Hydraulic device for the wellhead of oilfield injection wells

Abstract

The present invention relates to the field of oilfield development, and specifically to a hydraulic device for an oilfield injection wellhead, comprising: an extraction interface, which is connected and communicated with the wellhead device; a fluid pressure actuator, the fluid pressure actuator being a hydraulic cylinder; a discharge port; the fluid pressure actuator is connected to the extraction interface and the discharge port respectively through pipelines; and a fluid control component is included in the pipelines. The fluid control component includes an extraction valve between the extraction interface and the fluid pressure actuator, and a discharge valve between the fluid pressure actuator and the discharge port; alternatively, the fluid control component includes a three-way valve, and its three ends are respectively connected to the extraction interface, the fluid force actuator, and the discharge port through pipelines. The present invention extracts pressure from the wellhead device to drive the fluid pressure actuator, solving the problem that the lifting mechanism of the wellhead operation equipment components has limited power supply by batteries and cannot last long.

Description

Technical Field

[0001] The present invention relates to the field of oilfield development, and specifically to a hydraulic device for the wellhead of an oilfield injection well. Background Art

[0002] The main production facilities in oilfield development and exploitation are oil production wells, gas production wells, and injection wells. These wells include above-ground and underground facilities. The part of the wellhead located above the ground is called the wellhead device, commonly known as the "Christmas tree", which is the interface connecting the ground to the underground. When minor repairs are carried out on the wellhead devices of oil production wells, gas production wells, and injection wells, or when well logging and well testing operations are performed, some operating equipment components need to be lifted and erected. Generally, heavier wellhead operating equipment components need to rely on a lifting mechanism and additional power. For example, the well testing pipe commonly used in the well testing operation of an injection well is about 5 meters long and weighs about 100 kilograms. During the operation, it usually needs to be lifted and lowered multiple times by a lifting mechanism powered by a storage battery. There are also some maintenance tools for wellhead devices that require additional power drive, such as electric or hydraulic power. During the maintenance operation of larger wellhead devices, there are usually dedicated mobile power vehicles to directly provide power; however, during the maintenance of small wellhead devices and well logging and well testing operations, such as when replacing a 250 valve, it is not worth using dedicated power equipment or it is inconvenient to use. Generally, when there is power electricity at the wellhead, the wellhead power electricity is used to drive a hydraulic pump station; however, for the minor maintenance of wellhead devices, using equipment such as a hydraulic pump station is too complex and uneconomical. For injection wells without available wellhead power electricity sources, only electric devices powered by storage batteries can be used. The power supply of the storage battery is very limited and often cannot be used continuously. Moreover, the storage battery often lacks power in winter. Summary of the Invention

[0003] Problems to be Solved by the Invention: The problem that the power supply of the lifting mechanism for lifting wellhead operating equipment components is limited and cannot last during well logging, well testing operations, or minor maintenance of small wellhead devices, and the problem that the drive of maintenance tools for small wellhead devices requires the use of a hydraulic pump station, resulting in complex equipment.

[0004] Summary of the Invention: To solve the above problems, the present invention proposes a hydraulic device for the wellhead of an oilfield injection well, including a wellhead device, and further including:

[0005] An extraction interface, which is connected and communicated with the wellhead device;

[0006] A fluid pressure actuator, and the fluid pressure actuator is a hydraulic cylinder;

[0007] A discharge port;

[0008] The fluid pressure actuator is connected to the extraction interface and the discharge port respectively through pipelines;

[0009] The pipeline includes a fluid control component;

[0010] The fluid control component includes an extraction valve between the extraction interface and the fluid pressure actuator, and a discharge valve between the fluid pressure actuator and the discharge port;

[0011] Alternatively, the fluid control component includes a three-way valve, and its three ends are respectively connected to the extraction interface, the fluid force actuator, and the discharge port through pipelines.

[0012] Preferably, for the wellhead hydraulic device of the oilfield injection well, a throttle valve is provided between the fluid pressure actuator and the three-way valve.

[0013] Preferably, for the wellhead hydraulic device of the oilfield injection well, the fluid control component further includes a safety valve.

[0014] Preferably, for the wellhead hydraulic device of the oilfield injection well, the fluid control component further includes a pressure regulating valve.

[0015] Advantages of the present invention: The technical solution proposed by the present invention extracts the pressure of the injection well itself from the wellhead devices of oil production, gas production, and injection wells, and converts it into mechanical power through a fluid pressure actuator, solving the problems that when maintaining small wellhead devices and conducting well logging and well testing operations, the lifting mechanism of the wellhead operation equipment components has limited power supplied by a battery and cannot last, and the complexity of the equipment caused by the need to use a hydraulic pump station to drive the maintenance tools of small wellhead devices. Description of the Drawings

[0016] Figure 1 is a schematic structural diagram of the first embodiment of the present invention;

[0017] Figure 2 is a schematic structural diagram of the second embodiment of the present invention;

[0018] In the figure, 1, wellhead device; 2, extraction interface; 3, fluid pressure actuator; 4, well testing operation pipe; 501, extraction valve; 502, discharge valve; 503, control valve; 504, three-way valve; 505, safety valve; 506, pressure regulating valve; 6, discharge port; 7, gas-liquid tank. Detailed Embodiments

[0019] The technical solution proposed by the present invention extracts the pressure of the injection well, oil production well, or gas production well itself from the wellhead device 1 of the injection well, oil production well, or gas production well, and converts it into mechanical power through a fluid pressure actuator. The fluid control component of the present invention is located in the pipeline and includes valves and metering and display components for detecting the fluid state and controlling the direction and flow rate of the fluid. The structural principle of the technical solution of the present invention will be described below in two embodiments with reference to the drawings.

[0020] The hydraulic device for the wellhead of an oilfield injection well proposed by the present invention includes:

[0021] An extraction interface 2, which is connected and communicated with the wellhead device 1, extracts the pressure of the injection well, production well or gas production well itself from the wellhead device 1 of the injection well, production well or gas production well. Usually, the existing vent valve, sampling valve or metering valve on the wellhead device 1 can be utilized.

[0022] A fluid pressure actuator 3; the fluid pressure actuator 3 described in the present invention is a hydraulic cylinder, air cylinder or other hydraulic or pneumatic actuator;

[0023] A discharge port 6, which is an essential structure for the operation of the fluid pressure actuator 3; the pressure from the wellhead can only push the air cylinder to move in one direction; when it is necessary to move in the opposite direction, the pressure in the air cylinder needs to be released through the discharge port 6, and under the action of an external force, the air cylinder can return to its initial position;

[0024] The fluid pressure actuator 3 is respectively connected to the extraction interface 2 and the discharge port 6 through pipelines;

[0025] The pipeline described in the present invention is used to connect the extraction interface 2 and the fluid pressure actuator 3, and to connect the fluid pressure actuator 3 and the discharge port 6, so that the pressure from the wellhead acts on the fluid pressure actuator, converting the fluid pressure into mechanical power; the pipeline includes a fluid control component, and the fluid control component is used to achieve at least two functions. One is to control the on-off and flow rate of the fluid between the fluid pressure actuator 3 and the extraction interface 2, so as to control the presence, absence and magnitude of the pressure transmitted from the wellhead device 1 to the fluid pressure actuator 3, and to achieve the control of the output power of the fluid pressure actuator 3; the other is to control the on-off and flow rate of the fluid between the fluid pressure actuator 3 and the discharge port 6, so as to achieve the control of the pressure relief process of the fluid pressure actuator 3, and ultimately achieve the purpose of reverse return control of the fluid pressure actuator 3.

[0026] The structural principle of the first embodiment is as Figure 1As shown in the figure. In the well testing operation of an injection well, the hydraulic device at the wellhead of the oilfield injection well of the present invention is used to lift and lower the well testing operation pipe 4. The well testing operation pipe 4 is about 5 meters long and weighs about 100 kilograms. It is a part of the well testing equipment and usually needs to be lifted and lowered multiple times by a lifting mechanism powered by a storage battery during the operation. Among them, the fluid pressure actuator 3 is a hydraulic cylinder, and the lead-out interface 2 is the vent valve on the wellhead device 1; the fluid control components include a lead-out valve 501 between the lead-out interface 2 and the fluid pressure actuator 3, and a discharge valve 502 between the fluid pressure actuator 3 and the discharge port 6. The lead-out valve 501 is used to control the presence, absence, and magnitude of the pressure transmitted from the wellhead device 1 to the fluid pressure actuator 3, so as to control the output power of the fluid pressure actuator 3; the discharge port 6 controls the pressure relief process of the fluid pressure actuator 3. The vent valve on the wellhead device 1 connected to the lead-out interface 2 can also replace the lead-out valve 501.

[0027] During its working process: First, the pipeline and the hydraulic cylinder are filled with liquid, and all possible accumulated gases are discharged.

[0028] In the lifting stage, when the discharge valve 502 is closed, the lead-out valve 501 is gradually opened, and the pressure in the wellhead device 1 pushes the piston in the hydraulic cylinder to move upward; after the well testing operation pipe 4 is lifted to the wellhead working position, the lead-out valve 501 is closed, and the existing pressure is maintained in the hydraulic cylinder. The well testing operation pipe 4 is stabilized at the operation position, and the well testing operation starts. To ensure that the well testing operation pipe 4 can be reliably, stably, and safely at the operation position, a mechanical locking mechanism is provided on the hydraulic cylinder. When the hydraulic cylinder pushes the well testing operation pipe 4 to the operation position, the mechanical locking mechanism provided on the hydraulic cylinder is locked to ensure that the piston will not fall due to pressure leakage.

[0029] In the falling stage, after the well testing operation is completed, first open the lead-out valve 501 to supplement the pressure drop in the hydraulic cylinder caused by leakage, so that the piston of the hydraulic cylinder bears the weight of the well testing operation pipe 4, and then close the lead-out valve 501 and unlock the mechanical locking mechanism provided on the hydraulic cylinder; then gradually open the discharge valve 502, and the piston of the hydraulic cylinder gradually descends as the hydraulic medium is discharged, and the well testing operation pipe 4 gradually falls back to the initial position. During the process of opening the discharge valve 502 for discharging, the liquid flowing out from the discharge port 6 is collected in a container to prevent environmental pollution. For safety, a safety valve is provided in the pipeline.

[0030] In the above embodiment, the lead-out valve 501 and the discharge valve 502 as the fluid control components can be replaced by a three-way valve 504. Its three ends are respectively connected to the lead-out interface 2, the fluid pressure actuator 3, and the discharge port 6 through pipelines to realize the switching of pressurizing and depressurizing the hydraulic cylinder. To control the action speed of the hydraulic cylinder, a throttle valve is provided between the hydraulic cylinder of the fluid pressure actuator 3 and the three-way valve 504, and the action speed of the hydraulic cylinder can be controlled by adjusting the throttle valve.

[0031] In the second embodiment, during the well testing operation of an oil production well, the hydraulic device at the wellhead of the oilfield water injection well of the present invention is used to lift and lower the well testing operation pipe 4. Its structural principle is as Figure 2 shown. Since the fluid in the wellhead device of an oil production well usually contains both gas and liquid, in this embodiment, a gas-liquid tank 7 and a control valve 503 are added on the basis of the structure of the first embodiment. The gas-liquid tank 7 is a gas-liquid separation tank, which is used to prevent gas from entering the hydraulic cylinder and the pipeline connected to the hydraulic cylinder, affecting the operation of the hydraulic cylinder. During operation, the gas-liquid tank 7 is filled with liquid. The gas-liquid tank 7 is a closed container that can work under the wellhead pressure, and is provided with an inlet, a liquid outlet and a gas outlet; the liquid outlet is arranged at the lower part of the gas-liquid tank 7, and the gas outlet is arranged at the upper part of the gas-liquid tank 7. The inlet is connected to the lead-out interface 2 through the lead-out valve 501, and the lead-out interface 2 in this embodiment is the pressure gauge valve on the wellhead device 1; the fluid pressure actuator 3 in this embodiment is a hydraulic cylinder, and the fluid control component is increased with a control valve 503, and the control valve 503 is located in the pipeline between the liquid outlet and the fluid pressure actuator 3; the gas outlet of the gas-liquid tank 7 is connected to the discharge port 6 through the discharge valve 502; a safety valve is installed on the upper part of the gas-liquid tank 7; a pressure regulating valve 506 is provided between the inlet of the gas-liquid tank 7 and the pressure gauge valve.

[0032] During its working process: First, the pipeline, the gas-liquid tank 7 and the hydraulic cylinder are filled with liquid, and all possible accumulated gas is drained.

[0033] In the lifting stage, when the discharge valve 502 and the control valve 503 are closed, the lead-out valve 501 is gradually opened to pressurize the gas-liquid tank 7 with the pressure in the wellhead device 1; then the control valve 503 is gradually opened, and the pressure in the wellhead device 1 pushes the piston in the hydraulic cylinder to move upward; after the well testing operation pipe 4 is lifted to the wellhead working position, the control valve 503 is closed, and the existing pressure is maintained in the hydraulic cylinder, and the well testing operation pipe 4 is stabilized at the operation position, and the mechanical locking mechanism set on the hydraulic cylinder is locked, and the well testing operation is started.

[0034] In the falling stage, after the well testing operation is completed, first open the control valve 503 to make up for the pressure drop in the hydraulic cylinder caused by leakage, so that the piston of the hydraulic cylinder bears the weight of the well testing operation pipe 4, and then close the lead-out valve 501 and unlock the mechanical locking mechanism set on the hydraulic cylinder; then gradually open the discharge valve 502, and the piston of the hydraulic cylinder gradually descends as the hydraulic medium is discharged, and the well testing operation pipe 4 gradually falls back to the initial position. To maintain a clean environment, a recovery container is arranged under the discharge port 6 to recover the discharged fluid.

[0035] In practical applications, the existing vent valve, sampling valve, metering valve and other valves on the wellhead device 1 can be used as the lead-out interface 2 at the wellhead site. Since the wellhead pressure of most oil wells, gas wells and water injection wells in the oil field is above 1MPa, the power is sufficient to reach the output power of the hydraulic pump station, replacing the hydraulic pump station, and no additional electric energy is required. For water injection well sites without power electricity, it can completely replace the battery-powered electric power device, and the output power is large and will not be exhausted. Therefore, the technical solution of the present invention can be applied to the maintenance, logging and testing of small wellhead devices in water injection wells, oil wells or gas wells, the lifting of wellhead operation equipment components and the driving of small wellhead device maintenance tools.

Claims

1. A hydraulic device for the wellhead of an oilfield injection well, including a wellhead device (1), characterized in that, It further includes: A lead-out interface (2) which is connected and communicated with the wellhead device (1); the lead-out interface (2) is a vent valve on the wellhead device (1) of the injection well, and the pressure of the injection well itself is extracted from the wellhead device (1) of the injection well; A fluid pressure actuator (3), and the fluid pressure actuator is a hydraulic cylinder; a mechanical locking mechanism is arranged on the hydraulic cylinder, and when the mechanical locking mechanism is locked, it ensures that the piston will not fall due to pressure leakage; A discharge port (6); The fluid pressure actuator (3) is respectively connected to the lead-out interface (2) and the discharge port (6) through pipelines; The pipeline includes a fluid control component; The fluid control component includes a lead-out valve (501) between the lead-out interface (2) and the fluid pressure actuator (3), and a discharge valve (502) between the fluid pressure actuator (3) and the discharge port (6); Alternatively, the fluid control component includes a three-way valve (504), and its three ends are respectively connected to the lead-out interface (2), the fluid pressure actuator (3), and the discharge port (6) through pipelines.

2. The hydraulic device for the wellhead of an oilfield water injection well according to claim 1, characterized in that, A throttle valve is provided between the fluid pressure actuator (3) and the three-way valve (504).

3. The hydraulic device for the wellhead of an oilfield injection well according to claim 1, wherein, The fluid control component further includes a safety valve (505).

4. The hydraulic device for the wellhead of an oilfield injection well according to claim 2, characterized in that, The fluid control component further includes a safety valve (505).

5. The hydraulic device for the wellhead of an oilfield injection well according to any one of claims 1, 2, 3, and 4, wherein The fluid control component further includes a pressure regulating valve (506).

6. The hydraulic device for the wellhead of an oilfield injection well according to claim 5, characterized in that, It further includes a gas-liquid tank (7) and a control valve (503); the gas-liquid tank (7) is provided with an inlet, a liquid outlet, and a gas outlet; the inlet is connected to the lead-out interface (2) through the lead-out valve (501), the liquid outlet is connected to the fluid pressure actuator (3) through the control valve (503); the gas outlet is connected to the discharge port (6) through the discharge valve (502).

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