Apparatus and method for regulating a choke with a downhole robot

Abstract

The application discloses a device for adjusting a flow regulator by using a downhole robot, comprising a wellhead control unit, a downhole robot and an adjustable flow regulator; the wellhead control unit is in communication connection with the downhole robot, and the wellhead control unit can control the downhole robot to run up and down in a wellbore; the adjustable flow regulator is connected with the downhole robot to complete the adjustment of the size of a gas nozzle. The application further discloses a method for adjusting a flow regulator by using a downhole robot. The application makes full use of gravity and the upthrust of gas flow during gas well production, and realizes the upgoing and downgoing of the downhole robot in the oil pipe through the expansion and contraction of a rubber cylinder. When the current gas nozzle diameter cannot meet the production requirement along with the reduction of the production pressure of the gas well, the downhole robot is combined with the adjustable flow regulator to complete the adjustment of the size of the gas nozzle, thereby effectively shortening the construction period and improving the operation efficiency.

Description

Technical Field

[0001] This invention belongs to the technical field of natural gas extraction equipment, and relates to a device for adjusting a throttle using a downhole robot, as well as a method for adjusting a throttle using a downhole robot. Background Technology

[0002] In natural gas extraction, downhole chokes are often installed in the wellbore for pressure reduction, flow control, production limitation, and production adjustment. Downhole chokes are further classified into slip-type chokes and pre-installed chokes based on their setting method. Slip-type chokes are deployed via well testing wireline operations and anchored at any position within the production tubing to control production. When production is adjusted or no flow control is required, the choke is retrieved using a retrieval tool connected via well testing wireline operations. Pre-installed chokes are deployed via well testing wireline operations and anchored within a pre-installed working tube (connected to the production tubing and lowered into the well along with it). When production is adjusted or no flow control is required, the choke core is retrieved using a GS retrieval tool connected via well testing wireline operations. The success rates of retrieval for the slip-type choke and the pre-installed choke are 67% and 75% respectively, which are both low. Moreover, when either of these two types of chokes fails to be retrieved, it affects the smooth implementation of gas well production adjustment, mid-term drainage and gas production processes, and later production needs such as pressurized pipe pulling.

[0003] Existing research indicates that the only currently available intelligent downhole chokes are (e.g., Chinese patents such as "An Adjustable Intelligent Downhole Choke Valve for Gas Wells," publication number CN213016307U; "An Intelligent Downhole Choke Valve with Emergency Shutdown Capability for Gas Wells," publication number CN206338053U; "An Intelligent Downhole Choke Device," publication number CN209398399U; "An Intelligent Choke for Natural Gas Wells," publication number CN108343404B; and "An Intelligent Downhole Choke Applicable to Oil and Gas Field Production," publication number C). Both N215332773U and others integrate electromechanical systems into downhole chokes. However, downhole batteries, storage batteries, and electronic components suffer from poor stability and high costs downhole, affecting downhole choke adjustment. Furthermore, in these designs, the choke nozzle automatically adjusts based on bottom hole pressure fluctuations. This method is susceptible to temporary downhole pressure fluctuations or pressure changes caused by sudden events in the gas well, potentially leading to frequent nozzle activation or misoperation. Additionally, the pressure wave command signal may be distorted when transmitted downhole, affecting reception efficiency and thus impacting nozzle adjustment. Summary of the Invention

[0004] The purpose of this invention is to provide a device for adjusting a choke using a downhole robot, which can move up and down inside the well to adjust the choke.

[0005] Another object of the present invention is to provide a method for adjusting a throttle using a downhole robot.

[0006] The technical solution adopted in this invention is a device for adjusting a throttle using a downhole robot, comprising a wellhead control unit, a downhole robot, and an adjustable throttle; the wellhead control unit and the downhole robot are communicatively connected, and the wellhead control unit can control the downhole robot to move up and down inside the wellbore; the adjustable throttle is connected to the downhole robot to complete the adjustment of the nozzle size.

[0007] The invention is further characterized in that,

[0008] The downhole robot includes a first retrieval neck with a T-shaped pressure tapping channel inside; a centering ring welded to the outer periphery of the first retrieval neck; a pressure sensor inside the first retrieval neck; a second pressure sensor located below the pressure tapping channel; the second pressure sensor is connected to the upper end of a communication and control module, and the lower end of the communication and control module is electrically connected to the upper end of a reduction motor; it also includes an adjusting core rod, with the lower end of the reduction motor inserted into a square hole connected to the upper end of the adjusting core rod; both ends of the cross shaft at the upper end of the adjusting core rod are provided with plane bearings; a fixing component is sleeved on the outer wall of the adjusting core rod, the upper end of the fixing component pressing against the lower end of the plane bearing, and the lower end threadedly connected to a hexagonal fitting; a rubber sleeve is sleeved on the outer wall of the fixing component, the upper end of the rubber sleeve threadedly connected to the lower end of the first retrieval neck; and the lower end of the adjusting core rod is threadedly connected to an external adjusting hexagonal fitting.

[0009] A sealing ring is also provided between the two ends of the cross shaft of the plane bearing and the adjusting core rod.

[0010] The adjustable flow device includes a second retrieval neck, a docking hexagonal connector, an adjusting hexagonal connector, a fixing ring, a spring plate, a clamp block, a rubber sleeve support block, a sealing rubber sleeve, an inner adjusting component, an adjusting thread, an inner ceramic ring, an outer slit throttling ring, and a sand shield. The second retrieval neck has a concave step inside that matches the docking hexagonal connector and the adjusting hexagonal connector. An outer cylinder is fitted in the middle of the outer wall of the second retrieval neck. Clamp blocks are symmetrically arranged in the through hole at the lower end of the outer cylinder. The fixing ring is placed in the ring formed by the threaded section of the outer wall of the second retrieval neck and the groove in the inner wall of the outer cylinder. A rubber sleeve support block is fitted on the upper outer wall of the inner adjusting component. The rubber sleeve support block is threadedly connected to the inner adjusting component. The upper end of the rubber sleeve support block is threadedly connected to the lower end of the second retrieval neck. An inner ceramic ring is glued to the lower end of the outer wall of the inner adjusting component. The sealing rubber sleeve is fitted on the upper outer wall of the rubber sleeve support block.

[0011] The sand shield is threadedly connected to the rubber sleeve support block, and the outer wall of the sand shield has multiple radial cuts.

[0012] An outer slit throttling ring is fitted on the outer wall of the inner ceramic ring, and the lower part of the rubber sleeve support block is fitted on the outer wall of the inner ceramic ring and the outer slit throttling ring.

[0013] Another technical solution adopted in this invention is a method of adjusting the throttle using a downhole robot, specifically as follows:

[0014] S1: In the working state, the adjustable flow device is installed at the bottom of the gas well shaft and is fixed by the clamping blocks. The expansion of the rubber sleeve separates the well shaft. After the high-pressure gas produced by the gas well flows into the well shaft, it passes through the internal regulating component of the adjustable flow device and the throttling nozzle formed by the inner ceramic ring. Due to the throttling effect, the pressure in the well shaft above the adjustable flow device drops to medium and low pressure. At this time, the gas flow velocity increases. The high-speed gas flow carries droplets to the wellhead and is then transported to the downstream unit to complete the normal throttling and pressure reduction production.

[0015] S2: During gas well production, if the size of the throttle formed by the inner regulating component and inner ceramic ring of the adjustable flow device cannot meet the gas well production needs, adjust the second fishing neck connected to the hexagonal fitting. The reduction motor rotates, and the reduction motor drives the adjusting core rod and the adjusting hexagonal fitting to rotate in sequence, thereby driving the inner regulating component of the adjustable flow device to rotate, changing the size of the throttle formed by the inner regulating component and inner ceramic ring, and achieving the required gas well production.

[0016] The beneficial effects of this invention are:

[0017] This invention fully utilizes gravity and the upward thrust of gas flow during gas well production. Through the expansion and contraction of the rubber sleeve, the downhole robot moves upward and downward within the tubing. As the gas well production pressure decreases, and the current nozzle diameter can no longer meet production needs, the downhole robot descends in combination with an adjustable flow device to adjust the nozzle size. This effectively shortens the construction cycle, improves operational efficiency, and reduces costs. It not only saves manpower, materials, and time but also protects the ecological environment, aligning with the concept of "cost reduction and efficiency improvement." Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the device structure for adjusting the throttle using a downhole robot, as per the present invention.

[0019] Figure 2 This is a structural diagram of the wellhead control unit in the device for adjusting the throttle using a downhole robot, as described in this invention.

[0020] Figure 3 This is a structural diagram of the downhole robot in the device for adjusting the throttle using a downhole robot, as described in this invention.

[0021] Figure 4 This is a structural diagram of the adjustable flow device in the device for adjusting the flow regulator using a downhole robot, as described in this invention.

[0022] Figure 5 This invention provides a remote control operation diagram of a device for adjusting a throttle using a downhole robot.

[0023] In the diagram, 1. Wellhead control unit, 2. Downhole robot, 3. Regulated flow meter, 4. Blowout preventer, 5. Communication and charging device, 6. Electric capture device, 7. Regulating valve, 8. Flow meter, 9. First pressure sensor, 10. First retrieval neck, 11. Pressure tapping channel, 12. Second pressure sensor, 13. Centralizing ring, 14. Communication and control module, 15. High-temperature battery, 16. Control circuit board, 17. Temperature sensor, 18. Gear motor, 19. Flat... 20. Face bearing, 21. Sealing ring, 22. Adjusting mandrel, 23. Rubber sleeve, 24. External fixing part, 25. Connecting hexagonal part, 26. Adjusting hexagonal part, 27. Second salvage neck, 28. Connecting internal hexagonal part, 29. Adjusting internal hexagonal part, 30. Fixing retaining ring, 31. Spring plate, 32. Clamping block, 33. Rubber sleeve support block, 34. Sealing rubber sleeve, 35. Internal adjusting part, 36. Adjusting thread, 37. Internal ceramic ring, 38. External slit throttling ring, 39. Sandproof cover. Detailed Implementation

[0024] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0025] Example 1

[0026] This invention utilizes a device for adjusting a throttle via a downhole robot, such as... Figure 1 As shown, it includes a wellhead control unit 1, a downhole robot 2, and an adjustable flow device 3;

[0027] The wellhead control unit 1 communicates with the downhole robot 2, sending commands and charging information to the robot. Simultaneously, it can read various data from the downhole robot 2, such as operating pressure, temperature, and gravitational acceleration, and transmit this data remotely. The downhole robot 2 can move up and down within the wellbore and can be used in conjunction with the wellhead control unit 1 or independently to adjust the adjustable flow device 3. The adjustable flow device 3 has an internal gas nozzle adjustment mechanism, consisting only of mechanical parts, ensuring the reliability of the device. The downhole robot 2 can descend to the adjustable flow device 3, dock with it, and adjust the gas nozzle to achieve different gas production rates from the gas well.

[0028] Example 2

[0029] like Figure 2As shown, the wellhead control unit 1 includes a blowout preventer 4, a communication and charging device 5, an electric capture device 6, a regulating valve 7, a flow meter 8, and a first pressure sensor 9. The communication and charging device 5, the electric capture device 6, the regulating valve 7, the flow meter 8, and the first pressure sensor 9 are connected by cables. The blowout preventer 4 is connected to the wellhead to buffer the impact force of the downhole robot reaching the wellhead. When charging of the downhole robot 2 is required, the electric capture device 6 moves, and the downhole robot 2 remains at the wellhead, communicating and charging through the communication and charging device 5. The second pressure sensor 12 and the temperature sensor 17 in the downhole robot 2 can be linked with the regulating valve 7, the flow meter 8, and the first pressure sensor 9 through intelligent control to control the upward and downward speeds of the downhole robot 2.

[0030] like Figure 3 As shown, the downhole robot 2 includes a first retrieval neck 10, which has a T-shaped pressure tapping channel 11 inside. A straightening ring 13 is welded to the outer periphery of the first retrieval neck 10. A pressure sensor 12 is also installed inside the first retrieval neck 10. A second pressure sensor 12 is located below the pressure tapping channel 11. The second pressure sensor 12 is connected to the upper end of the communication and control module 14 via a convenient connector. The lower end of the communication and control module 14 is electrically connected to the upper end of the geared motor 18 via a convenient connector. The communication and control module 14 includes an electrically connected high-temperature battery 15, a control circuit board 16, and a temperature sensor 17.

[0031] It also includes an adjusting core rod 21, with the lower end of the geared motor 18 inserted into the square hole at the upper end of the adjusting core rod 21; both ends of the cross shaft at the upper end of the adjusting core rod 21 are provided with plane bearings 19; a sealing ring 20 is also provided between the plane bearings 19 and the two ends of the cross shaft of the adjusting core rod 21; a fixing member 23 is sleeved on the outer wall of the adjusting core rod 21, the upper end of the fixing member 23 presses against the lower end of the plane bearing 19, and the lower end is threadedly connected to the docking hexagonal piece 24; a rubber sleeve 22 is sleeved on the outer wall of the fixing member 23, the upper end of the rubber sleeve 22 is threadedly connected to the lower end of the first retrieval neck 10; the lower end of the adjusting core rod 21 is threadedly connected to the outer adjusting hexagonal piece 25;

[0032] The rubber sleeve 22 is used to seal the pipe wall, enabling the downhole robot 2 to move up or down inside the wellbore. The external fixing part 23, the docking hexagonal part 24, and the adjusting hexagonal part 25 are for docking with the adjustable flow device 3.

[0033] like Figure 4As shown, the adjustable flow device 3 includes a second salvage neck 26, a docking hexagonal joint 27, an adjusting hexagonal joint 28, a fixing ring 29, a spring plate 30, a clamp block 31, a rubber tube support block 32, a sealing rubber tube 33, an inner adjusting component 34, an adjusting thread 35, an inner ceramic ring 36, an outer slit throttling ring 37, and a sandproof cover 38. The second salvage neck 26 has a concave step inside that matches the docking hexagonal piece 24 and the adjusting hexagonal piece 25; an outer cylinder 28 is fitted in the middle of the outer wall of the second salvage neck 26 and locked by a pin; clamp blocks 31 are symmetrically arranged in the through hole at the lower end of the outer cylinder 28, and the clamp blocks 31 are embedded in the outer cylinder 28 by spring plates 30; a fixing ring 29 is placed in the ring formed by the threaded section of the outer wall of the salvage neck 26 and the groove of the inner wall of the outer cylinder 28; an inner ceramic ring 36 is glued to the lower end of the outer wall of the inner adjusting piece 34, and there is a boss adjusting thread in the lower middle part of the outer wall of the inner adjusting piece 34; an outer slit throttling ring 37 is fitted on the outer wall of the inner ceramic ring 36, and the lower end is inserted into the groove of the locking cover;

[0034] The upper outer wall of the inner adjusting component 34 is fitted with a rubber tube support block 32, which is threadedly connected to the inner adjusting component 34. The upper end of the rubber tube support block 32 is threadedly connected to the lower end of the second salvage neck 26. The lower part of the rubber tube support block 32 is fitted on the outer wall of the inner ceramic ring 36 and the outer slit throttling ring 37, and is threadedly connected to the lock cover. The sealing rubber tube 33 is fitted on the upper outer wall of the rubber tube support block 32. The sandproof cover 38 is threadedly connected to the rubber tube support block 32, and the outer wall of the sandproof cover 38 has multiple radial slits.

[0035] The docking hexagonal component 24 and the adjusting hexagonal component 25 in the downhole robot 2 are matched and connected with the second retrieval neck 26 in the adjustable flow device 3.

[0036] Example 3

[0037] The present invention utilizes a downhole robot to adjust a throttle, specifically as follows:

[0038] S1: In the working state, the adjustable flow device 3 is installed at a certain position below the gas well shaft (depth > 1000m) and fixed by the clamping block 31. The rubber sleeve 32 expands to separate the well shaft. After the high-pressure gas (≥20MPa) produced by the gas well flows into the well shaft, it passes through the throttling nozzle formed by the inner regulating component 34 and the inner ceramic ring 36 of the adjustable flow device 3. Due to the throttling effect, the pressure in the well shaft above the adjustable flow device 3 drops to medium-low pressure (<6.4MPa). At this time, the gas flow velocity increases, and the high-speed gas flow carries droplets to the wellhead and is then transported to the downstream unit, completing the normal throttling and pressure reduction production.

[0039] S2: During gas well production, when the size of the throttle formed by the inner regulating component 34 and the inner ceramic ring 36 of the adjustable flow device 3 cannot meet the gas well production needs, the fishing neck 26 connected to the adjusting hexagonal component 24 is adjusted, the reduction motor 18 rotates, and the reduction motor 18 drives the adjusting core rod 21 and the adjusting hexagonal component 25 to rotate in sequence. The adjusting hexagonal component 25 relies on the rotation of the reduction motor 18 to drive the inner regulating component 34 of the adjustable flow device 3 to rotate, thereby changing the size of the throttle formed by the inner regulating component 34 and the inner ceramic ring 36 to achieve the required gas well production.

[0040] This invention's downhole adjustable flow device retains only a mechanical structure, with adjustment achieved through a downhole robot, avoiding the instability of electronic components operating downhole over long periods. The downhole robot can be combined with the flow control device, communicating and adjusting via wellhead control. In case of power failure, the downhole robot ascends to the wellhead for charging; simultaneously, communication between the surface and downhole systems can be achieved via pressure waves. This invention fully utilizes gravity and the upward thrust of gas flow during well production, combined with the closed pipeline of the downhole robot to achieve its upward and downward movement. This invention can establish communication with a remote terminal via the wellhead control device, enabling remote adjustment of the downhole flow control device.

[0041] Example 4

[0042] like Figure 5 The diagram shown is a general overview of the remote control operation of this invention. Under normal operating conditions, the downhole robot 2 remains located downhole and can communicate with the wellhead via pressure wave changes. The wellhead generates pressure fluctuations through the regulating valve 7, thereby achieving remote adjustment of gas well production. When the downhole robot 2's battery is low, according to the built-in program on the control circuit board 16, the downhole robot 2 uses the reduction motor 18 to push the regulating rod 21, causing the rubber sleeve 22 to seal the pipe wall, and the downhole robot 2 moves upward to the wellhead. At the wellhead, the electric capture device 6 is activated, positioning the downhole robot 2 at the wellhead position, where it is recharged via the communication and charging device 5.

[0043] This invention allows the downhole robot 2 to be permanently positioned on the downhole adjustable flow device 3, enabling timely remote control. Alternatively, the downhole robot 2 can be kept at the wellhead normally, with adjustments only required when a command is issued via wellhead communication. The downhole robot 2 then descends to complete the adjustment and returns to the wellhead to await further instructions.

Claims

1. A device for adjusting a throttle using a downhole robot, characterized in that, It includes a wellhead control unit (1), a downhole robot (2), and an adjustable flow device (3); the wellhead control unit (1) and the downhole robot (2) are connected in communication, and the wellhead control unit (1) can control the downhole robot (2) to move up and down in the wellbore. The adjustable flow device (3) is connected to the downhole robot (2) to adjust the size of the gas nozzle. The downhole robot (2) includes a first retrieval neck (10), which has a T-shaped pressure tapping channel (11) inside; a straightening ring (13) is welded to the outer periphery of the first retrieval neck (10); a second pressure sensor (12) is also installed inside the first retrieval neck (10); the second pressure sensor (12) is located at the lower part of the pressure tapping channel (11); the second pressure sensor (12) is connected to the upper end of the communication and control module (14), and the lower end of the communication and control module (14) is electrically connected to the upper end of the reduction motor (18); it also includes an adjusting core rod (21), which... The lower end of the geared motor (18) is inserted into the square hole at the upper end of the connecting adjusting core rod (21); both ends of the cross shaft at the upper end of the adjusting core rod (21) are provided with plane bearings (19); an outer fixing part (23) is sleeved on the outer wall of the adjusting core rod (21), the upper end of the outer fixing part (23) presses the lower end of the plane bearing (19), and the lower end is threadedly connected to the docking hexagonal part (24); a rubber sleeve (22) is sleeved on the outer wall of the outer fixing part (23), the upper end of the rubber sleeve (22) is threadedly connected to the lower end of the first retrieval neck (10); the lower end of the adjusting core rod (21) is threadedly connected to the adjusting hexagonal part (25); The adjustable flow device (3) includes a second retrieval neck (26), a docking hexagonal fitting (27), an adjusting hexagonal fitting (28), a fixing ring (29), a spring plate (30), a clamp block (31), a rubber sleeve support block (32), a sealing rubber sleeve (33), an inner adjusting component (34), an adjusting thread (35), an inner ceramic ring (36), an outer slit throttling ring (37), and a sandproof cover (38). The second retrieval neck (26) has a concave step inside that matches the docking hexagonal fitting (24) and the adjusting hexagonal fitting (25). An outer cylinder is fitted in the middle of the outer wall of the second retrieval neck (26). A clamp block (31) is symmetrically arranged in the through hole at the lower end of the outer cylinder. The fixing ring (29) is placed on the threaded section of the outer wall of the second retrieval neck (26) and the concave section of the inner wall of the outer cylinder. In the annular groove formed by the inner adjusting component (34), a rubber tube support block (32) is fitted on the outer wall of the upper end of the inner adjusting component (34). The rubber tube support block (32) is threadedly connected to the inner adjusting component (34). The upper end of the rubber tube support block (32) is threadedly connected to the lower end of the second salvage neck (26). An inner ceramic ring (36) is glued to the lower end of the outer wall of the inner adjusting component (34). The sealing rubber tube (33) is fitted on the outer wall of the upper end of the rubber tube support block (32). The sandproof cover (38) is threadedly connected to the rubber tube support block (32). The outer wall of the sandproof cover (38) has multiple radial slits. An outer slit throttling ring (37) is fitted on the outer wall of the inner ceramic ring (36). The lower part of the rubber tube support block (32) is fitted on the outer wall of the inner ceramic ring (36) and the outer slit throttling ring (37).

2. The device for adjusting the throttle using a downhole robot according to claim 1, characterized in that, A sealing ring (20) is also provided between the two ends of the cross shaft of the plane bearing (19) and the adjusting core rod (21).

3. A method for adjusting a throttle using a downhole robot, employing the device described in claim 2, characterized in that... Specifically: S1: In the working state, the adjustable flow device (3) is installed under the well casing of the gas well. The sealing rubber tube (33) expands and separates the well casing. After the high-pressure gas produced by the gas well flows into the well casing, it passes through the throttle nozzle formed by the inner regulating component (34) and the inner ceramic ring (36). The gas flow rate increases, and the high-speed gas flow carries the droplets to the wellhead and is then transported to the downstream unit to complete the normal throttling and pressure reduction production. S2: During the gas well production process, the second fishing neck (26) connected to the adjustment docking hexagonal piece (24) is adjusted, the reduction motor (18) rotates, and the reduction motor (18) drives the adjustment core rod (21) and the adjustment hexagonal piece (25) to rotate in sequence, thereby driving the inner adjustment piece (34) to rotate, changing the size of the throttle formed by the inner adjustment piece (34) and the inner ceramic ring (36), and completing the required gas well production.

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