RU2693120C1 - Hydraulic protection with device for prevention of turbine rotation - Google Patents

Abstract

FIELD: engines and pumps.

SUBSTANCE: invention relates to pumping equipment and can be used in oil industry as part of submersible electric centrifugal pump units. Hydroprotection consists of a head, a base, a body, a shaft of hydraulic protection with radial and thrust bearings, at least one compensating module, which includes a body, an upper and a lower nipple, an end seal and a compensating element. Between the lower nipple and the base there is a device for prevention of turbine rotation, which consists of a lower shaft installed on the bearing support, connected to the shaft of hydraulic protection through a cam clutch with the possibility of free movement in circumferential direction. In the lower nipple overrunning clutch is installed, providing torque transfer in the forward direction from the lower shaft to the hydraulic protection shaft and preventing reverse rotation of the hydraulic protection shaft. Overrunning coupling is connected with shaft of hydraulic protection through coupling clutch, movable part of which is installed on shaft of hydraulic protection with possibility of axial movement, and fixed part is rigidly connected with overrunning clutch. Coupling of coupling is provided by spring, and disconnection by pusher, which is installed on shaft of hydraulic protection with possibility of axial movement and on one side is connected to moving part of coupling coupling, and on other side – with bushing with inclined end surface rigidly installed on lower shaft.

EFFECT: technical result consists in improvement of reliability and safety of ESP operation.

7 cl, 4 dwg

Description

Hydroprotection with a device to prevent turbine rotation

The invention relates to the field of pumping equipment and can be used in the oil industry in the composition of the submersible installations of electrical centrifugal pumps.

The most common method for extracting formation fluid from wells is the method of production using a submersible installation of an electric centrifugal pump (ESP). ESP consists of the following main components: submersible electric motor, hydroprotection and multistage centrifugal pump. The ESP unit is lowered into the well on the tubing string. Power and control of the motor using ground control station (SU) is carried out by cable, lowered from the wellhead. At the outlet of the pump, a check valve is installed, which serves to hold the liquid column in the tubing string when the pump is turned off and to prevent the liquid from returning through the pump, which will lead to turbine rotation of the ESP shaft. As a result of turbine rotation, the following problems arise:

- failure of the electric motor when it is restarted during turbine rotation;

- loss of time associated with the need to wait for the complete discharge of fluid from the tubing string for the re-start of the electric motor;

- when used as part of a valve motor installation (permanent magnet electric motor), electric current is generated, which is transmitted through the cable to the control system, which can lead to its failure, as well as injury to the staff and even death.

Known check valves, for example, such as patent for utility model RU55018 E21B34 / 06, RU56940 E21B34 / 06, RU70544 E21B34 / 06, RU76380 E21B34 / 06, RU83799 E21B34 / 06, RU100579 F16K15 / 00, installed at the outlet of the pump do not have sufficient reliability. During operation when closing the valve, mechanical impurities contained in the reservoir fluid may interfere with the hermetic closure of the locking element, preventing it from being pressed tightly against the saddle. As a result, the liquid begins to flow through the valve, which leads to turbine rotation of the installation.

Modern SUs have the function of protection against turbine rotation, which excludes the launch of an electric motor during turbine rotation, and thus prevents its failure as a result of overload. This type includes such well-known and used control systems like Elektron-04 of the Elekton company, IRZ-200 of the Izhevsk radio factory, etc.

However, such SUs solve only one problem associated with turbine rotation.

Known SU with soft start function, which can ensure a smooth start of the electric motor, including during turbine rotation. In the startup mode during turbine rotation, the SU provides a smooth stopping of the motor shaft and starting in the forward direction. This type includes such well-known and used control systems as Elektron-05 of Elekton company, IRZ-500, IRZ-700 of Izhevsk radio plant, etc.

Such SUs solve two of the three above-mentioned problems associated with turbine rotation.

From the analysis of the field of technology it follows that to solve the above problems, a device is needed that will block the turbine rotation, but at the same time ensure the transmission of torque from the electric motor both in the forward and in the reverse direction. It is most advisable to install such a device in the lower part of the protection above the electric motor.

Known devices for hydraulic protection of a submersible oil-filled electric motor (hydraulic protection) according to patents RU 2118033 NC 5/12, NC 5/132, RU 2484306 F04D 13/10, RU 27416 F04D 13/10, NC 5/12, RU 32933 NC 5/12 , RU 120729 F04D 13/10, RU 132638 Н02К 5/12, which have fundamentally similar structures and consist of the following main parts: head, base, housing, shaft with radial and thrust bearings, at least one compensating module, which includes the housing, the upper and lower nipples, the mechanical seal and the compensating element (rubber diaphragm, piston b, metallophone, labyrinth).

The disadvantage of these devices, as well as all known hydroprotection, is the impossibility of blocking the turbine rotation.

The technical result, the achievement of which the invention is directed, is to improve the reliability and safety of operation of ESP by using in the installation of hydroprotection with a device to prevent turbine rotation.

This technical result is achieved in that the hydraulic protection consists of a head, a base, a housing, a hydraulic protection shaft with radial and thrust bearings of at least one compensating module, which includes a housing, an upper and lower nipple, an end seal and a compensating element, and characterized in that in the lower part between the bottom nipple and the base there is a device for preventing turbine rotation, which consists of a lower shaft mounted on a bearing support connected to the shaft; rozashchity through a cam clutch with the possibility of free running in the circumferential direction, an overrunning clutch is installed in the lower nipple, providing torque transmission in the forward direction from the lower shaft to the hydraulic shaft and preventing reverse rotation of the hydraulic shaft, the overrunning clutch is connected to the hydraulic shaft through the coupling clutch, movable part which is mounted on the hydraulic protection shaft with the possibility of axial movement, and the fixed part is rigidly connected with the overrunning clutch, the coupling coupling is provided zhinoy and disconnection pusher which is mounted on the shaft seal section with the possibility of axial movement with one hand is connected to the movable clutch, and the other - with a sleeve with an inclined end surface fixedly mounted on the lower shaft.

In addition, the bottom nipple can be made composite.

In addition, the coupling coupling can be a cam or a friction clutch, for example, a disc, multi-plate, cone.

The invention is illustrated by the following drawings:

FIG. 1 - hydroprotection with a device to prevent turbine rotation, longitudinal section;

FIG. 2 - hydraulic protection shaft with a pusher;

FIG. 3 - lower shaft with a sleeve with an inclined end surface;

FIG. 4 - use of the device in the composition of the ESP.

Hydraulic protection with a device to prevent turbine rotation (Fig. 1) consists of a head 1, a base 2, a housing 3, a hydraulic shaft 4 with radial 5 and thrust 6 bearings and at least one compensating module 7. The compensating module 7 includes the housing 3, the upper 8 and the lower 9 nipples, the mechanical seal 10 and the compensating element 11, which is a rubber diaphragm. In the lower part between the bottom nipple 9 and the base 2, a device for preventing turbine rotation is installed, which consists of a lower shaft 13 mounted on a bearing support 12 connected to the hydroprotection shaft 4 via a cam coupling 14 with the possibility of free running in the circumferential direction. In the lower nipple 9, an overrunning clutch 15 is installed, which is connected to the shaft 4 through a clutch 16. The movable part 17 of the clutch 16 is mounted on the shaft 4 by means of a key 18 with the possibility of axial movement, and the fixed part 19 of the clutch 16 is rigidly connected to the overrun clutch 15. The coupling coupling 16 is provided with a spring 20, which presses the movable part 17 to the fixed part 19.

The bottom nipple 9 is made of a composite of two parts to facilitate the installation of the thrust bearing 6.

On the shaft 4 (Fig. 2) installed the plunger 21 by means of a key 18 with the possibility of axial movement. On the pusher 21, the stop 22 is mounted.

On the lower shaft 13 (Fig. 3) with the help of pins 23 mounted sleeve 24 with an inclined end surface 25.

Hydroprotection with a device to prevent turbine rotation 26 is used in the ESP system (Fig. 4), consisting of the following main components: submersible electric motor 27, centrifugal pump 28, non-return valve 29. ESP is suspended on the tubing string 30. Power is supplied to motor 27 by cable 31 .

Application.

Hydroprotection 26 before descending into the well is filled with dielectric oil together with the electric motor 27.

After supplying power to the electric motor 27, the electric motor shaft transmits a direct rotation to the lower shaft 13, which transmits rotation to the shaft 4 through the cam clutch 14, then the rotation is transmitted to the shaft of the centrifugal pump 22. The formation fluid is extracted.

When the motor 27 is stopped and the check valve 29 leaks, the liquid from the tubing string 30 begins to flow through the pump, creating torque on the pump shaft (turbine rotation), which is transmitted to shaft 4 connected through the clutch 16 with the overrunning clutch 15, which prevents reverse rotation . As a result, the reverse rotation of the shafts of all ESP units is blocked.

Sometimes, when performing technological operations at the well, it is necessary to ensure the transmission of reverse rotation from the electric motor 27 to the pump 28. In this case, the reverse rotation of the electric motor shaft is transmitted to the lower shaft 13. Due to the free running of the cam clutch 14, the sleeve 24 with an inclined end surface 25 acts on the stop 22 , turning relative to it, and moving the pusher 21 in the axial direction, compresses the spring 20 and separates the coupling clutch 16. As a result, the overrunning clutch 15 stops blocking the reverse rotation and 4. Next, the reverse rotation is transmitted to the pump shaft.

Hydroprotection with a device to prevent turbine rotation prevents the motor shaft from rotating backward when the check valve is leaky or missing, and thus prevents the motor from overloading and makes it easier to start when the fluid is drained, eliminating the generation of electric current during the reverse rotation of the motor.

Thus, the solutions used in the invention improve the reliability and safety of operation of the ESP by using hydroprotection with a device to prevent turbine rotation in the installation and ensure the achievement of a technical result.

Claims (7)

1. Hydraulic protection consisting of a head, a base, a housing, a hydraulic protection shaft with radial and thrust bearings of at least one compensating module consisting of a housing, an upper and lower nipple, a mechanical seal and a compensating element, characterized in that between a bottom nipple and a base have a device for preventing turbine rotation, which consists of a lower shaft mounted on a bearing support connected to a hydroprotection shaft through a cam clutch with a possibility of free running in the circumferential direction, in the lower nipple, an overrunning clutch is installed, which ensures the transmission of torque in the forward direction from the lower shaft to the hydroprotection shaft and prevents the hydroprotection shaft from reverse rotation; displacement, and the fixed part is rigidly connected with the overrunning clutch, the coupling coupling is secured by a spring, and the separation by the pusher, which is mounted on the shaft axially moveable shields and, on the one hand, are connected to the movable part of the clutch, and on the other hand, to the hub with an inclined end surface rigidly mounted on the lower shaft. 2. Hydroprotection under item 1, characterized in that the bottom nipple is made composite. 3. Hydroprotection under item 1 or 2, characterized in that the clutch is made cam. 4. Hydroprotection under item 1 or 2, characterized in that the clutch coupling is made friction. 5. Hydroprotection under item 4, characterized in that the friction clutch is made disk. 6. Hydroprotection under item 4, characterized in that the friction clutch is made multi-disc. 7. Hydraulic protection under item 4, characterized in that the friction clutch is tapered.

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