Compression device and compression system for pressurizing underground gas

Abstract

The invention provides a compression device and a compression system for pressurizing underground gas, and belongs to the field of well completion engineering. The compression device comprises a rotor rotating shaft, a plurality of rotor blade discs arranged on the rotor rotating shaft, an outer casing, and an inlet guide blade disc, a plurality of stator blade discs and an outlet guide blade disc which are arranged in the outer casing. The front end of the outer casing is connected with the rear end of the front supporting cover, and a flange plate is arranged at the rear end of the outer casing. A front bearing and a rear bearing are installed at the two ends of the rotor rotating shaft respectively, the rotor rotating shaft and the outer casing are coaxially arranged, and the rotor blade discs and the stator blade discs are arranged in a staggered mode. The rotor blade disc is matched and connected with the rotor rotating shaft; a plurality of rotor blades are arranged on the outer surface of the rotor blade disc, and the rotor blades and the rotor blade disc are of an integrated structure; a plurality of stator blades are arranged on the outer surface of the stator blade disc, and the stator blades and the stator blade disc are of an integrated structure. Machining and assembling difficulty can be reduced, and the compression device is simple in structure.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of well completion engineering, and particularly relates to a compression device and compression system for downhole gas pressurization. BACKGROUND

[0002] In well completion operation, the use of downhole gas pressurization device can achieve effective pressurization of gas well, inject external energy into natural gas, maximize the reduction of reservoir abandonment pressure, extend the service life of gas well and obtain economic benefits exceeding conventional surface pressurization exploitation, and improve the exploitation efficiency and service life of gas well. However, due to the limitation of gas well size, in order to achieve effective pressurization, the rotational speed of the compression device needs to be increased to 40000 rpm, which puts forward requirements for the power of the motor and the compression device under a specific size. The smaller size of the gas well limits the increase of the motor power, and the corresponding torque is also limited. If the rotational inertia of the compression device is too large (i.e. the starting torque of the compression device is greater than the torque of the motor), it will cause the compression device to fail to start normally and adjust the working state, resulting in pressurization failure.

[0003] In the traditional compression device, the blades are connected to the blade disc using tenon, and in the small size compression device, this method will greatly increase the processing difficulty, and the blade disc cannot be designed to reduce weight. In addition, the rotor blade disc and the rotor rotating shaft are integrated, which also increases the processing difficulty. At the same time, due to the small fillet radius of the tenon, the stress concentration phenomenon is serious, and fatigue cracks or even breakage may occur. Therefore, the structure of the blade and the blade disc under high rotational speed needs to be redesigned. SUMMARY

[0004] The present application aims to solve the problems existing in the prior art, and provides a compression device and compression system for downhole gas pressurization, which can strictly control the rotational inertia of the rotor rotating shaft and the rotor blade disc, effectively improve the adjustment range of the motor rotational speed under the same power, reduce the processing and assembly difficulty, reduce the blade root stress, and improve the safety of the compression device.

[0005] The present application is achieved by the following technical solutions:

[0006] A compression device for downhole gas pressurization, comprising: a rotor rotating shaft and a plurality of rotor blade discs arranged thereon, an outer casing and an inlet guide vane disc, a plurality of stator blade discs and an outlet guide vane disc arranged in the outer casing; the front end of the outer casing is connected with the rear end of the front support cover, and the rear end of the outer casing is provided with a flange plate; the front bearing and the rear bearing are respectively arranged at the two ends of the rotor rotating shaft, the rotor rotating shaft is coaxially arranged with the outer casing, and each rotor blade disc is arranged alternately with a stator blade disc.

[0007] The rotor blade disc is connected with the rotor rotating shaft in cooperation;

[0008] A plurality of rotor blades are arranged on the outer surface of the rotor blade disc, and the rotor blade and the rotor blade disc are integrated;

[0009] A plurality of stator blades are arranged on the outer surface of the stator blade disc, and the stator blade and the stator blade disc are integrated.

[0010] Preferably, the rotor blade disc is provided with a rotor blade disc lightening hole and / or a rotor blade disc rib plate.

[0011] Preferably, the root of the rotor blade and / or the stator blade is rounded.

[0012] Preferably, a plurality of shaft through holes parallel to the central axis are arranged on the rotor rotating shaft, and the plurality of shaft through holes are uniformly distributed around the central axis.

[0013] Preferably, the front end of the rotor rotating shaft is provided with a front end baffle, and the first rotor blade disc is provided with a clamping groove matched with the front end baffle of the rotor rotating shaft.

[0014] Preferably, the front end baffle is provided with a hole.

[0015] Preferably, the rotor blade disc is in interference fit with the rotor rotating shaft, and the stator blade disc is in interference fit with the outer casing.

[0016] Preferably, the front bearing is arranged in the central through hole of the first support part of the front support cover, and a first limiting assembly is arranged between the first support part and the rotor rotating shaft.

[0017] The rear bearing is arranged in the central through hole of the second support part of the outlet guide vane disc, and a second limiting assembly is arranged between the second support part and the rotor rotating shaft.

[0018] Preferably, a flow guide cover is installed at the front end of the rotor rotating shaft, and the flow guide cover is located in the inner cavity of the front support cover.

[0019] The front end of the front bearing is in contact with the flow guide cover, and the rear end of the front bearing is in contact with the first limiting assembly.

[0020] The front end of the rear bearing is in contact with the shoulder end face of the rotor rotating shaft and the second limiting assembly, and the rear end of the rear bearing is in contact with the second limiting assembly.

[0021] A compression system for downhole gas pressurization, the compression system comprising the compression device and the motor as described above, and the motor is connected with the rotor rotating shaft.

[0022] Compared with the prior art, the compression system has the following beneficial effects:

[0023] This invention provides a compression device and system for downhole gas pressurization. By using a hollow rotor blade disk and rotor rotating shaft optimized by combining static structural strength analysis and rotor dynamics simulation, the moment of inertia of the rotor rotating shaft and rotor blade disk is strictly controlled, which effectively improves the speed adjustment range of the motor under the same power and improves the adjustability of the downhole compression device.

[0024] The present invention provides a compression device and compression system for downhole gas pressurization, which uses an integrated structure of blades and blade disks (including rotor blades and rotor blade disks, stator blades and stator blade disks), and the rotor blade disks are connected to the rotor rotating shaft, which can reduce the difficulty of processing and assembly; the rounded design of the blade root can effectively reduce the blade root stress, making the compression device simple in structure, less prone to failure, and ensuring that it can work in the downhole environment for a long time. Attached Figure Description

[0025] Figure 1 This is a cross-sectional view of a compression device for downhole gas pressurization according to the present invention;

[0026] Figure 2 This is a schematic diagram of the front support cover in the compression device of the present invention;

[0027] Figure 3 This is a schematic diagram of the structure of the outlet guide vane disk in the compression device of the present invention;

[0028] Figure 4 This is a schematic diagram of the rotor shaft in the compression device of the present invention;

[0029] Figure 5 This is an isometric view of the rotor blade disk in the compression device of the present invention;

[0030] Figure 6 This is a front view of the rotor blade disk in the compression device of the present invention;

[0031] Figure 7 This is a rear view of the rotor blade disk in the compression device of the present invention;

[0032] Figure 8 This is a schematic diagram of the stator blade disk in the compression device of the present invention.

[0033] The components marked in the diagram are: 1. Draft shield, 2. Front support shield, 3. Front bearing outer ring, 4. Front bearing inner ring, 5. Rotor rotating shaft, 6. First rotor blade disk, 7. Second rotor blade disk, 8. Third rotor blade disk, 9. Fourth rotor blade disk, 10. Fifth rotor blade disk, 11. Outer casing, 12. Rear bearing pressure ring, 13. Motor flange, 14. Motor ferrule, 15. Motor pressure sleeve, 16. Rear bearing inner ring, 17. Rear bearing outer ring, 18. Rear bearing, 19. Outlet draft shield disk, 20. 5. Stator blade disk, 21. Fourth stator blade disk, 22. Third stator blade disk, 23. Second stator blade disk, 24. First stator blade disk, 25. Inlet guide vane disk, 26. Disc spring pressure ring, 27. Disc spring, 28. Front bearing; 40. Central shaft, 41. Outer shaft, 42. Shaft through hole, 43. Baffle flange hole; 50. Rotor blade disk, 501. Rotor blade, 502. Rotor blade disk rib, 503. Rotor blade disk weight reduction hole; 60. Stator blade disk, 601. Stator blade. Detailed Implementation

[0034] The present invention will now be described in further detail with reference to the accompanying drawings:

[0035] like Figure 1 As shown, the present invention provides a compression device for downhole gas pressurization, comprising a rotor rotating shaft 5, rotor blade disks 50, stator blade disks 60, inlet guide vane disks 25, outlet guide vane disks 19, an outer casing 11, a front support cover 2, a front bearing 28, and a rear bearing 18. The number of rotor blade disks 50 and stator blade disks 60 is determined by the number of stages of the compression device. Figure 1 The left side is the front, and the right side is the back.

[0036] The outer casing 11 has a cylindrical structure, and its front end is connected to the rear end of the front support cover 2. The rear end of the outer casing 11 is provided with a flange for connecting the motor flange 13. The inner diameter of the flanged end of the outer casing 11 is slightly smaller, forming a stepped surface. The outlet guide vane disk 19, the stator vane disk 60, and the inlet guide vane disk 25 are arranged sequentially from the rear end to the front end along the central axis of the outer casing 11. The rear end face of the outlet guide vane disk 19 is in contact with the stepped surface, and the front end face of the inlet guide vane disk 25 is in contact with the rear end face of the front support cover 2.

[0037] like Figure 2 As shown, the front support cover 2 has a cylindrical structure with an open front end and a first support portion coaxial with it at the rear end. The first support portion is connected to the inner wall of the front support cover 2 through multiple ribs. The front bearing 28 is disposed in the central through hole of the first support portion of the front support cover 2. A first limiting assembly is provided between the first support portion and the rotor rotating shaft 5. The rear end of the front support cover 2 is inserted into the front end of the outer casing 11. The inlet guide vane disk 25 provides inlet guiding function. Figure 3As shown, the outlet guide vane disk 19 provides an outlet guide function and is also provided with a second support part coaxial with it. The second support part is connected to the inner wall of the outlet guide vane disk 19 through multiple ribs. The rear bearing 18 is provided in the central through hole of the second support part of the outlet guide vane disk 19. A second limiting component is provided between the second support part and the rotor rotating shaft 5.

[0038] The rotor blade disks 50 are mounted on the rotor shaft 5, which is coaxially aligned with the outer casing 11. The rotor blade disks 50 and stator blade disks 60 are staggered to prevent collisions between the rotor blades 501 and the stator blades 601. The front bearing 28 and the rear bearing 18 are respectively mounted at both ends of the rotor shaft 5 to support it and limit its axial position. During operation, the rotor shaft 5 drives the rotor blade disks 50 to rotate, which, in conjunction with the stator blade disks 60, compress the downhole gas.

[0039] The compression device provided by the present invention further includes: a flow guide shroud 1 and a motor flange 13.

[0040] The air deflector 1 is installed at the front end of the rotor shaft 5 and located inside the front support cover 2. The functions of the air deflector 1 are: to regulate airflow speed and distribution, reduce noise and vibration, and protect the equipment. The air deflector 1 controls the speed and distribution of the airflow. By adjusting its shape and position, it optimizes the speed and distribution of the airflow as it passes through the rotor, reducing airflow vortices and turbulence, thereby improving compression efficiency and stability. While improving airflow conditions, the air deflector 1 also reduces blade and casing vibration, decreases noise generation, and ensures stable compressor operation. Furthermore, the air deflector 1 protects the blades, reducing damage from the external environment and extending the equipment's lifespan.

[0041] The motor flange 13 includes an outer casing connecting plate and a motor connecting plate connected in parallel. The outer casing connecting plate and the motor connecting plate are respectively provided with flange holes for installing screws to connect the outer casing 11 and the motor housing together. The motor flange 13 has a hollow structure, and through holes are provided at the center of its front and rear ends for the rotor rotating shaft 5 and the motor shaft to pass through.

[0042] like Figure 4As shown, the rotor rotating shaft 5 includes a central shaft 40 and an outer shaft 41 sleeved on the central shaft 40. The diameter of the middle section of the central shaft 40 is larger than the diameters of the front and rear sections. The joint between the middle section and the front and rear sections forms a shoulder, which can axially position the front bearing 28 and the rear bearing 18, respectively. The front and rear ends of the central shaft 40 are respectively provided with coaxial inner holes at the front and rear ends. The inner hole at the front end is used to install the guide shield 1, and the inner hole at the rear end is used to connect the motor main shaft. The outer shaft 41 of the rotor rotating shaft 5 is sleeved on the middle section of the central shaft 40. Multiple shaft through holes 42 parallel to the central axis are opened on the outer shaft 41, and the multiple shaft through holes 42 are evenly distributed around the central axis. A front end baffle is provided at the front end of the outer shaft 41, and a hole is opened at a specific position (determined according to the simulation experiment) on the front end baffle.

[0043] like Figures 5 to 7 As shown, the rotor blade disk 50 has a cylindrical structure with multiple rotor blades 501 arranged on its outer cylindrical surface. Each rotor blade 501 forms a preset angle with the central axis of the rotor blade disk 50, and the multiple rotor blades 501 are evenly distributed on the circumference. The rotor blades 501 and the rotor blade disk 50 are an integral structure, and the root of the rotor blade 501 (i.e., the position where the rotor blade 501 connects to the rotor blade disk 50) is rounded. Preferably, the rotor blade disk 50 has rotor blade disk weight reduction holes 503 and rotor blade disk ribs 502. The rotor blade disk weight reduction holes 503 are holes opened at specific positions on the rotor blade disk 50 (positions determined according to simulation experiments), and the portion between two adjacent rotor blade disk weight reduction holes 503 forms the rotor blade disk ribs 502. The rotational inertia of the rotor blade disk 50 is controlled by controlling the number and size of the holes. Since the rotor blade disk 50 is hollow, in order to maintain a good shape at a speed of 40,000 rpm, the thickness of the rotor blade disk rib 502 needs to be reasonably controlled so that its structural strength meets the requirements.

[0044] like Figure 8 As shown, the stator blade disk 60 has a cylindrical structure with multiple stator blades 601 arranged on its inner cylindrical surface. Each stator blade 601 forms a predetermined angle with the central axis of the stator blade disk 60, and the multiple stator blades 601 are evenly distributed on the circumference. The stator blades 601 and the stator blade disk 60 are an integral structure, and the root of the stator blade 601 (i.e., the position where the stator blade 601 connects to the stator blade disk 60) is rounded.

[0045] A compressor (i.e., a compression device) is a mechanical device that compresses gases such as air to increase their pressure and temperature. In a compressor, the working space between each rotor (rotor blade disk 50) and stator (stator blade disk 60) is called a "stage". A compressor consisting of multiple stages in sequence is called the compressor stage number. Methods for determining the compressor stage number include the design procedure method, the empirical method, and the theoretical method. When determining the stage number, the relationship between compression ratio and efficiency needs to be considered, and the optimal stage number should be determined based on the actual application conditions. The compression device provided by this invention is currently designed with 5 stages.

[0046] Specifically, this invention includes five rotor blade disks 50: a first rotor blade disk 6, a second rotor blade disk 7, a third rotor blade disk 8, a fourth rotor blade disk 9, and a fifth rotor blade disk 10, all with essentially the same structure. The first rotor blade disk 6, the second rotor blade disk 7, the third rotor blade disk 8, the fourth rotor blade disk 9, and the fifth rotor blade disk 10 are all connected to the outer shaft 41 of the rotor rotating shaft 5 using a cold-fitting method (interference fit), and are tightly stacked axially from front to back, utilizing inter-disk friction to achieve axial and circumferential limiting. Different interference fits provide different frictional forces for axial and circumferential limiting. The first rotor blade disk 6 has a slot at its front end, which engages with the front end baffle of the rotor rotating shaft 5, providing axial and circumferential limiting for the first rotor blade disk 6.

[0047] This invention includes five stator blade disks 60: a first stator blade disk 24, a second stator blade disk 23, a third stator blade disk 22, a fourth stator blade disk 21, and a fifth stator blade disk 20. These disks have similar structures, and their blade shapes can be designed based on existing aerodynamic design results. The inlet guide vane disk 25, the first stator blade disk 24, the second stator blade disk 23, the third stator blade disk 22, the fourth stator blade disk 21, the fifth stator blade disk 20, and the outlet guide vane disk 19 are all connected to the inner surface of the outer casing 11 using a cold-fit method (interference fit) to achieve axial and circumferential positioning of the stator blade disks 60.

[0048] It should be noted that the positions of the openings on the rotor blade disk 50 and the rotor rotating shaft 5, as well as the dimensions of the shaft through hole 42 on the rotor rotating shaft 5, were determined using existing structural strength simulation methods. The rotor blade disk 50 and the stator blade disk 60 are made of low-density, high-strength materials, such as 7075 aluminum alloy; the rotational inertia of the rotating parts is minimized to reduce the starting torque and the torque required to maintain high-speed rotation, thereby expanding the working range of the compression device.

[0049] During the design of the rotor blade disk 50 and rotor shaft 5, structural statics simulation is required to evaluate the impact of openings and rib thickness on the structural strength of the rotor blade disk 50 under high-speed rotation. The stress on the rotating components can be reduced by appropriately adjusting the opening position, number, and rib thickness. Rotor dynamics simulation is used to evaluate the resonant frequency of the rotating components, and the dimensions and hollowing method of the rotor shaft 5 are adjusted accordingly to offset the resonant frequency of the rotating components from the design speed range of 0.8 to 1.2 times, thereby improving the operational stability and safety of the compression device.

[0050] This invention provides a compression device for downhole gas pressurization, comprising components such as a rotor shaft, rotor blade disks, and stator blade disks. The rotor blade disks are connected to the rotor shaft using a cold-fitting method and are tightly stacked axially, utilizing inter-disk friction for axial and circumferential positioning. The stator blade disks are connected to the casing using a cold-fitting method, achieving axial and circumferential positioning. The rotor blade disks and stator blade disks are staggered, maintaining consistency in axial dimensions to prevent collisions between rotor and stator blades. The rotor shaft rotation drives the rotor blade disks to rotate, cooperating with the stator blade disks to compress the downhole gas. This compression device for downhole gas pressurization, by using hollow rotor blade disks and a rotor shaft optimized through static structural strength analysis and rotor dynamics simulation, effectively improves the speed adjustment range of the motor at the same power, enhancing the adjustability of the downhole compression device. The compression device uses an integrated structure of blades and blade disks, with the rotor blade disks and rotor rotating shaft connected together, which can reduce the difficulty of processing and assembly. The rounded design at the blade root can effectively reduce blade root stress and improve the working safety of the downhole compression system.

[0051] The embodiments of the present invention are as follows:

[0052] Example 1

[0053] like Figure 1As shown, this embodiment provides a compression device for downhole gas pressurization, including a rotor shaft 5 and an outer casing 11. The rotor shaft 5 is disposed inside the outer casing 11 and is collinear with the central axis of the outer casing 11. From front to back, a first rotor blade disk 6, a second rotor blade disk 7, a third rotor blade disk 8, a fourth rotor blade disk 9, and a fifth rotor blade disk 10 are sequentially installed on the rotor shaft 5. From front to back, an inlet guide vane disk 25, a first stator blade disk 24, a second stator blade disk 23, a third stator blade disk 22, a fourth stator blade disk 21, a fifth stator blade disk 20, and an outlet guide vane disk 19 are sequentially installed inside the outer casing 11. The rotor blade disks 50 and stator blade disks 60 are staggered, that is, the inlet guide vane disk 25, the first rotor blade disk 6, the first stator blade disk 24, the second rotor blade disk 7, the second stator blade disk 23, the third rotor blade disk 8…the outlet guide vane disk 19 are installed sequentially along the axial direction. Axially, the rotor blades on each rotor blade disk are offset from the stator blades on the stator blade disk. The inlet guide vane disk 25 and the outlet guide vane disk 19 engage with the end of the front support cover 2 and the stepped surface of the outer casing 11, respectively, to achieve axial positioning. The front support cover 2, the inlet guide vane disk 25, the first stator blade disk 24, the second stator blade disk 23, the third stator blade disk 22, the fourth stator blade disk 21, the fifth stator blade disk 20, and the outlet guide vane disk 19 are all provided with pin holes in the circumferential direction for circumferential positioning, ensuring that the installation angle of each stator blade disk on the casing (the angle of the stator blade disk relative to the casing) is consistent with the designed angle.

[0054] In this embodiment, the front end baffle of the rotor rotating shaft 5 is disposed on the outer cylindrical surface of the rotor rotating shaft 5 and is annular. The front end baffle is tightly connected (interference fit) to the groove at the front end of the first rotor blade disk 6. When each rotor blade disk 50 compresses gas, it will be subjected to a thrust to the left along the axial direction. Using this baffle can prevent the rotor blade disk 50 from sliding along the axial direction.

[0055] Example 2

[0056] The rotor shaft 5 is axially positioned by a front bearing 28 and a rear bearing 18, respectively. The front bearing 28 and the rear bearing 18 can be tandem angular contact ball bearings or deep groove ball bearings. Figure 1 The image shows angular contact ball bearings arranged in series.

[0057] The front and rear ends of the front bearing 28 are in contact with the guide shield 1 and the first limiting assembly, respectively, which restrict the axial displacement of the front bearing 28. The first limiting assembly includes: the inner ring 4 of the front bearing, the outer ring 3 of the front bearing, the disc spring 27, and the disc spring pressure ring 26. The inner ring 4 of the front bearing is a cylindrical structure and is fitted onto the front end of the rotor rotating shaft 5. The front end face of the inner ring 4 is in contact with the inner ring of the front bearing 28, and the rear end face is in contact with the shoulder end face of the front end of the rotor rotating shaft 5. The outer ring 3 of the front bearing is fitted onto the outside of the inner ring 4. The longitudinal section (the surface passing through the central axis) of the outer ring 3 is L-shaped. One end face of the L-shape is in contact with the outer ring of the front bearing 28, and the other end face is in contact with the front support cover 2. The disc spring retainer ring 26 is annular and is fitted onto the shoulder of the inner ring 4 of the front bearing and the rotor shaft 5. The front end face of the disc spring retainer ring 26 contacts the front support cover 2, and the rear end face contacts the front end face of the inlet guide vane disk 25. The disc spring 27 is disposed in the cavity between the outer ring 3 of the front bearing and the disc spring retainer ring 26. The disc spring 27 can apply a preload to the outer ring 3 of the front bearing, and the disc spring retainer ring 26 restricts the axial displacement of the disc spring 27.

[0058] The rear bearing 18 is limited at both ends by a second limiting assembly and the shoulder end face of the rear end of the rotor shaft 5. The second limiting assembly includes: a rear bearing retaining ring 12 disposed at the front end of the rear bearing 18, and a rear bearing inner ring 16 and a rear bearing outer ring 17 disposed at the rear end of the rear bearing 18. The rear bearing retaining ring 12 is annular and is fitted onto the shoulder of the rear end of the rotor shaft 5. The front end face of the rear bearing retaining ring 12 contacts the rear end face of the fifth stator blade disk 20, and the rear end face simultaneously contacts the outlet guide vane disk 19 and the outer ring of the rear bearing 18, thus limiting the axial displacement of the rear bearing 18. The front end of the inner ring of the rear bearing 18 contacts the shoulder end face of the rotor shaft 5. The rear bearing inner ring 16 is cylindrical, with the front outer diameter smaller than the rear outer diameter. The rear bearing inner ring 16 is fitted onto the rear end of the rotor shaft 5, and its front end face contacts the inner ring of the rear bearing 18. The rear bearing outer ring 17 is fitted onto the front end of the rear bearing inner ring 16. The longitudinal section of the rear bearing outer ring 17 is L-shaped. One end face of the L-shape contacts the outer ring of the rear bearing 18, and the other end is connected to the outlet guide vane disk 19.

[0059] Example 3

[0060] A flow guide shroud 1 is installed at the front end of the rotor shaft 5. The front end of the flow guide shroud 1 is hemispherical, and the rear end is cylindrical. A connecting hole is opened at the center, and a screw passes through the connecting hole and is screwed into the inner hole at the front end of the rotor shaft 5. A motor retainer 14 and a motor pressure sleeve 15 are installed at the rear end of the rotor shaft 5. The outer surface of the motor retainer 14 forms two conical surfaces, and the large diameter ends of the two conical surfaces are connected. An annular groove is opened at the connection. The front end of the motor retainer 14 is inserted into the inner hole at the rear end of the central shaft 40, and the flange at the end of the inner hole at the rear end of the shaft is engaged in the annular groove. The motor pressure sleeve 15 is sleeved on the end of the rotor shaft 5. Its inner surface fits against the outer surface of the rear end of the motor retainer 14 and is engaged with the external thread at the end of the rotor shaft 5. A through hole is opened at the center of the motor retainer 14 and the motor pressure sleeve 15 for connecting and locking the motor main shaft, thereby realizing the rotation of the rotor shaft 5 of the compression device driven by the motor.

[0061] The motor flange 13 is installed at the rear end of the outer casing 11 via the outer casing connecting plate. The front end face of the motor flange 13 contacts the rear end face of the outlet guide vane disk 19. The rear end of the motor flange 13 is the motor connecting plate, which has flange holes. Screws pass through the flange holes to connect with the motor housing.

[0062] Example 4

[0063] like Figure 4 As shown, in this embodiment, a baffle flange hole 43 is provided on the front end baffle of the rotor rotating shaft 5 (the position of the hole can be determined according to the simulation experiment). The baffle flange hole 43 can reduce the weight of the rotor rotating shaft 5. A high-precision shaft through hole 42 is drilled on the outer shaft 41 of the rotor rotating shaft 5 using a deep hole drill. The central axis of the shaft through hole 42 is parallel to the axis of the rotor rotating shaft 5. Multiple shaft through holes 42 are evenly distributed on the circumference to reduce the rotational inertia of the rotor rotating shaft 5 and improve the stability of the shaft when rotating at high speed.

[0064] like Figures 5 to 7 As shown, in this embodiment, the weight-reducing holes 503 of the rotor blade disk are evenly distributed around the central axis of the rotor blade disk 50, and the portion between two adjacent rotor blade disk weight-reducing holes 503 forms a rotor blade disk rib 502. The rotor blade disk weight-reducing holes 503 are blind holes, and circular through holes are opened at the blind ends of four of them to ensure that the installation angle of each rotor blade disk on the rotor rotation axis (the angle of the rotor blade disk relative to the rotor rotation axis) is consistent with the designed angle. The first rotor blade disk 6, the second rotor blade disk 7, the third rotor blade disk 8, the fourth rotor blade disk 9, and the fifth rotor blade disk 10 all have this structure, but the dimensions of the weight-reducing holes and ribs are adjusted according to the actual situation. The root of the rotor blade 501 is rounded, and the rounding radius is determined according to the blade height.

[0065] like Figure 8As shown, in this embodiment, the preset angle of the stator blade 601 should match the preset angle of the rotor blade 501 (the specific matching can be determined according to existing aerodynamic design methods), and the outer diameter of the stator blade disk 60 should match the inner diameter of the outer casing 11. The stator blade 601 and the stator blade disk 60 adopt an integrated structure, and the root of the stator blade 601 is rounded, with the rounding radius determined according to the blade height.

[0066] In summary, this specific embodiment realizes a compression device for downhole gas pressurization. By using a hollow rotor blade disk and rotor shaft optimized through static structural strength analysis and rotor dynamics simulation, the speed adjustment range of the motor at the same power is effectively improved, thus enhancing the adjustability of the downhole compression device. The compression device uses an integrated blade and blade disk structure, with the rotor blade disk and rotor shaft connected in a mating manner, reducing machining and assembly difficulties. The rounded design at the blade root effectively reduces blade root stress, improving the operational safety of the downhole compression system.

[0067] The present invention also provides a compression system for downhole gas pressurization, the compression system including the above-mentioned compression device and motor, the motor being connected to the rotor rotating shaft to provide power to the compression device, and the compression system being installed at the bottom of the well during well completion operations.

[0068] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0069] In the description of this invention, unless otherwise stated, the terms "upper," "lower," "left," "right," "inner," "outer," 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 limitations on this invention.

[0070] The above technical solution is only one embodiment of the present invention. For those skilled in the art, based on the principles disclosed in the present invention, it is easy to make various types of improvements or modifications, and not limited to the technical solutions described in the specific embodiments of the present invention. Therefore, the foregoing description is only a preferred option and is not restrictive.

Claims

1. A compression device for downhole gas pressurization, comprising: The rotor rotating shaft and the plurality of rotor blade discs arranged thereon, the outer casing and the inlet guide vane disc, the plurality of stator blade discs and the outlet guide vane disc arranged in the outer casing; the front end of the outer casing is connected with the rear end of the front support cover, and the rear end of the outer casing is provided with a flange plate; the front bearing and the rear bearing are respectively arranged at the two ends of the rotor rotating shaft, the rotor rotating shaft is coaxially arranged with the outer casing, and the rotor blade discs and the stator blade discs are arranged alternately, characterized in that: The rotor blade disc is connected with the rotor rotating shaft in a matched mode; A plurality of rotor blades are arranged on the outer surface of the rotor blade disc, and the rotor blade and the rotor blade disc are in an integrated structure. A plurality of stator blades are arranged on the outer surface of the stator blade disc, and the stator blade and the stator blade disc are in an integrated structure.

2. The compression device for downhole gas pressurization of claim 1, wherein: The rotor blade disc is provided with a rotor blade disc lightening hole and / or a rotor blade disc rib plate.

3. The compression device for downhole gas pressurization of claim 1, wherein: The root of the rotor blade and / or the stator blade is rounded.

4. The compression device for downhole gas pressurization of claim 1, wherein: A plurality of shaft through holes parallel to the central axis are arranged on the rotor rotating shaft, and the plurality of shaft through holes are uniformly distributed around the central axis.

5. The compression device for downhole gas pressurization of claim 1, wherein: The front end of the rotor rotating shaft is provided with a front end baffle, and the first rotor blade disc is provided with a clamping groove matched with the front end baffle of the rotor rotating shaft.

6. A compression device for downhole gas pressurization according to claim 5, characterized in that: The front end baffle is provided with a hole.

7. The compression device for downhole gas pressurization of claim 1, wherein: The rotor blade disc is in interference fit with the rotor rotating shaft, and the stator blade disc is in interference fit with the outer casing.

8. The compression device for downhole gas pressurization according to claim 1, characterized in that: The front bearing is arranged in the central through hole of the first support part of the front support cover, and a first limiting assembly is arranged between the first support part and the rotor rotating shaft; The rear bearing is arranged in the central through hole of the second support part of the outlet guide vane disc, and a second limiting assembly is arranged between the second support part and the rotor rotating shaft.

9. A compression device for downhole gas pressurization according to claim 8, characterized in that: A flow guide cover is arranged at the front end of the rotor rotating shaft, and the flow guide cover is located in the inner cavity of the front support cover; The front end of the front bearing is in contact with the flow guide cover, and the rear end of the front bearing is in contact with the first limiting assembly; The front end of the rear bearing is in contact with the shoulder end surface of the rotor rotating shaft and the second limiting assembly, and the rear end of the rear bearing is in contact with the second limiting assembly.

10. A compression system for downhole gas pressurization, comprising the compression device according to any one of claims 1-9 and a motor connected with the rotor rotating shaft.

Images