Differential pressure regulation structure, downhole tools, and drive methods for downhole tools

Abstract

This invention relates to a differential pressure regulating structure, a downhole tool, and a driving method for the downhole tool, belonging to the field of oil drilling technology. The differential pressure regulating structure of this invention includes an outer cylinder, an inner cylinder, a magnetic induction device, and a control device. The outer cylinder is disposed within the wellbore; the inner cylinder is disposed within the outer cylinder; the magnetic induction device is disposed within the outer cylinder and located at the end of the inner cylinder closer to the drilling rig, and includes an induction coil; a throttling device is disposed within the outer cylinder and located at the end of the inner cylinder furthest from the drilling rig; a magnetic trigger element can pass through the induction coil with the flow of the fluid medium, causing the induction coil to generate a corresponding induced electrical signal; the control device can receive the induced electrical signal and control the throttling device to open to the target opening degree according to the induced electrical signal, so that the internal and external pressure difference of the outer cylinder reaches the target pressure difference. The technical solution disclosed in this invention can solve the problem that the internal and external pressure difference at the drill string location where the tool is located is relatively fixed in the existing drilling process.

Description

Technical Field

[0001] This invention relates to the field of oil drilling technology, and particularly to a differential pressure regulating structure, a downhole tool, and a method for driving the downhole tool. Background Technology

[0002] In oil exploration and oilfield development, oil drilling plays a very important role. Oil drilling is an engineering project that uses specialized equipment to establish a channel between the surface and underground oil wells, so as to collect underground oil and gas along the oil pipeline to the surface for use.

[0003] Some downhole tools used in oil drilling operations rely on the pressure difference between the inside and outside of the drill string for power, such as variable diameter stabilizers. Once the drill string assembly is finalized and deployed into the well, the pressure difference between the inside and outside of the downhole tools is generally adjusted by the displacement rate. However, because parameters such as drilling fluid displacement and density are difficult to change over a wide range, the adjustable range of the displacement rate during drilling is small. The pressure difference between the inside and outside of the drill string at the tool's location is relatively fixed, which limits the performance of the downhole tools and affects operational efficiency. Summary of the Invention

[0004] This invention provides a differential pressure regulating structure, a downhole tool, and a driving method for the downhole tool, which can solve the problem that the internal and external pressure difference at the location of the tool in the existing drilling process is relatively fixed.

[0005] In a first aspect, embodiments of the present invention provide a differential pressure regulating structure, comprising:

[0006] An outer cylinder is disposed inside the wellbore, one end of which is used to connect to the drilling equipment and provide a flow channel for the fluid medium;

[0007] The inner cylinder is disposed within the outer cylinder;

[0008] A magnetic induction device is disposed inside the outer cylinder and located at one end of the inner cylinder near the drilling device. The magnetic induction device includes at least one induction coil.

[0009] A throttling device is disposed inside the outer cylinder and located at the end of the inner cylinder away from the drilling device;

[0010] A magnetic trigger, capable of flowing through the induction coil with the fluid medium, and causing the induction coil to generate a corresponding induced electrical signal; and

[0011] A control device is installed inside the inner cylinder. The control device can receive the induced electrical signal and control the throttling device to open to the target opening degree according to the induced electrical signal, so that the pressure difference between the inside and outside of the outer cylinder reaches the target pressure difference.

[0012] In one embodiment, the magnetic induction device includes:

[0013] The main body is provided with multiple magnetic induction channels;

[0014] Multiple induction coils, each corresponding one-to-one with a plurality of magnetic induction channels, are disposed within the corresponding magnetic induction channels; and

[0015] An analog-to-digital converter is disposed within the main body and is electrically connected to a plurality of the induction coils to convert the induced electrical signals generated by the induction coils into digital signals and transmit them to the control device.

[0016] In one embodiment, the magnetic trigger includes:

[0017] magnets; and

[0018] A protective layer is applied to the outer surface of the magnet.

[0019] In one embodiment, the throttling device includes:

[0020] A throttle valve assembly is disposed within the outer cylinder; and

[0021] A motor assembly is disposed within the inner cylinder. The output shaft of the motor assembly is connected to the throttle valve assembly to drive the throttle valve assembly to rotate, thereby opening the throttle valve assembly to the target opening degree.

[0022] In one embodiment, the throttle valve assembly includes:

[0023] A stator is disposed on the outer wall of the inner cylinder, and the stator is provided with at least one static flow channel that extends through the stator in the axial direction;

[0024] The rotor is connected to the output shaft of the motor assembly. The rotor is provided with at least one dynamic flow channel that runs through the rotor in the axial direction. The at least one dynamic flow channel corresponds one-to-one with at least one static flow channel.

[0025] The motor assembly can drive the rotor to rotate, thereby changing the overlap area between the dynamic flow channel and the corresponding static flow channel.

[0026] In one embodiment, the rotor is provided with a plurality of dynamic flow channels and a plurality of limiting female magnetic sheets. The plurality of dynamic flow channels are arranged at equal intervals around the rotor in the circumferential direction. The plurality of limiting female magnetic sheets are arranged at equal intervals around the rotor in the circumferential direction, and the plurality of dynamic flow channels and the plurality of limiting female magnetic sheets are arranged alternately in the circumferential direction.

[0027] The inner wall of the outer cylinder is provided with multiple limiting areas, and each of the multiple limiting areas corresponds to a multiple limiting female piece. Each limiting area is provided with multiple limiting male magnetic pieces arranged at intervals around the outer cylinder in the circumferential direction.

[0028] The limiting female magnetic sheet is magnetically attracted to one of the limiting male magnetic sheets in the corresponding limiting area.

[0029] In one embodiment, the control device includes:

[0030] A control module is disposed inside the inner cylinder. The control module is capable of receiving the induced electrical signal and controlling the motor assembly to drive the rotor to rotate to a preset position according to the induced electrical signal.

[0031] A power module is disposed inside the inner cylinder and located between the control module and the magnetic induction device. The power module is electrically connected to the control module, the motor assembly and the magnetic induction device respectively.

[0032] In one embodiment, the differential pressure regulating structure further includes:

[0033] A floating sealing device is disposed on one end of the inner cylinder near the throttling device;

[0034] A partition is disposed within the inner cylinder and located between the floating sealing device and the control module. The partition, the floating sealing device, and the inner cylinder together form a motor cavity, which is filled with hydraulic oil.

[0035] The motor assembly is disposed within the motor cavity.

[0036] Secondly, embodiments of the present invention provide a downhole tool, including the differential pressure adjustment structure as described above; and

[0037] A drilling device is connected to one end of the outer cylinder, and the drilling device is capable of operating under the drive of the target pressure difference.

[0038] Thirdly, embodiments of the present invention provide a driving method for a downhole tool, applied to the downhole tool as described above, comprising:

[0039] Place the downhole tool inside the wellbore;

[0040] The fluid medium and the magnetic trigger are inserted into the downhole tool, so that the magnetic trigger passes through the induction coil along with the fluid medium, and the induction coil generates an induced electrical signal.

[0041] Based on the induced electrical signal, the opening of the throttling device is opened to the target opening to adjust the pressure difference between the inside and outside of the outer cylinder to the target pressure difference;

[0042] Based on the target pressure difference, the torque of the drilling equipment is adjusted to the target torque.

[0043] Compared with the prior art, the advantages of the embodiments of the present invention are as follows:

[0044] (1) By adjusting the opening of the throttling device, the cross-sectional area of ​​the flow channel in the outer cylinder is changed, thereby regulating the flow rate of the fluid medium passing through the changed cross-sectional area. This, in turn, changes the pressure inside the outer cylinder, achieving the purpose of regulating the pressure difference between the inside and outside of the outer cylinder. This solves the problem that the pressure difference between the inside and outside of the drill string where the tool is located is relatively fixed in the existing drilling process, expands the adjustment range of the pressure difference, avoids limiting the performance of downhole tools, and makes them more adaptable to complex downhole conditions. When the opening of the throttling device increases, the flow velocity of the fluid medium increases, the resistance decreases, the pressure inside the outer cylinder decreases, and the pressure difference between the inside and outside of the outer cylinder decreases. When the opening of the throttling device decreases, the flow velocity of the fluid medium decreases, the resistance increases, the pressure inside the outer cylinder increases, and the pressure difference between the inside and outside of the outer cylinder increases.

[0045] (2) The induced electrical signal generated by the magnetic trigger through the induction coil is used as the adjustment signal to adjust the pressure difference between the inside and outside of the wellbore. Users only need to put the magnetic trigger into the outside of the wellbore on the ground to realize the adjustment function. The adjustment method is simple, convenient and accurate. Attached Figure Description

[0046] The invention will now be described in more detail with reference to embodiments and the accompanying drawings.

[0047] Figure 1 This is a cross-sectional view of a differential pressure regulating structure provided in an embodiment of the present invention in the main viewing direction;

[0048] Figure 2 yes Figure 1 A sectional view of the magnetic induction device provided in the Chinese embodiment in a side view direction;

[0049] Figure 3 yes Figure 1 A cross-sectional view of the stator in the side view direction provided in the Chinese embodiment;

[0050] Figure 4 yes Figure 1 A cross-sectional view of the rotor in the side view direction provided in the embodiment;

[0051] Figure 5 yes Figure 1 A schematic diagram of the structure of the No. 1 magnetic trigger provided in the embodiment;

[0052] Figure 6 yes Figure 1 A schematic diagram of the structure of magnetic trigger element No. 2 provided in the embodiment;

[0053] Figure 7 yes Figure 1 A schematic diagram of the structure of magnetic trigger element No. 3 provided in the embodiment;

[0054] Figure 8 This is a schematic diagram of the structure of a downhole tool provided in another embodiment of the present invention;

[0055] Figure 9 This is a flowchart of a driving method for a downhole tool provided in another embodiment of the present invention.

[0056] Figure label:

[0057] 1. Differential pressure regulating structure; 2. Drilling equipment; 3. Drill pipe; 4. Wellbore;

[0058] 10. Outer cylinder;

[0059] 20. Inner cylinder; 210. Motor compartment;

[0060] 30. Magnetic induction device; 310. Main body; 3101. Magnetic induction channel; 320. Induction coil; 330. Analog-to-digital converter;

[0061] 40. Throttling device; 410. Throttling valve assembly; 4101. Stator; 4102. Static flow passage; 4103. Rotor; 4104. Dynamic flow passage; 4105. Limiting female magnetic sheet; 4106. Limiting male magnetic sheet; 420. Motor assembly;

[0062] 50. Magnetic trigger; 510. Magnet; 520. Protective layer;

[0063] 60. Control device; 610. Control module; 620. Power supply module;

[0064] 70. Floating sealing device;

[0065] 80. Partition;

[0066] 90. Alignment device. Detailed Implementation

[0067] The invention will now be further described with reference to the accompanying drawings.

[0068] In oil exploration and oilfield development, oil drilling plays a very important role. Oil drilling is an engineering project that uses specialized equipment to establish a channel between the surface and underground oil wells, so as to collect underground oil and gas along the oil pipeline to the surface for use.

[0069] In oil drilling operations, some downhole tools rely on the pressure difference between the inside and outside of the drill string for power. For example, variable diameter stabilizers use this pressure difference to increase the diameter, while rotatable drill string directional drilling tools generate torque by controlling the pressure difference. Once the drill string assembly is finalized and deployed, the pressure difference between the inside and outside of the downhole tools is typically adjusted using the displacement rate. However, because parameters such as drilling fluid displacement and density are difficult to change significantly, the adjustable range of the displacement rate during drilling is limited. The pressure difference between the inside and outside of the drill string at the tool's location is relatively fixed, which restricts the performance of the downhole tools and affects operational efficiency.

[0070] Example 1

[0071] like Figure 1 As shown, to solve the above-mentioned technical problems, this embodiment of the invention provides a differential pressure regulating structure 1, including an outer cylinder 10, an inner cylinder 20, a magnetic induction device 30, a throttling device 40, a magnetic trigger 50, and a control device 60; the outer cylinder 10 is disposed inside the wellbore 4, and one end of the outer cylinder 10 is used to connect to the drilling device 2 and provide a flow channel for the fluid medium; the inner cylinder 20 is disposed inside the outer cylinder 10; the magnetic induction device 30 is disposed inside the outer cylinder 10 and located at the end of the inner cylinder 20 near the drilling device 2, and the magnetic induction... The device 30 includes at least one induction coil 320; a throttling device 40 is disposed inside the outer cylinder 10 and located at the end of the inner cylinder 20 away from the drilling device 2; a magnetic trigger 50 can pass through the induction coil 320 with the flow of the fluid medium and cause the induction coil 320 to generate a corresponding induced electrical signal; a control device 60 is disposed inside the inner cylinder 20, and the control device 60 can receive the induced electrical signal and control the throttling device 40 to open to the target opening degree according to the induced electrical signal, so that the pressure difference between the inside and outside of the outer cylinder 10 reaches the target pressure difference.

[0072] As can be seen from the above, by adjusting the opening of the throttling device 40, the cross-sectional area of ​​the flow channel of the outer cylinder 10 is changed, thereby regulating the flow rate of the fluid medium passing through the changed flow channel cross-sectional area. This, in turn, changes the pressure inside the outer cylinder 10, achieving the purpose of regulating the pressure difference between the inside and outside of the outer cylinder 10. This solves the problem that the pressure difference between the inside and outside of the drill string at the tool location is relatively fixed in the existing drilling process, expands the adjustment range of the pressure difference, avoids limiting the performance of downhole tools, and makes them more adaptable to complex downhole conditions. When the opening of the throttling device 40 increases, the flow velocity of the fluid medium increases, the resistance decreases, and the pressure inside the outer cylinder 10 decreases, thus reducing the pressure difference between the inside and outside of the outer cylinder 10. Conversely, when the opening of the throttling device 40 decreases, the flow velocity of the fluid medium decreases, the resistance increases, and the pressure inside the outer cylinder 10 increases, thus increasing the pressure difference between the inside and outside of the outer cylinder 10.

[0073] The induced electrical signal generated by the magnetic trigger 50 through the induction coil 320 is used as the adjustment signal to adjust the pressure difference between the inside and outside of the outer cylinder 10 inside the wellbore 4. The user only needs to insert the magnetic trigger 50 into the outer cylinder 10 from the ground to realize the adjustment function. The adjustment method is simple, convenient and accurate.

[0074] It should be noted that drilling device 2 is a differential pressure driven type of drilling device 2, such as a variable diameter stabilizer or a rotatable drill string directional drilling tool.

[0075] It should also be noted that the induced electrical signal includes, but is not limited to, induced electromotive force. The magnetic trigger 50 is magnetic and can generate a magnetic field; the induction coil 320 is a ring structure made of insulated wire, typically copper wire; based on the principle of electromagnetic induction, a change in the magnetic flux within the coil generates an induced electromotive force. When the magnetic trigger 50 enters the coil, the magnetic flux of the coil changes, thus generating an induced electromotive force.

[0076] It should also be noted that the fluid medium is drilling fluid, which is a type of groundwater used in the drilling process. Its main functions are to provide support and protection during the drilling process, as well as to remove rocks and minerals to facilitate drilling operations.

[0077] It should also be noted that, such as Figure 1 , Figure 8 As shown, both the outer cylinder 10 and the inner cylinder 20 are cylindrical; the two ends of the outer cylinder 10 are designed as drill pipe 3 threads, which can be connected to the drilling device 2 through the drill pipe 3 threads; the interior of the outer cylinder 10 is provided with a stepped cylindrical flow channel to facilitate the installation of various devices; the inner cylinder 20 has a pressure-resistant function to protect the devices located inside the inner cylinder 20.

[0078] Example 2

[0079] like Figure 1As shown, the differential pressure regulating structure 1 includes an outer cylinder 10, an inner cylinder 20, a magnetic induction device 30, a throttling device 40, a magnetic trigger 50, and a control device 60. The outer cylinder 10 is disposed inside the wellbore 4, and one end of the outer cylinder 10 is used to connect to the drilling device 2 and provide a flow channel for the fluid medium. The inner cylinder 20 is disposed inside the outer cylinder 10. The magnetic induction device 30 is disposed inside the outer cylinder 10 and located at the end of the inner cylinder 20 near the drilling device 2. The magnetic induction device 30 includes at least one induction coil 320. The throttling device 40 is disposed inside the outer cylinder 10 and located at the end of the inner cylinder 20 away from the drilling device 2. The magnetic trigger 50 can pass through the induction coil 320 with the flow of the fluid medium and cause the induction coil 320 to generate a corresponding induced electrical signal. The control device 60 is disposed inside the inner cylinder 20. The control device 60 can receive the induced electrical signal and control the throttling device 40 to open to the target opening degree according to the induced electrical signal so that the pressure difference between the inside and outside of the outer cylinder 10 reaches the target pressure difference.

[0080] As can be seen from the above, by adjusting the opening of the throttling device 40, the cross-sectional area of ​​the flow channel of the outer cylinder 10 is changed, thereby regulating the flow rate of the fluid medium passing through the changed flow channel cross-sectional area. This, in turn, changes the pressure inside the outer cylinder 10, achieving the purpose of regulating the pressure difference between the inside and outside of the outer cylinder 10. This solves the problem that the pressure difference between the inside and outside of the drill string at the tool location is relatively fixed in the existing drilling process, expands the adjustment range of the pressure difference, avoids limiting the performance of downhole tools, and makes them more adaptable to complex downhole conditions. When the opening of the throttling device 40 increases, the flow velocity of the fluid medium increases, the resistance decreases, and the pressure inside the outer cylinder 10 decreases, thus reducing the pressure difference between the inside and outside of the outer cylinder 10. Conversely, when the opening of the throttling device 40 decreases, the flow velocity of the fluid medium decreases, the resistance increases, and the pressure inside the outer cylinder 10 increases, thus increasing the pressure difference between the inside and outside of the outer cylinder 10.

[0081] The induced electrical signal generated by the magnetic trigger 50 through the induction coil 320 is used as the adjustment signal to adjust the pressure difference between the inside and outside of the outer cylinder 10 inside the wellbore 4. The user only needs to insert the magnetic trigger 50 into the outer cylinder 10 from the ground to realize the adjustment function. The adjustment method is simple, convenient and accurate.

[0082] It should be noted that drilling device 2 is a differential pressure driven type of drilling device 2, such as a variable diameter stabilizer or a rotatable drill string directional drilling tool.

[0083] It should also be noted that the induced electrical signal includes, but is not limited to, induced electromotive force. The magnetic trigger 50 is magnetic and can generate a magnetic field; the induction coil 320 is a ring structure made of insulated wire, typically copper wire; based on the principle of electromagnetic induction, a change in the magnetic flux within the coil generates an induced electromotive force. When the magnetic trigger 50 enters the coil, the magnetic flux of the coil changes, thus generating an induced electromotive force.

[0084] It should also be noted that the fluid medium is drilling fluid, which is a type of groundwater used in the drilling process. Its main functions are to provide support and protection during the drilling process, as well as to remove rocks and minerals to facilitate drilling operations.

[0085] It should also be noted that, such as Figure 1 , Figure 8 As shown, both the outer cylinder 10 and the inner cylinder 20 are cylindrical; the two ends of the outer cylinder 10 are designed as drill pipe 3 threads, which can be connected to the drilling device 2 through the drill pipe 3 threads; the interior of the outer cylinder 10 is provided with a stepped cylindrical flow channel to facilitate the installation of various devices; the inner cylinder 20 has a pressure-resistant function to protect the devices located inside the inner cylinder 20.

[0086] like Figure 1 , Figure 2 As shown, in some embodiments, the magnetic induction device 30 includes a main body 310, a plurality of induction coils 320, and an analog-to-digital converter 330; the main body 310 is provided with a plurality of magnetic induction channels 3101; the plurality of induction coils 320 correspond one-to-one with the plurality of magnetic induction channels 3101, and the induction coils 320 are disposed in the corresponding magnetic induction channels 3101; the analog-to-digital converter 330 is disposed in the main body 310, and the analog-to-digital converter 330 is electrically connected to the plurality of induction coils 320 to convert the induced electrical signals generated by the induction coils 320 into digital signals and transmit them to the control device 60.

[0087] By setting up the magnetic induction channel 3101, a structural basis can be provided for the installation of the induction coil 320. Compared with setting up only one large-aperture magnetic induction channel 3101, the present invention sets up multiple small-aperture magnetic induction channels 3101, which allows the magnetic trigger component to be closer to the induction coil 320 when passing through the magnetic induction channel 3101, generating a clearer induced electrical signal, so as to ensure the reliability of the control differential pressure regulation.

[0088] It should be noted that, as Figure 1 As shown, the main body 310 is disposed on the inner wall of the outer cylinder 10, and the fluid medium flows through the magnetic induction channel 3101; the main body 310 is provided with four magnetic induction channels 3101, and the four magnetic induction channels 3101 are arranged at equal intervals around the axis of the main body 310.

[0089] It should also be noted that the main body 310 is provided with a slot for mounting the analog-to-digital converter 330.

[0090] In some embodiments, the magnetic trigger 50 includes a magnet 510 and a protective layer 520; the protective layer 520 covers the outer surface of the magnet 510.

[0091] The protective layer 520 protects the magnet 510, preventing it from cracking due to collisions during movement and ensuring the normal operation of the differential pressure regulating structure 1.

[0092] It should be noted that the magnet 510 is not limited to a spherical shape, and the protective layer 520 protects, but is not limited to, plastic materials.

[0093] It should also be noted that the size of the magnet 510 is closely related to the magnitude of the induced electrical signal. When the magnet 510 is spherical, the larger the diameter of the magnet 510, the larger the induced electrical signal. Different induced electrical signals correspond to different digital signals. Therefore, magnetic triggers 50 of different specifications can be designed according to requirements, that is, magnetic triggers 50 with different magnet diameters. Different specifications of magnetic triggers 50 can be used to generate different induced electrical signals to control the throttling device 40 to open to different target openings, so that different target pressure differences are generated inside and outside the outer cylinder 10, thereby increasing the adjustment range of the pressure difference adjustment device and meeting the performance requirements of the drilling device 2.

[0094] For example, such as Figures 5-7 As shown, three different specifications of magnetic triggers 50 are designed, namely three magnetic triggers 50 with different magnet diameters, namely magnetic trigger 1, magnetic trigger 2 and magnetic trigger 3. The magnet diameter of magnetic trigger 1 is larger than that of magnetic trigger 2, and the magnet diameter of magnetic trigger 2 is larger than that of magnetic trigger 3.

[0095] The induced electrical signal generated by the activation of magnetic trigger 1 is greater than that generated by magnetic trigger 2, and the induced electrical signal generated by the activation of magnetic trigger 2 is greater than that generated by magnetic trigger 3. Therefore, when magnetic trigger 1 is activated, the throttling device 40 opens to its maximum opening degree; when magnetic trigger 2 is activated, the throttling device 40 opens to its intermediate opening degree; and when magnetic trigger 3 is activated, the throttling device 40 opens to its minimum opening degree.

[0096] like Figure 1As shown, in some embodiments, the throttling device 40 includes a throttling valve assembly 410 and a motor assembly 420; the throttling valve assembly 410 is disposed inside the outer cylinder 10; the motor assembly 420 is disposed inside the inner cylinder 20, and the output shaft of the motor assembly 420 is connected to the throttling valve assembly 410 to drive the throttling valve assembly 410 to rotate, so that the throttling valve assembly 410 opens to the target opening degree.

[0097] The opening of the throttle valve assembly 410 is adjusted by setting the motor assembly 420 to drive the throttle valve assembly 410 to rotate, and the adjustment method is simple and convenient.

[0098] It should be noted that the motor assembly 420 includes a motor, a reducer, and a Hall sensor. The motor's output shaft is connected to the reducer's input shaft, and the reducer's output shaft is connected to the throttle valve assembly 410. The reducer reduces the motor's speed and increases torque. The Hall sensor is mounted on the motor. A Hall sensor is a device used to monitor magnetic fields. Based on the Hall effect, when current passes through a conductor, the magnetic field affects the movement of charges on the conductor, thereby generating a potential difference in the conductor. The Hall sensor is used to monitor the motor's speed and revolutions.

[0099] like Figure 1 , Figure 3 , Figure 4 As shown, in some embodiments, the throttle valve assembly 410 includes a stator 4101 and a rotor 4103; the stator 4101 is disposed on the outer wall of the inner cylinder 20, and at least one static flow channel 4102 is provided on the stator 4101 in the axial direction; the rotor 4103 is connected to the output shaft of the motor assembly 420, and at least one dynamic flow channel 4104 is provided on the rotor 4103 in the axial direction, and at least one dynamic flow channel 4104 corresponds one-to-one with at least one static flow channel 4102; wherein, the motor assembly 420 can drive the rotor 4103 to rotate, so as to change the overlap area of ​​the dynamic flow channel 4104 and the corresponding static flow channel 4102.

[0100] The motor assembly 420 drives the rotor 4103 to rotate relative to the stator 4101, causing a change in the overlap area between the moving flow channel 4104 and the stationary flow channel 4102. The overlap area S is positively correlated with the opening degree ω of the throttling device 40, specifically:

[0101] S=451.25+8.01ω(0°≦ω≦90°)

[0102] Therefore, the larger the opening of the throttling device 40, the larger the overlap area between the dynamic flow channel 4104 and the static flow channel 4102.

[0103] It should be noted that, as Figure 1As shown, the axial direction is parallel to the X direction; the stator 4101 is provided with two static flow channels 4102 that penetrate the stator 4101 in the axial direction, and the stator 4101 is provided with a through hole through which the output shaft of the power supply assembly 420 passes; the rotor 4103 is provided with two dynamic flow channels 4104 that penetrate the rotor 4103 in the axial direction.

[0104] It should also be noted that the cross-sectional shape of the moving flow channel 4104 is fan-shaped, and the cross-section of the stationary flow channel 4102 includes the first section and the second section connected to both ends of the first section. The first section is fan-shaped, and the second section is arc-shaped. In addition, the central angle subtended by the moving flow channel 4104 is larger than the central angle subtended by the stationary flow channel 4102, thereby giving the throttle valve assembly 410 the maximum opening.

[0105] like Figure 1 As shown, in some embodiments, the control device includes a control module 610 and a power module 620; the control module 610 is disposed inside the inner cylinder 20, and the control module 610 is capable of receiving induced electrical signals and controlling the motor assembly 420 to drive the rotor 4103 to rotate to a preset position according to the induced electrical signals; the power module 620 is disposed inside the inner cylinder 20 and located between the control module 610 and the magnetic induction device 30, and the power module 620 is electrically connected to the control module 610, the motor assembly 420 and the magnetic induction device 30 respectively.

[0106] By setting the power module 620, it can not only supply power to the control module 610, motor assembly 420 and magnetic induction device 30, but also has data transmission function, which transmits data between analog-to-digital converter 330 and control module 610, providing a structural basis for control device 60 to control the opening of throttle valve assembly 410 based on induced electrical signals.

[0107] It should be noted that when the control module 610 receives a new digital signal, the control module 610 will compare and calculate the current digital signal with the new digital signal, and then determine the rotation direction and number of rotations of the motor, so that the rotor 4103 rotates to the specified position.

[0108] It should also be noted that the control module 610 includes, but is not limited to, a PLC controller, the specific structure and working principle of which are existing technologies and will not be described in detail in this application.

[0109] Example 3

[0110] Example 3 differs from Example 2 in the following ways:

[0111] like Figure 1 , Figure 3 , Figure 4As shown, in some embodiments, the rotor 4103 is provided with a plurality of dynamic flow channels 4104 and a plurality of limiting female magnetic pieces 4105. The plurality of dynamic flow channels 4104 are arranged at equal intervals around the rotor 4103 in the circumferential direction; the plurality of limiting female magnetic pieces 4105 are arranged at equal intervals around the rotor 4103 in the circumferential direction, and the plurality of dynamic flow channels 4104 and the plurality of limiting female magnetic pieces 4105 are arranged alternately in the circumferential direction.

[0112] Multiple limiting zones are provided on the inner wall of the outer cylinder 10. Each limiting zone corresponds to a multiple limiting mother plate. Each limiting zone is provided with multiple limiting public magnetic plates 4106 arranged at intervals around the outer cylinder 10 in the circumferential direction.

[0113] The limiting female magnetic sheet 4105 is magnetically attracted to one of the limiting male magnetic sheets 4106 in the corresponding limiting area.

[0114] By setting the limiting female magnetic plate 4105 and the limiting male magnetic plate 4106, the rotor 4103 is ensured to remain in the target position after rotating to the target position, preventing the rotor 4103 from changing position due to the impact of the high fluid medium. This ensures that the throttle valve assembly 410 maintains the target opening degree, and the motor assembly 420 does not need to constantly correct the opening degree of the throttle valve assembly 410, thereby saving power and extending the service life of the differential pressure regulating structure 1. In addition, by setting multiple limiting male magnetic plates 4106 at intervals in each limiting zone, corresponding to multiple different target positions of the rotor 4103, and different target positions corresponding to different target opening degrees of the throttle valve assembly 410, the rotor 4103 can be kept in the required target position, improving practicality and flexibility, and further meeting the needs of the drilling equipment 2.

[0115] It should be noted that both the limiting female magnetic sheet 4105 and the limiting male magnetic sheet 4106 are magnetic; the number of the moving current channel 4104, the stationary current channel 4102, and the limiting female magnetic sheet 4105 can be set as needed. For example, as Figure 4 As shown, there are two moving flow channels 4104 and two limiting magnetic plates 4105. The two moving flow channels 4104 and the two limiting magnetic plates 4105 are arranged alternately in the circumferential direction. Two limiting areas are provided on the inner wall of the outer cylinder 10, and the two limiting areas correspond one-to-one with the two limiting magnetic plates.

[0116] It should also be noted that the number of limiting magnetic plates 4106 set in each limiting zone can be set as needed. The number of limiting magnetic plates 4106 can be equal to the number of magnetic triggers 50, thereby ensuring that the rotor 4103 can be kept at the target opening position corresponding to the current magnetic trigger 50, and ensuring the accuracy of the target opening and target pressure difference.

[0117] For example, when there are three types of magnetic trigger 50, namely magnetic trigger 1, magnetic trigger 2, and magnetic trigger 3 respectively;

[0118] like Figure 4 As shown, each limiting zone is provided with three limiting magnetic pieces 4106. The three limiting magnetic pieces 4106 are arranged at equal intervals in the circumference within the limiting zone. The three limiting magnetic pieces 4106 are numbered 1, 2, and 3 in a counterclockwise direction.

[0119] When the No. 1 magnetic trigger is engaged, the throttling device 40 opens to its maximum opening, and the limiting female magnetic piece 4105 is magnetically attracted to the corresponding No. 1 male magnetic piece; when the No. 2 magnetic trigger is engaged, the throttling device 40 opens to its intermediate opening, and the limiting female magnetic piece 4105 is magnetically attracted to the corresponding No. 2 male magnetic piece; when the No. 3 magnetic trigger is engaged, the throttling device 40 opens to its minimum opening, and the limiting female magnetic piece 4105 is magnetically attracted to the corresponding No. 3 male magnetic piece.

[0120] The other structures of Example 3 are the same as those of Example 2, and will not be described in detail here.

[0121] Example 4

[0122] Example 4 differs from Example 3 in the following ways:

[0123] like Figure 1 As shown, in some embodiments, the differential pressure regulating structure 1 further includes a floating sealing device 70 and a partition 80; the floating sealing device 70 is disposed on one end of the inner cylinder 20 near the throttling device 40; the partition 80 is disposed inside the inner cylinder 20 and located between the floating sealing device 70 and the control module, the partition 80, the floating sealing device 70 and the inner cylinder 20 together form a motor cavity, which is filled with hydraulic oil; wherein, the motor assembly 420 is disposed inside the motor cavity.

[0124] The floating sealing device 70 and the partition 80 provide space for the installation of the motor assembly 420. The hydraulic oil protects the motor assembly 420 and improves heat dissipation. The floating sealing device 70 not only makes the pressure inside the motor cavity equal to the pressure in the wellbore 4, avoiding pressure difference, but also reduces friction, ensuring that the motor assembly 420 can drive the rotor 4103 to rotate. It also prevents sand-containing drilling fluid from entering the motor and causing damage to the motor.

[0125] It should be noted that the motor is an oil-immersed motor, which can maintain a low temperature during operation and reduce mechanical wear, thereby improving the motor's service life and efficiency.

[0126] It should also be noted that, such as Figure 1As shown, the differential pressure adjustment structure 1 also includes a centralizer 90, which is installed on the inner cylinder 20 and located in the motor compartment 210. The centralizer 90 can position and adjust the object by physical or hydraulic means to keep it in a straight line.

[0127] The other structures of Example 4 are the same as those of Example 3, and will not be described in detail here.

[0128] In summary, compared to the existing technologies that commonly use pressure control and cable control to control downhole throttle valves, this invention uses magnetic trigger control. Users only need to insert the magnetic trigger into the outer cylinder from the ground to achieve the adjustment function. The adjustment method is simple, convenient, and accurate, eliminating the need for continuous cables of several thousand meters and avoiding the problem of pressure disturbances disrupting downhole control and causing the downhole throttle valve to become uncontrollable.

[0129] Example 5

[0130] like Figure 8 As shown, this embodiment of the invention also provides a downhole tool, including a differential pressure regulating structure 1 as described in any of the above embodiments and a drilling device 2. The drilling device 2 is connected to one end of the outer cylinder 10, and the drilling device 2 can operate under the drive of the target differential pressure.

[0131] This embodiment has all the technical effects brought about by the technical solutions of the above embodiments.

[0132] It should be noted that, as Figure 8 As shown, the downhole tools also include a drill bit, a screw drill string and a wireless measurement-while-drilling instrument, and a drill pipe 3. The drill bit, the screw drill string and the wireless measurement-while-drilling instrument, the differential pressure adjustment structure 1, and the drilling rig 2 are connected in sequence. The differential pressure adjustment structure 1 and the drilling rig 2 can be connected through the drill pipe 3, and the drilling rig 2 can also be connected to the surface device through the drill pipe 3. In addition, the differential pressure adjustment structure 1 is located on the end of the drilling rig 2 near the drill bit.

[0133] It should also be noted that the drilling device 2 is a pressure differential driven drilling device 2. For example, the drilling device 2 is a rotatable drill string directional drilling tool, which relies on the pressure differential inside and outside the drill string to control the torque. When performing rotary directional drilling, the rotatable drill string directional drilling tool needs to generate a relatively small torque. When performing composite drilling, the rotatable drill string directional drilling tool needs to generate a sufficiently large torque under a larger pressure differential. However, existing rotatable drill string directional drilling tools cannot generate the largest possible torque to meet drilling requirements. When encountering complex situations such as drill bit collapse and stuck drill bits, the rotatable drill string directional drilling tool is generally permanently locked. Compared with this method, the present invention provides a pressure differential to the rotatable drill string directional drilling tool through the pressure differential adjustment structure 1, adjusts the torque of the rotatable drill string directional drilling tool, broadens its working performance and functions, and makes it suitable for different drilling conditions.

[0134] Example 6

[0135] like Figure 9 As shown, this embodiment of the invention provides a driving method for a downhole tool, applied to a downhole tool as described in any of the above embodiments, comprising:

[0136] S101: Place the downhole tool inside the wellbore 4;

[0137] S102: The fluid medium and the magnetic trigger 50 are put into the downhole tool, so that the magnetic trigger 50 passes through the induction coil 320 along with the fluid medium, and the induction coil 320 generates an induced electrical signal;

[0138] It should be noted that the fluid medium is drilling fluid, and the magnetic trigger 50 flows with the fluid medium. During the flow, the magnetic trigger 50 passes through the induction coil 320. The magnitude of the induced electrical signal is related to the size of the magnet 510 of the magnetic trigger 50. For example, three different specifications of magnetic triggers 50 can be set, that is, the magnets 510 of the three magnetic triggers 50 are of different sizes. They are ordered from largest to smallest according to the diameter of the magnets 510 of the magnetic triggers 50, namely magnetic trigger 1, magnetic trigger 2, and magnetic trigger 3. The induced electrical signal generated by the activation of magnetic trigger 1 is greater than that generated by the activation of magnetic trigger 2, and the induced electrical signal generated by the activation of magnetic trigger 2 is greater than that generated by the activation of magnetic trigger 3.

[0139] S103: Based on the induced electrical signal, the opening of the throttling device 40 is opened to the target opening to adjust the pressure difference between the inside and outside of the outer cylinder 10 to the target pressure difference;

[0140] It should be noted that users can control the opening degree of the throttling device 40 by using magnetic triggers 50 of different specifications;

[0141] For example, design three different specifications of magnetic triggers 50, namely magnetic trigger 1, magnetic trigger 2, and magnetic trigger 3. The magnet diameter of magnetic trigger 1 is larger than that of magnetic trigger 2, and the magnet diameter of magnetic trigger 2 is larger than that of magnetic trigger 3. The three specifications correspond to three opening degrees.

[0142] When magnetic trigger 1 is engaged, throttling device 40 opens to its maximum opening degree; when magnetic trigger 2 is engaged, throttling device 40 opens to its intermediate opening degree; when magnetic trigger 3 is engaged, throttling device 40 opens to its minimum opening degree.

[0143] It should also be noted that before proceeding with step S102, a test must be performed first. The fluid medium and magnet No. 1 are inserted into the downhole tool, and the opening of the throttling device 40 is opened to the maximum opening to adjust the pressure difference between the inside and outside of the outer cylinder 10 to the minimum pressure difference before driving the downhole tool.

[0144] It should also be noted that the opening degree of the throttling device 40 is negatively correlated with the pressure difference inside and outside the outer cylinder 10. When the opening degree of the throttling device 40 increases, the pressure difference inside and outside the outer cylinder 10 decreases. This is because when the opening degree of the throttling device 40 increases, the flow velocity of the fluid medium increases and the resistance decreases, which reduces the pressure inside the outer cylinder 10 and the pressure difference inside and outside the outer cylinder 10. When the opening degree of the throttling device 40 decreases, the flow velocity of the fluid medium decreases and the resistance increases, which increases the pressure inside the outer cylinder 10 and the pressure difference inside and outside the outer cylinder 10.

[0145] For example, three different target openings—maximum opening, intermediate opening, and minimum opening—are set, along with three different target pressure differences—maximum pressure difference, intermediate pressure difference, and minimum pressure difference. When the throttling device 40 is opened to the maximum opening, the pressure difference between the inside and outside of the outer cylinder 10 is adjusted to the minimum pressure difference; when the throttling device 40 is opened to the intermediate opening, the pressure difference between the inside and outside of the outer cylinder 10 is adjusted to the intermediate pressure difference; and when the throttling device 40 is opened to the minimum opening, the pressure difference between the inside and outside of the outer cylinder 10 is adjusted to the maximum pressure difference.

[0146] S104: Based on the target pressure difference, adjust the torque of the drilling device 2 to the target torque.

[0147] It should be noted that the greater the target pressure difference, the greater the target torque that drilling device 2 can generate.

[0148] It should also be noted that the relationship between the throttling loss ΔP and the opening ω of the throttling device 40 is as follows:

[0149]

[0150] In the formula, ρ is the density of the fluid, in g / cm³. 3 Q is the fluid displacement, L / s, and ω is the opening degree, °.

[0151] Drilling equipment 2 includes, but is not limited to, rotatable drill string directional drilling tools. The following description uses rotatable drill string directional drilling tools as an example.

[0152] When encountering complex situations such as collapse and stuck drill bit during drilling, and it is necessary to increase the torque of the rotatable drill string directional drilling tool, the No. 2 magnetic trigger can be put in to open the throttling device 40 to the middle opening, generating a throttling loss of 2-3MPa, so as to increase the pressure difference between the inside and outside of the outer cylinder 10 by 2-3MPa, thereby enabling the rotatable drill string directional drilling tool to generate greater torque.

[0153] When encountering complex situations such as collapse or stuck drill bit during drilling, and it is necessary to increase the torque of the rotatable drill string directional drilling tool, the No. 3 magnetic trigger can be put in to open the throttling device 40 to the minimum opening, generating a throttling loss of 5-6 MPa, so as to increase the pressure difference between the inside and outside of the outer cylinder 10 by 5-6 MPa, thereby enabling the rotatable drill string directional drilling tool to generate greater torque.

[0154] According to drilling requirements, when the complex situation is dealt with, the No. 1 magnetic trigger can be put back into operation to restore the opening of the throttling device 40 to the maximum opening, so as to reduce the pressure difference inside and outside the outer cylinder 10, thereby reducing the torque that the directional drilling tool of the rotatable drill string can generate.

[0155] Although the invention has been described with reference to preferred embodiments, various modifications can be made and components can be replaced with equivalents without departing from the scope of the invention. In particular, the technical features mentioned in the various embodiments can be combined in any manner as long as there is no structural conflict. The invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A differential pressure regulating structure, characterized in that, include: An outer cylinder is disposed inside the wellbore, one end of which is used to connect to the drilling equipment and provide a flow channel for the fluid medium; The inner cylinder is disposed within the outer cylinder; A magnetic induction device is disposed inside the outer cylinder and located at one end of the inner cylinder near the drilling device. The magnetic induction device includes at least one induction coil. A throttling device is disposed inside the outer cylinder and located at the end of the inner cylinder away from the drilling device; A magnetic trigger is capable of passing through the induction coil along with the flow of the fluid medium, and causing the induction coil to generate a corresponding induced electrical signal; as well as A control device is installed inside the inner cylinder. The control device can receive the induced electrical signal and control the throttling device to open to the target opening degree according to the induced electrical signal, so that the pressure difference between the inside and outside of the outer cylinder reaches the target pressure difference.

2. The differential pressure regulating structure according to claim 1, characterized in that, The magnetic induction device includes: The main body is provided with multiple magnetic induction channels; Multiple induction coils, each corresponding one-to-one with a plurality of magnetic induction channels, are disposed within the corresponding magnetic induction channels; and An analog-to-digital converter is disposed within the main body and is electrically connected to a plurality of the induction coils to convert the induced electrical signals generated by the induction coils into digital signals and transmit them to the control device.

3. The differential pressure regulating structure according to claim 1 or 2, characterized in that, The magnetic trigger includes: magnets; and A protective layer is applied to the outer surface of the magnet.

4. The differential pressure regulating structure according to claim 1, characterized in that, The throttling device includes: A throttle valve assembly is disposed within the outer cylinder; and A motor assembly is disposed within the inner cylinder. The output shaft of the motor assembly is connected to the throttle valve assembly to drive the throttle valve assembly to rotate, thereby opening the throttle valve assembly to the target opening degree.

5. The differential pressure regulating structure according to claim 4, characterized in that, The throttle valve assembly includes: A stator is disposed on the outer wall of the inner cylinder, and the stator is provided with at least one static flow channel that extends through the stator in the axial direction; The rotor is connected to the output shaft of the motor assembly. The rotor is provided with at least one dynamic flow channel that runs through the rotor in the axial direction. The at least one dynamic flow channel corresponds one-to-one with at least one static flow channel. The motor assembly can drive the rotor to rotate, thereby changing the overlap area between the dynamic flow channel and the corresponding static flow channel.

6. The differential pressure regulating structure according to claim 5, characterized in that, The rotor is provided with multiple dynamic flow channels and multiple limiting magnetic sheets. The multiple dynamic flow channels are arranged at equal intervals around the rotor in the circumferential direction. The multiple limiting magnetic sheets are arranged at equal intervals around the rotor in the circumferential direction, and the multiple dynamic flow channels and the multiple limiting magnetic sheets are arranged alternately in the circumferential direction. The inner wall of the outer cylinder is provided with multiple limiting areas, and each of the multiple limiting areas corresponds to a multiple limiting female magnetic sheet. Each limiting area is provided with multiple limiting male magnetic sheets arranged at intervals around the outer cylinder in the circumferential direction. The limiting female magnetic sheet is magnetically attracted to one of the limiting male magnetic sheets in the corresponding limiting area.

7. The differential pressure regulating structure according to any one of claims 5-6, characterized in that, The control device includes: A control module is disposed inside the inner cylinder. The control module is capable of receiving the induced electrical signal and controlling the motor assembly to drive the rotor to rotate to a preset position according to the induced electrical signal. A power module is disposed inside the inner cylinder and located between the control module and the magnetic induction device. The power module is electrically connected to the control module, the motor assembly and the magnetic induction device respectively.

8. The differential pressure regulating structure according to claim 7, characterized in that, The differential pressure regulating structure further includes: A floating sealing device is disposed on one end of the inner cylinder near the throttling device; A partition is disposed within the inner cylinder and located between the floating sealing device and the control module. The partition, the floating sealing device, and the inner cylinder together form a motor cavity, which is filled with hydraulic oil. The motor assembly is disposed within the motor cavity.

9. A downhole tool, characterized in that, include: The differential pressure regulating structure as described in any one of claims 1-8; as well as A drilling device is connected to one end of the outer cylinder, and the drilling device is capable of operating under the drive of the target pressure difference.

10. A method for driving a downhole tool, applied to the downhole tool as described in claim 9, characterized in that, include: Place the downhole tool inside the wellbore; The fluid medium and the magnetic trigger are inserted into the downhole tool, so that the magnetic trigger passes through the induction coil along with the fluid medium, and the induction coil generates an induced electrical signal. Based on the induced electrical signal, the opening of the throttling device is opened to the target opening to adjust the pressure difference between the inside and outside of the outer cylinder to the target pressure difference; Based on the target pressure difference, the torque of the drilling equipment is adjusted to the target torque.

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