A kind of oil well underground power generation device

Abstract

The present application relates to the field of downhole oil equipment, and in particular to a downhole oil power generation device, which includes a driving nipple and a power generation nipple: the driving nipple includes an outer cylinder and a driving shaft, a cavity is formed in the outer cylinder, the driving shaft is arranged on the outer cylinder and can slide in the cavity along the length direction of the outer cylinder; the power generation nipple includes a shell, a rotor, a coil, a permanent magnet and a power transmission assembly, the rotor is rotatably connected to the shell, the driving shaft is threadedly connected to the rotor, the outer cylinder is connected to the shell, one end of the outer cylinder away from the shell and one end of the shell away from the outer cylinder are respectively connected to the pipe column, the coil is wound on the rotor, the permanent magnet is installed on the inner wall of the shell, the permanent magnet and the coil are arranged oppositely, the power transmission assembly is arranged on the rotor, and is used to transmit the electric energy generated by the coil to the downhole equipment, and the driving shaft and the rotor are both hollow structures and formed with a through channel. The present application has the effect of meeting the requirements of the full diameter in the pipe column while meeting the long-term power supply of downhole equipment in petroleum engineering.

Description

Technical Field

[0001] The present application relates to the field of oil well equipment, and in particular to an oil well power generation device. Background Art

[0002] Drilling engineering is the process of drilling a cylindrical hole at a certain depth using mechanical equipment. The main functions are: first, obtaining physical data from underground; second, as a geophysical channel, obtaining various geophysical data of the ore layer; third, used for drilling for exploration and development of groundwater, oil and gas, geothermal energy, etc. During the drilling process, various underground equipment is needed, so how to provide a reliable power source for the underground equipment is of utmost importance.

[0003] There are two main ways to power underground equipment as recorded in the relevant technology. One is cable power supply, which uses cables to power ground and underground equipment. This power supply method has obvious disadvantages. For deep well drilling, the length of the cable must reach several thousand meters, which not only brings inconvenience to the construction but also greatly increases the construction cost. Therefore, this power supply method is gradually eliminated. The other is battery power supply, which can be lowered with the underground equipment, which is convenient and fast; however, the battery is limited by the size of the device structure, and the battery capacity is limited, which is not suitable for powering systems that require long-term work and high power consumption.

[0004] In order to solve the problem of limited battery capacity and inability to provide long-term power, downhole generators are now used to convert the kinetic energy of circulating mud into electrical energy to ensure the power supply of equipment. Downhole turbine generators use the circulation of mud in the well to drive the turbine to rotate and generate electricity. However, in this method, the turbine, transmission mechanism, generator and other components need to be installed in the center of the pipe string, making it impossible to achieve full bore in the pipe. For completion and oil production and some well repair conditions, it is not applicable to the scene where some tools need to be lowered into the well for well repair. Summary of the invention

[0005] In order to meet the requirement of long-term power supply for downhole equipment in petroleum engineering and at the same time meet the requirement of full diameter in the pipe string, the present application provides a downhole petroleum power generation device.

[0006] The present application provides a petroleum underground power generation device adopts the following technical solution:

[0007] A petroleum underground power generation device, comprising a driving short section and a power generation short section:

[0008] The driving sub includes an outer cylinder and a driving shaft. A cavity is formed in the outer cylinder. The driving shaft is passed through the outer cylinder and can slide back and forth in the cavity along the length direction of the outer cylinder. When there is pressure in the pipe string, the force on the end of the driving shaft away from the rotor is greater than the force on the end of the driving shaft close to the rotor.

[0009] The power generation sub includes a shell, a rotor, a coil, a permanent magnet and a power transmission component. The rotor is rotatably connected to the shell, the drive shaft is threadedly connected to the rotor, the outer cylinder is connected to the shell, one end of the outer cylinder away from the shell and one end of the shell away from the outer cylinder are respectively connected to the pipe column, the coil is wound on the rotor, the permanent magnet is installed on the inner wall of the shell, the permanent magnet and the coil are arranged opposite to each other, the power transmission component is arranged on the rotor, and is used to transmit the electric energy generated by the coil to the downhole equipment, and the drive shaft and the rotor are both hollow structures and formed with a through channel.

[0010] By adopting the above technical solution, during assembly, the rotor and the drive shaft are first threaded together, and then the drive nipple and the power generation nipple are connected together, that is, the outer tube and the shell are connected together, and finally the end of the outer tube away from the shell and the end of the shell away from the outer tube are respectively connected to the pipe string, so that the installation work is completed. The drive nipple and the power generation nipple are both part of the overall pipe string. Since the drive shaft and the rotor are both hollow structures and have a through channel, in the subsequent well repair operation, some other tools can pass up and down in the completion / production pipe string through the channel, that is, full-diameter passage is achieved. When in use, pressure is applied to the pipe string from the ground, so that there is a certain pressure in the pipe string. At this time, the force on the end of the drive shaft away from the rotor is greater than the force on the end of the drive shaft close to the rotor, and the drive shaft moves in the direction close to the rotor. Since the rotor and the drive shaft are threadedly connected, when the drive shaft slides, the rotor rotates under the action of the thread pair, and then drives the coil to rotate together. The coil cuts the magnetic lines of force in the magnetic field formed by the permanent magnet, and then generates electrical energy on the coil, and finally transmits it to the downhole equipment through the power transmission component. In this way, the full-diameter requirement in the pipe string can be met while satisfying the long-term power supply requirement for downhole equipment in petroleum engineering.

[0011] Optionally, the driving short section also includes a first sealing ring, a second sealing ring and a compression spring, the first sealing ring and the second sealing ring are both located in the cavity, the first sealing ring is located at an end of the cavity away from the power generation short section and the second sealing ring is located at an end of the cavity close to the power generation short section, the sealing area of ​​the first sealing ring is larger than the sealing area of ​​the second sealing ring, and the two ends of the compression spring are respectively connected to the outer cylinder and the driving shaft.

[0012] By adopting the above technical solution, a sealed space is formed by using the first sealing ring and the second sealing ring. When a certain pressure exists in the pipe column, the force on the end of the driving shaft away from the rotor is greater than the force on the end of the driving shaft close to the rotor, the driving shaft slides, and the spring is compressed. When the compression spring moves to the limit position, the pressure in the pipe column is relieved, and the driving shaft is reset by the action of the compression spring. By continuously increasing and releasing pressure, the driving shaft can reciprocate in the cavity, thereby achieving the purpose of continuous power generation.

[0013] Optionally, the drive shaft includes a push shaft and a core shaft, the push shaft is sleeved on the core shaft, the compression spring is sleeved along the circumference of the push shaft, the length of the core shaft is greater than the length of the push shaft, and the channel is opened on the core shaft.

[0014] By adopting the above technical solution, the push shaft is used as a driving source to drive the rotor to rotate, and the core shaft can move with the push shaft to be used to insert other tools. In this way, the drive shaft is designed in a split style, which is convenient for connection and flexible use.

[0015] Optionally, the push shaft and the core shaft are threadedly connected.

[0016] By adopting the above technical solution, the threaded connection between the push shaft and the core shaft realizes a detachable connection, which is convenient for replacing the push shaft or the core shaft. At the same time, the threaded connection can ensure the compactness and sealing of the structure.

[0017] Optionally, the power transmission component includes a conductive block and a brush, both of which are connected to the rotor, the conductive block is electrically connected to the coil, the brush is electrically connected to the conductive block, a lead hole is provided on the shell, and the cable is electrically connected to the brush through the lead hole.

[0018] By adopting the above technical solution, the cable of the downhole equipment is connected to the brush through the lead hole. When the coil generates electrical energy, it is transferred to the brush through the conductive block, thereby realizing continuous power supply.

[0019] Optionally, two conductive blocks are provided, the brush is a two-body brush, and the two conductive blocks are in contact with the two-body brush respectively.

[0020] By adopting the above technical solution, when the rotor rotates, it can drive the conductive blocks to rotate, and the two conductive blocks are in contact with the two-body brushes at the same time. In this way, the device can be used to supply power to two underground devices at the same time.

[0021] Optionally, a watertight connector is embedded in the lead hole.

[0022] By adopting the above technical solution, the watertight connector can improve the sealing of the lead hole, prevent liquid from entering, and improve safety.

[0023] Optionally, the power transmission component further includes a brush holder, which is detachably connected to the housing, and the brush is disposed in the brush holder.

[0024] By adopting the above technical solution, since the brush is a consumable and needs to be replaced frequently, a detachable connection of the brush is achieved through the brush holder, which facilitates the replacement of the brush.

[0025] Optionally, the diameter of the channel is the same as the diameter of the column.

[0026] By adopting the above technical solution, the diameter of the channel is the same as the diameter of the pipe string, which is convenient for later well repair operations.

[0027] Optionally, the shell and the outer cylinder are connected by threads.

[0028] By adopting the above technical solution, the threaded connection between the shell and the outer cylinder realizes the detachable connection between the driving short section and the generating short section, which is convenient for replacing the driving short section or the generating short section. At the same time, the threaded connection can ensure the compactness and sealing of the finishing structure.

[0029] In summary, the present application includes at least one of the following beneficial technical effects:

[0030] 1. The present application provides an oil well downhole power generation device, which includes a driving pup joint and a power generation pup joint. The driving pup joint and the power generation pup joint are connected and power is transmitted through a threaded pair. The two pup joints are connected as one through the threads on the driving pup joint outer tube, the upper joint of the power generation pup joint, and the lower joint. The device can be connected to the completion and production tubing, and the hollow structure of the device can be consistent with the diameter of the completion and production tubing. When the ground pump truck pressurizes the completion and production tubing, the core shaft of the driving pup joint is designed with a pressure difference surface. When there is pressure in the pipe, the push shaft moves downward. When the pressure is released, it moves upward and resets with the cooperation of the spring. During the upward and downward processes, the rotor of the power generation pup joint is driven to rotate by the threaded pair, thereby achieving the purpose of converting the ground mechanical energy into electrical energy through the pressure energy of the liquid column. In this way, the full-diameter requirement in the tubing is met while meeting the long-term power supply requirements for downhole equipment in the completion and production stages of petroleum engineering;

[0031] 2. The oil downhole power generation device in this application adopts a hollow structure to ensure the full diameter of the working pipe string, which is convenient for other tools to pass up and down in the pipe string during the later well repair operation. Compared with the technical solution of placing the power generation device in the pipe string channel such as the downhole turbine generator, it has strong processability and well condition applicability;

[0032] 3. The oil downhole power generation device in this application can organize pump trucks on the ground at any time to generate electricity through orderly and controllable pressure to ensure the power supply of downhole equipment. There is no need for a supporting power supply network and other power equipment. Compared with downhole battery power supply and other methods, it is flexible to implement, has fewer limitations, and is more cost-effective. At the same time, the existing batteries can be charged downhole, and it is highly compatible with existing technologies. The ground energy is transmitted by means of liquid pressure in the pipe column. Compared with conventional downhole cable power supply, the hydraulic transmission energy loss is small and the utilization rate is high. The application advantages of deep wells and ultra-deep wells are more obvious. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 is a cross-sectional view of the oil well power generation device after assembly in the present application;

[0034] Figure 2 It is a schematic diagram of the state of the oil well power generation device in the present application, in which the push shaft is pushed downward to generate power;

[0035] Figure 3 is a cross-sectional view of the driving sub in the present application;

[0036] Figure 4 is a cross-sectional view of a power generation short section in the present application;

[0037] Figure 5 It is a schematic diagram of the installation of the rotor, coil, conductive block and brush in this application.

[0038] Explanation of the reference numerals: 1. driving nipple; 11. outer cylinder; 12. driving shaft; 121. push shaft; 122. core shaft; 13. first sealing ring; 14. second sealing ring; 15. compression spring; 16. cavity; 17. gland; 2. power generation nipple; 21. shell; 211. upper joint; 212. outer shell; 213. lower joint; 22. rotor; 23. coil; 24. permanent magnet; 25. power transmission component; 251. conductive block; 252. brush; 253. brush holder; 26. bobbin; 27. lead hole; 28. watertight connector; 3. channel; 4. ball bearing; 5. thrust bearing; 6. compression sleeve. DETAILED DESCRIPTION

[0039] The following is combined with Figure 1-5 This application is described in further detail.

[0040] The present application embodiment discloses a petroleum underground power generation device, referring to Figure 1 and Figure 2The oil well power generation device comprises a driving nipple 1 and a power generation nipple 2. The driving nipple 1 and the power generation nipple 2 are connected and power transmitted by a threaded pair. The power generation nipple 2 can generate electric energy for use by the downhole equipment under the driving action of the driving nipple 1. The ends of the driving nipple 1 and the power generation nipple 2 that are away from each other are respectively connected to the pipe string, and the driving nipple 1 and the power generation nipple 2 form a penetrating channel 3.

[0041] During assembly, first connect the driving nipple 1 and the generating nipple 2 together to ensure that the driving nipple 1 can drive the generating nipple 2, and then connect the driving nipple 1 and the generating nipple 2 to the tubing string respectively. When in use, the driving nipple 1 acts as a driving source to prompt the generating nipple 2 to generate a continuous supply of electric energy for use by downhole equipment. In this way, the driving nipple 1 and the generating nipple 2 move together with the movement of the tubing string as part of the tubing string, and the driving nipple 1 and the generating nipple 2 form a through channel 3, through which some other tools can pass up and down in the completion / production tubing string, that is, full-diameter passage is achieved. Finally, on the premise of meeting the long-term power supply of downhole equipment in petroleum engineering, the full-diameter requirement in the tubing string is also met.

[0042] Specifically, refer to Figure 2 and Figure 3 The driving short section 1 includes an outer cylinder 11, a driving shaft 12, a first sealing ring 13, a second sealing ring 14 and a compression spring 15. A cavity 16 is formed in the outer cylinder 11. The driving shaft 12 is passed through the outer cylinder 11 and can slide back and forth in the cavity 16 along the length direction of the outer cylinder 11. The first sealing ring 13 and the second sealing ring 14 are both located in the cavity 16. The compression spring 15 is sleeved on the driving shaft 12 and its two ends are respectively connected to the inner wall of the outer cylinder 11 and the driving shaft 12. The first sealing ring 13 is located at one end of the cavity 16 away from the power generation short section 2 and the second sealing ring 14 is located at one end of the cavity 16 close to the power generation short section 2. The sealing area of ​​the first sealing ring 13 is greater than the sealing area of ​​the second sealing ring 14.

[0043] In this way, a closed space is formed between the first sealing ring 13 and the second sealing ring 14. When the construction workers apply pressure to the pipe column on the ground, since the sealing area of ​​the first sealing ring 13 is larger than the sealing area of ​​the second sealing ring 14, the force on the end of the drive shaft 12 away from the rotor 22 is greater than the force on the end of the drive shaft 12 close to the rotor 22, and the drive shaft 12 moves toward the rotor 22. When the compression spring 15 moves to the limit position, the pressure in the pipe column is released, and the end of the drive shaft 12 away from the rotor 22 is no longer stressed. Under the action of the compression spring 15, the drive shaft 12 moves away from the rotor 22 to achieve reset. By continuously pressurizing and releasing pressure, the drive shaft 12 can reciprocate.

[0044] Reference Figure 2 and Figure 4The power generation sub 2 includes a shell 21, a rotor 22, a coil 23, a permanent magnet 24 and a power transmission assembly 25. The rotor 22 is rotatably connected to the shell 21, the drive shaft 12 is threadedly connected to the rotor 22, the outer cylinder 11 is connected to the shell 21, and the end of the outer cylinder 11 away from the shell 21 and the end of the shell 21 away from the outer cylinder 11 are respectively connected to the pipe column. The coil 23 is wound on the rotor 22, the permanent magnet 24 is installed on the inner wall of the shell 21, and the permanent magnet 24 and the coil 23 are arranged oppositely. The power transmission assembly 25 is arranged on the rotor 22 for transmitting the electric energy generated by the coil 23 to the downhole equipment. During assembly, the drive shaft 12 and the rotor 22 are first connected together, and then the outer cylinder 11 is connected to the shell 21, that is, the connection between the drive sub 1 and the power generation sub 2 is realized.

[0045] The power generation process is as follows: the staff applies pressure to the pipe string on the ground, the driving shaft 12 slides under the force, and under the action of the threaded pair of the driving shaft 12 and the rotor 22, the rotor 22 rotates, thereby driving the coil 23 to rotate together, and the coil 23 cuts the magnetic lines of force in the magnetic field formed by the permanent magnet 24, thereby generating electrical energy on the coil 23, and finally transmitting it to the downhole equipment through the power transmission component 25. Since the driving shaft 12 can achieve reciprocating movement, this can ensure the continuous rotation of the rotor 22, thereby achieving continuous supply of electrical energy.

[0046] In this embodiment, the pipe column pressurization method can directly add clean water to the pipe column through the pump truck on the ground. In this way, the ground can organize the pump truck at any time to generate electricity through orderly and controllable pressure to ensure the power supply of underground equipment. There is no need for supporting power supply network and other power equipment. The implementation is flexible, with few limitations and higher cost performance. In addition, the ground energy is transmitted by the way of pipe column liquid pressure transmission. On the one hand, it will not be limited by the depth of the well and can meet the needs of deep wells and ultra-deep wells; on the other hand, the hydraulic transmission energy loss is small and the utilization rate is high.

[0047] Further, refer to Figure 2 and Figure 3 The driving sub 1 further includes a gland 17, which is embedded in the cavity 16 and located at one end of the cavity 16 close to the first sealing ring 13. When the pressure is released, the driving shaft 12 rebounds under the action of the compression spring 15, and the gland 17 can play a limiting role. Of course, the connection method of the gland 17 is not specifically limited in this embodiment, and a detachable connection is preferred.

[0048] Reference Figure 1 and Figure 2The driving shaft 12 includes a push shaft 121 and a core shaft 122. The push shaft 121 is sleeved on the core shaft 122. The compression spring 15 is sleeved along the circumference of the push shaft 121. The length of the core shaft 122 is greater than that of the push shaft 121. The channel 3 is opened on the core shaft 122. The end of the push shaft 121 away from the gland 17 is processed with an external thread, and the rotor 22 is processed with an internal thread. The external thread of the push shaft 121 and the internal thread of the rotor 22 form a thread pair. The staff applies pressure to the inside of the pipe column from the ground, and the end of the push shaft 121 close to the gland 17 is subjected to force, so that the push shaft 121 moves in the direction close to the rotor 22. Under the action of the thread pair, the rotor 22 rotates, thereby driving the coil 23 to rotate. The coil 23 cuts the magnetic lines of force in the magnetic field formed by the permanent magnet 24, and then generates electrical energy on the coil 23.

[0049] Reference Figure 1 and Figure 2 , the push shaft 121 and the mandrel 122 are detachably connected, preferably threadedly connected. During installation, the mandrel 122 is inserted into the push shaft 121, and the mandrel 122 is screwed to achieve the connection and fixation of the mandrel 122 and the push shaft 121. The threaded connection design of the push shaft 121 and the mandrel 122 is convenient for the replacement and connection and fixation of the push shaft 121 or the mandrel 122, and the threaded connection can ensure the compactness and sealing of the structure. Of course, a sealing ring can be added at the connection between the mandrel 122 and the push shaft 121 to further improve the sealing. Since the drive shaft 12 is divided into two parts, the push shaft 121 and the mandrel 122, a split design can be achieved. The push shaft 121 is used as a driving source to drive the rotor 22 to rotate; the through channel 3 is opened on the mandrel 122 to ensure the full diameter of the pipe column for lowering some tools.

[0050] Further, refer to Figure 2 and Figure 4 The housing 21 includes an upper joint 211, an outer shell 212 and a lower joint 213. The upper joint 211 and the lower joint 213 are connected together through the outer shell 212. The connection between the upper joint 211 and the outer shell 212 and the connection between the outer shell 212 and the lower joint 213 are preferably detachable. In this embodiment, screw connection is adopted. It can be understood that the upper joint 211, the outer shell 212 and the lower joint 213 are all pre-processed with a space for the rotor 22 to be embedded. The upper joint 211 is used to connect the outer cylinder 11, and the lower joint 213 is used to connect the pipe column.

[0051] Reference Figure 2 and Figure 4The rotor 22 is rotatably connected to the housing 21 through two sets of ball bearings 4. The two ball bearings 4 are respectively installed at the junction of the upper joint 211 and the housing 212, and at the junction of the lower joint 213 and the housing 212. The ball bearing 4 near the upper joint 211 can achieve a limiting effect to prevent the rotor 22 from moving in the direction close to the driving short section 1. The end of the rotor 22 near the lower joint 213 is provided with a thrust bearing 5. The side of the thrust bearing 5 away from the upper joint 211 is provided with a clamping sleeve 6. The clamping sleeve 6 is threadedly connected to the rotor 22. The thrust bearing 5 and the clamping sleeve 6 are used to achieve a limiting effect to prevent the rotor 22 from moving in the direction away from the driving short section 1. The through channel 3 is opened on the rotor 22 and extends along the length direction of the rotor 22 for inserting some other tools.

[0052] Reference Figure 2 and Figure 4 In order to facilitate the winding of the coil 23, a bobbin 26 is installed on the circumference of the rotor 22. The bobbin 26 is arranged along the length direction of the rotor 22. The coil 23 is preferably a copper wire coil 23. The power transmission component 25 includes a conductive block 251 and a brush 252. The conductive block 251 and the brush 252 are both connected to the rotor 22. The conductive block 251 is electrically connected to the coil 23, and the brush 252 is electrically connected to the conductive block 251. A lead hole 27 is opened on the housing 21, and the cable is electrically connected to the brush 252 through the lead hole 27. The cable of the downhole equipment is connected to the brush 252 through the lead hole 27. When the coil 23 generates electrical energy, it is transferred to the brush 252 through the conductive block 251, thereby realizing continuous power supply.

[0053] Reference Figure 4 and Figure 5 Specifically, a groove is provided on the rotor 22, and the conductive block 251 is embedded in the groove to fix the conductive block 251. The power transmission component 25 also includes a brush 252 seat, which is detachably connected to the housing 21, and the brush 252 is arranged in the brush 252 seat. Since the brush 252 is a consumable and needs to be replaced frequently, the brush 252 seat realizes a detachable connection, which facilitates the replacement of the brush 252.

[0054] According to the actual situation, the device is in a hydraulic environment, so it is necessary to ensure the safety of electricity use. A watertight connector 28 is embedded in the lead hole 27. While the cable connection is achieved through the watertight connector 28, it can also be isolated from the external environment to improve safety.

[0055] In particular, refer to Figure 4 and Figure 5There are two conductive blocks 251, and the brush 252 is a two-body brush 252. The two conductive blocks 251 are in contact with the two-body brush 252 respectively. When the rotor 22 rotates, the conductive block 251 can be driven to rotate, and the two conductive blocks 251 are in contact with the two-body brush 252 at the same time. In this way, the device can be used to supply power to two downhole devices at the same time, so it has multifunctionality and practicality.

[0056] It should be noted that the lower joint 213 and the outer tube 11 are both formed with special connection threads for oil pipes, which are used to connect the pipe column. The special connection threads for oil pipes can have a self-sealing effect to ensure the sealing. The shell 21 and the outer tube 11 are connected by threads. The threads of the shell 21 and the outer tube 11 are preferably special connection threads for oil pipes. The threaded connection between the shell 21 and the outer tube 11 realizes the detachable connection between the driving short section 1 and the generating short section 2, which is convenient for the replacement of the driving short section 1 or the generating short section 2. At the same time, the threaded connection can ensure the compactness and sealing of the finishing structure. During installation, first connect the push shaft 121 and the rotor 22, and then connect the shell 21 and the outer tube 11.

[0057] It should be noted that the diameter of the channel 3 is the same as the diameter of the pipe string, so as to achieve full diameter, facilitate subsequent well repair operations, and facilitate the lowering of some well repair tools.

[0058] Of course, according to actual installation requirements, sealing rings are added at corresponding positions to improve the sealing and compactness of the structure. This is a well-known technology among those skilled in the art and will not be described in detail in this embodiment.

[0059] The implementation principle of an oil downhole power generation device in an embodiment of the present application is as follows: during assembly, first insert the core shaft 122 into the channel 3 of the rotor 22, then thread the rotor 22 and the push shaft 121, then thread the outer cylinder 11 and the upper joint 211 together, and finally thread the end of the outer cylinder 11 away from the shell 21 and the end of the lower joint 213 away from the outer cylinder 11 to the pipe string, respectively. In this way, the installation work is completed. The driving short section 1 and the power generation short section 2 are both part of the overall pipe string. Since the driving shaft 12 and the rotor 22 are both hollow structures and have a through channel 3, in this way, during subsequent well repair operations, some other tools can pass up and down in the completion / oil production pipe string through the channel 3, that is, full-diameter passage is achieved. When in use, the staff applies pressure to the pipe string from the ground, so that there is a certain pressure in the pipe string. At this time, the force on the end of the push shaft 121 away from the rotor 22 is greater than the force on the end of the push shaft 121 close to the rotor 22, and the push shaft 121 moves in the direction close to the rotor 22. Since the rotor 22 and the push shaft 121 are threadedly connected, when the push shaft 121 slides, the rotor 22 rotates under the action of the thread pair, and then drives the coil 23 to rotate together. The coil 23 cuts the magnetic lines of force in the magnetic field formed by the permanent magnet 24, and then generates electrical energy on the coil 23, and finally transmits it to the downhole equipment through the conductive block 251, the brush 252 and the cable. In this way, under the premise of meeting the long-term power supply of downhole equipment in petroleum engineering, the full-diameter requirement in the pipe string is met at the same time.

[0060] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. A petroleum underground power generation device, characterized in that: The invention comprises a driving pup joint (1) and a power generation pup joint (2): the driving pup joint (1) comprises an outer cylinder (11) and a driving shaft (12); a cavity (16) is formed in the outer cylinder (11); the driving shaft (12) is passed through the outer cylinder (11) and can slide back and forth in the cavity (16) along the length direction of the outer cylinder (11); the power generation pup joint (2) comprises a shell (21), a rotor (22), a coil (23), a permanent magnet (24) and a power transmission component (25); when there is pressure in the pipe column, the force on the end of the driving shaft (12) away from the rotor (22) is greater than that on the end of the driving shaft (12) The rotor (22) is rotatably connected to the housing (21), the drive shaft (12) and the rotor (22) are threadedly connected, the outer cylinder (11) is connected to the housing (21), one end of the outer cylinder (11) away from the housing (21) and one end of the housing (21) away from the outer cylinder (11) are respectively connected to the pipe column, the coil (23) is wound on the rotor (22), the permanent magnet (24) is installed on the inner wall of the housing (21), and the permanent magnet (24) and The coils (23) are arranged opposite to each other, the power transmission assembly (25) is arranged on the rotor (22), the drive shaft (12) and the rotor (22) are both hollow structures and are formed with a through channel (3); the drive nipple (1) further comprises a first sealing ring (13), a second sealing ring (14) and a compression spring (15), the first sealing ring (13) and the second sealing ring (14) are both located in the cavity (16), the first sealing ring (13) is located at one end of the cavity (16) away from the power generation nipple (2), and the second sealing ring (14) is located at one end of the cavity (16) away from the power generation nipple (2), and the second sealing ring (15) is located at one end of the cavity (16) away from the power generation nipple (2). The sealing ring (14) is located at one end of the cavity (16) close to the power generation short section (2), and the two ends of the compression spring (15) are respectively connected to the outer cylinder (11) and the driving shaft (12); the driving shaft (12) comprises a push shaft (121) and a core shaft (122), the push shaft (121) is sleeved on the core shaft (122), the compression spring (15) is sleeved along the circumference of the push shaft (121), the length of the core shaft (122) is greater than the length of the push shaft (121), and the channel (3) is opened on the core shaft (122).

2. The oil well power generation device according to claim 1, characterized in that: The push shaft (121) and the core shaft (122) are threadedly connected.

3. The oil well power generation device according to claim 1, characterized in that: The power transmission component (25) comprises a conductive block (251) and a brush (252); the conductive block (251) and the brush (252) are both connected to the rotor (22); the conductive block (251) is electrically connected to the coil (23); the brush (252) is electrically connected to the conductive block (251); a lead hole (27) is provided on the housing (21); and a cable of downhole equipment is electrically connected to the brush (252) through the lead hole (27).

4. The oil well power generation device according to claim 3 is characterized in that: Two conductive blocks (251) are provided, the brush (252) is a two-body brush (252), and the two conductive blocks (251) are in contact with the two-body brush (252) respectively.

5. The oil well power generation device according to claim 4 is characterized in that: A watertight connector (28) is embedded in the lead-in hole (27).

6. The oil well power generation device according to claim 4, characterized in that: The power transmission component (25) further comprises a brush (252) seat, the brush (252) seat being detachably connected to the housing (21), and the brush (252) being arranged in the brush (252) seat.

7. The oil well power generation device according to claim 1, characterized in that: The diameter of the channel (3) is the same as the diameter of the column.

8. The oil well power generation device according to claim 1, characterized in that: The shell (21) and the outer cylinder (11) are connected by threads.

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