THE WELL ROTARY ELECTRIC PUMP

The invention concerns to hydrodynamics and is intended for oil and water extraction from the deep well.

The one kind of the modern equipments, used in oil extraction is the well rotary electric pump. They must provide exploitation of oil well, having small diameter and large depth, and besides the prolonged reliable work in liquid, containing corrosive elements and mechanical admixtures, especially in the form of sand and salt.

The temperature of pumped out liquid in some wells runs up to 120 . The feature of these pumps is the absence of the intermediate link - pumping hoses, what increases the working period of the well work, simplifies maintenance and widens the area of usage of pumping oil production out of the deep wells, having low statistic level of liquid, when the large liquid inflow is provided. The present time the well rotary electric pumps are used at oil fields all over the world for oil production out of the deep wells.

The wide range of parameters, determining supply and pressure, the prolonged working period and the high coefficient of well exploitation, and also the number of another advantages allowed the well rotary electric pumps to take the leading place in the field of mechanized oil production. In the case of increase of the common scope of oil production their value will be much higher. The conditions of well rotary electric pumps usage in oil wells make the exacting requirements to constructions of this kind of machines. The exacting requirements are the followings:

1) Electric pump must be the high-pressured, as the height of the liquid lifting out of the well may amounts to 2000-3000 meters.

2) In spite of the small overall dimensions in diameter of plunged equipment, it must be high-powered, the increase of which can be reached only at the expense of increase of length of engine and pump. 3) The plunged equipment must have reliable and long work period in the medium with high temperature and containing sand, corrosive-active elements, gas and etc (1)

There is known the well rotary electric pump, including the pump body, shaft, plain bearings, netting, foundation, catching head, working wheels and directing devices. The working wheels and directing devices of the pump are usually made cast from the special alloyed iron, from steel casting or firm alloy. The working wheels consist of the driving

and driven disks. The blades, arranged between these two disks, have curved trajectories and are so-called blades of single curvature(cylindrical blades), which form is the same at all height(l)

As it is known, at movement of the liquid or solid matter by curved trajectory there is some acceleration. But this value is such little, that it can be considered the inertial, as the acceleration got by the liquid only at curved trajectory by the length of shovels and blades is very little. At rotation of the working wheel the flow of liquid in the wheel moves by the same curved trajectory, defined 'by the form of blade.

The liquid, flowing out of the worldng wheel directs into directing device, arranged in the pump body and is immovable ring. This ring consists of two disks, between which the shovels with curved trajectory are arranged, and are so-called shovels of single curvature (cylindrical shovels), having the same form at all the height. The directing device is intended for decrease the liquid speed, which flows out of the working 'wheel that is for transformation of the kinetic energy into potential energy (3). The directing devices are made in two types: radial directing devices and axled directing devices. We should describe only axled directing devices (since radial directing devices are usually used for the water production).

The main disadvantages of such well rotary electric pumps are the followings:

1) essential loss of the electric motor ρower( from 10% to 15%), promoting to quick fail of electric motor and hydraulic protection, low efficiency of the working elements, what in result noticeably influences at efficiency of electric pump;

2) the large axled pressure, acting on the working wheel, at the expense of formation of the liquid wedge pressure between working wheels and directing devices;

3) the low hydraulic quality of the oil stages, low disk efficiency of the working wheels, as the part of the liquid, flowing into the canal of working whee^ gets back from canal in absorption direction, that is there is recirculation of the liquid in working wheel canals. The all described disadvantages appear because of the so-called blades and shovels of single curvature, cylindrical and incline-cylindrical ones, not having optimal configuration of the surface at height, what results to the fact that the acceleration, got by the liquid only at curved trajectory by the length of blades and shovels has very little value.

4) the high prime cost and low repetition work of the working elements show the high price of used raw materials and very difficult technology of manufacture.

The task of invention is the decrease of loss of the electric motor power( from 10% to 15%), increase of the working elements efficiency, noticeable decrease of axled pressure, acting on the working wheels, increase of the disk efficiency of the working wheels, increase of the stage head ( of the working element) , and all this is at the expense of making double curved blades and shovels.

For solution of the said task in the well rotary electric pump, including the pump body, shaft, sliding bearings, .netting, foundation, catching head, working wheels and directing devices, in accordance with the invention the blades of the working wheels and shovels of directing devices have optimal configuration of the surface at all height of flowing liquid direction, that is input and output angles of the blades, and also input and output angles of the vanes at all the height are made with double curvature(we mean thrice-repeated and fourfold curvature at all height). The kinetic »energy is created in the working wheel. The kinetic energy is the energy of the movement and depends on the way of liquid flowing. That is why when using the double curvature at all the height it is possible to increase the movement energy in the necessary direction. We can reach this at the expense of the fact , that in the working wheel each particle of the liquid participates simultaneously in three( but not in two, as usual, cylindrical and incline- cylindrical forms) movements: it moves along ( at the length) the blade, rotates together with the wheel at speed equal to circle sped of the wheel, an also mqves across ( at height) the blade at the soft and uniform change of angles at all height.

But it is necessary to note, that the double curvature at all the height of the blade is not rectilinearly but with curved trajectory, and this influences upon the acceleration of the liquid flow. Forces, action of which depends on the way the body or the liquid transforms from one state into another, are named non conservative. There are states of the liquid in directing device, not depending from the way, but defined only by initial and final state of the liquid in the space. At the liquid flowing into the directing device (that is into deferent part), its speed is more than the pressure. At flowing out of the directing device (that is from the leading part) the liquid speed decreases, but the pressure increases. Simultaneously with this, when giving the form of double curvature to shovels of the directing device, is reached changing of direction of the liquid speed, flowing out of the working wheel and so we provide its soft, equal unstressed transfer into the speed in zigzag chamber.

For designing and making the profiles of shovels and the blades with double

curvature was used the law of kinetic energy, and for all construction of the working element (the stage) was used the Coulomb' s law, on the base of the fact , that during the working time the working ^heel and directing device interact with each other, resulting to sliding between them. At the end of 18 century , basing on a large number of experiments, Coulomb considered that the constant of friction depends neither on the value of relative speed of the bodies under the friction nor on the value of specific pressure, including the sliding time. It is necessary to note that this conclusion is right only at the definite speeds and specific pressures, and so it isn' t right ' to apply this law for all cases of technical solution. That' s why on this base and on the base of the law of kinetic energy, at working elements manufacturing should completely reject from the casting manufacture for technological and constructional reasons.

The vanes of directing device have transparent holes of the definite diameter for to decrease the axed pressure, acting upon the working wheels, and at this the holes must be arranged on the leading part of device. The directing device consists of three separate parts , the first part is the disk with vanes of double curvature, the second is the disk with bush, and the third is the special bush with grooves. The inside surface of the special bush consists of two oppositely arranged conical forms, having definite angles. The advantage of such

> construction is the possibility to make the input and output angles of the vanes with double curvature at all height and also together with disks. From the other side, this allows to make the bush with grooves. By the other words, for using the regularity of

Coulomb, the directing device must be made from three separate parts for technological and constructional reasons. The shovels with disks , the disks with bush, and the special bush are made collapsible, what allows to change elements partially, without making the new directing device.

The construction of the given sliding bearing is so, that at the liquid flow inside the pump the hydraulic resistance do'esn't t appear as it happens in the present pumps, and includes the metal bush, ring, fixing with shovels, disk, elastic bush.

The working wheels are made one-piece. The potential energy is created in directing device. When the liquid is in such condition, that in each point of the space it is under the influence of the other solids with the force, regularly changing from one point to another, and in this case they say, that the (solid ) liquid is in force field. In this case the force field is named potential, and the

forces-conservative. Potential energy is the energy of the state. In other words the state of the liquid in directing device does not depend on the way, and is defined only initial and final state of liquid in the space. . At the liquid flowing into the directing device (that is into deferent part), its speed is more than the pressure. At flowing out of the directing device (that is from the leading part) the liquid speed decreases, but the pressure increases. Simultaneously with this, when giving the form of double curvature to shovels of the directing device, is reached changing of direction of the liquid speed, flowing out of the working wheel and so we provide its soft, equal unstressed transfer into the speed in zigzag chamber. In the result, for making the disks with vanes, the disk with bush, and the special bush we have possibility to increase the prime cost in dozens of time and to increase the repeatedly manufacture more than once.

The essence of invention is explained by diagrammatic drawings, where there are shown:

Fig 1- the well rotary electric pump;

Fig 2-the construction of the directing device with the shovel of double, curvature Fig 3- the construction of the working wheel with the blade of double curvature Fig 4- working element or the oil stage The well rotary electric pump consists of the pump body 1, directing devices 2, working wheels 3, shaft 4,sliding bearings 5, netting 6 , foundation 7, catching head 8. The directing device 2 consists of three separate parts. The first and the second part consist of the shovels of double curvature 10 and disks 9. The shovels have double curvature as in exterior part 11 as in back part 12. The shovels with disks , the disks with bush, and the special bush are made collapsible, what allows to change elements partially, without making the new directing device when failing. The third part consists of the special bush 13 with grooves , with the aid of which the first and the second part are installed in the third part, creating the single directing device 2. The inside surface of the special bush 13 consists of two oppositely arranged conical forms, having definite angles. As in the first as in the second part of directing device are installed rubber washers 17 with the aid of which there is friction between the working wheel 3 and directing device 2. The working wheel 3 consists of the driving and driven disks and are made one-pieced. Between these disks are arranged the blades 14 of double

curvature. The blades have double curvature as in exterior part 15 as in back part 16. The catching head 8 has interior thread with the aid of which is installed to the tubing strings. The working wheels 3 and the directing devices 2 are arranged on the same shaft 4, which is supported by the sliding bearings 5. The working wheels 3 can fluently move on the shaft 4 in the axed direction. The directing devices 2 are motionlessry fixed. The working wheels 3 in the axed direction are limited in motion by lower and upper directing devices 2 The working wheels 3 and directing devices 2,which have the definite number of the stages, being installed on the shaft 3, create the pack of the stages. This pack of the stages is fixed _, in the pump body 1 with the aid of the winch. With the aid of the foundation 7, the shaft 4 of the pump with the spline socket, is connected with the plunged electric motor (isn't shown in the picture 1).

The sliding bearing 5 consists of the following constructive elements and includes the metal bush 18, ring 19, fixing 20, disk 21, elastic bush 22.The fixing 20 has the shovels 23. The disk 21 is installed on the fixing 20, that is set into the metal bush 18 without the aid of the lock. The ring 19 with the aid of the grooves and lock is set into the fixing 20. The elastic bush 22 is set into the fixing 20. After the assemblage the sliding bearing 5 is set into the working wheel 3.

The device works in the following way. At the shaft rotation (3000 rot/min) the torque is given from shaft 4 to the working wheels 5, in the result of which ^' the liquid flows into canals, made by blades 14 of he working wheel 3 and moves from pump axes to its periphery. The liquid, flowing between the blades, rotates and under centrifugal force is thrown to moveless shovels 10 of directing device 2, what results to decrease of the liquid speed, but its pressure increases more and more. In the result of liquid flowing from pump axes to periphery of the working wheel 3 at its input( near the pump shaft) is created the field of low pressure and happens the constant liquid flow to working wheels 3. Depending on the depth of well it is number of the pack stages. The new electric pumps can work at the depth 3500m.