WO2020093894A1

WO2020093894A1 - Novel pressurized water injection device for screw pump

Info

Publication number: WO2020093894A1
Application number: PCT/CN2019/113616
Authority: WO
Inventors: 李德印
Original assignee: 新乡市夏烽电器有限公司
Priority date: 2018-11-10
Filing date: 2019-10-28
Publication date: 2020-05-14
Also published as: CN109139455A

Abstract

A pressurized water injection device for a screw pump, comprising an electric motor (4) and a screw pump (16). The electric motor (4) is electrically connected to a controller, and is connected to the screw pump (16) by means of a flexible connection device. A motor shaft (7) is provided with positive and negative thrust bearings (5, 6) or a double-direction thrust bearing. A mechanical seal (12) is disposed on the motor shaft (7). A sealing compartment (8) is provided with a pressure balance device. The device supports a relay booster pump. The water can be fed without decreasing the pressure, and the high pressure feedwater is supported. On this basis, pressurization is carried out again by means of the screw pump so that the water of higher pressure is obtained and injected into the ground without damaging the electric motor.

Description

A new type of screw pump water injection device

Technical field

The invention relates to an oil field water injection device, in particular to a screw pump water injection device.

Background technique

Before the development of the oil field, the oil, natural gas and formation water in the reservoir were at a high temperature, high pressure and relatively static state. After the oil field was put into development, with the continuous exploitation of oil and natural gas in the reservoir, the bottom hole pressure It will inevitably continue to decline, and reservoir pressure will inevitably decrease with the development time. In order to improve the recovery rate of crude oil, it is a more mature method to maintain pressure and add pressure to the oil layer by means of water injection and pressurization. Therefore, water injection in oil wells has become one of the most important tasks in current oil production. With the development of the oil field, the water cut in the oil field continues to increase, and the amount of fluid produced is also increasing. The role of the water injection system of the oil field in increasing and stabilizing production is also becoming more and more prominent. .

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technical problem

Oilfield water injection needs to be injected after the water injection station is pressurized. The main line pressure is generally 10-20MPa. Blocks requiring pressurized water injection use block pressurized water injection. The branch pressure is generally less than 25MPa, but the actual well conditions are different and some wells often occur If the pressure is not enough, the phenomenon of water injection can not be entered. For accurate water injection and higher pressure water injection, it needs to be solved by single well pressurization, but increasing the pressure of water injection will make the internal motor oil of the motor between the external high-pressure water The pressure is out of balance, which damages the sealing device of the motor, resulting in the motor not running normally. At the same time, the two media of the motor oil and water in the motor will mix with each other under the pressure imbalance, which affects the use of the motor. How to solve the above problems , The existing technology does not give solutions and technologies, and urgently needs to be resolved.

Technical solution

The purpose of the present invention is to provide a new type of screw pump water injection device to overcome the deficiencies of the prior art. The utility model provides a relay type booster pump. The inlet water does not need to reduce the pressure, but can be high-pressure incoming water. On this basis, it continues to be boosted again by the screw pump, and higher pressure water is injected into the ground without damaging the motor.

The technical solutions adopted by the present invention for the purpose are:

A new type of screw pump water injection device includes a motor 4 and a screw pump 16, the motor 4 is electrically connected to the controller, the motor 4 is connected to the screw pump 16 through a flexible connection device, and the motor shaft 7 of the motor 4 Two positive and negative thrust bearings 5, 6 or one bidirectional thrust bearing are provided, and a mechanical seal 12 is installed on the motor shaft 7, which is characterized in that a pressure balancing device is provided in the sealed chamber 8.

The pressure balancing device may be a spiral elongated tube 17, one end of which is fixedly connected to the sealed inner tube 11, a through hole is opened in the sealed inner tube 11, the motor oil in the motor 4 enters the spiral elongated tube 17 through the through hole , The other end is fixedly connected to the sealing base 10, and the sealing base 10 also has a through hole, water enters the spiral elongated tube 17 through the through hole on the sealing base 10, and the two ends of the spiral elongated tube 17 are respectively connected to the motor oil and water Connected. In this way, a pressure balance of water and oil is formed in the spiral elongated tube 17. It should be noted that the pressure balancing device of the spiral elongated tube 17 structure can be used in the vertical screw pump pressurized water injection device, but cannot be used in the horizontal screw pump pressurized water injection device.

The pressure balancing device may be a serpentine channel, and more than two settling tubes are installed in the sealed chamber 8. Taking two as an example, the settling tube 18 is fixedly connected to the sealing chamber 8, the settling tube 19 is fixedly connected to the sealing base 10, so that a closed motor oil serpentine channel is formed between the sedimentation tubes. One end of the serpentine channel is connected to the seal The tube 11 is fixedly connected, and a through hole is opened in the sealed inner tube 11. The motor oil in the motor 4 enters the serpentine channel through the through hole, and the other end is fixedly connected to the sealing base 10, and the sealing base 10 also has a through hole, water The serpentine channel is entered through the through hole on the sealing base 10, and the two ends of the serpentine channel communicate with the motor oil and water, respectively. Motor oil and water form a pressure balance in the serpentine channel. It should be noted that this serpentine channel pressure balancing device can be used in the vertical screw pump pressurized water injection device, but cannot be used in the horizontal screw pump pressurized water injection device.

  The pressure balance device is a capsule 20. The capsule 20 is mounted on the sealed inner tube 11. The upper and lower ends of the capsule 20 are tightly connected to the outer wall of the sealed inner tube 11. The sealed inner tube 11 is provided with a through hole. The motor oil can enter the capsule 20 through the above-mentioned through holes, and a through hole is also opened on the sealing base 10, and the water enters the outside of the capsule 20 through the through hole on the sealing base 10, and the capsule 20 isolates the motor oil and water. It should be noted that this capsule 20 type pressure balancing device can be used in a vertical screw pump pressurized water injection device or a horizontal screw pump pressurized water injection device.

Preferably, the motor is a permanent magnet synchronous motor. The structure of the permanent magnet synchronous motor is simple and durable, which can achieve low speed and high torque output. The motor rotor has no induced current excitation, and its power factor reaches more than 0.9, thereby improving the quality factor of the grid. The compensation equipment in the corresponding power grid is reduced and eliminated, which reduces the investment cost, simplifies the power grid structure, and facilitates management.

Preferably, the controller in the control cabinet 1 realizes three closed-loop control of the current feedback, speed feedback and position feedback of the permanent magnet synchronous motor 3.

Preferably, the controller of the control cabinet 1 can be equipped with a GPRS remote control module.

The above is a new type of screw pump water injection device of the invention, which can be installed vertically or horizontally. Most of them are vertical installations. However, in actual work, there are also horizontal installations due to the needs of the work. Happening.

Beneficial effect

The present invention overcomes the deficiencies of the prior art and provides a booster water injection device for a new type of screw pump. By setting a pressure balancing device in the sealed chamber 8, the screw pump keeps the motor oil and water inlet during the pressure injection process Incoming water pressure balance, so that the mechanical seal 5 can work normally, and the medium will not be fully mixed, so that the motor is always insulated motor oil, high-pressure rotary seal can be achieved, so that the equipment can work normally,

Therefore, the high-pressure water that can pass through the water inlet does not need to reduce the pressure, but can be high-pressure incoming water. On this basis, it continues to be pressurized again by the screw pump, and higher pressure water is injected into the ground without damaging the motor.

BRIEF DESCRIPTION

Figure 1 is a schematic diagram of the utility model.

FIG. 2 is a schematic cross-sectional view of a structure in which the pressure balancing device is a spiral elongated tube.

3 is a schematic cross-sectional view of a structure in which the pressure balancing device is a serpentine channel.

4 is a schematic cross-sectional view of a structure in which the pressure balancing device is a capsule.

图中标号说明：Explanation of labels in the figure:

1-Control cabinet, 2-junction box, 3-cable, 4-motor, 5-thrust bearing one, 6-thrust bearing two, 7-motor shaft, 8-sealed compartment, 9-balanced structure, 10-sealed Base, 11-sealed inner tube, 12-mechanical seal, 13-coupling, 14-water inlet, 15-flexible rod, 16-screw pump, 17-spiral slender tube, 18-settler tube one, 19-settler Guan Er

Best Mode of the Invention

As shown in FIG. 1, FIG. 2, FIG. 3, and FIG. 4, a pressurized water injection device of a new screw pump includes a motor 4 and a screw pump 16, the motor 4 is connected to the control cabinet 1 through a junction box 2 and a cable 3 The device controller is electrically connected, and the motor 4 is connected to the screw pump 16 through a flexible connection device. The motor shaft 7 of the motor 4 is provided with two forward and reverse thrust bearings 5, 6, or a bidirectional thrust bearing, and a mechanical seal 12 It is mounted on the motor shaft 7 and is characterized in that a pressure balancing device is provided in the sealed chamber 8.

The flexible connecting device may be a coupling plus a flexible rod, or may be one of a universal joint, a coupling, etc. Those skilled in the art understand that the motor shaft 7 of the motor cannot be rigidly connected to the screw pump 16, However, the problem of the flexible connection between the two can be solved in the above-mentioned various ways. The embodiment and schematic diagram of the present invention use the coupling 13 and the flexible rod 15 to form a flexible connection device.

The motor 4 is provided with two forward and reverse thrust bearings. When the equipment is not started, the water inlet 14 enters the water, and there is pressure from the incoming water pressure, the motor shaft 7 will be subjected to downward axial force, and the thrust bearing 2 6 To bear this axial force, after the equipment is running normally, the outlet pressure of the screw pump 16 is greater than the inlet pressure, the rotor will generate an upward axial force, and will be transmitted to the flexible rod 15 and the motor shaft 7, thrust bearing 15 when the equipment works Transmit the axial force.

Install a thrust bearing on the upper and lower sides of the motor shaft in the opposite direction. The purpose is to prevent the motor shaft from moving along the axial direction, and to solve the problem that the motor shaft is sometimes pulled downward and sometimes pushed upward, resulting in excessive displacement. The mechanical seal 12 is invalidated. Therefore, the two forward and reverse thrust bearings can also be replaced by a bidirectional thrust bearing, which has the same function as the two thrust bearings. Those skilled in the art can fully understand and install according to the actual situation .

As shown in FIG. 2, the pressure balance device may be a spiral elongated tube 17, one end of which is fixedly connected to the sealed inner tube 11, a through hole is opened in the sealed inner tube 11, and the motor oil in the motor 4 passes through the through hole Entering the spiral elongated tube 17, the other end is fixedly connected to the sealing base 10, and a through hole is also opened in the sealing base 10, and water enters the spiral elongated tube 17 through the through hole on the sealing base 10, both ends of the spiral elongated tube 17 Communicate with motor oil and water respectively. In this way, a pressure balance of water and oil is formed in the spiral elongated tube 17. Because the specific gravity of the motor oil is about 0.8, which is lighter than water, the two will form a layering phenomenon, and the oil-water contact surface is in the sealed pipeline 11, when the motor oil expands and contracts, the contact surface floats up and down in the pipeline, the pipeline The volume must meet the expansion and contraction of the motor oil to prevent water from entering the motor. In this way, the pressure of the motor oil and the water inlet 14 is balanced, so that the mechanical seal 5 can work normally, and the medium will not be fully mixed , So that the motor oil is always insulated in the motor, so that the equipment can work normally, the high-pressure rotating mechanical seal 12 can be realized, and the engine 4 is protected during operation. It should be noted that the pressure balance structure of this spiral elongated tube 17 can be used in a vertical screw pump pressurized water injection device, but cannot be used in a horizontal screw pump pressurized water injection device.

As shown in FIG. 3, the pressure balance device may be a serpentine channel. More than two settling pipes are installed in the sealed chamber 8. Taking two additional installations as an example, the settling pipe 18 is fixedly connected to the sealed chamber 8. The settling tube two 19 is fixedly connected to the sealing base 10, so that a closed serpentine channel of motor oil is formed between the settling tubes, and one end of the serpentine channel is fixedly connected to the sealed inner tube 11, a through hole is opened on the sealed inner tube 11, and the motor 4 The motor oil inside enters the serpentine channel through the above-mentioned through hole, and the other end is fixedly connected to the sealing base 10. The sealing base 10 also has a through hole. Water enters the serpentine channel through the through hole on the sealing base 10. Both ends are connected with motor oil and water. Motor oil and water form a pressure balance in the serpentine channel. The diameter of the settling tube may be the same or different. Because the specific gravity of the motor oil is about 0.8, it is lighter than water and will form a stratification phenomenon, and the oil-water contact surface is in the settling cavity. When the motor oil expands and contracts, the oil-water contact surface floats up and down in the settling cavity The volume must meet the expansion and contraction of the motor oil to prevent water from entering the motor. In this way, the motor oil and the water inlet 14 are balanced in water pressure, so that the mechanical seal 12 can work normally and protect the engine 4. It should be noted that the pressure balance structure of this serpentine channel structure can be used in the vertical screw pump pressurized water injection device, but cannot be used in the horizontal screw pump pressurized water injection device.

The pressure balance structure is a capsule 20. The capsule 20 is mounted on the sealed inner tube 11. The upper and lower ends of the capsule 20 are tightly connected to the outer wall of the sealed inner tube 11. The sealed inner tube 11 is provided with a through hole. The motor oil can enter the capsule 20 through the above-mentioned through holes, and a through hole is also opened on the sealing base 10, and the water enters the outside of the capsule 20 through the through hole on the sealing base 10, and the capsule 20 isolates the motor oil and water. Because the capsule isolates the motor oil and water, this prevents water from entering the motor. At the same time, the capsule is made of a flexible material that can be expanded and contracted to meet the thermal expansion and contraction of the motor oil. It can also balance the liquid pressure on both sides. In this way, the motor oil and the water are balanced. The water pressure of the water inlet 14 is balanced, so that the mechanical seal 10 can work normally and protect the motor 4. It should be noted that this capsule 20 type pressure balance structure can be used in a vertical screw pump pressurized water injection device or a horizontal screw pump pressurized water injection device.

Preferably, the motor is a permanent magnet synchronous motor. The structure of the permanent magnet synchronous motor is simple and durable, which can achieve low speed and high torque output. The motor rotor has no induced current excitation, and its power factor reaches more than 0.9, thereby improving the quality factor of the power grid. The compensation equipment in the corresponding power grid is reduced and eliminated, which reduces the investment cost, simplifies the power grid structure, and facilitates management.

Preferably, the controller in the control cabinet 1 realizes three closed-loop control of the current feedback, speed feedback and position feedback of the permanent magnet synchronous motor 3, accurately controls the speed and torque of the motor, drives the motor flexibly and smoothly, and greatly reduces system losses, To achieve the maximum efficiency of the overall system operation.

Preferably, the controller of the control cabinet 1 can be equipped with a GPRS remote control module, which can transmit the equipment operation data and the water inlet and outlet pressure data to the server and the background to realize real-time monitoring and control on the visual platform without on-site operation. The whole process of water injection is carried out in an orderly manner.

The above is a pressurized water injection device of a new type screw pump of the present invention. The present invention can be installed vertically or horizontally. Most of them are vertical installations. In actual work, there are also horizontal installations due to work needs. The technical solution for the installation is: a new type of screw pump water injection device, including a motor 4 and a screw pump 16, the motor 4 is electrically connected to the controller, the motor 4 is connected to the screw pump 16 through the flexible connection device 15 Connection, the motor 4 is provided with two forward and reverse thrust bearings 5, 6 or a two-way thrust bearing, and a mechanical seal 12 is installed on the motor shaft 7, characterized in that a capsule 20 is provided in the sealed compartment 8 The capsule 20 is installed on the sealed inner tube 11. The upper and lower ends of the capsule 20 are tightly connected to the outer wall of the sealed inner tube 11. The sealed inner tube 11 has a through hole through which the motor oil in the motor 4 can enter the capsule 20. Inside, a through hole is also opened in the sealing base 10, and water enters the outside of the capsule 20 through the through hole in the sealing base 10, and the capsule 20 isolates motor oil and water.

Claims

A new type of screw pump water injection device includes a motor (4) and a screw pump (16), the motor (4) is electrically connected to the controller, and the motor (4) is connected to the screw pump (16) through a flexible connection device , The motor shaft (7) is provided with two positive and negative thrust bearings (5, 6) or a two-way thrust bearing, the mechanical seal (12) is installed on the motor shaft (7), characterized in that, in the sealed warehouse (8 ) There is a pressure balancing device inside.
The pressurized water injection device of a new type screw pump according to claim 1, characterized in that the pressure balance device is a spiral elongated tube (17), one end of which is fixedly connected to the sealed inner tube (11), sealed The inner tube (11) has a through hole, the motor oil in the motor (4) enters the spiral elongated tube (17) through the through hole, and the other end is fixedly connected to the sealing base (10). A through hole is opened, and water enters the spiral elongated tube (17) through the through hole on the sealing base (10), and the two ends of the spiral elongated tube (17) communicate with the motor oil and water respectively.
The pressurized water injection device of a new type screw pump according to claim 1, characterized in that the pressure balancing device is a serpentine channel, and more than two settling tubes are installed in the sealed chamber (8) , Settling tube one (18) is fixedly connected to the sealed warehouse (8), and settling tube two (19) is fixedly connected to the sealing base (10), so that a closed motor oil serpentine channel is formed between the sedimentation tubes, one end of the serpentine channel It is fixedly connected to the sealed inner tube (11). A through hole is opened in the sealed inner tube (11). The motor oil in the motor (4) enters the serpentine channel through the through hole. The other end is fixedly connected to the sealed base (10). The sealing base (10) is also provided with a through hole, and water enters the serpentine channel through the through hole on the sealing base (10), and the two ends of the serpentine channel communicate with the motor oil and water respectively.
The pressurized water injection device of a novel screw pump according to claim 1, characterized in that the pressure balancing device is a capsule (20), and the capsule (20) is installed in a sealed inner tube (11) ), The upper and lower ends of the capsule (20) are tightly connected to the outer wall of the sealed inner tube (11), a through hole is opened in the sealed inner tube (11), and motor oil in the motor (4) can enter the capsule (20) through the through hole ), There is also a through hole in the sealing base (10), water enters the outside of the capsule (20) through the through hole in the sealing base (10), and the capsule (20) isolates the motor oil and water.
The pressurized water injection device of a novel screw pump according to claim 1 or 2 or 3 or 4, characterized in that the electric motor (4) is a permanent magnet synchronous motor.
The pressurized water injection device of a new type screw pump according to claim 5, characterized in that the controller in the control cabinet (1) realizes the current feedback, speed feedback and position feedback of the permanent magnet synchronous motor Three closed-loop control.
The pressurized water injection device of a new type screw pump according to claim 6, characterized in that the controller of the control cabinet (1) is equipped with a GPRS remote control module to realize real-time monitoring and control on the visualization platform.