Electromagnetic integrated submersible motor screw pump structure and use method

Abstract

The present invention relates to a submersible motor screw pump structure and a method of use, and belongs to the technical field of submersible screw pumps. The technical scheme is: a motor stator (4) surrounds a screw pump stator (7), a motor rotor (3) surrounds the motor stator (4), the bottom of the motor rotor (3) is connected to a motor rotor connecting sleeve (10), an outer ring (9) of a magnetic coupling is fixed in the motor rotor connecting sleeve (10), the outer ring (9) of the magnetic coupling located outside the screw pump stator (7) matches the inner ring (11) of the magnetic coupling located inside the screw pump stator (7), and the outer ring of the magnetic coupling drives the inner ring of the magnetic coupling to rotate through electromagnetic induction. The present invention places the rotor outside, and the magnetic coupling ensures the absolute sealing of the cavity, thereby forming a leak-free electromagnetic integrated submersible screw pump; the inner ring of the magnetic coupling is sealed inside the cavity of the screw pump chamber, and is driven to rotate through electromagnetic induction, thereby avoiding the problem of motor damage caused by mechanical seal failure.

Description

Technical Field

[0001] The invention relates to a submersible motor screw pump structure and a use method, belonging to the technical field of submersible screw pumps. Background Art

[0002] Submersible screw pump oil production is a newly developed mechanical oil production process in recent decades. It is widely used in the oil production field because it is suitable for high-viscosity and high-sand content original mining operations, and is particularly suitable for offshore operating platforms. It can realize inclined well and horizontal well operations, has the advantages of no rod pipe wear and low manufacturing cost. However, some oil wells have low liquid output and large inclination, which are prone to leakage, causing failure of the mechanical seal of the submersible screw pump and damage to the motor. Summary of the invention

[0003] The purpose of the present invention is to provide a submersible motor screw pump structure and a method of using the same, wherein the rotor is placed externally, the motor rotor rotates, and the screw pump is driven to work through a magnetic coupling, the magnetic coupling ensures the absolute sealing of the cavity, and constitutes a leak-free electromagnetic integrated submersible screw pump; the inner ring of the magnetic coupling is sealed inside the cavity of the screw pump chamber, and is driven to rotate by electromagnetic induction, thereby avoiding the problem of motor damage caused by mechanical seal failure, and has the characteristics of reduced unit length, compact structure, and reduced manufacturing cost; the motor has a small outer diameter, low rotation speed, and large torque; the sealing is extremely good, thereby avoiding motor damage due to well fluid leakage, and solving the problems existing in the background technology.

[0004] The technical solution of the present invention is:

[0005] A submersible motor screw pump structure comprises a motor rotor, a motor stator, a screw pump rotor, a screw pump stator, a flexible shaft, an outer ring of a magnetic coupling, a motor rotor connecting sleeve, an inner ring of a magnetic coupling and a hollow oil production pipe arranged in a housing. The screw pump stator is tubular and has a screw pump rotor arranged therein. The bottom of the screw pump rotor is connected to the hollow oil production pipe through a flexible shaft. An oil outlet is arranged at the upper end of the hollow oil production pipe. An inner ring of a magnetic coupling is arranged on the hollow oil production pipe below the oil outlet. The inner ring of the magnetic coupling is located at the screw pump stator. The screw pump stator and the motor stator are connected together and fixed inside the housing, the motor stator surrounds the screw pump stator, the motor rotor is arranged outside the motor stator, the motor rotor surrounds the motor stator, the bottom of the motor rotor is connected to the motor rotor connecting sleeve, the outer ring of the magnetic coupling is fixed in the motor rotor connecting sleeve, the outer ring of the magnetic coupling located outside the screw pump stator matches the inner ring of the magnetic coupling located inside the screw pump stator, and the outer ring of the magnetic coupling drives the inner ring of the magnetic coupling to rotate through electromagnetic induction.

[0006] The shell is divided into two independent spaces, namely the screw pump chamber and the oil production chamber. A thrust ball bearing group is arranged at the dividing part, and the hollow oil production pipe passes through the thrust ball bearing group and rotates; the bottom of the hollow oil production pipe is connected with the oil inlet.

[0007] The top end of the screw pump stator is connected to the connecting oil pipe.

[0008] Bearings are respectively arranged at the upper and lower ends of the motor rotor.

[0009] A mechanical seal is provided between the bottom end of the screw pump stator and the hollow oil production pipe.

[0010] The oil production chamber is provided with a protector, which is sealed with the bottom of the hollow oil production pipe through a second mechanical seal.

[0011] A wire inlet is arranged on the top of the screw pump chamber, and a power cable provides power to the motor through the wire inlet.

[0012] A method for using a submersible motor screw pump structure, using the submersible motor screw pump structure, the steps are as follows:

[0013] The power cable provides power to the motor. When the motor works, the motor rotor starts to rotate, and drives the motor rotor connecting sleeve to rotate together. The outer ring of the magnetic coupling fixed in the motor rotor connecting sleeve also rotates together, and the inner ring of the magnetic coupling matching the outer ring of the magnetic coupling is driven to rotate synchronously through electromagnetic induction. The hollow oil production pipe fixedly connected to the inner ring of the magnetic coupling also rotates synchronously and is transmitted upward step by step, driving the flexible shaft and the screw pump rotor to rotate synchronously together; the well fluid enters the oil production chamber in the shell through the oil inlet, and is discharged to the inside of the screw pump chamber through the bottom hole of the hollow oil production pipe to the oil outlet, and the well fluid is produced to the ground along the connecting oil pipe through the rotation of the screw pump rotor, thereby realizing the oil production process.

[0014] The screw pump stator is an extra-long tube that extends to the bottom of the screw pump chamber and is connected to the housing. A mechanical seal is installed to ensure that the well fluid in the screw pump chamber will not leak.

[0015] The thrust ball bearing group is guaranteed to withstand a certain axial force in the working environment.

[0016] The second mechanical seal ensures the sealing of the well fluid entering the hollow oil production pipe from the oil inlet, preventing the well fluid from entering the protector, thereby better protecting the motor.

[0017] The present invention integrates a submersible motor and a screw pump into one, and adds a magnetic coupling for power transmission.

[0018] The beneficial effects of the present invention are as follows: the rotor is placed outside, the motor rotor rotates, and the screw pump is driven to work through the magnetic coupling. The magnetic coupling ensures the absolute sealing of the cavity, forming a leak-free electromagnetic integrated submersible screw pump; the inner ring of the magnetic coupling is sealed inside the cavity of the screw pump chamber, and is driven to rotate by electromagnetic induction, thereby avoiding the problem of motor damage caused by mechanical seal failure, and has the characteristics of reduced unit length, compact structure, and reduced manufacturing cost; the motor has a small outer diameter, low rotation speed, and large torque; the sealing is extremely good, avoiding motor damage due to well fluid leakage. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the structure of the present invention;

[0020] In the figure: inlet 1, bearing 2, motor rotor 3, motor stator 4, connecting oil pipe 5, screw pump rotor 6, screw pump stator 7, flexible shaft 8, magnetic coupling outer ring 9, motor rotor connecting sleeve 10, magnetic coupling inner ring 11, mechanical seal 1 12, thrust ball bearing group 13, protector 14, mechanical seal 2 15, oil inlet 16, housing 17, oil outlet 18, hollow oil production pipe 19. DETAILED DESCRIPTION

[0021] The present invention will be further described below by way of embodiments with reference to the accompanying drawings.

[0022] A submersible motor screw pump structure, comprising a motor rotor 3, a motor stator 4, a screw pump rotor 6, a screw pump stator 7, a flexible shaft 8, a magnetic coupling outer ring 9, a motor rotor connecting sleeve 10, a magnetic coupling inner ring 11 and a hollow oil production pipe 19 arranged in a housing 17, wherein the screw pump stator 7 is tubular, and has a screw pump rotor 6 arranged therein, the bottom of the screw pump rotor 6 is connected to the hollow oil production pipe 19 through the flexible shaft 8, an oil outlet 18 is arranged at the upper end of the hollow oil production pipe 19, and a magnetic coupling inner ring 11 is arranged on the hollow oil production pipe 19 below the oil outlet 18, and the magnetic coupling inner ring 11 is located at Inside the screw pump stator 7; the screw pump stator 7 and the motor stator 4 are connected together and fixed inside the housing 17, the motor stator 4 surrounds the screw pump stator 7, the motor rotor 3 is arranged outside the motor stator 4, the motor rotor 3 surrounds the motor stator 4, the bottom of the motor rotor 3 is connected to the motor rotor connecting sleeve 10, the magnetic coupling outer ring 9 is fixed in the motor rotor connecting sleeve 10, the magnetic coupling outer ring 9 located outside the screw pump stator 7 is matched with the magnetic coupling inner ring 11 located inside the screw pump stator 7, and the magnetic coupling outer ring 9 drives the magnetic coupling inner ring 11 to rotate through electromagnetic induction.

[0023] The shell 17 is divided into two independent spaces, namely the screw pump chamber and the oil production chamber. A thrust ball bearing group 13 is set at the dividing point. The hollow oil production pipe 19 passes through the thrust ball bearing group 13 and rotates; the bottom of the hollow oil production pipe 19 is connected to the oil inlet 16.

[0024] The top end of the screw pump stator 7 is connected to the connecting oil pipe 5 .

[0025] The upper and lower ends of the motor rotor 3 are respectively provided with bearings 2 .

[0026] A mechanical seal 12 is provided between the bottom end of the screw pump stator 7 and the hollow oil production pipe 19.

[0027] The oil production chamber is provided with a protector 14 and is sealed with the bottom of the hollow oil production pipe 19 through a mechanical seal 15 .

[0028] A cable inlet 1 is provided on the top of the screw pump chamber, and a power cable provides power to the motor through the cable inlet 1.

[0029] A method for using a submersible motor screw pump structure, using the submersible motor screw pump structure, the steps are as follows:

[0030] The power cable provides power to the motor, and when the motor works, the motor rotor 3 starts to rotate, and drives the motor rotor connecting sleeve 10 to rotate together, and the outer ring 9 of the magnetic coupling fixed in the motor rotor connecting sleeve 10 also rotates together, and the inner ring 11 of the magnetic coupling matching the outer ring 9 of the magnetic coupling is driven to rotate synchronously through electromagnetic induction, and the hollow oil production pipe 19 fixedly connected to the inner ring 11 of the magnetic coupling also rotates synchronously, and is transmitted upward step by step, driving the flexible shaft 8 and the screw pump rotor 6 to rotate synchronously together; the well fluid enters the oil production chamber in the shell 17 through the oil inlet 16, and is discharged into the inside of the screw pump chamber through the bottom hole of the hollow oil production pipe 19 to the oil outlet 18, and the well fluid is produced to the ground along the connecting oil pipe 5 through the rotation of the screw pump rotor 6, thereby realizing the oil production process.

[0031] The screw pump stator 7 is an extra-long tube that extends to the bottom of the screw pump chamber and is connected to the housing 17. A mechanical seal 12 is installed to ensure that the well fluid in the screw pump chamber will not leak.

[0032] The thrust ball bearing group 13 is guaranteed to withstand a certain axial force in the working environment.

[0033] The second mechanical seal ensures the sealing of the well fluid entering the hollow oil production pipe from the oil inlet, preventing the well fluid from entering the protector, thereby better protecting the motor.

[0034] The present invention integrates a submersible motor and a screw pump into one, and adds a magnetic coupling for power transmission.

Claims

1. A submersible motor screw pump structure, characterized in that: The invention comprises a housing (17), a motor rotor (3), a motor stator (4), a screw pump rotor (6), a screw pump stator (7), a flexible shaft (8), a magnetic coupling outer ring (9), a motor rotor connecting sleeve (10), a magnetic coupling inner ring (11) and a hollow oil production pipe (19), wherein the screw pump stator (7) is tubular, the screw pump stator (7) is provided with the screw pump rotor (6), the bottom of the screw pump rotor (6) is connected to the hollow oil production pipe (19) through the flexible shaft (8), the upper end of the hollow oil production pipe (19) is provided with an oil outlet (18), the hollow oil production pipe (19) below the oil outlet (18) is provided with a magnetic coupling inner ring (11), and the magnetic coupling inner ring (11) is provided with a magnetic coupling inner ring (11). Located in the screw pump stator (7); the screw pump stator (7) and the motor stator (4) are connected together and fixed inside the housing (17); the motor stator (4) surrounds the screw pump stator (7); the motor rotor (3) is arranged outside the motor stator (4); the motor rotor (3) surrounds the motor stator (4); the bottom of the motor rotor (3) is connected to the motor rotor connecting sleeve (10); the magnetic coupling outer ring (9) is fixed in the motor rotor connecting sleeve (10); the magnetic coupling outer ring (9) located outside the screw pump stator (7) matches the magnetic coupling inner ring (11) located inside the screw pump stator (7); the magnetic coupling outer ring (9) drives the magnetic coupling inner ring (11) to rotate through electromagnetic induction; The housing (17) is divided into two independent spaces, namely a screw pump chamber and an oil production chamber. A thrust ball bearing group (13) is provided at the dividing point, and a hollow oil production pipe (19) passes through the thrust ball bearing group (13) and rotates; the bottom of the hollow oil production pipe (19) is connected to the oil inlet (16); the upper and lower ends of the motor rotor (3) are respectively provided with bearings (2); a mechanical seal 1 (12) is provided between the bottom end of the screw pump stator (7) and the hollow oil production pipe (19); a protector (14) is provided in the oil production chamber and is sealed with the bottom of the hollow oil production pipe (19) through a mechanical seal 2 (15).

2. A submersible motor screw pump structure according to claim 1, characterized in that: The top end of the screw pump stator (7) is connected to the connecting oil pipe (5).

3. A submersible motor screw pump structure according to claim 1, characterized in that: A cable inlet (1) is provided at the top of the screw pump chamber, and a power cable provides power to the motor through the cable inlet (1).

4. A method for using the submersible motor screw pump structure according to any one of claims 1 to 3, characterized in that Follow these steps: The power cable provides power to the motor. When the motor works, the motor rotor (3) starts to rotate and drives the motor rotor connecting sleeve (10) to rotate together. The outer ring (9) of the magnetic coupling fixed in the motor rotor connecting sleeve (10) also rotates together. Through electromagnetic induction, the inner ring (11) of the magnetic coupling matching the outer ring (9) of the magnetic coupling is driven to rotate synchronously. The hollow oil production pipe (19) fixedly connected to the inner ring (11) of the magnetic coupling also rotates synchronously and is transmitted upward step by step, driving the flexible shaft (8) and the screw pump rotor (6) to rotate synchronously together. The well fluid enters the oil production chamber in the housing (17) through the oil inlet (16), and is discharged into the inside of the screw pump chamber through the bottom hole of the hollow oil production pipe (19) to the oil outlet (18). The well fluid is produced to the ground along the connecting oil pipe (5) through the rotation of the screw pump rotor (6), thereby realizing the oil production process.

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