JP2022148726A - mining pump - Google Patents

Abstract

To provide a mining pump that is less affected by a slurry component.SOLUTION: A mining pump comprises a production pipe, a pump rotor, and a pump stator surrounding the pump rotor. The pump rotor has a pump shaft, and an impeller rotating with the pump shaft. The pump stator has a stator body forming a flow path outside the impeller, a stator shroud, and a plurality of vanes connecting the stator body and the stator shroud. The stator shroud has a guide surface formed on an extension line in an outflow direction of the flow outflowing from the vanes, and a step surface connected to an upper edge of the guide surface and extending in a direction intersecting the guide surface.SELECTED DRAWING: Figure 2

Description

The present disclosure relates to mining pumps.

A pump called ESP (Electrical Submersible Pump) has been widely used as a device for pumping up crude oil from an oil well. As shown in Patent Document 1, this type of pump includes a rotating shaft that rotates about the rotating shaft, a plurality of impellers integrally provided on the rotating shaft, and a casing that covers the rotating shaft and the impellers from the outer peripheral side. and have. This pump is placed in a pipe inserted into a well (oil field), and a rotating shaft is rotated by an electric motor to pump underground oil upwards.

Japanese Patent Publication No. 2018-508701

Here, it is known that the crude oil to be mined contains many slurry components, which are fine solid particles, in addition to liquid components. If such a slurry component mixes with the bearing of the rotating shaft or the surface of the rotating shaft, there is a risk that wear and tear will progress and normal pump performance will not be obtained.

The present disclosure has been made to solve the above problems, and an object thereof is to provide a mining pump that is less affected by slurry components.

In order to solve the above problems, a mining pump according to the present disclosure includes a production pipe having a cylindrical shape along an axis extending in a vertical direction, a pump rotor extending in the production pipe in the axial direction, the production pipe and the pump. a pump stator surrounding the pump rotor between itself and a rotor, the pump rotor comprising a plurality of pump shafts sequentially connected in the axial direction; an impeller that rotates with the shaft to pump the crude oil upward; the pump stator has a cylindrical shape extending along the axis to form a flow path outside the impeller; A stator shroud that forms the flow path by facing the impeller from above in the axial direction, and a plurality of vanes that connect the stator body and the stator shroud and are arranged at intervals in the circumferential direction. and the stator shroud includes a guide surface formed on an extension line in the outflow direction of the flow discharged from the vane, and an upper edge of the guide surface in the axial direction to intersect the guide surface. and a stepped surface extending in the direction of

According to the present disclosure, it is possible to provide a mining pump that is less affected by slurry components.

1 is a longitudinal sectional view showing the configuration of a mining pump according to an embodiment of the present disclosure; FIG. 1 is an enlarged cross-sectional view of a main portion of a mining pump according to an embodiment of the present disclosure; FIG. FIG. 3 is an illustration showing fluid flow during operation of a mining pump according to an embodiment of the present disclosure; FIG. 5 is an enlarged cross-sectional view of a main part showing a modification of the mining pump according to the embodiment of the present disclosure;

(Composition of mining pump)
A mining pump according to an embodiment of the present disclosure will be described below with reference to FIGS. 1 to 3. FIG. A mining pump 100 according to this embodiment is a device for pumping up crude oil from an oil well. As shown in FIGS. 1 and 2 , this mining pump 100 includes a pump body 90 , a motor 80 , a drilling pipe 9 , and a lower end thrust bearing 10 . The pump body 90 is driven by power supplied from the motor 80 . The excavation pipe 9 covers the pump body 90, the motor 80, and the lower end thrust bearing portion 10 from the outer peripheral side, and has a tubular shape centered on an axis O extending in the vertical direction.

The pump body 90 has a production pipe body 1 a, a pump rotor 21 and a pump stator 3 . The production pipe main body 1 a is a cylindrical member coaxial with the drilling pipe 9 and arranged on the inner peripheral side of the drilling pipe 9 . The pump rotor 21 includes a plurality of pump shafts 21s connected in the direction of the axis O, a coupling sleeve (not shown) connecting the pump shafts 21s, and a plurality of impellers 5 fixed to the pump shafts 21s. have. The configuration of the impeller 5 will be described later.

The pump stator 3 has a stator main body 3h that covers the impeller 5 from the outer peripheral side, and a stator extension portion 3e. The stator body 3h accommodates the impeller 5 and defines a stator flow path Fs through which the crude oil flows by repeating expansion and contraction in diameter from bottom to top. The configurations of the impeller 5 and the pump stator 3 will be described later. The stator extension portion 3e is integrally provided below the stator main body 3h and has a tubular shape centered on the axis O. As shown in FIG. A lower end thrust pad 7d is attached to the lower end of the stator extension 3e.

The motor 80 has a production pipe tip 1b, a motor rotor 22, a coil 81, and a magnetic member 22m. The production pipe tip portion 1b has a cylindrical shape and is integrally provided below the production pipe main body 1a. The production pipe body 1a and the production pipe tip 1b form a production pipe 1 as a whole. A plurality of coils 81 arranged in the circumferential direction are provided on the inner peripheral surface of the production pipe distal end portion 1b. This coil 81 generates an electromagnetic force by a current supplied from the outside. The motor rotor 22 is arranged inside the coils 81 and has a columnar shape extending along the axis O. As shown in FIG. The motor rotor 22 is connected to the lowermost pump shaft 21s of the plurality of pump shafts 21s forming the pump rotor 21 via a lower end spline coupling 30d. 21 s of these pump shafts and the motor rotor 22 form the rotor 2 as a whole. A permanent magnet as a magnetic member 22m is provided on the outer peripheral surface of the motor rotor 22 . Rotational force is applied to the rotor 2 by an electromagnetic force generated between the magnetic field generated by energizing the coil 81 and the magnetic field of the magnetic member 22m.

The leading end portion 1b of the production pipe is supported from below by an annular support portion 4 projecting radially inwardly from the inner peripheral surface of the excavation pipe 9. As shown in FIG. An opening on the inner peripheral side of the support portion 4 is an opening H for taking in the crude oil. The lower end of the motor rotor 22 is inserted through this opening H. Inside the motor rotor 22, in addition to the opening H, a suction passage F for sucking crude oil is formed. The suction flow path F communicates with a stator flow path Fs formed on the inner peripheral side of the pump stator 3 .

Further, on the outer peripheral surface of the motor rotor 22 and above the magnetic member 22m, an annular lower end thrust collar 6d projecting radially outward and centered on the axis O is provided. The bottom thrust collar 6d is supported from above and below by bottom thrust pads 7d provided on the inner peripheral surface of the pump stator 3 (stator extension 3e). The lower end thrust collar 6d and the lower end thrust pad 7d form a lower end thrust bearing portion 10. As shown in FIG. The rotor 2 (the pump rotor 21 and the motor rotor 22) is rotatably supported around the axis O with respect to the pump stator 3 by the lower end thrust bearing portion 10 and an intermediate thrust bearing portion Bs, which will be described later.

Next, the configuration of the impeller 5 will be described with reference to FIG. The impeller 5 has a disk 51 , blades 52 and a shroud cover 53 . The disk 51 is fixed to the outer peripheral surface of the pump shaft 21s and has a disc shape centered on the axis O. As shown in FIG. The downward facing surface of the disk 51 is a disk main surface 51m. The disk main surface 51m is curved from the inner side to the outer side in the radial direction from the lower side to the upper side.

A plurality of blades 52 arranged at intervals in the circumferential direction are provided on the disk main surface 51m. Although not shown in detail, each blade 52 is curved forward in the rotational direction of the rotor 2 from the radially inner side to the outer side. Also, the blade height of the blade 52 (rising dimension from the disk main surface 51m) gradually decreases from the bottom to the top.

The shroud cover 53 has a funnel shape covering the plurality of blades 52 from below. The shroud cover 53 is curved from the inner side to the outer side in the radial direction from the bottom to the top.

The impeller 5 configured as described above is covered with the stator main body 3h from the outer peripheral side. Of the inner peripheral surface of the stator main body 3h, the surface facing the shroud cover 53 is a facing surface 31. As shown in FIG. A connection surface 32 is formed in an area of the inner peripheral surface of the stator main body 3h that is above and adjacent to the facing surface 31 . The connection surface 32 is recessed in a curved shape toward the radially outer side. Furthermore, a region above and adjacent to the connecting surface 32 is a downstream surface 33 . The downstream surface 33 extends from the radially outer side to the inner side as it goes upwards from below. The downstream surface 33 is provided with a plurality of vanes 60 and a stator shroud 3 s fixed to the inner peripheral side of the vanes 60 . Each vane 60 has a plate shape protruding radially inward from the downstream surface 33 . A plurality of vanes 60 are arranged at intervals in the circumferential direction. The stator shroud 3s faces the disk 51 described above from above.

The outer peripheral surface of the stator shroud 3 s is composed of a guide surface 34 , a cylindrical surface 35 and a stepped surface 36 . The guide surface 34 extends radially inward from the lower end side of the stator shroud 3s as it goes upward. Further, the guide surface 34 is curved so as to be concaved radially inward. The guide surface 34 is positioned on an extension line of the outflow direction of the flow outflowing from the vane 60, as indicated by the arrow in FIG. In other words, all straight lines normal to the trailing edge of vane 60 extend toward this guide surface 34 . A cylindrical surface 35 is connected above the guide surface 34 . The cylindrical surface 35 extends parallel to the axis O. A step surface 36 is connected to the upper edge of the cylindrical surface 35 . The stepped surface 36 extends in a radial direction that intersects the guide surface 34 and the cylindrical surface 35 . A rectangular step is formed by the cylindrical surface 35 and the step surface 36 in a cross-sectional view. A radially inner edge of the step surface 36 faces the outer peripheral surface of the pump shaft 21s.

(Effect)
Next, the operation of the mining pump 100 will be described. In operating the mining pump 100, first, the rotor 2 is rotated by supplying electric power to the motor 80 described above. When the rotor 2 rotates, the crude oil in the oil well is sucked up by the pump body 90 through the opening H formed at the lower end of the drilling pipe 9 . At this time, the crude oil is also sucked up by the suction passage F formed in the motor rotor 22 .

Here, it is known that the crude oil to be mined contains many slurry components, which are fine solid particles, in addition to liquid components. If such a slurry component mixes with the surface of the bearing or the pump shaft 21s, there is a possibility that wear and tear will progress and normal pump performance will not be obtained.

Therefore, in this embodiment, the guide surface 34, the cylindrical surface 35, and the stepped surface 36 are formed on the outer peripheral surface of the stator shroud 3s as described above. As shown in FIG. 3 , the main stream F1 of crude oil containing slurry components that has flowed along the guide surface 34 passes through the step surface 36 after being given a component in the direction of the axis O by the cylindrical surface 35 . Due to the formation of this step surface 36, the main stream F1 is separated. Due to this separation, a separated vortex flow F2 is formed above the stepped surface 36 . Since the separated vortex flow F2 stays, the main flow F1 is less likely to flow into the region radially inward of the guide surface 34 and the cylindrical surface 35 . As a result, the possibility of the slurry component flowing toward the outer peripheral surface of the pump shaft 21s is reduced.

Furthermore, the guide surface 34 is curved so as to gradually extend in the direction of the axis O as it goes radially inward. According to this configuration, the flow of the fluid can be smoothly guided in the direction of the axis O by the guide surface 34 .

Moreover, the above configuration further includes a cylindrical surface 35 formed between the guide surface 34 and the stepped surface 36 and extending in the direction of the axis O. As shown in FIG. According to this configuration, the cylindrical surface 35 can impart a larger component in the direction of the axis O in the flow direction of the fluid. As a result, it is possible to further reduce the possibility that the slurry component contained in the main flow F1 described above will move radially inward.

In addition, in the above configuration, the step surface 36 extends radially. According to this configuration, since the step surface 36 extends in the radial direction, it is possible to more stably form the separated vortex flow F2 with respect to the flow outflowing from the guide surface 34 . As the separation vortex flow F2 develops, the possibility of the main flow F1 moving radially inward can be reduced. As a result, the mining pump 100 can be operated more stably.

The embodiments of the present disclosure have been described above. Various changes and modifications can be made to the above configuration without departing from the gist of the present disclosure. For example, in the above embodiment, the mining pump 100 was described as an example. However, the above-described guide surface 34, cylindrical surface 35, and step surface 36 can be suitably applied to any rotary machine that handles fluid containing solid components such as slurry.

Furthermore, unlike the above embodiment, it is also possible to form the step surface 36 directly on the upper edge of the guide surface 34 without forming the cylindrical surface 35 . With such a configuration, it is possible to obtain the same effects as those described above.

Further, as shown in FIG. 4, it is also possible to configure the step surface 36b to extend downward in the direction of the axis O as it extends radially inward. According to such a configuration, it is possible to positively and stably form a vortex flow in the flow outflowing from the guide surface 34 and the cylindrical surface 35 .

<Appendix>
The mining pump 100 described in each embodiment is understood, for example, as follows.

(1) The mining pump 100 according to the first aspect includes a production pipe 1 having a cylindrical shape along an axis O extending in the vertical direction, a pump rotor 21 extending in the direction of the axis O within the production pipe 1, and the production a pump stator 3 surrounding the pump rotor 21 between the pipe 1 and the pump rotor 21; the pump rotor 21 includes a plurality of pump shafts 21s sequentially connected in the direction of the axis O; 21s is provided with a plurality of stages, and has an impeller 5 that rotates together with the pump shaft 21s to pump up the crude oil, and the pump stator 3 has a tubular shape extending along the axis O. A stator body 3h forming a flow path outside the impeller 5, a stator shroud 3s facing the impeller 5 from above in the direction of the axis O to form the flow path, the stator body 3h and the stator and a plurality of vanes 60 connected to the shroud 3 s and arranged at intervals in the circumferential direction, and the stator shroud 3 s is formed on an extension line in the outflow direction of the flow that has flowed out from the vane 60. It has a guide surface 34 and a stepped surface 36 connected to the upper edge of the guide surface 34 in the direction of the axis O and extending in a direction intersecting the guide surface 34 .

According to the above configuration, the fluid flowing out of the vane flows upward along the guide surface 34 . After that, when the flow passes through the stepped surface 36 , the flow is separated by the stepped surface 36 and a vortex is formed above the stepped surface 36 . The formation of this vortex makes it difficult for the main flow of fluid to enter directly above the step surface 36 . That is, slurry components are less likely to enter this area. As a result, it is possible to reduce the possibility that the slurry component is mixed into the surface of the pump shaft 21s located on the inner peripheral side of the stator shroud 3s.

(2) In the mining pump 100 according to the second aspect, the guide surface 34 is curved so as to gradually extend in the direction of the axis O as it goes radially inward.

According to the above configuration, the flow of the fluid can be smoothly guided in the direction of the axis O by the guide surface 34 .

(3) The mining pump 100 according to the third aspect further has a cylindrical surface 35 formed between the guide surface 34 and the stepped surface 36 and extending in the axis O direction.

According to the above configuration, the cylindrical surface 35 can impart a larger component in the direction of the axis O in the flow direction of the fluid.

(4) In the mining pump 100 according to the fourth aspect, the step surface 36 extends radially.

According to the above configuration, since the step surface 36 extends in the radial direction, a vortex can be formed more stably in the flow that flows out from the guide surface 34 .

(5) In the mining pump 100 according to the fifth aspect, the step surface 36 extends downward in the direction of the axis O as it extends radially inward.

According to the above configuration, the step surface 36 extends downward in the direction of the axis O as it extends radially inward, so that the flow flowing out from the guide surface 34 forms a vortex more positively and stably. can be made

100 mining pump 1 production pipe 1a production pipe main body 1b production pipe tip 2 rotor 3 pump stator 3e stator extension 3h stator main body 4 support 5 impeller 6d lower end thrust collar 7d lower end thrust pad 9 excavation pipe 10 lower end thrust bearing 21 pump Rotor 21s Pump shaft 22m Magnetic member 30d Lower end spline coupling 31 Opposing surface 32 Connecting surface 33 Downstream surface 34 Guide surface 35 Cylindrical surfaces 36, 36b Step surface 51 Disk 51m Disk main surface 52 Blade 53 Shroud cover 60 Vane 80 Motor 81 Coil 90 Pump body F Suction flow path F1 Main flow F2 Eddy flow O Axis

Claims (5)

a cylindrical production pipe along an axis extending in the vertical direction;
a pump rotor extending axially within the production tube;
a pump stator enclosing the pump rotor between the production tube and the pump rotor;
with
The pump rotor is
a plurality of pump shafts sequentially connected in the axial direction;
an impeller that is provided with a plurality of stages on each of these pump shafts and pumps up the crude oil by rotating together with the pump shaft;
has
The pump stator is
a stator body having a cylindrical shape extending along the axis to form a flow path outside the impeller;
a stator shroud that forms the flow path by facing the impeller from above in the axial direction;
a plurality of vanes connecting the stator body and the stator shroud and arranged at intervals in the circumferential direction;
has
The stator shroud is
a guide surface formed on an extension of the outflow direction of the flow outflowing from the vane;
a step surface connected to an upper edge of the guide surface in the axial direction and extending in a direction intersecting the guide surface;
Mining pump with. 2. The mining pump according to claim 1, wherein the guide surface is curved so as to gradually extend in the axial direction as it goes radially inward. 3. A mining pump according to claim 1 or 2, further comprising a cylindrical surface formed between said guide surface and said stepped surface and extending in said axial direction. 4. A mining pump according to any one of claims 1 to 3, wherein the step surface extends radially. The mining pump according to any one of claims 1 to 3, wherein the step surface extends downward in the axial direction as it extends radially inward.

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