Slip type underground throttler

Abstract

The invention belongs to the technical field of natural gas extraction, and particularly provides a slip type underground throttler which comprises a throttler body, a slip and a plurality of installation guide mechanisms, the lower portion of the throttler body is connected with the slip, the outer side of the upper portion of the throttler body is connected with the installation guide mechanisms, and the installation guide mechanisms are distributed in the circumferential direction at equal intervals. The mounting guide mechanism comprises a guide mechanism and a mounting mechanism, and the guide mechanism is connected outside the throttler through the mounting mechanism; the problem that an existing throttler is damaged due to the fact that the existing throttler is prone to colliding or rubbing with the well wall when being put is solved. When the surface of the well wall is concave and convex in the well entering process, impact caused by the concave and convex surface of the well wall is effectively absorbed and dispersed through the guide mechanism, and the influence of vibration or impact on the flow controller is reduced.

Description

Technical Field

[0001] This invention belongs to the field of natural gas extraction technology, specifically relating to a slip-type downhole choke. Background Technology

[0002] In the early stages of natural gas well development, the wellhead pressure is high. If all valves are fully open for production, it will result in excessive flow and overpressure in the downstream pipeline. Therefore, the common production method is to install a needle valve at the wellhead to control the gas flow, a process known as throttling. For high-pressure gas wells, because the fluid temperature at the wellhead is low, controlling the flow will lower the temperature downstream of the throttling valve, leading to the formation of hydrates. This ice can block the fluid passage, preventing the well from producing. Furthermore, the throttling process also reduces the pressure of the high-pressure fluid; therefore, throttling is a process of cooling and depressurizing.

[0003] The traditional development model involves allowing high-pressure fluids from numerous wells to be naturally transported from the wellhead to the gas gathering station. A heater at the station first heats the low-temperature fluid to above 40°C. Then, the high-temperature, high-pressure fluid is passed through a throttling valve, transforming it into a low-temperature, low-pressure fluid. At this point, the temperature is still higher than the hydrate formation temperature, and the pressure after throttling is significantly reduced, thus changing the gas gathering station's external transmission pipeline from a high-pressure to a low-pressure level. In this model, the wellhead to the gas gathering station is high-pressure, hence the high-pressure transmission pipeline. Furthermore, the station requires a supporting heater, resulting in high costs and significant management difficulties.

[0004] Downhole throttling involves moving the throttling valve from the gas gathering station to a location above 40°C inside the wellbore, allowing the constant geothermal temperature to replace the heating furnace. This downhole throttling valve prevents hydrate formation and reduces pressure downstream of the valve, thus lowering the pressure of the pipeline from the wellhead to the gas gathering station from high pressure to low pressure, reducing pipeline grade and costs. This model eliminates the need for a heating furnace, lowers the pressure of the pipeline from the wellhead to the gas gathering station, and requires no personnel for management, resulting in a significant reduction in overall costs.

[0005] The slip-type downhole throttling device is a core tool in downhole throttling technology and plays a crucial role in natural gas extraction in gas fields. It is primarily placed at an appropriate location within the production tubing to achieve throttling and pressure reduction within the wellbore, thereby transferring the throttling process from the surface to the wellbore. This design fully utilizes geothermal heating, ensuring that the temperature of the gas flow after throttling is higher than the maximum temperature at which hydrates form under the pressure conditions after throttling, effectively preventing hydrate blockage in the wellbore, wellhead, and surface pipelines.

[0006] A throttle valve controls fluid flow through its built-in throttling device (such as a nozzle). During oil well production, the flow rate of fluid entering the wellhead can be controlled by adjusting the opening of the throttle device according to production needs. When the wellhead pressure is too high, the throttle valve will appropriately reduce the fluid flow rate, thereby lowering the wellhead pressure; conversely, when the wellhead pressure is too low, the throttle valve will appropriately increase the fluid flow rate to raise the wellhead pressure. In this way, by continuously adjusting the flow rate, the throttle valve keeps the wellhead pressure within a reasonable range, ensuring stable oil well production.

[0007] Slip-type downhole chokes utilize a slip mechanism to secure them within the wellbore. Under predetermined conditions (such as pressure changes or operational commands), the slips expand outwards and grip the wellbore wall tightly, ensuring the choke's stable position downhole. This securing method not only improves the choke's operational stability but also effectively prevents displacement or damage caused by vibration or impact.

[0008] According to the public announcement (CN216950330U), an easy-to-release slip-type downhole choke is disclosed. This technology discloses "an easy-to-release slip-type downhole choke, which relates to the field of choke technology. The invention includes a retrieval component and a choke component. The retrieval component is located at the top of the choke component. The choke component includes a mandrel, an outer central tube, slips, an upper slip seat, a lower slip seat, a guide head, and connecting components. The mandrel is located inside the outer central tube. The upper slip seat is sleeved on the annular side of the outer central tube. The slips are connected to the upper slip seat by screws. The lower slip seat is fixedly connected to the outer surface of the outer central tube. The guide head is connected to the bottom end of the outer central tube by a connecting component. The retrieval component includes a release connector, a retrieval neck, an upper cap, and a shear pin seat. The release connector is connected to the mandrel through a pin." This technology has the technical effect of "facilitating stable installation of the choke by setting up a retrieval component and a choke component, while improving the retrieval success rate of the choke."

[0009] During the deployment of the choke, if the operator's control over the lowering speed and direction is not precise enough, the choke is highly likely to collide unexpectedly with the wellbore. This is especially true when navigating bends or narrow areas, where even minor operational errors can significantly increase the risk of collision. Furthermore, the presence of various protrusions, irregular surfaces, or deposits within the wellbore can pose potential obstacles during choke deployment, further increasing the likelihood of collision. Summary of the Invention

[0010] The present invention provides a slip-type downhole choke, which aims to overcome the problem that existing chokes are prone to collision or friction with the well wall during deployment, leading to damage.

[0011] Therefore, the present invention provides a slip-type downhole choke, including a choke, slips and multiple installation guide mechanisms. The slips are connected to the lower part of the choke, and multiple installation guide mechanisms are connected to the upper outer side of the choke. The multiple installation guide mechanisms are distributed circumferentially at equal intervals. The installation guide mechanism includes a guide mechanism and an installation mechanism. The guide mechanism is connected to the outside of the choke through the installation mechanism.

[0012] Preferably, the guiding mechanism includes an execution component, a buffer component, and a drive component, with the lower outer side of the execution component connected to the buffer component via the drive component.

[0013] Preferably, the execution component includes a main frame, a support frame, a wheel frame, and multiple guide wheels. The inner side of the main frame is connected to an installation mechanism, and the upper outer side of the main frame is connected to the wheel frame through the support frame. Multiple guide wheels are connected to the wheel frame, and the multiple guide wheels are distributed at intervals from top to bottom.

[0014] Preferably, the main frame includes a base plate and a connecting plate, both of which are vertically arranged, with the connecting plate vertically connected to the middle of the outer side of the base plate.

[0015] Preferably, the base plate has two first holes, which are symmetrically distributed around the connecting plate.

[0016] Preferably, the buffer assembly includes an outer cylinder, a piston, a guide rod, a connector, a slide block, and a first spring. The slide block is slidably connected to the connecting plate inside, and the lower part of the slide block is connected to the connector. The connector is connected to the piston through the guide rod. The first spring is sleeved on the guide rod, and the outer cylinder is sleeved on the piston. The lower part of the outer cylinder is connected to the outer side of the connecting plate.

[0017] Preferably, a reinforcing rib is provided between the connector and the slide.

[0018] Preferably, the connecting plate has a vertical groove in the middle.

[0019] Preferably, the drive assembly includes two drive units, with the lower ends of the two drive units pivotally connected to slides and the upper ends of the two drive units pivotally connected to wheel frames.

[0020] Preferably, the drive unit includes a connecting frame, a cylindrical rod, a cylindrical frame, and a second spring. The cylindrical rod is connected to the connecting frame, the cylindrical rod is slidably connected inside the cylindrical frame, the second spring is sleeved on the cylindrical rod, the connecting frame is pivotally connected to a slide block, and the cylindrical frame is pivotally connected to a wheel frame.

[0021] The beneficial effects of this invention are:

[0022] 1. The slip-type downhole choke provided by this invention includes a choke, slips, and multiple installation guide mechanisms. Slips are connected to the lower part of the choke, and multiple installation guide mechanisms are connected to the upper outer side of the choke. These installation guide mechanisms are evenly spaced circumferentially. Each installation guide mechanism includes a guide mechanism and an installation mechanism, with the choke connected to the guide mechanism via the installation mechanism. During the wellbore insertion process, when encountering uneven surfaces, the guide mechanism effectively absorbs and disperses the impact caused by these surfaces, reducing the influence of vibration or impact on the choke itself. Once the choke is lowered to the appropriate position, the slips expand outward under predetermined conditions (such as pressure changes or operating commands), tightly gripping the wellbore, thereby ensuring the stable position of the choke downhole. This improves the working stability of the choke and effectively prevents displacement or damage caused by vibration or impact.

[0023] 2. The slip-type downhole choke provided by this invention has a buffer component connected to the lower outer side of the actuator component via the drive component. When encountering uneven surfaces on the well wall during the well entry process, the drive component can work with the buffer component to buffer the impact caused by the uneven surface of the well wall, effectively absorbing and dispersing the impact caused by the uneven surface of the well wall, and reducing the impact of vibration or impact on the choke itself.

[0024] 3. The slip-type downhole choke provided by this invention includes a drive unit comprising a connecting frame, a cylinder rod, a cylinder frame, and a second spring. The actuation components include a main frame, a support frame, a wheel frame, and multiple guide wheels. During the well entry process, the pressure of the second spring's rebound pushes the cylinder frame and wheel frame, while the support frame, in conjunction with it, causes the guide wheels in the wheel frame to contact the inner wall of the wellbore. This allows the choke to be smoothly lowered along a predetermined path, effectively reducing the contact area and friction with the inner wall of the wellbore, thereby reducing the risk of damage caused by impacts or friction. This helps improve the accuracy and stability of the choke's lowering, ensuring that it can accurately reach the predetermined position. Attached Figure Description

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

[0026] Figure 1 A three-dimensional structural diagram of a kava-type downhole choke;

[0027] Figure 2 This is a schematic diagram of the guiding mechanism;

[0028] Figure 3 A cross-sectional structural diagram of the guiding mechanism;

[0029] Figure 4 This is a schematic diagram of the drive unit.

[0030] Figure 5 This is a schematic diagram of the installation mechanism.

[0031] Explanation of reference numerals in the attached drawings: 1. Throttling device; 2. Slipper; 3. Guide mechanism; 4. Mounting mechanism;

[0032] 31. Execution component; 32. Buffer component; 33. Driver component;

[0033] 311. Main frame; 312. First support frame; 313. Wheel frame; 314. Second support frame; 315. Guide wheel; 316. First hole; 317. Slide groove;

[0034] 311-1, Base plate; 311-2, Connecting plate;

[0035] 321. Outer cylinder; 322. Piston; 323. Guide rod; 324. Connector; 325. Slide; 326. First spring; 327. Reinforcing rib;

[0036] 331. Connecting frame; 332. Tube rod; 333. Tube frame; 334. Second spring;

[0037] 332-1, Slide rod; 333-1, Tube frame slide groove;

[0038] 41. Mounting base; 41-1. Mounting base plate; 41-2. Mounting connecting plate; 42. Second hole; 43. Mounting hole. Detailed Implementation

[0039] The principles and features of the present invention are described below with reference to the accompanying drawings. The examples given are only for explaining the present invention and are not intended to limit the scope of the present invention.

[0040] Example 1:

[0041] like Figure 1 As shown, a slip-type downhole choke includes a choke 1, slips 2, and multiple installation guide mechanisms. The slips 2 are connected to the lower part of the choke 1, and multiple installation guide mechanisms are connected to the upper outer side of the choke 1. The multiple installation guide mechanisms are distributed circumferentially at equal intervals. The installation guide mechanism includes a guide mechanism 3 and an installation mechanism 4. The guide mechanism 3 is connected to the outside of the choke 1 through the installation mechanism 4.

[0042] Specifically, the slip 2 is used to support and fix the choke 1 inside the wellbore, the guide mechanism 3 is used to guide the choke 1 during its insertion into the wellbore, and the mounting mechanism 4 is used to fix the guide mechanism 3 onto the choke 1. During insertion, when encountering uneven surfaces on the wellbore, the guide mechanism 3 effectively absorbs and disperses the impact caused by these surfaces, reducing the influence of vibration or impact on the choke itself. Once the choke is lowered to the appropriate position, the slip 2 expands outward under predetermined conditions (such as pressure changes or operating commands), tightly gripping the wellbore, thereby ensuring the stable position of the choke downhole. This improves the working stability of the choke and effectively prevents displacement or damage caused by vibration or impact.

[0043] Preferably, the number of installation guide mechanisms is three.

[0044] Specifically, the three installation guide mechanisms form three contact points on the horizontal plane, and a relatively small number of them can ensure stability during use.

[0045] Example 2:

[0046] Based on Example 1, such as Figure 2 As shown, the guide mechanism 3 includes an execution component 31, a buffer component 32, and a drive component 33. The lower outer side of the execution component 31 is connected to the buffer component 32 through the drive component 33.

[0047] Specifically, when encountering uneven surfaces on the well wall during the well entry process, the drive component 33 can work in conjunction with the buffer component 32 to buffer the impact caused by the uneven surface of the well wall, thereby reducing the impact of vibration or impact on the throttle itself.

[0048] Preferred, such as Figure 3 As shown, the execution component 31 includes a main frame 311, a support frame, a wheel frame 313 and a plurality of guide wheels 315. The inner side of the main frame 311 is connected to the mounting mechanism 4. The upper outer side of the main frame 311 is connected to the wheel frame 313 through the support frame. A plurality of guide wheels 315 are connected to the wheel frame 313, and the plurality of guide wheels 315 are distributed at intervals from top to bottom.

[0049] Specifically, the support frame and the main frame 311, and the wheel frame 313 and the support frame are pivotally connected. The wheel frame 313 has three equally spaced guide wheels 315 rotatably mounted inside. The guide wheels 315 contact the inner wall of the well shaft to reduce friction during movement.

[0050] Preferably, the support frame includes a first support frame 312 and a second support frame 314. The first support frame 312 is pivotally connected to both sides of the upper end of the main frame 311, and a wheel frame 313 is pivotally connected between the other ends of the two first support frames 312. The second support frame 314 is pivotally connected to both sides of the lower end of the wheel frame 313, and the other end of the second support frame 314 is pivotally connected to the main frame 311. The first support frame 312 and the second support frame 314 are of equal length and parallel to each other.

[0051] Specifically, with the cooperation of the first support 312 and the second support 314, the wheel frame 313 always remains parallel to the throttle 1 during the movement, so that each guide wheel 315 on the wheel frame 313 can contact the inner wall of the well.

[0052] Preferably, the main frame 311 includes a base plate 311-1 and a connecting plate 311-2. Both the base plate 311-1 and the connecting plate 311-2 are vertically arranged, and the connecting plate 311-2 is vertically connected to the middle of the outer side of the base plate 311-1.

[0053] Specifically, the main frame 311 of this structure is simple in structure and easy to connect to other components.

[0054] Preferably, the base plate 311-1 has two first holes 316, which are symmetrically distributed with the connecting plate 311-2 as the center.

[0055] Specifically, the guide mechanism 3 is fixed to the mounting mechanism 4 by bolts and nuts through the first hole 316, so that the guide mechanism 3 can be fixed at different height positions on the throttle 1 as needed.

[0056] Preferably, the first hole 316 is a vertical, oblong hole. This facilitates fixing the guide mechanism 3 at different height positions on the throttle 1 as needed.

[0057] Preferably, the wheel frame 313 is a U-shaped frame. It has a simple structure and good stability after connection.

[0058] Example 3:

[0059] Based on Embodiment 2, the buffer assembly 32 includes an outer cylinder 321, a piston 322, a guide rod 323, a connector 324, a slide block 325, and a first spring 326. The slide block 325 is slidably connected to the connecting plate 311-2 inside, and the lower part of the slide block 325 is connected to the connector 324. The connector 324 is connected to the piston 322 through the guide rod 323. The first spring 326 is sleeved on the guide rod 323. The outer cylinder 321 is sleeved on the piston 322. The lower part of the outer cylinder 321 is connected to the outer side of the connecting plate 311-2.

[0060] Specifically, the lower outer side of the connecting plate 311-2 is pivotally connected to the outer cylinder 321. A piston 322 is installed inside the outer cylinder 321, which is filled with a viscous fluid. A guide rod 323 is fixed to the upper end of the piston 322, and a connector 324 is slidably mounted on the upper end of the guide rod 323. A slide block 325 is fixed to the upper end of the connector 324. A first spring 326 is mounted on the guide rod 323, located between the top of the piston 322 and the bottom of the connector 324. During well entry, when encountering uneven surfaces on the well wall, the drive assembly 33, in conjunction with the buffer assembly 32, provides cushioning. Specifically, the drive assembly 33 drives the piston 322 to move up and down within the outer cylinder 321 via the connector 324, effectively absorbing and dispersing the impact caused by the uneven surface of the well wall, reducing the impact of vibration or impact on the throttle device 1 itself. When the piston 322 moves up and down inside the outer cylinder 321, the elastic force of the first spring 326 makes it easy for the outer cylinder 321 to return to its original position.

[0061] Preferably, a reinforcing rib 327 is provided between the connector 324 and the slide 325.

[0062] Specifically, the reinforcing rib 327 can increase the strength and rigidity between the mating surfaces of the connector 324 and the slide 325, preventing deformation under stress.

[0063] Preferably, the connecting plate 311-2 has a vertical groove 317 in the middle.

[0064] Specifically, the slide block 325 is slidably installed on the main frame 311 via the slide groove 317. This allows the slide block 325 to slide along the main frame 311 when it is under force and moves, while also causing the connector 324 to slide along the guide rod 323.

[0065] Example 4:

[0066] Based on embodiment 3, the drive assembly 33 includes two drive units, with the lower ends of the two drive units pivotally connected to a slide block 325 and the upper ends of the two drive units pivotally connected to a wheel frame 313.

[0067] Specifically, the two drive units are symmetrically arranged with the connecting plate 311-2 as the center to ensure the stability of the structure.

[0068] Preferred, such as Figure 4 As shown, the drive unit includes a connecting frame 331, a cylindrical rod 332, a cylindrical frame 333, and a second spring 334. The connecting frame 331 is connected to the cylindrical rod 332, which is slidably connected inside the cylindrical frame 333. The cylindrical rod 332 is sleeved with the second spring 334. The connecting frame 331 is pivotally connected to the slide block 325, and the cylindrical frame 333 is pivotally connected to the wheel frame 313.

[0069] Specifically, the drive component 33 is mounted on the execution component 31 and is used to control the execution component 31 to always fit against the inner wall of the wellbore; the slide 325 is pivotally connected to the connecting frame 331 at both ends, the upper end of the connecting frame 331 is fixed with the cylinder rod 332, the cylinder frame 333 is slidably mounted on the cylinder rod 332, and the upper end of the cylinder frame 333 is pivotally connected to the wheel frame 313. The cylinder rod 332 is mounted with a second spring 334, and the second spring 334 is located between the top of the connecting frame 331 and the bottom of the cylinder frame 333.

[0070] During the well entry process, the pressure of the rebound of the second spring 334 pushes the cylinder frame 333 and wheel frame 313. At the same time, with the cooperation of the first support frame 312 and the second support frame 314, the guide wheel 315 in the wheel frame 313 contacts the inner wall of the well, so that the throttle 1 is smoothly lowered along the predetermined path, effectively reducing the contact area and friction with the inner wall of the well, thereby reducing the risk of damage caused by bumps or friction. This helps to improve the accuracy and stability of the throttle 1, ensuring that it can accurately reach the predetermined position.

[0071] Preferably, a sliding rod 332-1 is provided on the outer side of the cylinder rod 332, and a cylinder frame groove 333-1 is provided on the side wall of the cylinder frame 333, with the sliding rod 332-1 located inside the cylinder frame groove 333-1.

[0072] Specifically, the slide bar 332-1 slides within the slide groove 333-1 of the tube frame, facilitating the movement of the tube bar 332 within the tube frame 333.

[0073] Example 5:

[0074] Based on embodiment 4, the mounting mechanism 4 includes a mounting base 41, which includes a mounting base plate 41-1 and a mounting connecting plate 41-2. The mounting base 41 is connected to the outer side of the mounting connecting plate 41-2. The mounting base 41 has an arc-shaped surface, and the mounting connecting plate 41-2 has a U-shaped shape with the U-shaped opening facing the mounting connecting plate 41-2. Two second holes 42 are provided on the outer side of the mounting connecting plate 41-2. The two second holes 42 are symmetrically distributed front and back, and the second holes 42 are vertical oblong holes.

[0075] Specifically, the curved mounting base 41 fits the throttle 1 better, resulting in better stability after connection. The main frame 311 can be fixed to the second hole 42 on the mounting base 41 through the first hole 316 with bolts and nuts, so that the guide mechanism 3 can be fixed at different height positions on the throttle 1 as needed.

[0076] Preferably, mounting holes 43 are provided at each of the four corners of the mounting base plate 41-1.

[0077] Specifically, the mounting base 41 can be fixed to the outer wall of the throttle 1 through the mounting hole 43 and bolts.

[0078] The method of using this invention is as follows:

[0079] First, the mounting base 41 can be fixed to the outer wall of the throttle 1 through the mounting hole 43 with bolts; then the main frame 311 can be fixed to the second hole 42 on the mounting base 41 through the first hole 316 with bolts and nuts.

[0080] Then, before lowering it into the well, the choke 1 is disengaged from the connector and assembled with the suspension mechanism, and lowered into the well at the normal well entry speed. During the well entry process, the pressure of the second spring 334 pushes the cylinder frame 333 with the wheel frame 313, and with the cooperation of the first support frame 312 and the second support frame 314, the guide wheel 315 in the wheel frame 313 contacts the inner wall of the well, so that the choke 1 is smoothly lowered along the predetermined path. In addition, when encountering uneven surfaces on the well wall during the well entry process, the drive assembly 33 can be used in conjunction with the buffer assembly 32 to buffer the impact. Specifically, when the slide 325 moves under force, it can slide along the main frame 311, and at the same time drive the connector 324 along the guide rod 323, so that the piston 322 moves up and down in the outer cylinder 321, effectively absorbing and dispersing the impact caused by the uneven surface of the well wall, and reducing the impact of vibration or impact on the choke 1 itself.

[0081] Finally, when the choke 1 is lowered to the appropriate position, the slip 2 expands outward under predetermined conditions (such as pressure changes or operating commands) and tightly grips the well wall, thereby ensuring the stable position of the choke 1 downhole; improving the working stability of the choke 1 and effectively preventing displacement or damage caused by vibration or impact.

[0082] In the description of this invention, it should be understood that if terms such as "upper," "inner," or "lower" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, it does 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, the terms used to describe positional relationships in the drawings are for illustrative purposes only and should not be construed as limiting the invention.

[0083] The above examples are merely illustrative of the present invention and do not constitute a limitation on the scope of protection of the present invention. All designs that are the same as or similar to the present invention are within the scope of protection of the present invention.

Claims

1. A slip-type downhole choke, characterized in that: It includes a throttle (1), a slip (2) and multiple installation guide mechanisms. The slip (2) is connected to the lower part of the throttle (1), and multiple installation guide mechanisms are connected to the upper outer side of the throttle (1). The multiple installation guide mechanisms are distributed circumferentially at equal intervals. The installation guide mechanism includes a guide mechanism (3) and an installation mechanism (4). The throttle (1) is connected to the guide mechanism (3) through the installation mechanism (4).

2. The slip-type downhole choke as described in claim 1, characterized in that: The guiding mechanism (3) includes an execution component (31), a buffer component (32) and a drive component (33), with the lower outer side of the execution component (31) connected to the buffer component (32) via the drive component (33).

3. The slip-type downhole choke as described in claim 2, characterized in that: The execution component (31) includes a main frame (311), a support frame, a wheel frame (313), and multiple guide wheels (315). The inner side of the main frame (311) is connected to the mounting mechanism (4), and the upper outer side of the main frame (311) is connected to the wheel frame (313) through the support frame. Multiple guide wheels (315) are connected to the wheel frame (313), and the multiple guide wheels (315) are distributed at intervals from top to bottom.

4. The slip-type downhole choke as described in claim 3, characterized in that: The main frame (311) includes a base plate (311-1) and a connecting plate (311-2). Both the base plate (311-1) and the connecting plate (311-2) are vertically arranged, and the connecting plate (311-2) is vertically connected to the middle of the outer side of the base plate (311-1).

5. The slip-type downhole choke as described in claim 4, characterized in that: The base plate (311-1) has two first holes (316), which are symmetrically distributed with the connecting plate (311-2) as the center.

6. The slip-type downhole choke as described in claim 4, characterized in that: The buffer assembly (32) includes an outer cylinder (321), a piston (322), a guide rod (323), a connector (324), a slide (325), and a first spring (326). The slide (325) is slidably connected to the connecting plate (311-2) inside, and the lower part of the slide (325) is connected to the connector (324). The connector (324) is connected to the piston (322) through the guide rod (323). The first spring (326) is sleeved on the guide rod (323). The outer cylinder (321) is sleeved on the piston (322). The lower part of the outer cylinder (321) is connected to the outer side of the connecting plate (311-2).

7. The slip-type downhole choke as described in claim 6, characterized in that: A reinforcing rib (327) is provided between the connector (324) and the slide (325).

8. The slip-type downhole choke as described in claim 6, characterized in that: The connecting plate (311-2) has a vertical groove (317) in the middle.

9. The slip-type downhole choke as described in claim 6, characterized in that: The drive assembly (33) includes two drive units, with the lower ends of the two drive units pivotally connected to a slide (325) and the upper ends of the two drive units pivotally connected to a wheel frame (313).

10. The slip-type downhole choke as described in claim 9, characterized in that: The drive unit includes a connecting frame (331), a cylindrical rod (332), a cylindrical frame (333), and a second spring (334). The connecting frame (331) is connected to the cylindrical rod (332), which is slidably connected inside the cylindrical frame (333). The cylindrical rod (332) is sleeved with the second spring (334). The connecting frame (331) is pivotally connected to the slide (325), and the cylindrical frame (333) is pivotally connected to the wheel frame (313).

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