RU49588U1 - SUBMERSIBLE HIGH SPEED PUMP UNIT - Google Patents

Abstract

The utility model relates to petroleum engineering, namely to submersible pumping units. Submersible pumping unit consists of a high-speed submersible centrifugal multistage pump with a valve motor with a heat exchanger. The pump contains at least one module section, which includes at least two stage packages. The total number of steps in the specified module section is at least 12, and the bearings fixing the shafts in the module section in the radial and axial directions are made in the form of sliding bearings. EFFECT: provision of the possibility of installing submersible units in increasing the reliability of a submersible borehole unit.

Description

The utility model relates to hydraulic engineering, namely to submersible pumping modular units for oil production with increased service life and high pressure.

Submersible high-speed pump unit - part of the pumping unit. It consists of a pump section (hereinafter referred to as the pump) and an engine with a shaft rotation speed exceeding 3000 rpm. The concept of a module section is introduced in submersible pump units designed according to the sectional principle, it is defined as the functional part of the unit made in one unit and having interface units with other modules, in which there are necessarily impellers located on the shaft and placed in a separate housing ( for example, see the materials of the official website of the company http://www.novomet.ru, RU 2147083 (OJSC Almetyevsk Pumping Plant). The pump section may contain several such module sections. Accordingly, we define the module section as a separate structural unit comprising at least a separate housing, at least one shaft and a sliding bearing, a package or packages of steps, nodes for interfacing with other modules-pump Step package - a set of working stages with its radial and axial bearings, which can be placed as on a single shaft, and have your own separate shaft (see. Borehole pumping units for oil production. V.N. Ivanovsky, V.I. Darishchev, A.A.Sabirov, V.S. Kashtanov, S.S. Pekin. M. State Unitary Enterprise. Publishing House "Oil and Gas" Russian State University of Oil and Gas. Gubkina, 2002, 824 s, p. 92).

A well-known submersible pump unit, including a centrifugal pump and an induction motor ([1], p.15), using the module-sections of the pump, each of which can contain from 38 to 211 stages (International translator. Installations of submersible centrifugal pumps for oil production. International Engineering Encyclopedia. Series "Oil and Gas Installations. Edited by Yu.V. Alekperov and V. Ya. Kershenbaum. Publishing House" Oil and Gas "Moscow. 1998., pp. 112-117). The engine speed, as a rule, is not more than 3000 rpm. (Equipment for oil and gas production V.N. Ivanovsky, V.I. Darishchev, A.A.Sabirov, V.S.Kashtanov, S.S. Pekin. State Unitary Enterprise. Oil and Gas Publishing House of the Russian State University of Oil and gas named after Gubkin, 2002, 767 s, p. 351). The disadvantage of this design is the high load on the axial support of the shaft due to the relatively large number of steps in it and increased bending vibrations of the long shaft of the module section, accelerating the process of wear of tribo-joints of the module section.

As the closest analogue of the invention, we consider a well-known submersible pump unit with a high-speed valve motor of a centrifugal pump (Equipment for oil and gas V.N. Ivanovsky, V.I. Darishchev, A.A. Sabirov, V.S. .Beijing.

SUE. Publishing House "Oil and Gas" Russian State University of Oil and Gas. Gubkina, 2002, 767 s, p. 629). The pump contains 65 stages. Adjustable rotor speed of the engine from 3000 to 6000 rpm. The vane motor provides a higher number of revolutions than the squirrel-cage induction motor. The design drawback is the increased high load on the axial shaft support, and accordingly the heel, in combination with an increased number of revolutions, can lead to thermal shock destruction of the tribocontact zone of the heel-upper bearing. This design is also characterized by increased bending vibrations of the pump shaft and overheating of thermally loaded electric motor elements is possible due to inefficient heat removal in deep low-yield wells (the heat flux through the lateral surface of a submersible motor can reach 30,000 W / m2.)

The present utility model is aimed at eliminating the indicated drawbacks of known technical solutions. The technical result achieved is to increase the reliability of the submersible borehole unit, in particular by reducing vibrations and beating of the pump shaft, more favorable temperature conditions in the pumping unit by eliminating the destruction of the working surface of the upper shaft support during "thermoshock" failure, reducing the overheating of thermally loaded submersible valve elements electric motor.

The specified technical result is achieved due to the fact that in the well-known submersible high-speed pump unit, consisting of a valve motor, configured to adjust the frequency and a centrifugal pump, the valve motor is made with a heat exchanger unit, there is at least one module section containing at least two stages packages , the total number of steps in the specified module section is at least 12, each package of steps has its own separate shaft, the number of steps in a separate package is not more than 12, axial and radial The bearings supporting the shafts in the module section respectively in the radial and axial directions are made in the form of sliding bearings, the module section also contains at least one coupling for connecting the shaft packages of the steps, the axial support can be made bilateral, the shaft of the package of steps can be fixed at least two radial bearings, the working surfaces of the bearings can be formed by the surfaces of carbide materials, the coupling for connecting the shafts can be spline type.

In fig. 1. The view of the inventive submersible pump unit.

A submersible high-speed pump unit contains a pump with a module section (1), a high-speed electric motor with a heat exchanger block (7). The module section contains two packages of steps (4), each of which in turn contains a shaft (6), steps, bearings upper and lower, axial and radial (3, 5, respectively), the shafts of the packages of steps are connected by a spline coupling (2) .

An example of execution of a submersible high-speed pump unit. The pump unit had an engine made in the form of a submersible oil-filled valve electric motor with the ability to control the number of revolutions (a typical speed range of 6000 to 15,000 thousand rpm). The module section contained a housing in which two packages of steps were placed with a separate shaft for each package - each of which contained radial and axial bearings (3, 5). The shafts of the packages were connected by a spline coupling (2). Each package has 6 steps (4) (guiding devices with impellers), a stainless steel shaft (2) 34 cm long, radial bearings (5) that hold the shaft from lateral displacements. The emerging axial force is perceived by the working surfaces of the upper axial support (3). The diameter of the working surface of the upper support is 48 mm. The diameter of the upper working surface (tribocontact area with the heel surface) of the upper support (3) lay in the range from 30 to 60 mm.

It is with such (and fewer) steps in the package of steps that the tribosystem is unloaded in the upper support to such an extent that the probability of destruction of the tribological conjugation is sharply reduced. The shaft diameter is selected, for example, from a range of 10-25 mm. The number of steps N <12 in the package of steps is determined empirically for a high-speed submersible assembly, provided that the friction pair in the tribo-conjugation area is formed by carbide materials processed so that grinding and polishing the surface roughness Rmax from 0.1 to 0.2 μm)

From a qualitative point of view, the existence of restrictions on the number of steps can be explained as follows. Let E = kPV be the maximum power of heat sources in the tribocontact zone, where k is the friction coefficient depending on the physicomechanical properties of the friction pair, P is the contact pressure in the tribo-conjugation region (directly proportional to the number of steps in the package of steps), V is the maximum linear velocity in the field of tribo-conjugation (directly proportional to n - engine speed). E must not exceed a predetermined critical value at which a "thermal shock" occurs. When the specified critical value is exceeded, the heat generated in the tribocontact zone does not have time to be removed from the contact zone and the contact zone is heated. As a result, the tribo-conjugation zone is destroyed (the “thermal shock” effect). Therefore, for a given range of engine speeds, there is a maximum allowable Ncr - the number of steps at which E does not exceed the critical threshold. We also note that for N <Ncr the shaft is short (less than 60 cm) and, therefore, there are practically no bending vibrations of the shaft, leading to increased wear of tribo-joints in the module section.

Submersible unit operates as follows. A high-speed valve motor with a heat exchanger block is used. The heat exchanger helps align the temperature balance of the engine, reducing the temperature of thermally loaded elements

motor (stator winding first). When the pump is turned on in the operating mode, the axial forces in the module section are perceived by the upper support. With the number of steps in the package less than 12 and the number of engine revolutions from 6000 to 20,000 rpm, the axial support operates in a mode that excludes "thermal shock" destruction of the tribo-conjugation area of the upper support. The diameter of the heel is selected more than the diameter of the upper support. Short shafts of stage packages were connected by a spline coupling. The bending vibrations of the shaft, and the corresponding wear processes, are absent in the module section.

Claims (5)

1. Submersible high-speed pump unit containing a centrifugal multistage pump and a rotary motor, configured to adjust the rotation speed, characterized in that the rotary motor is made with a heat exchanger block, the pump contains at least one module section having at least two packages steps, the total number of steps in the specified module section is at least 12, each package of steps has its own separate shaft, and the number of steps in a separate package is not more than 12, radial and axial bearings, fi the coding shafts in the module section, respectively, in the radial and axial directions, are made in the form of sliding bearings, the module, the section also contains at least one coupling for connecting the shafts of the packages of steps. 2. Submersible high-speed pump unit according to claim 1, characterized in that the axial support of the shaft of the package of stages is made bilateral. 3. Submersible high-speed pump unit according to claim 1 or 2, characterized in that the shaft of the package of stages is fixed by at least two radial bearings. 4. Submersible high-speed pump unit according to claim 1 or 2, characterized in that the working surfaces of the axial bearings are formed by the surfaces of carbide materials. 5. Submersible high-speed pump unit according to claim 3, characterized in that the coupling for connecting the shafts is made spline.