Downhole electromagnetic damping turbine generator and power generation control system

Abstract

This invention relates to the field of generator manufacturing technology, and discloses a downhole electromagnetic damping turbine generator and a power generation control system. The generator includes: a main shaft; a housing sleeved on the outside of the main shaft; a turbine drivenly connected to the housing; a power generation unit, including a rotor assembly disposed on the inner peripheral wall of the housing and a stator assembly disposed on the outer peripheral wall of the main shaft; a damping unit disposed on the main shaft and axially offset from the power generation unit; and lead wires for electrical connection to the power generation unit and the damping unit respectively, the lead wires extending axially along the outer peripheral wall of the main shaft, and the damping unit including lead wires extending axially along the outer peripheral wall of the main shaft; wherein, the turbine is configured to rotate when subjected to fluid impact, the turbine rotation driving the housing and rotor assembly to rotate, causing the power generation unit to generate electrical energy, and the damping unit is configured to cause the power generation unit to generate a preset value of electrical energy. Therefore, the lead wires extending axially along the outer peripheral wall of the main shaft avoid the housing, which generates significant heat.

Description

Technical Field

[0001] This invention relates to the field of generator manufacturing technology, specifically to a downhole electromagnetic damping turbine generator. Furthermore, it relates to a downhole power generation control system. Background Technology

[0002] An electromagnetic damping turbine generator is a device that uses hydrodynamics to drive turbine blades to rotate, thereby generating electricity through electromagnetic induction. Downhole electromagnetic damping turbine generators are typically used in the oil drilling industry in underground environments to power downhole equipment during drilling and logging processes. In particular, with the development of modern drilling technology towards intelligent drilling, the functions of downhole intelligent tools have evolved from simply measuring data and transmitting signals to integrating measurement, control, and transmission, thus increasing the demand for current. By installing a downhole electromagnetic damping turbine generator inside the drill collar, when high-pressure fluid, such as drilling fluid or mud, passes through the turbine, the high-pressure fluid impacts the turbine blades, causing them to rotate. This rotates the rotor in the downhole electromagnetic damping turbine generator, inducing an electromotive force in the generator's winding coils, thus achieving downhole power generation and powering downhole intelligent instruments.

[0003] Because downhole electromagnetic damping turbine generators utilize the kinetic energy of high-pressure fluid within the drill collar to generate electricity, the flow rate (i.e., velocity) of this fluid is unstable. This instability leads to unstable rotor speed and consequently, unstable output voltage, potentially causing overload and burnout of downhole instruments. Therefore, downhole electromagnetic damping turbine generators typically incorporate damping units to ensure stable output voltage. During operation, the damping unit generates highly variable eddy currents on its corresponding casing, causing significant heating. However, in existing downhole electromagnetic damping turbine generators, the damping unit's lead wires generally extend along the inner wall of the casing and exit through it. Furthermore, since downhole electromagnetic damping turbine generators operate in high-temperature underground environments, the lead wires require strong temperature resistance. As drilling depth increases, bottom-hole temperatures rise, making the temperature resistance of the lead wires a significant weakness of downhole electromagnetic damping turbine generators. Summary of the Invention

[0004] The purpose of this invention is to overcome the problem that the lead wires of damping units in the prior art require high temperature resistance.

[0005] To achieve the above objectives, the present invention provides a downhole electromagnetic damping turbine generator, comprising: a main shaft; a housing, the housing being sleeved on the outside of the main shaft; a turbine, the turbine being drively connected to the housing; a power generation unit, the power generation unit including a rotor assembly disposed on the inner peripheral wall of the housing and a stator assembly disposed on the outer peripheral wall of the main shaft; a damping unit, the damping unit being disposed on the main shaft and axially offset from the power generation unit; and lead wires, the lead wires being used for electrical connection to the power generation unit and the damping unit respectively, the lead wires extending axially along the outer peripheral wall of the main shaft; wherein, the turbine is configured to rotate when the turbine is subjected to fluid impact, the rotation of the turbine driving the housing and the rotor assembly to rotate, causing the power generation unit to generate electrical energy, and the damping unit is configured to cause the power generation unit to generate a preset value of electrical energy.

[0006] In the downhole electromagnetic damping turbine generator provided by this invention, the downhole electromagnetic damping turbine generator can be installed inside the oil drill collar. High-pressure fluid inside the drill collar, such as drilling fluid or mud, impacts the turbine, driving it to rotate. The turbine is connected to the outer casing, and the turbine's rotation drives the outer casing to rotate, causing the rotor assembly mounted on the inner peripheral wall of the outer casing to rotate. During the rotation of the rotor assembly, the main shaft remains stationary, keeping the stator assembly mounted on the outer peripheral wall of the main shaft stationary. That is, when the high-pressure fluid impacts the turbine, the rotor assembly rotates relative to the stator assembly, thereby generating electrical energy.

[0007] During the power generation process, the unstable flow rate of the high-pressure fluid inside the drill collar causes instability in the rotation speed of the rotor assembly, resulting in unstable power generation. A damping unit helps stabilize the power generation, providing a preset power level to the downhole equipment. For example, if the flow rate of the high-pressure fluid inside the drill collar suddenly increases, causing the rotor assembly to rotate faster, the power generation unit will produce more power than the preset value. In this case, current is supplied to the damping unit, generating a magnetic field. This magnetic field acts on the outer casing, applying a torque opposite to the direction of rotation, reducing the outer casing's rotation speed. This, in turn, reduces the rotation speed of the rotating assembly, ensuring that the power generation remains at the preset value and preventing overload and burnout of the downhole equipment.

[0008] In addition, in the downhole electromagnetic damping turbine generator of the present invention, the lead wire of the damping unit extends axially along the outer peripheral wall of the main shaft, thereby extending beyond the coverage area of ​​the outer casing and connecting to the external power supply. Since the outer casing of the damping unit heats up significantly during operation, the lead wire avoids direct contact with the outer casing in the present invention, thereby reducing the heating rate of the lead wire during the damping process and also reducing the requirements for the temperature resistance of the lead wire.

[0009] In some embodiments, the damping unit further includes salient pole teeth disposed on the outer peripheral wall of the main shaft and a damping coil wound on the salient pole teeth.

[0010] In some embodiments, the salient pole teeth and the spindle are integrally formed.

[0011] In some embodiments, the turbine includes a turbine body and turbine blades disposed on the outer wall of the turbine body, with at least a portion of the housing formed as the turbine body.

[0012] In some embodiments, the turbine blades are disposed radially outside the damping unit.

[0013] In some embodiments, the generator further includes a first bearing assembly and a second bearing assembly sleeved on the main shaft, wherein the first bearing assembly and the second bearing assembly are rotatably connected to the inner peripheral walls at both ends of the housing.

[0014] In some embodiments, both the first bearing assembly and the second bearing assembly include an axially arranged tapered roller bearing and a deep groove ball bearing.

[0015] In some embodiments, the first bearing assembly is rotatably connected to one end of the housing near the damping unit, and the generator further includes a first sleeve disposed between the first bearing assembly and the lead wire.

[0016] In some embodiments, the first sleeve is connected to the spindle by a key.

[0017] In some embodiments, the stator assembly includes a silicon steel stator sleeved on the outer peripheral wall of the main shaft and a generator winding wound on the silicon steel stator.

[0018] In some embodiments, the generator further includes a second sleeve fitted on the outer peripheral wall of the main shaft and connected between the silicon steel stator and the damping unit.

[0019] In some embodiments, the rotor assembly includes a plurality of magnet rotors, which are uniformly arranged on the inner peripheral wall of the housing.

[0020] In some embodiments, the generator includes a bearing assembly sleeved on the main shaft and rotatably connected to the inner peripheral wall of the end of the housing. The generator also includes a third sleeve sleeved on the radially outer side of the main shaft, the two ends of which are respectively used to abut against the magnetic rotor and the bearing assembly.

[0021] In some embodiments, the generator further includes a damping pad disposed between the third sleeve and the bearing assembly.

[0022] Based on this, the present invention also provides a downhole power generation control system, including the aforementioned downhole electromagnetic damping turbine generator.

[0023] Other features and advantages of the embodiments of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the structure of the downhole electromagnetic damping turbine generator disclosed in this invention; Figure 2 This is a cross-sectional view of the power generation unit disclosed in this invention; Figure 3 This is a cross-sectional view of the damping unit disclosed in this invention; Figure 4 This is a schematic diagram of the structure of the downhole electromagnetic damping turbine generator disclosed in this invention after the outer casing has been cut open; Figure 5 This is a schematic diagram of one embodiment of the lead wire arrangement of the downhole electromagnetic damping turbine generator disclosed in this invention.

[0025] Explanation of reference numerals in the attached figures 1-Lead wire; 2-Key; 3-First sleeve; 4-Outer shell; 5-Turbine blade; 6-Second sleeve; 7-Damping coil; 8-Generator winding; 9-Magnetic rotor; 10-Main shaft; 11-Silicon steel stator; 12-Third sleeve; 13-Shock damping pad; 14-Tap roller bearing; 15-Deep groove ball bearing; 16-Sagittal pole tooth. Detailed Implementation

[0026] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0027] In this invention, unless otherwise stated, the terms "upper," "lower," "left," "right," "inner," "outer," "top," "bottom," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0028] Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0029] In this invention, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0030] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0031] This invention primarily addresses the issue of high temperature resistance requirements for the lead wires in existing downhole electromagnetic damping turbine generators. In existing downhole electromagnetic damping turbine generators, the lead wires extend from the inner circumference of the casing. During the operation of the damping unit, strong eddy current changes are generated at the casing, causing significant heating. Since the lead wires are in direct contact with the casing, high temperature resistance is essential. As drilling depth increases, bottom hole temperatures rise, making the temperature resistance of the lead wires a bottleneck in downhole electromagnetic damping turbine generators, potentially rendering them unsuitable for downhole environments.

[0032] Therefore, the present invention provides a downhole electromagnetic damping turbine generator, with reference to Figures 1-5As shown, the generator includes: a main shaft 10, a housing 4 sleeved on the outside of the main shaft 10, a turbine drively connected to the housing 4, a power generation unit and a damping unit axially offset from each other, and lead wires 1 for electrical connection to the power generation unit and the damping unit respectively. The power generation unit includes a rotor assembly disposed on the inner peripheral wall of the housing 4 and a stator assembly disposed on the outer peripheral wall of the main shaft 10. The damping unit is disposed on the main shaft 10, and the lead wires 1 extend axially along the outer peripheral wall of the main shaft 10. The turbine is configured such that when high-pressure fluid, such as drilling fluid, impacts the turbine, it rotates. Simultaneously, the turbine rotation drives the housing 4 and the rotor assembly to rotate. During the rotation of the rotor assembly, the main shaft 10 remains stationary, and the stator assembly disposed on the outer peripheral wall of the main shaft 10 also remains stationary. The rotor assembly rotates relative to the stator assembly, thereby generating electrical energy from the power generation unit. The damping unit is configured to generate a preset value of electrical energy from the power generation unit. When the flow rate of the high-pressure fluid in the drill collar suddenly increases, the rotational speed of the outer casing 4 and the rotor assembly increases, and the power generation unit generates electrical energy higher than the preset value. At this time, the damping unit can apply a reverse torque to the outer casing 4 to reduce the rotational speed of the outer casing 4 and the rotor assembly, thereby maintaining the electrical energy generated by the power generation unit near the preset value and preventing the downhole electrical equipment from being overloaded and damaged.

[0033] Furthermore, in the downhole electromagnetic damping turbine generator provided by the present invention, the lead wire 1 extends axially along the outer peripheral wall of the main shaft 10, thereby extending beyond the coverage area of ​​the outer casing 4 and connecting to the external power source. As mentioned above, since the outer casing 4 heats up significantly during the operation of the damping unit, the lead wire 1 extends axially along the outer peripheral wall of the main shaft 10 to avoid direct contact with the outer casing 4, thereby reducing the heating rate of the lead wire 1 and reducing the requirements for the temperature resistance of the lead wire 1. This is beneficial for the application of the downhole electromagnetic damping turbine generator of the present invention in downhole working environments.

[0034] In some embodiments, the damping unit may include a damping coil 7, which may be helically wound around the outer peripheral wall of the main shaft 10 in a circumferential direction. Alternatively, according to an embodiment of the downhole electromagnetic damping turbine generator of the present invention, referring to... Figure 1 , Figure 3 and Figure 4 As shown, the damping unit includes salient pole teeth 16 disposed on the outer peripheral wall of the main shaft 10 and a damping coil 7 wound on the salient pole teeth 16. A gap is left between the salient pole teeth 16 and the inner peripheral wall of the outer casing 4. When the flow rate of the high-pressure fluid in the drill collar suddenly increases, causing the power generation unit to generate electrical energy higher than the preset value, an external power source supplies electrical energy to the damping coil 7 (or the power generation unit supplies part of the generated electrical energy to the damping coil 7), causing the damping coil 7 to generate a magnetic field, applying a torque to the outer casing 4 in the opposite direction of its rotation, thereby causing the outer casing 4 to decelerate, and thus reducing the electrical energy generated by the power generation unit until the electrical energy generated by the power generation unit is the same as the preset value.

[0035] It should be noted that in existing electromagnetic damping turbine generators, the damper uses a damping coil spirally wound around the inner wall of the outer casing in a circumferential direction. When the damping coil is energized, it generates axial magnetic flux along the axis of the main shaft. Influenced by the maximum magnetic flux density of the main shaft, magnetic saturation occurs when the main shaft length reaches a predetermined length. At this point, even if the main shaft length continues to increase, the braking effect generated by the damping coil will not increase. However, in the downhole electromagnetic damping turbine generator of this invention, the damping coil 7 is wound around a salient pole tooth 16, the length extension direction of which is parallel to the axial direction of the main shaft 10. When the damping coil 7 is energized, it generates radial magnetic flux along the radial direction of the main shaft 10. Thus, as the axial length of the damping unit increases, the braking and adjustment capability of the damping unit for the power generation unit improves, thereby facilitating the regulation and control of the electrical energy generated by the power generation unit.

[0036] In some embodiments, refer to Figure 3 and Figure 4 As shown, there are multiple salient pole teeth 16 and damping coils 7. Multiple salient pole teeth 16 are evenly arranged on the outer peripheral wall of the main shaft 10, and multiple damping coils 7 are connected in parallel, which can reduce the inductance generated during the operation of the damping unit and thus improve the response speed of the damping unit to the torque generated by the housing 4.

[0037] In some embodiments, refer to Figure 3 As shown, the salient pole tooth 16 and the main shaft 10 are integrally formed, meaning the salient pole tooth 16 can be machined on the outer peripheral wall of the main shaft 10, and the damping coil 7 is wound around the salient pole tooth 16. Of course, the salient pole tooth 16 and the main shaft 10 can also be detachably connected, for example, the salient pole tooth 16 can be bonded or welded to the outer peripheral wall of the main shaft 10.

[0038] In some embodiments, refer to Figure 1 , Figures 3-5As shown, the turbine includes a turbine body and turbine blades 5 disposed on the outer wall of the turbine body. At least a portion of the outer shell 4 is formed as the turbine body, that is, this portion of the outer shell 4 serves as the turbine body of a conventional turbine. The turbine blades 5 are disposed on this portion of the outer shell 4, achieving a high degree of integration between the turbine and the outer shell 4. This is beneficial to reducing the axial length of the downhole electromagnetic damping turbine generator of the present invention, thereby reducing the length of the drilling tool. This can bring the following beneficial effects: First, a shorter drilling tool is beneficial to improving the control of the wellbore direction. A shorter drilling tool can more accurately control the drill bit direction during the drilling process, thereby controlling the wellbore direction and preventing the drill bit from deviating from the predetermined trajectory, thereby improving the drilling efficiency and success rate. Especially under complex geological conditions, this improved wellbore direction control capability can significantly reduce the additional re-drilling or workover time caused by wellbore direction deviation. Meanwhile, shorter drilling tools are beneficial to enhancing safety during the drilling process. On the one hand, shorter tripping and tripping operations can promptly remove sand beds formed on the wellbore, preventing stuck drill bits caused by excessive sand bed accumulation and ensuring the safe conduct of drilling operations. On the other hand, after drilling through the oil and gas layer, shorter tripping and tripping operations can promptly understand the upward velocity of the oil and gas layer, thereby grasping the balance of fluid column pressure and preventing well kicks and blowouts caused by prolonged static time.

[0039] In some embodiments, refer to Figure 5 As shown, there are multiple turbine blades 5, which are evenly arranged on the outer peripheral wall of the outer casing 4.

[0040] Furthermore, the turbine blade 5 can be disposed on the outer casing 4 of the damping unit on the radially outer side. In this case, the turbine blade 5 can serve as a heat dissipation fin for this part of the casing 4. When the high-pressure fluid in the drill collar flows through the turbine blade 5, it carries away at least part of the heat generated by the damping unit on the casing 4, thereby improving the heat dissipation capacity of this part of the casing 4.

[0041] In some embodiments, the downhole electromagnetic damping turbine generator provided by the present invention further includes a first bearing assembly and a second bearing assembly sleeved on the main shaft 10, wherein the first bearing assembly and the second bearing assembly are rotatably connected to the inner peripheral walls at both ends of the outer casing 4.

[0042] In some embodiments, refer to Figure 1 and Figure 4 As shown, both the first bearing assembly and the second bearing assembly include an axially arranged tapered roller bearing 14 and a deep groove ball bearing 15, thereby protecting the main shaft 10 and the components mounted on the main shaft 10 when the turbine blades 5 are subjected to high-pressure fluid impact. Optionally, the tapered roller bearing 14 is disposed on the side of the deep groove ball bearing 15 near the damping unit.

[0043] In the downhole electromagnetic damping turbine generator of the present invention, when the flow velocity of the high-pressure fluid increases, the torque on the turbine blades 5 increases. At this time, the reverse torque of the damping unit on the housing 4 increases, thereby reducing the mechanical impact on the housing 4 and bearing assemblies such as the tapered roller bearing 14 and the deep groove ball bearing 15. Therefore, when the fluid flow velocity suddenly increases, the damping unit of the present invention can stabilize the electrical energy generated by the power generation unit while also reducing the mechanical impact on the housing 4 and bearing assemblies such as the tapered roller bearing 14 and the deep groove ball bearing 15.

[0044] In some embodiments, refer to Figure 1 and Figure 4 As shown, the first bearing assembly is rotatably connected to one end of the housing 4 near the damping unit. The downhole electromagnetic damping turbine generator provided by the present invention also includes a first sleeve 3 disposed between the first bearing assembly and the lead wire 1. The first sleeve 3 separates the lead wire 1 from the first bearing assembly, thereby protecting the lead wire 1 and the main shaft 10.

[0045] In some embodiments, refer to Figure 1 and Figure 4 As shown, the first sleeve 3 is connected to the spindle 10 via key 2, which improves the stability of the connection between the first sleeve 3 and the spindle 10.

[0046] In some embodiments, the stator assembly includes stator laminations and a generator winding 8 wound on the stator laminations. The stator laminations are disposed on the outer peripheral wall of the main shaft 10. The stator laminations may include alloys such as silicon steel, copper, or aluminum. For example, in one embodiment of the downhole electromagnetic damping turbine generator according to the present invention, the stator laminations are silicon steel stators 11 formed by die casting of silicon steel sheets. (Refer to...) Figure 1 , Figure 2 and Figure 4 As shown, the silicon steel stator 11 is sleeved on the outer peripheral wall of the main shaft 10, and the generator winding 8 can be formed by winding copper wire, aluminum wire or other conductive wire around the silicon steel stator 11.

[0047] In some embodiments, refer to Figure 1 As shown, the downhole electromagnetic damping turbine generator provided by the present invention further includes a second sleeve 6 sleeved on the outer peripheral wall of the main shaft 10. The two ends of the second sleeve 6 abut against the ends of the silicon steel stator 11 and the damping unit, respectively, thereby separating the damping unit from the power generation unit. Combined with... Figure 1As shown, a first groove for mounting a silicon steel stator 11 is formed on the outer peripheral wall of the main shaft 10. The end of the silicon steel stator 11 away from the damping unit abuts against the wall of the first groove. There is a first gap between the other end of the silicon steel stator 11 and the damping unit. The second sleeve 6 is disposed in the first gap and the two ends of the second sleeve 6 abut against the ends of the silicon steel stator 11 and the damping unit, respectively, so that the second sleeve 6 fills the first gap, separating the damping unit from the power generation unit while maintaining the connection stability between the damping unit and the power generation unit.

[0048] In some embodiments, the rotor assembly includes a plurality of magnet rotors 9, which are uniformly disposed on the inner peripheral wall of the housing 4, as shown in the figure. Figure 2 and Figure 4 As shown, multiple magnetic rotors 9 are evenly arranged on the inner peripheral wall of the outer casing 4. When the turbine blades 5 are impacted by high-pressure fluid, the magnetic rotors 9 can rotate together with the outer casing 4, thereby generating electrical energy in the power generation unit. Of course, the rotor assembly can also be made of materials such as cast iron.

[0049] In some embodiments, the downhole electromagnetic damping turbine generator provided by the present invention includes a bearing assembly sleeved on the main shaft 10 and rotatably connected to the inner peripheral wall of the end of the housing 4. The bearing assembly includes, for example, the aforementioned first bearing assembly and second bearing assembly, referring to... Figure 1 As shown, the downhole electromagnetic damping turbine generator provided by the present invention also includes a third sleeve 12 sleeved on the radially outer side of the main shaft 10. The two ends of the third sleeve 12 are respectively used to abut against the magnetic steel rotor 9 and the bearing assembly, thereby separating the magnetic steel rotor 9 and the bearing assembly.

[0050] In some embodiments, refer to Figure 1 and Figure 4 As shown, the downhole electromagnetic damping turbine generator provided by the present invention also includes a shock-absorbing pad 13 disposed between the third sleeve 12 and the bearing assembly. The bearing assembly may include a first bearing assembly and a second bearing assembly sleeved on the main shaft 10. The first bearing assembly and the second bearing assembly are rotatably connected to the inner peripheral walls of both ends of the housing 4, respectively. The first bearing assembly is rotatably connected to the end of the housing 4 near the damping unit, and the second bearing assembly is rotatably connected to the end of the housing 4 near the power generation unit. (Combined with...) Figure 1 As shown, a second groove for mounting the magnet rotor 9 is formed on the inner peripheral wall of the outer casing 4. One end of the magnet rotor 9 near the damping unit abuts against the wall of the second groove, and a second gap exists between the other end of the magnet rotor 9 and the second bearing assembly. A third sleeve 12 is disposed within the second gap, and one end of the third sleeve 12 abuts against the other end of the magnet rotor 9. A shock-absorbing pad 13 can be disposed between the other end of the third sleeve 12 and the second bearing assembly, thereby improving the ability of the downhole electromagnetic damping turbine generator of the present invention to resist fluid shock.

[0051] The working process of the downhole electromagnetic damping turbine generator provided by the present invention will be specifically described below according to one embodiment of the present invention.

[0052] In this invention, an electromagnetic damping turbine generator is lowered into the drill collar. During drilling, the high-pressure fluid inside the drill collar impacts the turbine blades 5 on the outer casing 4, causing the turbine blades 5 to rotate. The rotation of the turbine blades 5 drives the outer casing 4 and the magnetic rotor 9 mounted on the inner peripheral wall of the outer casing 4 to rotate together, while the main shaft 10 and the silicon steel stator 11 on the outer peripheral wall of the main shaft 10 remain stationary. Therefore, the magnetic rotor 9 rotates relative to the silicon steel stator 11, causing the generator winding 8 to cut the magnetic field generated by the magnetic rotor 9, thereby generating electrical energy. The electrical energy generated by the generator unit is related to the rotational speed of the outer casing 4 and the magnetic rotor 9. The higher the rotational speed of the outer casing 4, the greater the electrical energy generated by the generator unit; the lower the rotational speed of the outer casing 4, the less electrical energy generated by the generator unit.

[0053] To ensure that the electrical energy generated by the power generation unit can be maintained at a preset value, the downhole electromagnetic damping turbine generator of the present invention is also equipped with a damping unit. The damping unit includes salient pole teeth 16 disposed on the outer peripheral wall of the main shaft 10 and a damping coil 7 wound on the salient pole teeth 16. When the flow velocity of the high-pressure fluid in the drill collar increases, the rotational speed of the turbine blades 5, the outer casing 4, and the magnetic rotor 9 increases, thereby increasing the electrical energy generated by the power generation unit. This may cause downhole equipment, such as electric motors, to overload and be damaged. At this time, by supplying current to the damping coil 7, the damping coil 7 generates a magnetic field. This magnetic field acts on the outer casing 4 and can generate a torque in the opposite direction on the outer casing 4. The magnitude of this torque in the opposite direction can be adjusted by adjusting the magnitude of the supplied current. This torque in the opposite direction is opposite to the rotational direction of the outer casing 4, thus reducing the rotational speed of the outer casing 4, thereby reducing the electrical energy generated by the power generation unit until the electrical energy generated by the power generation unit is reduced to the preset value. Of course, when the flow rate of the high-pressure fluid inside the drill collar decreases, and the rotational speed of the turbine blades 5, the outer casing 4, and the magnetic rotor 9 decreases, the electrical energy generated by the power generation unit decreases, preventing the downhole equipment from operating normally. At this time, by reducing the current supplied to the damping coil 7, the magnitude of the reverse torque generated by the magnetic field of the damping coil 7 on the outer casing 4 decreases, thereby increasing the rotational speed of the outer casing 4 and the magnetic rotor 9, increasing the electrical energy generated by the power generation unit until the electrical energy generated by the power generation unit reaches the preset value. Thus, the damping unit can generate braking torque on the power generation unit, so that the electrical energy generated by the power generation unit is basically maintained at the preset value.

[0054] The downhole electromagnetic damping turbine generator provided by the present invention, through the above technical solution, has the following beneficial effects: (1) The lead wire extends axially along the outer peripheral wall of the main shaft to avoid direct contact between the lead wire and the outer casing, which generates more heat, thereby reducing the requirement for the temperature resistance of the lead wire and improving the overall temperature resistance of the generator of the present invention. (2) The turbine and housing are integrated, which shortens the axial length of the generator, which is conducive to improving the control of the wellbore direction, improving drilling efficiency and success rate, and also helps to enhance the safety of the drilling process; (3) The turbine blades are arranged on the radial outer side of the damping unit as heat dissipation fins of the shell, which can improve the heat dissipation capacity of high power heat-generating locations. (4) The damping coil is wound on the salient pole tooth. After the damping coil is energized, it generates radial magnetic flux. As the length of the salient pole tooth along the axial direction of the main shaft increases, the damping unit's ability to regulate the power generation unit is improved. (5) The damping unit with multiple damping coils reduces the number of turns of each damping coil, and the multiple damping coils are connected in parallel to reduce the inductance generated when the damping coil is energized, thereby reducing the energizing time of the damping coil and accelerating the response speed of the damping coil to brake the shell. (6) When the flow rate of the fluid changes drastically, the damping unit can reduce the mechanical impact on the housing and bearing assembly.

[0055] In addition, the present invention also provides a downhole power generation control system, including the aforementioned downhole electromagnetic damping turbine generator and a control circuit. The electrical energy generated by the power generation unit can be transmitted to the control circuit. The control circuit can rectify and transmit the electrical energy transmitted by the power generation unit. Part of the electrical energy is transmitted to the downhole installation for powering the downhole equipment, and the other part of the electrical energy is transmitted to the damping unit for the operation of the damping unit.

[0056] The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various specific technical features in any suitable manner. To avoid unnecessary repetition, the present invention will not describe the various possible combinations separately. However, these simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A downhole electromagnetic damping turbine generator, characterized in that, include: Main spindle (10); The outer casing (4) is fitted over the outside of the main shaft (10); The turbine is connected in drive to the housing (4); The power generation unit includes a rotor assembly disposed on the inner peripheral wall of the housing (4) and a stator assembly disposed on the outer peripheral wall of the main shaft (10); A damping unit is disposed on the main shaft (10) and axially offset from the power generation unit; as well as, Lead wire (1), the lead wire (1) is used to electrically connect to the power generation unit and the damping unit respectively, and the lead wire extends axially along the outer peripheral wall of the main shaft (10); The turbine is configured to rotate when it is subjected to fluid impact, and the rotation of the turbine drives the outer casing (4) and the rotor assembly to rotate, thereby generating electrical energy in the power generation unit. The damping unit is configured to generate a preset value of electrical energy in the power generation unit.

2. The downhole electromagnetic damping turbine generator according to claim 1, characterized in that, The damping unit also includes salient pole teeth (16) disposed on the outer peripheral wall of the main shaft (10) and damping coils (7) wound on the salient pole teeth (16).

3. The downhole electromagnetic damping turbine generator according to claim 2, characterized in that, The salient pole tooth (16) and the spindle (10) are integrally formed.

4. The downhole electromagnetic damping turbine generator according to claim 1, characterized in that, The turbine includes a turbine body and turbine blades (5) disposed on the outer wall of the turbine body, and at least part of the outer casing (4) is formed as the turbine body.

5. The downhole electromagnetic damping turbine generator according to claim 4, characterized in that, The turbine blade (5) is disposed on the radial outer side of the damping unit.

6. The downhole electromagnetic damping turbine generator according to claim 1, characterized in that, The generator also includes a first bearing assembly and a second bearing assembly mounted on the main shaft (10), the first bearing assembly and the second bearing assembly being rotatably connected to the inner peripheral walls at both ends of the housing (4).

7. The downhole electromagnetic damping turbine generator according to claim 6, characterized in that, Both the first bearing assembly and the second bearing assembly include an axially arranged tapered roller bearing (14) and a deep groove ball bearing (15).

8. The downhole electromagnetic damping turbine generator according to claim 6, characterized in that, The first bearing assembly is rotatably connected to one end of the housing (4) near the damping unit, and the generator further includes a first sleeve (3) disposed between the first bearing assembly and the lead wire (1).

9. The downhole electromagnetic damping turbine generator according to claim 8, characterized in that, The first sleeve (3) is connected to the main shaft (10) by a key (2).

10. The downhole electromagnetic damping turbine generator according to claim 1, characterized in that, The stator assembly includes a silicon steel stator (11) sleeved on the outer peripheral wall of the main shaft (10) and a generator winding (8) wound on the silicon steel stator (11).

11. The downhole electromagnetic damping turbine generator according to claim 10, characterized in that, The generator also includes a second sleeve (6) sleeved on the outer peripheral wall of the main shaft (10) and connected between the silicon steel stator (11) and the damping unit.

12. The downhole electromagnetic damping turbine generator according to claim 1, characterized in that, The rotor assembly includes multiple magnet rotors (9), which are evenly arranged on the inner peripheral wall of the outer shell (4).

13. The downhole electromagnetic damping turbine generator according to claim 12, characterized in that, The generator includes a bearing assembly mounted on the inner circumferential wall of the end of the main shaft (10) and rotatably connected to the housing (4). The generator also includes a third sleeve (12) mounted on the radially outer side of the main shaft (10). The two ends of the third sleeve (12) are respectively used to abut against the magnet rotor (9) and the bearing assembly.

14. The downhole electromagnetic damping turbine generator according to claim 13, characterized in that, The generator also includes a shock-absorbing pad (13) disposed between the third sleeve (12) and the bearing assembly.

15. A downhole power generation control system, characterized in that, Includes the downhole electromagnetic damping turbine generator according to any one of claims 1-14.

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