An adjustable downhole choke

Abstract

The application relates to a downhole adjustable throttling device, which comprises a connector, a flow regulating mechanism and a downhole setting mechanism connected to the upper and lower ends of the connector respectively, the downhole setting mechanism is used for setting the downhole adjustable throttling device in a downhole oil pipe, and the assembly of the connector and the downhole setting mechanism has a gas flow channel for gas passing through, the inlet of the gas flow channel is located on the downhole setting mechanism, and the outlet is located on the connector, the flow regulating mechanism comprises a shell connected to the connector, the inner cavity of the shell is communicated with the outlet of the gas flow channel, the shell is provided with a gas outlet hole for communicating the inner cavity of the shell with the inner cavity of the oil pipe, the gas path between the outlet of the gas flow channel and the gas outlet hole is a gas outlet channel, and the flow regulating mechanism further comprises a valve plug used for regulating the flow capacity of the gas outlet channel; the scheme can reduce the probability of damage of the downhole adjustable throttling device caused by gas flow impact.

Description

Technical Field

[0001] This invention relates to an adjustable downhole throttling device. Background Technology

[0002] In order to control the gas volume during the production process, an adjustable throttling device is installed in the gas pipeline of the gas well to throttle the gas flow. As the pressure and temperature of natural gas decrease after throttling, water in natural gas will form dense, snow-white crystalline hydrates with molecules such as methane and ethane. This can easily cause blockage of the gas nozzle of the adjustable throttling device and affect the normal production of the gas field.

[0003] To address this issue, a downhole adjustable throttling device is typically installed at an appropriate location within the tubing. This utilizes geothermal heat to heat the throttled gas, preventing hydrate formation. For example, Chinese invention patent CN106996280A, published on August 1, 2017, discloses a pre-set adjustable throttling device. Its structure consists of an adjustment device and a dynamic control device. The dynamic control device receives commands from a ground-based computer to control a motor rotation. The motor's forward and reverse motion is converted into the reciprocating linear motion of the throttling nozzle valve stem, allowing for real-time bidirectional reversible adjustment of the orifice diameter between the valve seat and the valve stem cone, thereby regulating the gas production. Specifically, gas enters the lower housing cavity after being throttled by the regulating valve from the bottom filter. It then flows through the outer annular space of the valve stem, past the slip seat and the central tube, before entering the tubing from the outlet.

[0004] While this downhole adjustable throttling device achieves downhole throttling and adjustment, it has several problems. Firstly, the increased impact force after gas throttling intensifies the erosion effect on components in the gas flow channel. Secondly, during operation, the gas flows sequentially through the lower housing cavity, then through the annular space outside the valve stem, past the slip seat and central tube, before entering the tubing from the outlet. This results in an excessively long gas flow path, which can easily damage the components it passes through, leading to frequent malfunctions. Thirdly, because the valve stem and seat have a conical contact, even slight movements of the valve stem during adjustment cause significant changes in the flow area of ​​the annular channel between them, resulting in relatively low adjustment accuracy. Summary of the Invention

[0005] The purpose of this invention is to provide a downhole adjustable throttling device to solve the technical problem in the prior art where the working components of the downhole adjustable throttling device are easily damaged by the throttled gas, leading to easy failure of the downhole adjustable throttling device.

[0006] To achieve the above objectives, the technical solution of the downhole adjustable throttling device provided by the present invention is as follows:

[0007] A downhole adjustable throttling device includes an adapter and a flow regulating mechanism and a downhole setting mechanism respectively connected to the upper and lower ends of the adapter. The downhole setting mechanism is used to set the downhole adjustable throttling device in the downhole tubing. The component consisting of the adapter and the downhole setting mechanism has a gas flow channel in the middle for gas passage. The inlet of the gas flow channel is located on the downhole setting mechanism, and the outlet is located on the adapter. The flow regulating mechanism includes a housing connected to the adapter. The inner cavity of the housing is connected to the outlet of the gas flow channel. The housing has an internal and external air outlet. The gas passage between the outlet of the gas flow channel and the air outlet is an air outlet channel. The flow regulating mechanism also includes a valve plug for regulating the flow rate of the air outlet channel.

[0008] The beneficial effects are as follows: The entire downhole setting mechanism of the downhole adjustable throttling device is located below the adapter. During operation, gas enters the inner cavity of the housing through the outlet of the airflow channel and then flows out through the outlet hole. The path between the outlet of the airflow channel and the outlet hole forms the outlet channel. The valve plug in the inner cavity of the housing adjusts the flow capacity of the outlet channel. The throttled gas flows out of the downhole adjustable throttling device through the inner cavity of the housing and the outlet hole. The flow path is short, which avoids damage to the components of the downhole adjustable throttling device caused by the high impact force of the gas generated after throttling, reduces the failure rate of the downhole adjustable throttling device, and improves the durability of the downhole adjustable throttling device.

[0009] As a further improvement, a valve cylinder is provided inside the housing. The lower end of the valve cylinder is sealed to the outlet of the airflow channel, and an air port is provided on the cylinder wall for gas to pass through, so as to connect the inner cavity of the valve cylinder with the inner cavity of the housing. The valve plug cooperates with the valve cylinder in the up-down direction to control the opening degree of the air port.

[0010] The beneficial effects are: the air port is located on the wall of the valve cylinder, and the flow rate of the air outlet can be controlled by controlling the size of the air port opening. In specific adjustment, the opening of the air port can be changed with a smaller rate of change by moving the valve plug up and down, thereby achieving high-precision throttling control.

[0011] As a further improvement, the air inlet is an elongated hole extending vertically.

[0012] The beneficial effect is that the air inlet adopts an upward and downward extending hole structure, which enables higher precision control of the flow rate.

[0013] As a further improvement, the valve cylinder is vertically continuous, and the upper end of the valve cylinder is sealed to the housing, with the valve plug disposed inside the valve cylinder.

[0014] The beneficial effects are: the valve plug is located inside the valve cylinder, which avoids the high-impact gas after throttling from impacting the valve plug, thus protecting the valve plug and reducing the failure rate of the downhole adjustable throttling device.

[0015] As a further improvement, the air inlet and the air outlet are staggered.

[0016] The beneficial effect is that the air inlet and the air outlet are staggered, so that the gas ejected through the air inlet can be buffered in the inner cavity of the shell, reducing the impact force of the gas after throttling.

[0017] As a further improvement, the air outlet is inclined upwards.

[0018] The beneficial effect is that the vent is tilted upwards, which gives the gas ejected through the vent a certain upward speed, thus helping the gas in the oil pipe to be discharged upwards.

[0019] As a further improvement, a protective sleeve is provided inside the cavity of the housing to protect the cavity wall.

[0020] The beneficial effects are: the protective sleeve can protect the inner cavity of the casing and improve the durability of the downhole adjustable throttling device.

[0021] As a further improvement, the upper end of the adapter extends into and is fixed inside the adapter, and the upper end face of the adapter supports the protective sleeve.

[0022] The beneficial effect is that the adapter can be used to support the protective sleeve directly, eliminating the need to design and set up a corresponding support structure for the protective sleeve, thus making the structure of the downhole adjustable throttling device simpler.

[0023] As a further improvement, the lower end of the adapter extends into and is fixed inside the packer outer cylinder of the downhole setting mechanism, and the lower end of the adapter limits the movement of the components inside the packer outer cylinder of the downhole setting mechanism.

[0024] The beneficial effect is that by using an adapter to limit the components inside the downhole setting mechanism, there is no need to design and set a limiting structure for the components inside the packer outer cylinder of the downhole setting mechanism, making the structure of the downhole adjustable throttling device simpler.

[0025] As a further improvement, the flow regulating mechanism includes a rotating component that transmits power to the valve plug, and a driving component that converts the rotational motion of the rotating component into an up-and-down motion. The rotating component is circumferentially rotated and axially limited on the housing, and the rotating component is rotatably sealed to the housing. The valve plug is connected to the driving component.

[0026] The beneficial effect is that during the power transmission process, the rotation of the rotating part is converted into the up-and-down movement of the driving part, avoiding the rotating part from moving up and down at the same time. Based on this, the sealing cooperation between the driving part and the housing can be achieved through the rotational sealing cooperation between the rotating part and the housing, ensuring the reliability of the seal. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the structure of Embodiment 1 of the downhole adjustable throttling device of the present invention;

[0028] Figure 2 This is a schematic diagram of the structure of the downhole adjustable throttling device in Embodiment 1 of the present invention, in conjunction with the driving device;

[0029] Explanation of reference numerals in the attached figures:

[0030] 1. Adapter; 2. Packer outer cylinder; 3. Unsealing pin; 4. Packer inner cylinder; 5. Setting pin; 6. Center tube; 7. Slip; 8. Packer; 9. Airflow channel; 10. Inlet; 11. Filter element; 12. Mounting base; 13. Lower housing; 14. Valve cylinder; 15. Air port; 16. Valve plug; 17. Upper housing; 18. Rotating component; 19. Drive component; 20. Drive device; 21. Air outlet; 22. Protective sleeve. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of this invention clearer, the invention 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 only for explaining the invention and are not intended to limit the invention; that is, the described embodiments are merely some embodiments of the invention, and not all embodiments. The components of the embodiments of the invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0032] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0033] It should be noted that relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the process or method that includes said element.

[0034] In the description of this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" 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; and they can refer to the internal connection of two components. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0035] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the term "provided with" should be interpreted broadly. For example, the object "provided with" can be a part of the main body, or it can be separately arranged from the main body and connected to the main body. This connection can be a detachable connection or a non-detachable connection. Those skilled in the art can understand the specific meaning of the above terms in this invention through specific circumstances.

[0036] The present invention will be further described in detail below with reference to the embodiments.

[0037] Specific embodiment 1 of the downhole adjustable throttling device provided by the present invention:

[0038] like Figure 1 As shown, the downhole adjustable throttling device includes an adapter 1, a flow regulating mechanism connected to the upper part of the adapter 1, and a downhole setting mechanism connected to the lower part of the adapter 1. The downhole adjustable throttling device is set in the downhole tubing through the downhole setting mechanism, and the flow regulating mechanism is used to regulate the gas flow of the downhole adjustable throttling device.

[0039] Specifically, the downhole setting mechanism includes a packer outer cylinder 2, a release pin 3, a packer inner cylinder 4, a setting pin 5, a center tube 6, slips 7, and a packer 8. In actual use, the downhole adjustable throttling device is lowered to a certain depth in the tubing and then suddenly stopped. The setting pin 5 is sheared off under inertia, and the slips 7 and packer 8 open to achieve setting of the downhole adjustable throttling device in the tubing. The specific structure and working principle of the downhole setting mechanism are existing technology and will not be elaborated upon here.

[0040] The assembly consisting of the downhole setting mechanism and the adapter 1 has an airflow channel 9. To allow downhole gas to enter the airflow channel 9, the inlet of the airflow channel 9 is located below the packer. In this embodiment, the inlet 10 of the airflow channel 9 is specifically located on the bottom surface of the downhole setting mechanism. Additionally, in this embodiment, to filter the gas, the downhole adjustable throttling device also includes a filter element 11 disposed within the airflow channel 9, such as... Figure 1As shown, the filter element 11 is mounted on the adapter 1 via the mounting base 12, and its columnar filter element extends into the airflow channel 9. The air outlet of the filter element 11 constitutes the outlet of the airflow channel 9, so that the outlet is located on the adapter 1.

[0041] Regarding the connection method between the adapter 1 and the downhole setting mechanism, in this embodiment, the downhole setting mechanism is fitted and screwed onto the lower side of the adapter 1 through the packer outer cylinder 2. The lower end of the adapter 1 extends into the packer outer cylinder 2 to limit the components of the downhole setting mechanism located inside the packer outer cylinder 2.

[0042] The flow regulating mechanism includes a housing, specifically a lower housing 13, such as... Figure 1 As shown, the lower housing 13 is fitted and screwed onto the upper side of the adapter 1. The lower housing 13 includes an inner cavity and a central hole communicating with the inner cavity. The inner cavity of the lower housing 13 is connected to the outlet of the airflow channel 9. In order to throttle the gas flow, the flow regulating mechanism also includes a valve cylinder 14 disposed in the inner cavity and central hole of the lower housing 13. The valve cylinder 14 is made of hard alloy. The lower end of the valve cylinder 14 is sealed to the outlet of the airflow channel 9, and the upper end is sealed to the wall of the central hole. An air port 15 is provided on the cylinder wall of the section of the valve cylinder 14 located in the inner cavity of the lower housing 13. The air port 15 is an elongated hole extending vertically. In this embodiment, the size of the elongated hole is 0.5*20mm. The flow regulating mechanism also includes a valve plug 16 disposed in the valve cylinder 14. In order to drive the valve plug 16 to move up and down, the flow regulating mechanism also includes a transmission component that transmits power to the valve plug 16. Specifically, the housing of the flow regulating mechanism also includes an upper housing 17, which is screwed onto and locked to the lower housing 13 by a pin 18. The diameter of the inner hole at the end of the upper housing 17 that mates with the lower housing 13 is larger than the diameter of the central hole of the lower housing 13. At the same time, the inner wall surface at the upper end of the inner hole of the upper housing 17 has a stepped structure. The transmission component includes a rotating member 18 disposed in the inner cavity of the upper housing 17. The lower end face of the rotating member 18 mates with the upper end face of the lower housing 13, and the upper end face mates with the stepped surface in the inner cavity of the upper housing 17, thereby realizing the circumferentially rotatable and axially limited installation of the rotating member 18 between the upper housing 17 and the lower housing 13. The transmission component also includes a driving member 19 connected to the valve plug 16. Specifically, the upper end of the driving member 19 is inserted into the rotating member 18 and anti-rotationally engaged, and the lower end is screwed into the central hole of the lower housing 13 by a thread. The upper end of the rotating member 18 has a transmission engagement structure that anti-rotates with the drive shaft of the driving device. The upper end of the rotating component 18 is sealed to the upper housing 17, and the lower end of the driving component 19 is sealed to the valve cylinder 14. A retrieval structure is provided on the top of the upper housing 17.

[0043] The lower housing 13 has vent holes 21. In this embodiment, six vent holes 21 are provided around the lower housing 13, and each vent hole 21 is arranged obliquely upwards. Specifically, the inner opening of the vent hole 21 is located on the top wall of the inner cavity of the lower housing, and the outer opening is located on the outer wall of the lower housing 13 corresponding to the position of the central hole. Because the impact force of the throttled gas is relatively large, the flow regulation mechanism also includes a protective sleeve 22 disposed within the inner cavity of the lower housing 13 to protect the circumferential cavity wall of the lower housing 13. In this embodiment, the protective sleeve 22 is a ceramic sleeve.

[0044] When it is necessary to adjust the flow rate of the downhole adjustable throttling device, such as Figure 2 As shown, the drive device 20 is connected to the rotating component 18 via a transmission mechanism. Driven by the drive device 20, the rotating component 18 rotates, which in turn drives the drive component 19. Since the drive component 19 is threaded into the center hole of the lower housing 13, it can move up and down while rotating, thereby changing the opening of the air port 15 and achieving throttling adjustment. During the adjustment process, the sensor installed in front of the drive device 20 monitors the actual number of rotations and calculates the adjustment of the valve cylinder 14. During retrieval, the retrieval cylinder is directly lowered in, and after grasping the retrieval structure on the upper housing 14, it is vibrated upwards to disengage the upper part of the central tube 6 from the unsealing pin 3. Under the action of gravity, the central tube 6 moves downwards to open the range of motion of the rubber cylinder. The spring inside the rubber cylinder relaxes to unseal the rubber cylinder, and the slip 7 retracts inwards to achieve retrieval.

[0045] The specific embodiment 2 of the downhole adjustable throttling device provided by the present invention differs from embodiment 1 mainly in that: in embodiment 1, the valve cylinder is an open cylinder structure, while in this embodiment, the valve cylinder is only open at one end, and the opening is sealed and connected to the outlet of the airflow channel, and the valve plug is a ring-shaped structure fitted on the outside of the valve cylinder.

[0046] The specific embodiment 3 of the downhole adjustable throttling device provided by the present invention differs from embodiment 1 mainly in that: in embodiment 1, the flow regulation mechanism also includes a valve cylinder that is sealed and connected to the outlet of the gas flow channel. An air port is opened on the valve cylinder, and the opening degree of the air port is adjusted by moving the valve plug 16 up and down. Such an adjustment structure makes the gas flow regulation more precise. In this embodiment, under the premise of meeting the gas flow regulation accuracy requirements, the valve cylinder is no longer provided, and the valve plug is a conical plug that cooperates with the outlet of the gas flow channel.

[0047] The specific embodiment 4 of the downhole adjustable throttling device provided by the present invention differs from embodiment 1 mainly in that: in this embodiment, the transmission component is a push rod that slides and seals with the housing of the flow regulating mechanism, and correspondingly, the driving device adopts an electric push rod.

[0048] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still make modifications to the technical solutions described in the foregoing embodiments without creative effort, or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A downhole adjustable throttling device, characterized in that, The device includes an adapter and a flow regulating mechanism and a downhole setting mechanism connected to the upper and lower ends of the adapter, respectively. The downhole setting mechanism is used to set the adjustable downhole throttling device inside the downhole tubing. The assembly consisting of the adapter and the downhole setting mechanism has a gas flow channel in the middle for gas passage. The inlet of the gas flow channel is located on the downhole setting mechanism and below the packer of the downhole setting mechanism, and the outlet is located on the adapter. The flow regulating mechanism includes a housing connected to the adapter. The inner cavity of the housing communicates with the outlet of the gas flow channel. The housing has inner and outer... The air outlet is connected to the air passage, and the air passage between the outlet of the airflow channel and the air outlet is the air outlet channel; a valve cylinder is provided inside the housing, the valve cylinder is vertically connected, the upper end of the valve cylinder is sealed to the housing, and a valve plug is provided inside the valve cylinder. The lower end of the valve cylinder is sealed to the outlet of the airflow channel, and an air port is opened on the cylinder wall of the valve cylinder to allow gas to pass through, so as to connect the inner cavity of the valve cylinder with the inner cavity of the housing. The upper end of the valve plug is connected to a transmission component for transmitting power to the valve plug. The upper end of the transmission component is used to connect to a drive device to make the valve plug move and cooperate with the valve cylinder in the vertical direction, thereby controlling the opening of the air port. The inner cavity of the housing is provided with a protective sleeve for protecting the cavity wall. The upper end of the adapter extends into the adapter and is fixed. The upper end face of the adapter supports the protective sleeve. The lower end of the adapter extends into and is fixed inside the packer outer cylinder of the downhole setting mechanism, and the lower end of the adapter limits the components inside the packer outer cylinder of the downhole setting mechanism. The transmission component includes a rotating component that transmits power to the valve plug, and a driving component that converts the rotational motion of the rotating component into up-and-down motion. The rotating component is circumferentially rotated and axially limited on the housing. The rotating component and the housing are in a rotational sealing fit. The valve plug is connected to the driving component.

2. The downhole adjustable throttling device according to claim 1, characterized in that, The air vent is an elongated hole extending vertically.

3. The downhole adjustable throttling device according to claim 1 or 2, characterized in that, The air inlet and the air outlet are staggered.

4. The downhole adjustable throttling device according to claim 1 or 2, characterized in that, The air outlet is inclined upwards.

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