Double-drive multi-stage variable flow regulating mechanism for downhole choke

Abstract

The invention relates to a dual-drive multi-stage variable flow regulating mechanism for an underground throttle, comprising a shell, a conical sleeve installed on the inner wall of the shell, a clutch sleeve installed in the shell above the conical sleeve, a petal elastic claw structure formed at the lower end of the clutch sleeve, a boss structure formed on the outer wall of the clutch sleeve, a spring sleeved on the clutch sleeve, both ends of the spring are limited by the boss structure and the conical sleeve, a plurality of flow holes are arranged on the side wall of the clutch sleeve, a positioning guide sleeve and a reversing guide sleeve are also fixedly installed on the inner wall of the shell, a plurality of reversing grooves are circumferentially arranged on the reversing guide sleeve, a plurality of positioning grooves are circumferentially arranged on the positioning guide sleeve, the depth of the positioning grooves is cyclically deepened, and a guide key is installed on the side wall of the clutch sleeve; the flow regulating mechanism of the invention has a dual-drive mode, can automatically adjust the mechanism to change the flow, can also change the flow by external mechanical force, and can cyclically change gears, so it is more suitable for working under complex working conditions underground.

Description

Technical Field

[0001] The invention belongs to the technical field of underground throttling and centralized mining of petroleum and natural gas resources, and in particular relates to a dual-drive multi-stage variable flow regulating mechanism for an underground throttle. Background Art

[0002] In the process of oil and gas field development, downhole throttling technology is one of the key technologies of "low-cost development". Through the throttling effect of the downhole throttle, a series of medium and low pressure gathering and transportation technology technologies are formed, such as no heating at the wellhead, no alcohol injection, well-to-well series connection, medium and low pressure centralized production, normal temperature separation, two-stage pressurization, centralized processing, etc., which can realize the effective development of oil and gas fields on an economic scale.

[0003] However, as mining progresses and the underground environment changes, conventional underground throttles have a fixed throttling flow rate and cannot meet later mining requirements. They need to be salvaged from the wellbore, which brings higher construction risks and costs. To solve this problem, an intelligent throttle has been developed that can collect underground working conditions and automatically adjust the flow rate without salvaging.

[0004] The existing intelligent downhole throttle can only change the throttling flow rate through the motor-driven adjustment mechanism. The circuit system working in the complex underground environment for a long time will reduce the stability of the power supply and electronic control system. Once the system is damaged, the throttle will lose its adjustment ability. Therefore, a more reliable flow adjustment mechanism is needed to solve the current technical problems.

[0005] In view of the above problems, it is necessary to study a dual-drive multi-stage variable flow regulating mechanism for a downhole choke that can have a longer downhole service life and avoid the risks and economic losses caused by the salvage and re-entry process. Summary of the invention

[0006] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a dual-drive multi-stage variable flow regulating mechanism for a downhole throttle that can have a longer downhole service life and avoid the risks and economic losses caused by the salvage and re-entry process.

[0007] The present invention solves the technical problem by adopting the following technical solutions:

[0008] A dual-drive multi-stage variable flow regulating mechanism for a downhole throttle comprises a housing, a conical sleeve is installed on the inner wall of the housing, a clutch sleeve is installed in the housing above the conical sleeve, a petal elastic claw structure is formed at the lower end of the clutch sleeve, a boss structure is formed on the outer wall of the clutch sleeve, a spring is sleeved on the clutch sleeve, both ends of the spring are limited by the boss structure and the conical sleeve, a plurality of flow holes are arranged on the side wall of the clutch sleeve, a positioning guide sleeve and a reversing guide sleeve are also fixedly installed on the inner wall of the housing, a plurality of reversing grooves are circumferentially arranged on the reversing guide sleeve, a plurality of positioning grooves are circumferentially arranged on the positioning guide sleeve, the depth of the positioning groove is cyclically deepened, and a guide key is installed on the side wall of the clutch sleeve;

[0009] In the initial position, the flow hole is sealed and the throttle is in a closed state; when the clutch sleeve descends, the compression spring reaches the conical sleeve, and when it ascends, the guide key will be sequentially and cyclically inserted into the positioning grooves of different depths of the positioning guide sleeve, so that the number of flow holes that are unsealed increases successively, and the downhole fluid is circulated through the throttle hole, thereby realizing multi-stage variable flow regulation.

[0010] Furthermore, it also includes an automatic adjustment mechanism, which is installed inside the shell. The automatic adjustment mechanism can drive the clutch sleeve to descend multiple times to compress the spring, and when the clutch sleeve moves upward, the guide key will be sequentially and cyclically inserted into the positioning grooves of different depths of the positioning guide sleeve, so that the number of flow holes that are unsealed increases successively, and the downhole fluid can circulate through the throttling hole, thereby realizing multi-stage variable flow regulation.

[0011] Furthermore, the automatic adjustment mechanism includes a motor, a lead screw, and a moving rod. The output end of the motor is connected to the lead screw, which is threadedly connected to one end of the moving rod. The moving rod passes through the conical sleeve, and the other end of the moving rod is fixedly connected to a force transmission cap. The force transmission cap is cooperatively connected with the petal elastic claw structure of the clutch sleeve. When the motor drives the lead screw to rotate, the moving rod is limited to move axially along the shell, thereby driving the clutch sleeve to compress the spring downward.

[0012] Furthermore, a frustum structure is formed on the upper portion of the force transmission cap, so that when the motor drives the motion rod upward, the force transmission cap can enter the petal elastic claw structure of the clutch sleeve.

[0013] Furthermore, a throttle cap is fixedly mounted on the inner wall of the clutch sleeve, the throttle cap is a cap-shaped structure with an opening at the bottom, and a liquid passage matching with the flow hole is provided on the side wall of the throttle cap.

[0014] Furthermore, a sealing surface is formed between the housing and the clutch sleeve, and in the initial position, the flow hole is located below the sealing surface, so that the downhole fluid cannot communicate with the top of the housing through the flow hole, and the throttle is in a closed state.

[0015] Furthermore, it also includes a torque sensor, both ends of which are connected to the motor and the lead screw respectively through elastic couplings.

[0016] Furthermore, an anti-rotation key is fixedly mounted on the outer wall of the movement rod, and a slideway cooperating with the anti-rotation key is axially arranged on the inner wall of the shell.

[0017] Furthermore, it also includes a shell pressure cap, which is installed at one end of the shell, and the salvage rod passes through the shell pressure cap and is fixedly connected to the clutch sleeve.

[0018] Furthermore, the housing pressure cap is provided with a plurality of liquid holes.

[0019] The advantages and positive effects of the present invention are:

[0020] The present invention can realize the change of throttling flow rate underground without the need to salvage the throttle out of the wellbore, which can reduce construction risks and save construction costs; the flow regulating mechanism of the present invention has a dual drive mode, which can automatically adjust the mechanism to change the flow rate, and can also change the flow rate through external mechanical force, with better reliability and longer service life, and can cyclically change gears. This mechanical adjustment method has stronger fault tolerance and can still maintain a highly stable working state after the electronic control system ages and becomes inaccurate, and is more suitable for working under complex working conditions underground. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The technical solution of the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments, but it should be understood that these drawings are designed only for explanation purposes and are not intended to limit the scope of the present invention. In addition, unless otherwise specified, these drawings are intended only to conceptually illustrate the structural configurations described herein and are not necessarily drawn to scale.

[0022] Figure 1 A structural cross-sectional view of a dual-drive multi-stage variable flow regulating mechanism for a downhole choke provided by an embodiment of the present invention;

[0023] Figure 2 A structural cross-sectional view of the installation of the positioning guide sleeve and the reversing guide sleeve of the dual-drive multi-stage variable flow regulating mechanism for a downhole choke provided by an embodiment of the present invention; DETAILED DESCRIPTION

[0024] First, it should be noted that the specific structure, features and advantages of the present invention will be specifically described below by way of example, but all descriptions are only for illustration and should not be understood as limiting the present invention in any way. In addition, any single technical feature described or implied in the embodiments mentioned herein can still be combined or deleted between these technical features (or their equivalents) to obtain more other embodiments of the present invention that may not be directly mentioned herein.

[0025] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application may be combined with each other.

[0026] like Figure 1-2 As shown, the present invention provides a dual-drive multi-stage variable flow regulating mechanism for a downhole throttle, comprising a shell, a conical sleeve 8 is installed on the inner wall of the shell, a clutch sleeve 11 is installed in the shell above the conical sleeve 8, a petal elastic claw structure is formed at the lower end of the clutch sleeve 11, a boss structure is formed on the outer wall of the clutch sleeve 11, a rectangular spring 9 is sleeved on the clutch sleeve 11, and both ends of the spring 9 are limited by the boss structure and the conical sleeve 8, a plurality of flow holes 1101 are provided on the side wall of the clutch sleeve 11, a positioning guide sleeve 16 and a reversing guide sleeve 13 are also fixedly installed on the inner wall of the shell, a plurality of reversing grooves are circumferentially provided on the reversing guide sleeve 13, a plurality of positioning grooves are circumferentially provided on the positioning guide sleeve 16, the depth of the positioning groove is cyclically deepened, and a guide key 15 is installed on the side wall of the clutch sleeve 11;

[0027] In the initial position, the flow hole is sealed and the throttle is in a closed state; when the clutch sleeve 11 moves downward, the spring is compressed to the conical sleeve 8, and when it moves upward, the guide key 15 is sequentially and cyclically inserted into the positioning grooves of different depths of the positioning guide sleeve 16, so that the number of flow holes that are unsealed increases successively, and the downhole fluid is circulated through the throttle hole, thereby realizing multi-stage variable flow regulation.

[0028] In this embodiment, it can also be considered that: it also includes an automatic adjustment mechanism, which is installed inside the shell, and the automatic adjustment mechanism can drive the clutch sleeve 11 to descend multiple times to compress the spring, and when the clutch sleeve 11 goes up, the guide key 15 will be sequentially and cyclically inserted into the positioning grooves of different depths of the positioning guide sleeve 16, so that the number of flow holes that are unsealed increases in sequence, and the downhole fluid is circulated through the throttle hole, thereby realizing multi-stage variable flow regulation; specifically, the automatic adjustment mechanism includes a motor 1, a screw 5, and a motion rod 6, and the motor 1 is connected to the output end of the lead screw 5, the lead screw 5 is threadedly connected to one end of the moving rod 6, the moving rod 6 passes through the tapered sleeve 8, and the other end of the moving rod 6 is fixedly connected to the force transmission cap 10, the force transmission cap 10 is matched with the petal elastic claw structure of the clutch sleeve 11, an anti-rotation key 7 is fixedly installed on the outer wall of the moving rod 6, and a slideway matched with the anti-rotation key 7 is axially provided on the inner wall of the shell. When the motor 1 drives the lead screw 5 to rotate, the moving rod 6 is limited to move axially along the shell, thereby driving the clutch sleeve 11 to compress the spring downward.

[0029] The upper portion of the force transmission cap 10 forms a frustum structure, so that when the motor 1 drives the motion rod 6 upward, the force transmission cap 10 can enter the petal elastic claw structure of the clutch sleeve 11.

[0030] A throttle cap 14 is fixedly installed on the inner wall of the clutch sleeve 11. The throttle cap is a cap-shaped structure with an opening at the bottom. A liquid passage 1401 cooperating with the flow hole is provided on the side wall of the throttle cap. A sealing surface is formed between the shell and the clutch sleeve 11 through a sealing ring, and in the initial position, the flow hole is located below the sealing surface, so that the downhole fluid cannot communicate with the top of the shell through the flow hole, and the throttle is in a closed state.

[0031] It also includes a torque sensor 3 , both ends of which are connected to the motor 1 and the lead screw 5 respectively through an elastic coupling 2 .

[0032] It also includes a shell pressure cap 17, which is installed at one end of the shell. A salvage rod 18 passes through the shell pressure cap 17 and is fixedly connected to the clutch sleeve 11. The shell pressure cap 17 is provided with a plurality of liquid holes.

[0033] Furthermore, in this embodiment, the housing includes an outer shell 4 and a connecting shell 12, and the outer shell 4 and the connecting shell 12 are sealed and fixedly connected via threads and a sealing ring.

[0034] The installation process of the dual-drive multi-stage variable flow regulating mechanism for a downhole throttle of the present invention is as follows: a torque sensor 3 is fixed in a housing 4, and elastic couplings 2 are installed at the upper and lower ends thereof. The lower elastic coupling is connected to a motor 1, and the upper elastic coupling 2 is connected to a lead screw 5. The lead screw 5 has a disc-shaped structure at the lower end. After being inserted into the housing 4, it is limited by the inner reduction diameter of the corresponding position of the housing 4 through the disc-shaped structure. Six groups of flow holes are evenly distributed on the disc-shaped structure for conducting the fluid at the bottom of the wellbore. A groove is provided at the large diameter position of the moving rod 6 to embed an anti-rotation key 7. The moving rod 6 embedded with the anti-rotation key 7 is inserted into the corresponding inner reduction diameter position of the housing 4, and the anti-rotation key 7 is inserted into the slideway for overflow at the inner reduction diameter position to prevent the movement of the moving rod 6. The motion rod 6 rotates, the motion rod 6 has a thread inside and is connected to the thread on the upper end of the lead screw 5, the outer shell 4 and the matching surfaces of the torque sensor 3 and the motor 1 are all provided with a flower groove, which serves the purpose of passing current, the conical sleeve 8 is inserted into the upper end of the motion rod 6 and is screwed together with the outer shell 4, and the conical sleeve 8 is drilled with a hole for passing current, the force transmission cap 10 is screwed together with the motion rod 6, and the rectangular spring is installed in the outer shell 4, and the lower end of the clutch sleeve 11 has a petal elastic claw structure, and the elastic claw is expanded outward, and the clutch sleeve 11 wraps the force transmission cap 10 therein, at this time, the rectangular spring 9 is located between the outer shell 4 and the clutch sleeve 11, and the reversing guide sleeve 13 and the positioning guide sleeve 16 are inserted into the connecting shell 12 according to Figure 2 After the position relationship is fixed, plug welding is performed from the process hole at the corresponding position of the connecting shell 12 to fix the reversing guide sleeve 13 and the positioning guide sleeve 16 in the connecting shell 12, and then the connecting shell 12 is screwed to the upper end of the outer shell 4, and the guide key 15 is embedded in the upper end of the clutch sleeve 11 and inserted into the positioning groove of the positioning guide sleeve 16, and then the throttle cap 14 is installed in the clutch sleeve 11 The diameter reduction limit position, the clutch sleeve 11 is arranged with multiple groups of flow holes, corresponding to the position of the flow channel on the throttle cap 14, the shell is pressed After the cap 17 is inserted into the salvage rod 18, the salvage rod 18 is screwed together with the clutch sleeve 11. The lower end of the salvage rod 18 limits the throttle cap 14, and the outer wall of the salvage rod 18 limits the guide key 15. The shell pressure cap 17 is screwed together with the connecting shell 12. The shell pressure cap 17 is evenly distributed with liquid holes for flow. The connecting shell 12 has sealing ring grooves inside and outside, which respectively establish seals with the outer shell 4 and the clutch sleeve 11. Finally, the connector 19 is screwed together with the salvage rod 18 to complete the assembly of the entire mechanism.

[0035] When using a motor to control a multi-stage variable flow adjustment mechanism to change the throttling flow:

[0036] The motor 1 and the torque sensor 3 are installed in the housing 4, and elastic couplings 2 are installed at both ends of the torque sensor 3. The lower elastic coupling is used to receive the torque input by the motor 1, and the upper elastic coupling is used to transmit the torque to the lead screw 5. The lead screw 5 is connected to the moving rod 6 through a trapezoidal thread. Since the moving rod 6 is constrained to prevent axial rotation with the housing 4 through the anti-rotation key 7, when the lead screw 5 rotates, the moving rod 6 threadedly connected thereto does not rotate with it and a buckling action occurs, resulting in up and down movement. The upper end of the moving rod 6 is connected to the force transmission cap 10, and the initial position of the force transmission cap is installed in the petal elastic claw at the lower end of the clutch sleeve 11. The lower straight surface of the force transmission cap 10 cooperates with the inner step of the petal elastic claw to move up. The downward movement is transmitted to the clutch sleeve 11. A rectangular spring is installed between the clutch sleeve 11 and the housing 4. During the downward movement of the clutch sleeve 11, the rectangular spring is compressed and energy is gathered. When the movement rod 6 and the force transmission cap 10 drive the clutch sleeve 11 to reach the position of the conical sleeve 8, since the lower part of the petal elastic claw at the lower end of the clutch sleeve 11 is in the shape of a trumpet, after cooperating with the conical surface of the upper part of the conical sleeve 8, the axial force generated by the downward movement will be guided into a radial component force, so that the petal elastic claw will open, and the inner step of the petal elastic claw will expand outward, so that the clutch sleeve 11 will be freed from the restriction of the force transmission cap 10, and the rectangular spring will return to its position. The energy release drives the clutch sleeve 11 to move upward. This downward-then-upward movement process of the clutch sleeve 11 is the flow regulation workflow;

[0037] After the above action, after the clutch sleeve 11 is separated from the force transmission cap 10, the force transmission cap 10 continues to move downward to the limit position, the operation of the motor 1 is hindered and the torque increases. The torque sensor 3 transmits the positive torque increase signal to the control system of the intelligent throttle, and the control system changes the rotation direction of the motor 1. The motor 1 reverses, so that the movement rod 6 and the lead screw 5 are disengaged and move upward, and the movement rod 6 moves upward together with the force transmission cap 10. Since the upper end of the force transmission cap 10 is an inclined surface, after matching with the trumpet shape of the petal elastic claws at the lower end of the clutch sleeve 11, the upward force is transmitted to the radial direction to open the petal elastic claws, and the force transmission cap 10 can be reinserted into the clutch sleeve 11 to establish a linkage relationship with it, and the movement rod 6 moves upward to the limit position. After the torque sensor 3 is in position, the torque sensor 3 will transmit the reverse torque increase signal to the control system of the intelligent throttle, and the control system will stop the motor action. The force transmission cap 10 driven by the motor 1 first drives the clutch sleeve 11 to move downward, and then the clutch sleeve 11 is separated, and then the force transmission cap 10 moves upward to re-establish the connection with the clutch sleeve 11, which is the motor driving process; in the flow regulation workflow, the clutch sleeve 11 moves downward first and then upward, the clutch sleeve 11 is installed in the shell 4, and a guide key 15 is embedded in the upper end of the clutch sleeve 11. At the position of the shell 4 corresponding to the guide key 15, a positioning guide sleeve 16 and a reversing guide sleeve 13 are installed from top to bottom, and the positions of these two guide sleeves are shown in the attached figure. Figure 2As shown, each time the clutch sleeve 11 moves downward, the guide key 15 thereon will change its orientation under the action of the reversing guide sleeve 13, so that when the clutch sleeve 11 moves upward, it will be sequentially inserted into different positioning grooves of the positioning guide sleeve 16 in a cyclic manner, and the depth of each positioning groove will be cyclically deepened, so that the upward distance of the clutch sleeve 11 each time will also be cyclically lengthened. In this embodiment, there are three groups of flow holes axially arranged on the clutch sleeve 11. When the guide key 15 is inserted into the shortest closing position groove 1601 in the positioning guide sleeve 16, the upward distance of the clutch sleeve 11 is the shortest, and all the flow holes arranged thereon are not separated from the sealing surface established between the connecting shell 12 and the clutch sleeve 11. The fluid in the wellbore cannot flow out through the flow holes, and the entire throttle is in a closed state. At this time, a The flow regulation workflow; the guide key 15 enters the single set of open slots 1602 in the positioning guide sleeve 16. Compared with the closed position slot, the upward distance of the clutch sleeve 11 is lengthened, and the first set of flow holes arranged thereon passes through the sealing surface established by the connecting shell 12 and the clutch sleeve 11. The downhole fluid establishes communication with the upper part through this group of flow holes. Similarly, when the guide key 15 moves to the double set of open slots 1603 of the positioning guide sleeve 16, the clutch sleeve 11 will have 2 groups of flow holes to communicate with the upper part. When the guide key 15 moves to the three sets of open slots 1604 of the positioning guide sleeve 16, the clutch sleeve 11 will have 3 groups of flow holes to communicate with the upper part. The more flow holes that contact the seal, the greater the flow rate. In this way, multi-stage variable flow regulation is achieved.

[0038] When the multi-stage variable flow adjustment mechanism realized by external mechanical force changes the throttling flow:

[0039] The upper end of the clutch sleeve 11 is connected to the salvage rod 18 and the connecting head 19. When the flow needs to be changed, the wire operation inserts a hammer tool to hit the connecting head 19. The connecting head 19 drives the salvage rod 18 to directly transmit the impact force to the clutch sleeve 11. After the clutch sleeve 11 is forced to move downward to the limit, it will move upward under the action of the rectangular spring 9 to complete the flow regulation process. Through the action of the clutch sleeve 11 first down and then up, the guide key 15 installed thereon changes direction and enters different positioning grooves of the positioning guide rail sleeve 16. The number of throttle holes that are unsealed is controlled by the slot stroke difference to adjust the flow.

[0040] The above embodiments describe the present invention in detail, but the contents are only preferred embodiments of the present invention and cannot be considered to limit the scope of the present invention. All equivalent changes and improvements made within the scope of the present invention should still fall within the scope of the present invention.

Claims

1. A dual-drive multi-stage variable flow regulating mechanism for a downhole choke, characterized in that: It comprises a shell, a conical sleeve is installed on the inner wall of the shell, a clutch sleeve is installed in the shell above the conical sleeve, a petal elastic claw structure is formed at the lower end of the clutch sleeve, a boss structure is formed on the outer wall of the clutch sleeve, a spring is sleeved on the clutch sleeve, both ends of the spring are limited by the boss structure and the conical sleeve, a plurality of flow holes are arranged on the side wall of the clutch sleeve, a positioning guide sleeve and a reversing guide sleeve are also fixedly installed on the inner wall of the shell, a plurality of reversing grooves are circumferentially arranged on the reversing guide sleeve, a plurality of positioning grooves are circumferentially arranged on the positioning guide sleeve, the depth of the positioning grooves is cyclically deepened, and a guide key is installed on the side wall of the clutch sleeve; In the initial position, the flow hole is sealed and the throttle is in a closed state; when the clutch sleeve moves downward, the spring is compressed to the conical sleeve, and when it moves upward, the guide key is sequentially and cyclically inserted into the positioning grooves of different depths of the positioning guide sleeve, so that the number of flow holes that are unsealed increases in sequence, and the downhole fluid is circulated through the throttle hole, thereby realizing multi-stage variable flow regulation; It also includes an automatic adjustment mechanism, which is installed inside the housing, and can drive the clutch sleeve to descend multiple times to compress the spring, and when the clutch sleeve ascends, the guide key will be sequentially and cyclically inserted into the positioning grooves of different depths of the positioning guide sleeve, so that the number of flow holes that are unsealed increases in sequence, and the downhole fluid is circulated through the throttle hole, thereby realizing multi-stage variable flow regulation; It also includes a shell pressing cap, which is installed at one end of the shell. The fishing rod passes through the shell pressing cap and is fixedly connected to the clutch sleeve.

2. The dual-drive multi-stage variable flow regulating mechanism for a downhole choke according to claim 1, characterized in that: The automatic adjustment mechanism includes a motor, a lead screw, and a moving rod. The output end of the motor is connected to the lead screw, which is threadedly connected to one end of the moving rod. The moving rod passes through the tapered sleeve, and the other end of the moving rod is fixedly connected to a force transmission cap. The force transmission cap is cooperatively connected with the petal elastic claw structure of the clutch sleeve. When the motor drives the lead screw to rotate, the moving rod is limited to move axially along the shell, thereby driving the clutch sleeve to compress the spring downward.

3. The dual-drive multi-stage variable flow regulating mechanism for a downhole choke according to claim 2 is characterized in that: The upper part of the force transmission cap forms a frustum structure, so that when the motor drives the motion rod to move upward, the force transmission cap can enter the petal elastic claw structure of the clutch sleeve.

4. The dual-drive multi-stage variable flow regulating mechanism for a downhole choke according to claim 1, characterized in that: A throttle cap is fixedly mounted on the inner wall of the clutch sleeve. The throttle cap is a cap-shaped structure with an opening at the bottom. A liquid passage matching the flow hole is arranged on the side wall of the throttle cap.

5. The dual-drive multi-stage variable flow regulating mechanism for a downhole choke according to claim 4, characterized in that: A sealing surface is formed between the housing and the clutch sleeve, and in the initial position, the flow hole is located below the sealing surface, so that the downhole fluid cannot communicate with the top of the housing through the flow hole, and the throttle is in a closed state.

6. The dual-drive multi-stage variable flow regulating mechanism for a downhole choke according to claim 2, characterized in that: It also includes a torque sensor, both ends of which are connected to the motor and the lead screw respectively through elastic couplings.

7. The dual-drive multi-stage variable flow regulating mechanism for a downhole choke according to claim 2 or 3, characterized in that: An anti-rotation key is fixedly mounted on the outer wall of the movement rod, and a slideway cooperating with the anti-rotation key is axially arranged on the inner wall of the shell.

8. The dual-drive multi-stage variable flow regulating mechanism for a downhole choke according to claim 1, characterized in that: The housing pressure cap is provided with a plurality of liquid holes.

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