Differential pressure adjusting structure, downhole tool and driving method of downhole tool

Abstract

The invention relates to a differential pressure adjusting structure, a downhole tool and a driving method of the downhole tool, and relates to the technical field of petroleum drilling technologies. The pressure difference adjusting structure comprises an outer cylinder, an inner cylinder, a magnetic induction device and a control device. The outer barrel body is arranged in a shaft; the inner barrel is arranged in the outer barrel; the magnetic induction device is arranged in the outer barrel and located at the end, close to the well drilling device, of the inner barrel. The magnetic induction device comprises an induction coil. The throttling device is arranged in the outer barrel and located at the end, away from the well drilling device, of the inner barrel. The magnetic triggering piece can pass through the induction coil along with the flowing of the fluid medium, and enables the induction coil to generate a corresponding induction electric signal; the control device can receive the induction electric signals and control the throttling device to be opened to the target opening degree according to the induction electric signals so that the internal and external pressure difference of the outer barrel can reach the target pressure difference. According to the technical scheme, the problem that in the existing drilling process, the internal and external pressure difference of the drilling tool position where the tool is located is relatively fixed can be solved.

Description

Technical Field

[0001] The present invention relates to the technical field of oil drilling, and in particular to a pressure difference regulating structure, a downhole tool and a driving method for the downhole tool. Background Art

[0002] In oil exploration and oil field development, oil drilling plays a very important role. Oil drilling is a project that uses special equipment to build channels between the ground and underground oil wells so that the underground oil and gas can be collected to the ground along the oil pipeline for utilization.

[0003] Some downhole tools used in oil drilling operations, such as variable-diameter stabilizers, utilize the pressure differential between the inside and outside of the drill string as a driving force. Once the drill string assembly is inserted into the well, the pressure differential between the inside and outside of the downhole tool is typically adjusted by displacement. However, since parameters such as drilling fluid flow rate and density are difficult to vary widely, the adjustable range of displacement is limited during drilling. The pressure differential between the inside and outside of the drill string remains relatively fixed, limiting the performance of the downhole tool and impacting operation efficiency. Summary of the Invention

[0004] The embodiments of the present invention provide a pressure differential adjustment structure, a downhole tool, and a method for driving the downhole tool, which can solve the problem that the internal and external pressure differentials at the drill bit where the tool is located are relatively fixed during the existing drilling process.

[0005] In a first aspect, an embodiment of the present invention provides a pressure difference adjustment structure, including:

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

[0007] An inner cylinder, disposed within the outer cylinder;

[0008] a magnetic induction device, disposed in the outer cylinder and located at one end of the inner cylinder close to the drilling device, the magnetic induction device comprising at least one induction coil;

[0009] a throttling device, disposed in the outer cylinder and located at an end of the inner cylinder away from the drilling device;

[0010] a magnetic triggering member capable of passing through the induction coil as the fluid medium flows, and causing the induction coil to generate a corresponding induced electrical signal; and

[0011] The control device is arranged in the inner cylinder, and the control device can receive the induced electrical signal and control the throttling device to open to the target opening according to the induced electrical signal, so that the internal and external pressure difference of the outer cylinder reaches the target pressure difference.

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

[0013] A main body portion, wherein a plurality of magnetic induction channels are provided on the main body portion;

[0014] a plurality of induction coils, each corresponding to the plurality of magnetic induction channels, the induction coils being disposed in the corresponding magnetic induction channels; and

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

[0016] In one embodiment, the magnetic triggering member includes:

[0017] magnets; and

[0018] The protective layer is coated on the outer surface of the magnet.

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

[0020] a throttle valve assembly, disposed in the outer cylinder; and

[0021] The motor assembly is arranged in the inner cylinder, and the output shaft of the motor assembly is connected to the throttle valve assembly to drive the throttle valve assembly to rotate, so that the throttle valve assembly opens to the target opening.

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

[0023] a stator, disposed on the outer wall of the inner cylinder, wherein the stator is provided with at least one static flow passage penetrating the stator in the axial direction;

[0024] a rotor connected to the output shaft of the motor assembly, the rotor being provided with at least one dynamic flow channel penetrating the rotor in the axial direction, the at least one dynamic flow channel corresponding to the at least one static flow channel;

[0025] The motor assembly can drive the rotor to rotate so as to change the overlapping 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 mother magnetic sheets, wherein the plurality of dynamic flow channels are arranged at equal intervals around the rotor in the circumferential direction; the plurality of limiting mother 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 mother magnetic sheets are staggered in the circumferential direction;

[0027] A plurality of limiting areas are provided on the inner wall of the outer cylinder, and the plurality of limiting areas correspond one to one with the plurality of limiting female plates, and each of the limiting areas is provided with a plurality of limiting male magnetic plates arranged at intervals in the circumferential direction around the outer cylinder;

[0028] Wherein, the limiting female magnetic piece is magnetically adsorbed and connected to one of the limiting male magnetic pieces in the corresponding limiting area.

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

[0030] a control module disposed in the inner cylinder, the control module being 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 supply module is disposed in the inner cylinder and located between the control module and the magnetic induction device. The power supply module is electrically connected to the control module, the motor assembly and the magnetic induction device respectively.

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

[0033] A floating sealing device is provided on one end of the inner cylinder close to the throttling device;

[0034] a partition plate disposed within the inner cylinder and located between the floating seal device and the control module, wherein the partition plate, the floating seal device, and the inner cylinder together form a motor cavity filled with hydraulic oil;

[0035] Wherein, the motor assembly is arranged in the motor cavity.

[0036] In a second aspect, an embodiment of the present invention provides a downhole tool, comprising the pressure differential adjustment structure as described above; and

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

[0038] In a third aspect, an embodiment of the present invention provides a method for driving a downhole tool, which is applied to the downhole tool as described above, comprising:

[0039] placing the downhole tool in a wellbore;

[0040] Putting the fluid medium and the magnetic triggering element into the downhole tool, causing the magnetic triggering element to pass through the induction coil along with the fluid medium, and causing the induction coil to generate an induced electrical signal;

[0041] Based on the induced electrical signal, the throttling device is opened to a 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 device is adjusted to a target torque.

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

[0044] (1) By adjusting the opening of the throttling device, the cross-sectional area of ​​the flow channel of the outer cylinder is changed, so that the flow rate of the fluid medium passing through the changed cross-sectional area of ​​the flow channel can be adjusted, and then the pressure in the outer cylinder is changed, so as to achieve the purpose of adjusting the pressure difference between the inside and outside of the outer cylinder, thereby solving the problem that the internal and external pressure difference of the drill bit where the tool is located is relatively fixed in the existing drilling process, expanding the adjustment range of the internal and external pressure difference, avoiding the performance of the downhole tool being restricted, and making it more adaptable to complex downhole conditions. When the opening of the throttling device increases, the flow rate of the fluid medium increases and the resistance decreases, so that the pressure in the outer cylinder decreases and the internal and external pressure difference of the outer cylinder decreases; when the opening of the throttling device decreases, the flow rate of the fluid medium decreases and the resistance increases, so that the pressure in the outer cylinder increases and the internal and external pressure difference 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 outer cylinder in the wellbore. The user only needs to put the magnetic trigger into the outer cylinder on the ground to realize the adjustment function. The adjustment method is simple, convenient and accurate. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Hereinafter, the present invention will be described in more detail based on embodiments with reference to the accompanying drawings.

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

[0048] Figure 2 yes Figure 1 A cross-sectional view of a magnetic induction device provided in an embodiment of the present invention in a side view direction;

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

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

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

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

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

[0054] Figure 8 is a schematic structural diagram of a downhole tool provided by another embodiment of the present invention;

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

[0056] Reference numerals:

[0057] 1. Pressure differential adjustment 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. Throttle device; 410. Throttle valve assembly; 4101. Stator; 4102. Static flow channel; 4103. Rotor; 4104. Dynamic flow channel; 4105. Position-limiting female magnetic plate; 4106. Position-limiting male magnetic plate; 420. Motor assembly;

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

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

[0064] 70. Floating seal device;

[0065] 80. Partition;

[0066] 90. Straightener. DETAILED DESCRIPTION

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

[0068] In oil exploration and oil field development, oil drilling plays a very important role. Oil drilling is a project that uses special equipment to build channels between the ground and underground oil wells so that the underground oil and gas can be collected to the ground along the oil pipeline for utilization.

[0069] Some downhole tools used in oil drilling operations utilize the pressure differential between the inside and outside of the drill string as a driving force. For example, variable-diameter stabilizers utilize this pressure differential to expand their diameter, while rotatable drill string directional drilling tools rely on this pressure differential to generate torque. Once the drill string assembly is firmly established and inserted into the well, the pressure differential between the inside and outside of the downhole tool is typically adjusted by displacement. However, since parameters such as drilling fluid displacement and density are difficult to vary widely, the adjustable range of displacement during drilling is limited, and the pressure differential at the tool's location in the drill string is relatively fixed. This limits the performance of the downhole tool and impacts construction efficiency.

[0070] Example 1

[0071] like Figure 1 As shown, in order to solve the above technical problems, the embodiment of the present invention provides a pressure difference 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 arranged in the wellbore 4, one end of the outer cylinder 10 is used to be connected to the drilling device 2 and provide a flow channel for the fluid medium; the inner cylinder 20 is arranged in the outer cylinder 10; the magnetic induction device 30 is arranged in the outer cylinder 10 and is located at the end of the inner cylinder 20 close to the drilling device 2, and the magnetic induction device 30 is arranged in the outer cylinder 10. The device 30 includes at least one induction coil 320; the throttling device 40 is arranged in the outer cylinder 10 and is 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 as the fluid medium flows, and cause the induction coil 320 to generate a corresponding induced electrical signal; the control device 60 is arranged in 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 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, so that the flow rate of the fluid medium passing through the changed cross-sectional area of ​​the flow channel can be adjusted, and then the pressure inside the outer cylinder 10 is changed, so as to achieve the purpose of adjusting the internal and external pressure difference of the outer cylinder 10, thereby solving the problem that the internal and external pressure difference of the drill tool position where the tool is located is relatively fixed in the existing drilling process, expanding the adjustment range of the internal and external pressure difference, avoiding the performance of the downhole tool being limited, and making it more adaptable to complex downhole conditions. When the opening of the throttling device 40 is increased, the flow rate of the fluid medium increases and the resistance decreases, so that the pressure inside the outer cylinder 10 decreases and the internal and external pressure difference of the outer cylinder 10 decreases; when the opening of the throttling device 40 is decreased, the flow rate of the fluid medium decreases and the resistance increases, so that the pressure inside the outer cylinder 10 increases and the internal and external pressure difference of the outer cylinder 10 increases.

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

[0074] It should be noted that the drilling device 2 is a pressure differential driven drilling device 2, for example, the drilling device 2 is a directional drilling tool with a variable diameter stabilizer and a rotatable drill string.

[0075] It should also be noted that the induced electrical signal includes, but is not limited to, an induced electromotive force. The magnetic trigger 50 is magnetic and can generate a magnetic field. The induction coil 320 is a ring-shaped structure wound with insulated wire, typically made of copper wire. Based on the principle of electromagnetic induction, the magnetic flux within the coil changes, generating an induced electromotive force. When the magnetic trigger 50 enters the coil, the magnetic flux in the coil changes, 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 function is to provide support and protection during the drilling process, as well as to remove rocks and minerals during the drilling process in order to carry out drilling operations.

[0077] It should also be noted that if Figure 1 、 Figure 8 As shown, the outer cylinder 10 and the inner cylinder 20 are both cylindrical; the two ends of the outer cylinder 10 are designed as drill rod 3 buckles, which can be connected to the drilling device 2 through the drill rod 3 buckles; 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 and can protect the devices located inside the inner cylinder 20.

[0078] Example 2

[0079] like Figure 1As shown, the pressure differential 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 arranged in the wellbore 4, and one end of the outer cylinder 10 is used to be connected to the drilling device 2 and provide a flow channel for the fluid medium; the inner cylinder 20 is arranged in the outer cylinder 10; the magnetic induction device 30 is arranged in the outer cylinder 10 and is located at the end of the inner cylinder 20 close to the drilling device 2, and the magnetic induction device 30 includes at least one induction coil 320; the throttling device 40 is arranged in the outer cylinder 10 and is 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 as the fluid medium flows, and cause the induction coil 320 to generate a corresponding induced electrical signal; the control device 60 is arranged in 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 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, so that the flow rate of the fluid medium passing through the changed cross-sectional area of ​​the flow channel can be adjusted, and then the pressure inside the outer cylinder 10 is changed, so as to achieve the purpose of adjusting the internal and external pressure difference of the outer cylinder 10, thereby solving the problem that the internal and external pressure difference of the drill tool position where the tool is located is relatively fixed in the existing drilling process, expanding the adjustment range of the internal and external pressure difference, avoiding the performance of the downhole tool being restricted, and making it more adaptable to complex downhole conditions. When the opening of the throttling device 40 is increased, the flow rate of the fluid medium increases and the resistance decreases, thereby reducing the pressure inside the outer cylinder 10 and reducing the internal and external pressure difference of the outer cylinder 10; when the opening of the throttling device 40 is reduced, the flow rate of the fluid medium decreases and the resistance increases, thereby increasing the pressure inside the outer cylinder 10 and increasing the internal and external pressure difference of the outer cylinder 10.

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

[0082] It should be noted that the drilling device 2 is a pressure differential driven drilling device 2, for example, the drilling device 2 is a directional drilling tool with a variable diameter stabilizer and a rotatable drill string.

[0083] It should also be noted that the induced electrical signal includes, but is not limited to, an induced electromotive force. The magnetic trigger 50 is magnetic and can generate a magnetic field. The induction coil 320 is a ring-shaped structure wound with insulated wire, typically made of copper wire. Based on the principle of electromagnetic induction, the magnetic flux within the coil changes, generating an induced electromotive force. When the magnetic trigger 50 enters the coil, the magnetic flux in the coil changes, 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 function is to provide support and protection during the drilling process, as well as to remove rocks and minerals during the drilling process in order to carry out drilling operations.

[0085] It should also be noted that if Figure 1 、 Figure 8 As shown, the outer cylinder 10 and the inner cylinder 20 are both cylindrical; the two ends of the outer cylinder 10 are designed as drill rod 3 buckles, which can be connected to the drilling device 2 through the drill rod 3 buckles; 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 and can 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, multiple induction coils 320 and an analog-to-digital converter 330; multiple magnetic induction channels 3101 are provided on the main body 310; the multiple induction coils 320 correspond one-to-one to the multiple magnetic induction channels 3101, and the induction coils 320 are arranged in the corresponding magnetic induction channels 3101; the analog-to-digital converter 330 is arranged in the main body 310, and the analog-to-digital converter 330 is electrically connected to the multiple 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] The provision of the magnetic induction channel 3101 provides a structural foundation for the installation of the induction coil 320. Compared with providing only a single large-aperture magnetic induction channel 3101, the present invention provides multiple small-aperture magnetic induction channels 3101. This allows the magnetic trigger component to be closer to the induction coil 320 when passing through the magnetic induction channel 3101, thereby generating a clearer induced electrical signal to ensure the reliability of the pressure difference control regulation.

[0088] It should be noted that if Figure 1 As shown, the main body 310 is arranged on the inner wall of the outer cylinder 10, and the fluid medium flows through the magnetic induction channel 3101; four magnetic induction channels 3101 are provided on the main body 310, 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 a slot for mounting the analog-to-digital converter 330 is provided on the main body 310 .

[0090] In some embodiments, the magnetic triggering member 50 includes a magnet 510 and a protective layer 520 ; the protective layer 520 is coated on the outer surface of the magnet 510 .

[0091] The protective layer 520 is provided to protect the magnet 510 , thereby preventing the magnet 510 from colliding and cracking during movement, thereby ensuring the normal operation of the pressure difference regulating structure 1 .

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

[0093] It should also be noted that the size of the magnet 510 is closely related to the size 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 triggering members 50 of different specifications can be designed according to needs, that is, magnetic triggering members 50 with different magnet diameters, and different specifications of magnetic triggering members 50 are 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 to meet the performance requirements of the drilling device 2.

[0094] For example, Figure 5-Figure 7 As shown, three different specifications of magnetic triggering members 50 are designed, that is, three magnetic triggering members 50 with different magnet diameters, namely magnetic triggering member No. 1, magnetic triggering member No. 2, and magnetic triggering member No. 3. The magnet diameter of magnetic triggering member No. 1 is larger than the magnet diameter of magnetic triggering member No. 2, and the magnet diameter of magnetic triggering member No. 2 is larger than the magnet diameter of magnetic triggering member No. 3.

[0095] The induced electrical signal generated by the No. 1 magnetic trigger is greater than the induced electrical signal generated by the No. 2 magnetic trigger, and the induced signal generated by the No. 2 magnetic trigger is greater than the induced electrical signal generated by the No. 3 magnetic trigger. Therefore, when the No. 1 magnetic trigger is put into operation, the throttling device 40 is opened to the maximum opening; when the No. 2 magnetic trigger is put into operation, the throttling device 40 is opened to the middle opening; when the No. 3 magnetic trigger is put into operation, the throttling device 40 is opened to the minimum opening.

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

[0097] The motor assembly 420 is provided to drive the throttle valve assembly 410 to rotate so as to adjust the opening of the throttle valve assembly 410 , and the adjustment method is simple and convenient.

[0098] It should be noted that motor assembly 420 includes a motor, a reducer, and a Hall effect sensor. The motor's output shaft is connected to the reducer's input shaft, which in turn is connected to throttle valve assembly 410. The reducer can reduce the motor's speed and increase its torque. The Hall effect sensor, a device used to monitor magnetic fields, is used to monitor the motor's speed and number of revolutions. Based on the Hall effect, when current flows through a conductor, the magnetic field affects the movement of charges on the conductor, generating a potential difference across the conductor.

[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 arranged on the outer wall of the inner cylinder 20, and the stator 4101 is provided with at least one static flow channel 4102 that passes through the stator 4101 in the axial direction; the rotor 4103 is connected to the output shaft of the motor assembly 420, and the rotor 4103 is provided with at least one dynamic flow channel 4104 that passes through the rotor 4103 in the axial direction, and at least one dynamic flow channel 4104 corresponds one-to-one to at least one static flow channel 4102; wherein, the motor assembly 420 can drive the rotor 4103 to rotate to change the overlapping 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 the overlapping area of ​​the dynamic flow channel 4104 and the static flow channel 4102 to change. The overlapping area S is positively correlated with the opening ω of the throttling device 40. The specific relationship is:

[0101] S=451.25+8.01ω(0°≦ω≦90°)

[0102] It can be seen from this that the larger the opening of the throttling device 40 is, the larger the overlapping area between the dynamic flow channel 4104 and the static flow channel 4102 is.

[0103] It should be noted that if 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 dynamic flow channel 4104 is fan-shaped, and the cross-sectional shape of the static flow channel 4102 includes a first section and a second section connected to both ends of the first section respectively. The first section is fan-shaped and the second section is arc-shaped. In addition, the central angle of the dynamic flow channel 4104 is greater than the central angle of the static flow channel 4102, so that the throttle valve assembly 410 has a maximum opening.

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

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

[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, and its specific structure and working principle are all existing technologies and will not be described in detail in this application.

[0109] Example 3

[0110] The third embodiment differs from the second embodiment in the following aspects:

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

[0112] The inner wall of the outer cylinder 10 is provided with a plurality of limiting areas, each corresponding to a plurality of limiting female plates. Each limiting area is provided with a plurality of limiting male magnetic plates 4106 arranged at intervals in the circumferential direction around the outer cylinder 10.

[0113] The limiting female magnetic piece 4105 is magnetically adsorbed and connected to one of the limiting male magnetic pieces 4106 in the corresponding limiting area.

[0114] By providing a limiting female magnetic piece 4105 and a limiting male magnetic piece 4106, it is ensured that the rotor 4103 can remain in the target position after rotating to the target position, preventing the rotor 4103 from being impacted by a high degree of fluid medium and causing position changes, ensuring that the throttle valve assembly 410 maintains the target opening, and eliminating the need for the motor assembly 420 to constantly correct the opening of the throttle valve assembly 410, thereby saving electricity and extending the service life of the pressure differential regulating structure 1. In addition, by providing a plurality of limiting male magnetic pieces 4106 arranged at intervals in each limiting area, corresponding to a plurality of different target positions of the rotor 4103, and different target positions corresponding to different target openings of the throttle valve assembly 410, the rotor 4103 can be maintained at the required target position, thereby improving practicality and flexibility, and further meeting the needs of the drilling device 2.

[0115] It should be noted that the limiting female magnetic piece 4105 and the limiting male magnetic piece 4106 are both magnetic; the number of the dynamic flow channel 4104, the static flow channel 4102 and the limiting female magnetic piece 4105 can be set as needed. Figure 4 As shown, there are two dynamic flow channels 4104 and two limiting mother magnetic plates 4105, and the two dynamic flow channels 4104 and the two limiting mother 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 to the two limiting mother plates.

[0116] It should also be noted that the number of limiting male magnetic plates 4106 set in each limiting area is set according to needs, and the number of limiting male magnetic plates 4106 can be equal to the number of specifications of the magnetic triggering component 50, thereby ensuring that the rotor 4103 can be maintained at the target opening position corresponding to the current magnetic triggering component 50, ensuring the accuracy of the target opening and target pressure difference.

[0117] For example, when the number of specifications of the magnetic triggering member 50 is three, namely, magnetic triggering member No. 1, magnetic triggering member No. 2, and magnetic triggering member No. 3;

[0118] like Figure 4 As shown, three limiting male magnetic pieces 4106 are provided in each limiting area. The three limiting male magnetic pieces 4106 are arranged at equal intervals in the circumferential direction in the limiting area. The three limiting male magnetic pieces 4106 are male magnetic piece No. 1, male magnetic piece No. 2, and male magnetic piece No. 3 in the counterclockwise direction.

[0119] When magnetic trigger member No. 1 is put into operation, the throttling device 40 is opened to the maximum opening, and the limiting female magnetic piece 4105 is magnetically adsorbed and connected to the corresponding male magnetic piece No. 1; when magnetic trigger member No. 2 is put into operation, the throttling device 40 is opened to the middle opening, and the limiting female magnetic piece 4105 is magnetically adsorbed and connected to the corresponding male magnetic piece No. 2; when magnetic trigger member No. 3 is put into operation, the throttling device 40 is opened to the minimum opening, and the limiting female magnetic piece 4105 is magnetically adsorbed and connected to the corresponding male magnetic piece No. 3.

[0120] The other structures of the third embodiment are the same as those of the second embodiment, and will not be described in detail here.

[0121] Example 4

[0122] The fourth embodiment differs from the third embodiment in the following aspects:

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

[0124] By setting up a floating sealing device 70 and a partition 80, space is provided for the installation of the motor assembly 420, and hydraulic oil is used to protect the motor assembly 420 to improve the heat dissipation performance. The floating sealing device 70 is used not only to make the pressure in the motor cavity equal to the pressure of the wellbore 4, avoiding the pressure difference, but also to reduce the friction, ensuring that the motor assembly 420 can drive the rotor 4103 to rotate, but also to prevent 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 lower temperature during operation and reduce mechanical wear, thereby increasing the service life and efficiency of the motor.

[0126] It should also be noted that if Figure 1As shown, the pressure difference regulating structure 1 also includes a centralizer 90, which is arranged on the inner cylinder 20 and located at the motor compartment 210. The centralizer 90 realizes positioning and adjustment of the object by physical or hydraulic means to keep it in a straight line.

[0127] The other structures of the fourth embodiment are the same as those of the third embodiment, and will not be described in detail here.

[0128] To sum up, compared with the existing technology that generally adopts pressure control and cable control to control the downhole throttle valve, the present invention controls it through a magnetic trigger control method. The user only needs to put the magnetic trigger into the outer cylinder on the ground to realize the adjustment function. The adjustment method is simple and convenient, and the control is accurate. There is no need to use thousands of meters of continuous cables, and it also avoids the problem of pressure disturbance disrupting downhole control, resulting in the inability to control the downhole throttle valve.

[0129] Example 5

[0130] like Figure 8 As shown, an embodiment of the present invention also provides a downhole tool, including a pressure difference 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 work under the drive of the target pressure difference.

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

[0132] It should be noted that if Figure 8 As shown, the downhole tool also includes a drill bit, a screw drill tool and a wireless measurement while drilling instrument, and a drill pipe 3. The drill bit, the screw drill tool and the wireless measurement while drilling instrument, the pressure differential adjustment structure 1, and the drilling device 2 are connected in sequence, and the pressure differential adjustment structure 1 and the drilling device 2 can be connected through the drill pipe 3, and the drilling device 2 can also be connected to the device on the ground through the drill pipe 3; in addition, the pressure differential adjustment structure 1 is located on the end of the drilling device 2 close to 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 that relies on the pressure differential control inside and outside the drill string to generate torque. When performing rotary directional drilling, the rotatable drill string directional drilling tool needs to generate a smaller 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, the existing rotatable drill string directional drilling tools cannot generate the largest possible torque to meet the drilling requirements. When encountering complex situations such as collapse and stuck drill, the rotatable drill string directional drilling tool is generally permanently locked. Compared with this method, the present invention provides a pressure differential for the rotatable drill string directional drilling tool through a 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, an embodiment of the present invention provides a driving method for a downhole tool, which is applied to the downhole tool as described in any of the above embodiments, comprising:

[0136] S101: placing the downhole tool in the wellbore 4;

[0137] S102: Putting the fluid medium and the magnetic triggering member 50 into the downhole tool, causing the magnetic triggering member 50 to pass through the induction coil 320 along with the fluid medium, and causing the induction coil 320 to generate 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, passing through the induction coil 320 during the flow process. 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 sizes of magnetic triggers 50 can be provided, i.e., the magnets 510 of the three magnetic triggers 50 are of different sizes. The magnetic triggers 50 are arranged in descending order 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 magnetic trigger 1 is greater than the induced electrical signal generated by magnetic trigger 2, and the induced electrical signal generated by magnetic trigger 2 is greater than the induced electrical signal generated by magnetic trigger 3.

[0139] S103: Based on the induced electrical signal, the throttling device 40 is opened to a 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 the user can control the opening of the throttling device 40 by using magnetic triggering members 50 of different specifications;

[0141] For example, three different specifications of magnetic triggering members 50 are designed, namely magnetic triggering member No. 1, magnetic triggering member No. 2, and magnetic triggering member No. 3. The magnet diameter of magnetic triggering member No. 1 is larger than the magnet diameter of magnetic triggering member No. 2, and the magnet diameter of magnetic triggering member No. 2 is larger than the magnet diameter of magnetic triggering member No. 3. The three specifications correspond to three openings.

[0142] When the No. 1 magnetic trigger is put into operation, the throttling device 40 is opened to the maximum opening; when the No. 2 magnetic trigger is put into operation, the throttling device 40 is opened to the middle opening; when the No. 3 magnetic trigger is put into operation, the throttling device 40 is opened to the minimum opening.

[0143] It should also be noted that before performing step S102, debugging is required first. The fluid medium and magnet No. 1 are put into the downhole tool, the opening of the throttling device 40 is opened to the maximum opening, and the pressure difference inside and outside the outer cylinder 10 is adjusted to the minimum pressure difference, and then the downhole tool is started to be driven.

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

[0145] For example, three different target openings are set, namely, maximum opening, intermediate opening, and minimum opening; and three different target pressure differences are set, namely, maximum pressure difference, intermediate pressure difference, and minimum pressure difference. When the throttling device 40 is opened to the maximum opening, the internal and external pressure difference of the outer cylinder 10 is adjusted to the minimum pressure difference. When the throttling device 40 is opened to the intermediate opening, the internal and external pressure difference of the outer cylinder 10 is adjusted to the intermediate pressure difference. When the throttling device 40 is opened to the minimum opening, the internal and external pressure difference of the outer cylinder 10 is adjusted to the maximum pressure difference.

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

[0147] It should be noted that, the greater the target pressure difference, the greater the target torque that the 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] Where ρ is the density of the fluid, g / cm 3 , Q is the fluid displacement, L / s, ω is the opening, °.

[0151] The drilling device 2 includes but is not limited to a rotatable drill string directional drilling tool, and the following description will take the rotatable drill string directional drilling tool as an example;

[0152] When a complex situation such as collapse or stuck pipe is encountered during drilling, and the torque of the rotatable drill string directional drilling tool needs to be increased, the No. 2 magnetic trigger can be engaged to open the throttling device 40 to an intermediate opening, generating a throttling loss of 2-3 MPa, thereby increasing the pressure difference between the inside and outside of the outer cylinder 10 by 2-3 MPa, thereby enabling the rotatable drill string directional drilling tool to generate greater torque;

[0153] When encountering complex situations such as collapse and stuck pipe 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 into operation to open the opening of the throttling device 40 to the minimum opening to generate 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, so that the rotatable drill string directional drilling tool can generate greater torque;

[0154] According to drilling requirements, when the complex situation is handled, the No. 1 magnetic trigger can be put into use again to restore the opening of the throttling device 40 to the maximum opening to reduce the pressure difference inside and outside the outer cylinder 10, thereby reducing the torque that can be generated by the rotatable drill string directional drilling tool.

[0155] While the present invention has been described with reference to preferred embodiments, various modifications may be made and equivalent components may be substituted without departing from the scope of the present invention. In particular, the various technical features described in the various embodiments may be combined in any manner, provided no structural conflicts exist. The present invention is not limited to the specific embodiments disclosed herein, but encompasses all technical solutions within the scope of the claims.

Claims

1. A pressure difference regulating structure, characterized in that: include: An outer cylinder is disposed in the wellbore, one end of the outer cylinder being used to connect to the drilling device and provide a flow channel for the fluid medium; An inner cylinder, disposed within the outer cylinder; a magnetic induction device, disposed in the outer cylinder and located at one end of the inner cylinder close to the drilling device, the magnetic induction device comprising at least one induction coil; a throttling device, disposed in the outer cylinder and located at an end of the inner cylinder away from the drilling device; a magnetic triggering member capable of passing through the induction coil as the fluid medium flows, and causing the induction coil to generate a corresponding induced electrical signal; as well as The control device is arranged in the inner cylinder, and the control device can receive the induced electrical signal and control the throttling device to open to the target opening according to the induced electrical signal, so that the internal and external pressure difference of the outer cylinder reaches the target pressure difference.

2. The pressure difference regulating structure according to claim 1, characterized in that: The magnetic induction device comprises: A main body portion, wherein a plurality of magnetic induction channels are provided on the main body portion; a plurality of induction coils, each corresponding to the plurality of magnetic induction channels, the induction coils being disposed in the corresponding magnetic induction channels; and An analog-to-digital converter is disposed in the main body and is electrically connected to the plurality of induction coils to convert the induced electrical signals generated by the induction coils into digital signals and transmit the digital signals to the control device.

3. The pressure difference regulating structure according to claim 1 or 2, characterized in that: The magnetic triggering member comprises: magnets; and The protective layer is coated on the outer surface of the magnet.

4. The pressure difference regulating structure according to claim 1, characterized in that: The throttling device comprises: a throttle valve assembly, disposed in the outer cylinder; and The motor assembly is arranged in the inner cylinder, and the output shaft of the motor assembly is connected to the throttle valve assembly to drive the throttle valve assembly to rotate, so that the throttle valve assembly opens to the target opening.

5. The pressure difference regulating structure according to claim 4, characterized in that: The throttle valve assembly comprises: a stator, disposed on the outer wall of the inner cylinder, wherein the stator is provided with at least one static flow passage penetrating the stator in the axial direction; a rotor connected to the output shaft of the motor assembly, the rotor being provided with at least one dynamic flow channel penetrating the rotor in the axial direction, the at least one dynamic flow channel corresponding to the at least one static flow channel; The motor assembly can drive the rotor to rotate so as to change the overlapping area between the dynamic flow channel and the corresponding static flow channel.

6. The pressure difference regulating structure according to claim 5, characterized in that: The rotor is provided with a plurality of dynamic flow channels and a plurality of limiting mother magnetic sheets, wherein the plurality of dynamic flow channels are arranged at equal intervals in the circumferential direction around the rotor; the plurality of limiting mother magnetic sheets are arranged at equal intervals in the circumferential direction around the rotor, and the plurality of dynamic flow channels and the plurality of limiting mother magnetic sheets are staggered in the circumferential direction; A plurality of limiting areas are provided on the inner wall of the outer cylinder, and the plurality of limiting areas correspond one to one with the plurality of limiting female plates, and each of the limiting areas is provided with a plurality of limiting male magnetic plates arranged at intervals in the circumferential direction around the outer cylinder; Wherein, the limiting female magnetic piece is magnetically adsorbed and connected to one of the limiting male magnetic pieces in the corresponding limiting area.

7. The pressure difference regulating structure according to any one of claims 5 to 6, characterized in that: The control device comprises: a control module disposed in the inner cylinder, the control module being 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 supply module is disposed in the inner cylinder and located between the control module and the magnetic induction device. The power supply module is electrically connected to the control module, the motor assembly and the magnetic induction device respectively.

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

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

10. A method for driving a downhole tool, applied to the downhole tool according to claim 9, characterized in that: include: placing the downhole tool in a wellbore; Putting the fluid medium and the magnetic triggering element into the downhole tool, causing the magnetic triggering element to pass through the induction coil along with the fluid medium, and causing the induction coil to generate an induced electrical signal; Based on the induced electrical signal, the throttling device is opened to a 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 device is adjusted to a target torque.

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