector 1 and the pressure cap assembly 2, the connection between the ball seat 4 and the lower connector 8, and the mating point between the piston rod 5 and the through hole of the ball seat 4, so as to ensure the sealing performance of the entire double-acting valve 100, prevent high-pressure liquid leakage, and ensure its normal operation.

[0026] In one embodiment provided in this application, the pressure cap assembly 2 includes a pressure cap body and a limiting structure disposed within the pressure cap body. The limiting structure is used to limit the steel ball 3, so that the steel ball 3 maintains a predetermined position within the pressure cap body, ensuring that the steel ball 3 can accurately cooperate with the ball seat 4 during operation.

[0027] In this application, the upper connector 1 and the lower connector 8 are both key components with predetermined threaded structures at both ends. The upper end of the upper connector 1 and the lower end of the lower connector 8 are used to connect with the external tubing.

[0028] In practice: During the running-in operation of the tubing string in a high-pressure water injection well, the assembled double-acting valve 100 is installed into the tubing string to replace the original well-washing valve. At this time, the double-acting valve 100 is in its initial working state, the reverse pressure valve 7 is pushed to the upper limit by the reduced-diameter step, and the piston rod 5 supports the steel ball 3, maintaining a certain gap between the steel ball 3 and the ball seat 4, so that the steel ball 3 cannot sit directly on the ball seat 4.

[0029] When the tubing string is lowered into the well, high-pressure fluid is present in the casing. This high-pressure fluid acts on the reverse pressure valve 7. Because the reverse pressure valve 7 is limited and cannot move upward, and the steel ball 3 is supported by the piston rod 5, the passage inside the tubing is blocked. Therefore, the high-pressure fluid in the casing cannot enter the tubing, effectively preventing the high-pressure fluid in the well from being ejected from the wellhead through the tubing, thus achieving the blowout prevention function during the tubing string lowering process.

[0030] In pressurized operations, to prevent excessive negative pressure on the tubing string from damaging the packer or causing tubing deformation, a water priming operation is required every 30-50 tubing sections. For non-pressurized wells, after water return from the casing, water priming is also performed every 30-50 tubing sections. If water return is detected during drilling, it indicates a leak in the tubing string. In this case, tubing should be stopped immediately, the string retrieved, the cause of the leak investigated, and the problem rectified before resuming operations.

[0031] Once the tubing string is lowered to the designed position, a setting operation is required. First, the casing is opened to release pressure, reducing the pressure inside the casing. Then, high-pressure fluid is pumped into the tubing. As the pressure inside the tubing gradually increases, a pressure differential is created between the tubing pressure and the casing pressure.

[0032] When the pressure inside the tubing exceeds the casing pressure by a predetermined value, the downward force acting on the reverse pressure valve 7 increases. This force exceeds the shear strength of the release pin 6, causing the release pin 6 to shear off. At this point, the reverse pressure valve 7 loses the limiting function of the release pin 6 and falls downward into the tailpipe under the action of liquid pressure.

[0033] As the reverse pressure valve 7 moves downward, the supporting effect of the piston rod 5 on the steel ball 3 also changes. The steel ball 3 is no longer supported by the piston rod 5, but sits on the ball seat 4 under its own weight and liquid pressure, thus beginning to bear the pressure. At this time, the double-acting valve 100 changes from the blowout preventer state to the ordinary well-washing valve state.

[0034] High-pressure liquid continues to be pumped into the tubing. Since the steel ball 3 is already seated on the ball seat 4, it can withstand the pressure inside the tubing. This pressure can be transmitted to the packer, thereby achieving the setting of the packer.

[0035] During backwashing operations, the double-acting valve 100 is used as a standard backwashing valve to meet the normal backwashing procedure. The backwashing fluid enters from the casing, passes through the channels of the double-acting valve 100, and enters the tubing to clean the tubing string and formation inside the well.

[0036] During water injection, steel ball 3 sits on ball seat 4, bearing the pressure inside the oil pipe, ensuring that the water injection pressure can be stably transmitted to the formation and realizing normal water injection function.

[0037] As can be seen from the structure and specific implementation process of the double-acting valve 100 described above, after replacing the original well-washing valve and installing it in the tubing string, the high-pressure fluid in the casing acts on the reverse pressure valve 7. Because the reverse pressure valve 7 is limited by the reduced-diameter step and the piston rod 5 supports the steel ball 3, fluid does not enter the tubing, effectively preventing the high-pressure fluid in the well from spraying out of the wellhead through the tubing, ensuring the safety of the tubing string running operation; after the tubing string is in place, when the pressure in the tubing is higher than the casing pressure by a certain value, the release pin 6 shears off, the reverse pressure valve 7 falls, and the steel ball 3 sits on the ball seat 4 and begins to bear pressure. At this time, the double-acting valve 100 transforms into The standard well-washing valve can continue to pressurize and set the packer, and can meet the normal well-washing requirements during backwashing. During water injection, the steel ball 3 bears pressure to ensure water injection operation. Through the design of the release pin 6, when the pressure inside the tubing and the casing pressure reach the predetermined pressure difference, the release pin 6 shears off, realizing the automatic conversion from blowout preventer state to pressurized well-washing state without complicated operation, thus improving operation efficiency. The water injection frequency during tubing string running is specified for both pressurized and non-pressurized wells, which can prevent the tubing string from being damaged by negative pressure, thus reducing equipment damage and operation interruption caused by negative pressure problems.

[0038] In the description of the above embodiments, specific features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments or examples.

[0039] The above description is merely a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this utility model should be included within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the protection scope of the claims.

Claims

1. A double-acting valve, characterized in that, The device includes an upper connector, a pressure cap assembly, a steel ball, a ball seat, a piston rod, a release pin, a reverse pressure valve, a lower connector, and a sealing assembly. The upper connector is connected to the pressure cap assembly. The steel ball is disposed inside the pressure cap assembly. The ball seat is disposed below the steel ball. The ball seat has a through hole in the middle for the piston rod to pass through. One end of the piston rod is connected to the pressure cap assembly, and the other end extends downward and is connected to the reverse pressure valve. The release pin is disposed between the reverse pressure valve and the ball seat to limit the position of the reverse pressure valve. The lower connector is connected to the ball seat. The sealing assembly is disposed at the mating points of the various connecting components.

2. The double-acting valve according to claim 1, characterized in that, The upper connector is connected to the pressure cap assembly via a threaded structure, and the sealing component is provided on the threaded structure.

3. The double-acting valve according to claim 1, characterized in that, A reduced-diameter step is provided above the ball seat, and the reverse pressure valve is located below the reduced-diameter step. The reduced-diameter step is used to limit the upward movement of the reverse pressure valve.

4. The double-acting valve according to claim 1, characterized in that, The piston rod passes through the through hole of the ball seat and extends below the ball seat. The lower end of the piston rod is connected to the reverse pressure valve to support the steel ball so that it cannot sit directly on the ball seat.

5. The double-acting valve according to claim 1, characterized in that, The release pin is disposed between the outer peripheral wall of the reverse pressure valve and the inner peripheral wall of the ball seat. When the reverse pressure valve is subjected to a downward force that reaches a predetermined value, the release pin is sheared off.

6. The double-acting valve according to claim 1, characterized in that, The sealing assembly includes an O-ring, which is disposed at the connection between the upper connector and the pressure cap assembly, the connection between the ball seat and the lower connector, and the mating point between the piston rod and the through hole of the ball seat.

7. The double-acting valve according to claim 1, characterized in that, The pressure cap assembly includes a pressure cap body and a limiting structure disposed within the pressure cap body. The limiting structure is used to limit the steel ball so that the steel ball is kept in a predetermined position within the pressure cap body.

8. The double-acting valve according to any one of claims 1-7, characterized in that, Both the upper connector and the lower connector are key components with predetermined threaded structures at both ends. The upper end of the upper connector and the lower end of the lower connector are used to connect to an external tubing column.

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