Submersible electric multi-stage double-screw pump with thrust balance structure in axial force pump

Abstract

The utility model relates to the field of oil exploitation machinery, and discloses a submersible electric multi-stage double-screw pump with an axial force pump inner thrust balance structure, which comprises a multi-stage double-screw pump with an axial force pump inner thrust balance structure, a double-shaft submersible protector, a synchronous gear transmission mechanism, a submersible universal joint and a submersible motor which are integrally connected in sequence, the multi-stage double-screw pump with the thrust balance structure in the axial force pump comprises a thrust plate in the pump, a driven screw thrust bearing assembly, a driving screw thrust bearing assembly, a driven shaft, a driving shaft, a left-handed thread sleeve, a right-handed thread sleeve and the like which are integrally mounted. The utility model has long service life; machining and assembling precision is high, and machining cost is low; the displacement and lift range is large, and the system efficiency is high; high temperature resistance; the pump cannot be stuck under the formation condition; the high-temperature-resistant oil well pump is suitable for high-temperature oil well exploitation, high-viscosity thick oil exploitation, high-gas-content crude oil exploitation and multi-phase medium mixed crude oil conveying.

Description

Technical Field

[0001] The utility model relates to the field of oil extraction machinery, and particularly relates to a submersible electric multi-stage double screw pump with an axial force pump internal thrust balance structure. Background Art

[0002] Existing mechanical oil production screw pumps are generally surface-driven single screw pumps and downhole submersible motor-driven single screw pumps. This type of screw pump structure has good adaptability to the exploitation of viscous oil and high gas-content crude oil, and has made contributions to oil extraction. However, it also has the following disadvantages or deficiencies: ① Since the stator of the single screw pump is made of rubber, its temperature resistance grade is not high; ② The rubber stator is prone to swelling under formation conditions, resulting in pump jamming; ③ The single screw pump has a small displacement and low lift; ④ The axial force generated at the pump end is large, and the working life is short. Summary of the Utility Model

[0003] To overcome the defects of the prior art, the utility model provides a submersible electric multi-stage double screw pump with an axial force pump internal thrust balance structure, and its technical solution is as follows:

[0004] A submersible electric multi-stage double screw pump with an axial force pump internal thrust balance structure includes a multi-stage double screw pump with an axial force pump internal thrust balance structure, a double-shaft submersible protector, a synchronous gear transmission mechanism, a submersible universal joint, and a submersible motor that are integrally connected in sequence; the multi-stage double screw pump with an axial force pump internal thrust balance structure includes a pump discharge head, a pump head, a locking ring, an adjusting bushing, a centralizing bearing assembly, an internal thrust disk of the pump, a thrust bearing assembly of the driven screw, a bushing, an inner ring of the radial bearing, a thrust bearing bushing, a thrust bearing assembly of the driving screw, a first square key, a second square key, a housing, a driven shaft, a driving shaft, a left-handed screw sleeve, a right-handed screw sleeve, a screw housing, and a suction bushing that are integrally installed.

[0005] Further, the internal thrust disk of the pump, the thrust bearing assembly of the driven screw, the bushing, the inner ring of the radial bearing, the thrust bearing bushing, the thrust bearing assembly of the driving screw, the first square key, the second square key, the driven shaft, the driving shaft, the left-handed screw sleeve, the right-handed screw sleeve, and the screw housing form a standard stage of the multi-stage double screw pump; the number of standard stages is determined according to the required lifting head.

[0006] Further, the adjusting bushing, the centralizing bearing assembly, the thrust bearing assembly of the driven screw, the thrust bearing bushing, the thrust bearing assembly of the driving screw, the screw housing, and the suction bushing belong to non-moving parts, which are connected in series in the housing, and the locking ring is used for axial locking and positioning of them.

[0007] Further, the right-handed screw sleeve and the internal thrust disk of the pump are installed on the driven shaft through the first square key, and the axial force generated by the right-handed screw sleeve is borne by the thrust bearing assembly of the driven screw.

[0008] Further, the left-handed screw sleeve, the shaft sleeve, the inner ring of the radial bearing, and the inner thrust disk of the pump are installed on the driving shaft through a second square key, and the axial force generated by the left-handed screw sleeve is borne by the driving screw thrust bearing assembly.

[0009] Further, the axial forces on the driven shaft and the driving shaft are borne by the multi-stage thrust bearings in the double-shaft submersible oil protector.

[0010] Further, the multi-stage double-screw pump, the double-shaft submersible oil protector, and the synchronous gear transmission mechanism of the axial force inner thrust balance structure in the pump share the same housing.

[0011] Further, the multi-stage double-screw pump of the axial force inner thrust balance structure in the pump and the double-shaft submersible oil protector share the driven shaft and the driving shaft.

[0012] Further, the spline tooth profiles at the lower ends of the driven shaft and the driving shaft adopt the cylindrical straight-tooth involute spline tooth profile.

[0013] Further, the multi-stage double-screw pump of the axial force inner thrust balance structure in the pump further includes connection screws for connecting the pump discharge head and the pump head, and a first O-ring and a second O-ring for sealing.

[0014] Compared with the prior art, the submersible electric multi-stage double-screw pump with an axial force inner thrust balance structure provided by the present utility model mainly has the following advantages:

[0015] 1. This device adopts a multi-stage double-screw pump with an axial force inner thrust balance structure, which greatly reduces the load on the thrust bearings in the double-shaft submersible oil protector, thereby extending its working life.

[0016] 2. This device adopts a multi-stage double-screw pump structure, which is convenient for the processing of the screw and the screw housing, can effectively ensure the processing and assembly accuracy, reduce the processing cost, and improve the working performance of the pump.

[0017] 3. This device has a large displacement and head range, and high system efficiency.

[0018] 4. This device is heat-resistant and will not get stuck in the pump under formation conditions.

[0019] 5. This device is suitable for the exploitation of high-temperature oil wells, high-viscosity heavy oil, and high-gas-content crude oil, and can be widely used in the oil extraction pumping project.

[0020] 6. This device is suitable for the transportation of multi-phase medium mixed crude oil. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the overall layout structure of the present utility model;

[0022] Figure 1 (1) is Figure 1Schematic enlarged view of the first part structure from top to bottom;

[0023] Figure 1 (2) is Figure 1 Schematic enlarged view of the second part structure from top to bottom;

[0024] Figure 1 (3) is Figure 1 Schematic enlarged view of the third part structure from top to bottom;

[0025] In the figure: 1 - pump discharge head, 2 - connecting screw, 3 - first O-ring, 4 - pump head, 5 - second O-ring, 6 - locking ring, 7 - adjusting bushing, 8 - centralizing bearing assembly, 9 - internal thrust disk of the pump, 10 - thrust bearing assembly for driven screw, 11 - bushing, 12 - inner ring of radial bearing, 13 - thrust bearing bushing, 14 - thrust bearing assembly for driving screw, 15 - first square key, 16 - second square key, 17 - housing, 18 - driven shaft, 19 - driving shaft, 20 - left-handed screw sleeve, 21 - right-handed screw sleeve, 22 - screw housing, 23 - suction bushing, 24 - two-shaft submersible protector, 25 - synchronous gear transmission mechanism, 26 - submersible universal joint, 27 - submersible motor. Specific embodiments

[0026] The present utility model will be described in detail below in conjunction with embodiments and the accompanying drawings. Embodiment 1

[0027] Refer to Figure 1 、 Figure 1 (1), Figure 1 (2) and Figure 1 (3). A submersible electric multi-stage twin-screw pump with an internal thrust balance structure for axial force pump, comprising a multi-stage twin-screw pump with an internal thrust balance structure for axial force pump, a two-shaft submersible protector 24, a synchronous gear transmission mechanism 25, a submersible universal joint 26 and a submersible motor 27 which are integrally and sequentially connected; the multi-stage twin-screw pump with an internal thrust balance structure for axial force pump comprises a pump discharge head 1, a pump head 4, a locking ring 6, an adjusting bushing 7, a centralizing bearing assembly 8, an internal thrust disk of the pump 9, a thrust bearing assembly for driven screw 10, a bushing 11, an inner ring of radial bearing 12, a thrust bearing bushing 13, a thrust bearing assembly for driving screw 14, a first square key 15, a second square key 16, a housing 17, a driven shaft 18, a driving shaft 19, a left-handed screw sleeve 20, a right-handed screw sleeve 21, a screw housing 22 and a suction bushing 23 which are integrally installed. Embodiment 2

[0028] Refer to Figure 1 、 Figure 1 (1), Figure 1 (2) and Figure 1(3). A submersible electric multi-stage double screw pump with an axial force pump internal thrust balance structure. Based on the technical solution described in Embodiment 1, the internal thrust disc 9, driven screw thrust bearing assembly 10, shaft sleeve 11, radial bearing inner ring 12, thrust bearing bushing 13, driving screw thrust bearing assembly 14, first square key 15, second square key 16, driven shaft 18, driving shaft 19, left-handed screw sleeve 20, right-handed screw sleeve 21, and screw housing 22 in the pump combine to form a standard stage of the multi-stage double screw pump; the number of standard stages is determined according to the required lifting head. Embodiment 3

[0029] See Figure 1 、 Figure 1 (1)、 Figure 1 (2) and Figure 1 (3). A submersible electric multi-stage double screw pump with an axial force pump internal thrust balance structure. Based on the technical solution described in Embodiment 1, the bushing 7, centralizing bearing assembly 8, driven screw thrust bearing assembly 10, thrust bearing bushing 13, driving screw thrust bearing assembly 14, screw housing 22, and suction bushing 23 belong to non-moving parts, which are connected in series in the housing 17 and axially locked and positioned by the locking ring 6. Embodiment 4

[0030] See Figure 1 、 Figure 1 (1)、 Figure 1 (2) and Figure 1 (3). A submersible electric multi-stage double screw pump with an axial force pump internal thrust balance structure. Based on the technical solution described in Embodiment 1, the right-handed screw sleeve 21 and the internal thrust disc 9 in the pump are installed on the driven shaft 18 through the first square key 15, and the axial force generated by the right-handed screw sleeve 21 is borne by the driven screw thrust bearing assembly 10; the left-handed screw sleeve 20, shaft sleeve 11, radial bearing inner ring 12, and internal thrust disc 9 are installed on the driving shaft 19 through the second square key 16, and the axial force generated by the left-handed screw sleeve 20 is borne by the driving screw thrust bearing assembly 14; the axial forces on the driven shaft 18 and the driving shaft 19 are borne by the multi-stage thrust bearings in the double-shaft submersible protector 24. Embodiment 5

[0031] See Figure 1 、 Figure 1 (1)、 Figure 1 (2) and Figure 1 (3). A submersible electric multi-stage double screw pump with an axial force pump internal thrust balance structure. Based on the technical solution described in Embodiment 1, the multi-stage double screw pump with an axial force pump internal thrust balance structure, the double-shaft submersible protector 24, and the synchronous gear transmission mechanism 25 share the same housing 17; the multi-stage double screw pump with an axial force pump internal thrust balance structure and the double-shaft submersible protector 24 share the driven shaft 18 and the driving shaft 19. Example 6

[0032] See Figure 1 、 Figure 1 (1)、 Figure 1 (2)and Figure 1 (3). A submersible electric multi-stage twin-screw pump with a thrust balance structure inside the axial force pump. Based on the technical solution described in Example 1, the spline tooth profile at the lower ends of the driven shaft 18 and the driving shaft 19 adopts a cylindrical straight-tooth involute spline tooth type. Example 7

[0033] See Figure 1 、 Figure 1 (1)、 Figure 1 (2)and Figure 1 (3). A submersible electric multi-stage twin-screw pump with a thrust balance structure inside the axial force pump. Based on the technical solution described in Example 1, the multi-stage twin-screw pump with a thrust balance structure inside the axial force pump further includes a connecting screw 2 for connecting the pump discharge head 1 and the pump head 4, a first O-ring 3 for sealing, and a second O-ring 5.

[0034] To enable those skilled in the art to better understand the present invention, the basic working principle of the present invention is briefly introduced as follows:

[0035] When the submersible motor 27 works, its kinetic energy is transmitted to the driving shaft 19 and the driven shaft 18 of the multi-stage twin-screw pump through the submersible universal joint 26, the synchronous gear transmission mechanism 25, and the double-shaft submersible protector 24, and then drives the left-handed screw sleeve 20 and the right-handed screw sleeve 21 to rotate synchronously in opposite directions, and the well fluid in the sealed space formed by their tooth grooves and the screw housing 22 is discharged upward to the ground step by step to achieve the purpose of oil extraction. When the unit works, the axial force generated by the right-handed screw sleeve 21 is borne by the driven screw thrust bearing assembly 10, the axial force generated by the left-handed screw sleeve 20 is borne by the driving screw thrust bearing assembly 14, and the axial forces on the driven shaft 18 and the driving shaft 19 are borne by the multi-stage thrust bearings in the double-shaft submersible protector 24.

[0036] The functions of the double-shaft submersible protector 24 are: one is to isolate the well fluid to prevent the well fluid from directly entering the submersible motor 27; the second is to balance the pressure between the inside of the motor and the wellbore, and compensate for the expansion and contraction of the motor oil caused by temperature changes; the third is to balance the remaining axial force from the pump end.

[0037] The function of the synchronous gear transmission mechanism 25 is to transmit the power from the submersible motor 27 to the multi-stage twin-screw pump through the synchronous gears.

[0038] The function of the submersible universal joint 26 is to transmit the power from the submersible motor 27 to the driving gear shaft with a certain eccentricity in the synchronous gear transmission mechanism 25.

Claims

1. A submersible electric multi-stage twin-screw pump with an axial force pump internal thrust balance structure, comprising a multi-stage twin-screw pump with an axial force pump internal thrust balance structure, a double-axis submersible protector, a synchronous gear transmission mechanism, a submersible universal joint and a submersible motor, which are integrally connected in sequence, characterized in that: The multi-stage twin-screw pump with an axial force pump internal thrust balance structure includes an integrally installed pump discharge head, a pump head, a locking ring, an adjustment bushing, a straightening bearing assembly, a pump internal thrust plate, a driven screw thrust bearing assembly, a sleeve, an inner ring of a radial bearing, a thrust bearing bushing, an active screw thrust bearing assembly, a first square key, a second square key, a housing, a driven shaft, a driving shaft, a left-handed screw sleeve, a right-handed screw sleeve, a screw housing and a suction bushing.

2. The submersible electric multi-stage twin-screw pump with an axial force pump internal thrust balance structure according to claim 1, characterized in that: The pump internal thrust plate, driven screw thrust bearing assembly, shaft sleeve, radial bearing inner ring, thrust bearing bushing, active screw thrust bearing assembly, first square key, second square key, driven shaft, active shaft, left-handed screw sleeve, right-handed screw sleeve, and screw housing assembly constitute a standard stage of a multi-stage twin-screw pump; the number of standard stages is determined according to the required lifting head.

3. The submersible electric multi-stage twin-screw pump with an axial force pump internal thrust balance structure according to claim 1, characterized in that: The adjusting bushing, the straightening bearing assembly, the driven screw thrust bearing assembly, the thrust bearing bushing, the active screw thrust bearing assembly, the screw housing and the suction bushing are non-moving parts, which are connected in series in the housing and are axially locked and positioned by a locking ring.

4. The submersible electric multi-stage twin-screw pump with an axial force pump internal thrust balance structure according to claim 1, characterized in that: The right-handed screw sleeve and the thrust plate in the pump are installed on the driven shaft through a first square key, and the axial force generated by the right-handed screw sleeve is borne by the driven screw thrust bearing assembly.

5. The submersible electric multi-stage twin-screw pump with an axial force pump internal thrust balance structure according to claim 1, characterized in that: The left-handed screw sleeve, the shaft sleeve, the radial bearing inner ring and the pump inner thrust plate are installed on the driving shaft through a second square key, and the axial force generated by the left-handed screw sleeve is borne by the active screw thrust bearing assembly.

6. The submersible electric multi-stage twin-screw pump with an axial force pump internal thrust balance structure according to claim 1, characterized in that: The axial forces on the driven shaft and the driving shaft are borne by the multi-stage thrust bearings in the double-shaft submersible protector.

7. The submersible electric multi-stage twin-screw pump with an axial force pump internal thrust balance structure according to claim 1, characterized in that: The multi-stage twin-screw pump, the double-shaft submersible protector and the synchronous gear transmission mechanism of the thrust balance structure in the axial force pump share the same housing.

8. The submersible electric multi-stage twin-screw pump with an axial force pump internal thrust balance structure according to claim 1, characterized in that: The multi-stage twin-screw pump and the double-shaft submersible protector of the axial force pump internal thrust balance structure share a driven shaft and a driving shaft.

9. The submersible electric multi-stage twin-screw pump with an axial force pump internal thrust balance structure according to claim 1, characterized in that: The spline tooth shape of the connection between the lower ends of the driven shaft and the driving shaft adopts a cylindrical spur involute spline tooth shape.

10. The submersible electric multi-stage twin-screw pump with an axial force pump internal thrust balance structure according to claim 1, characterized in that: The multi-stage twin-screw pump with an internal thrust balance structure of the axial force pump further includes connecting screws for connecting the pump discharge head and the pump head, and a first O-ring and a second O-ring for sealing.

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