GB2184166A - A multistage pump and motor assembly for deep wells - Google Patents

Abstract

In the assembly the motor, e.g. a hydraulic motor 6, is provided downstream of the pump 11, 19 and is arranged to drive a shaft 9 to which pump impellers 16 are fixed. This arrangement permits the shaft 9 to work under a torsion and traction combined load. A pipe 3 surrounds the pump 11, 19, and an upstream seal 22 is provided so that the liquid pressure at the discharge of pump is transmitted to the space between the pipe 3 and the pump housing to enable the latter operate under compression. The pipe 3 is fitted with a filter 2 and is located in the drill hole 1 with a body of gravel 4 therebetween. <IMAGE>

Description

SPECIFICATION A multistage pump and engine The following invention, as indicated by the title of the present specification, relates to a multistage pump-and-engine for the pumping of deep wells with flooded engine and offers remarkable advantages with regard to pumpand-engines existing in the market.

The solutions offered by the pump-and-engine market for deep wells, are assemblies wherein the engine, usually an electric one, is arranged at the drafting side of the pump, an axial bearing (that of the engine) supporting the resulting axial load produced by the different runners during the pumping and transmitted as compression load from stage to stage, through the pump axis, up to the engine axis; as a consequence of this, the axes work at a torsion-and compression combined load, therefore being of a great diameter in order to support the possible bulging thereof.

On the other hand, these designs limit, in some occasions, the possibility of cooling of the engine when the water flow comes from the upper part of the pump, as it enters the draft body without circulating (and, consequently, without cooling) through the engine, which is arranged beneath the draft body.

In conventional submerged pumps, the pump bodies work at a pressure which is much high at the inner than at the outer part, the materials thereof working, thus, under traction, this load being as much greater as said pump body becomes farther away from the draft.

By means of the design according to the invention, the engines, being generally of a lesser diameter than the pump bodies, are arranged at the driving zone, the driving axis of the runners working at a torsion-and-traction combined load, avoiding the bulging and reducing the diameter thereof, which implies an improvement in the bearings behaviour by decreasing the PxV factor and improving the mechanical and vo lumetric output of the assembly by decreasing the inner leakages between stages through the axis.

Likewise, all the pumped water is in direct contact with the engine body, thereby cooling at the same time under the best conditions.

On the other hand, due to the fact that the watertightness between pipe and pump is carried out at the drafting body of the latter and by means of a joint specially designed for this function, the resultant pressure of the last driving body is transmitted between the pipe and the pump thereby making the driving bodies work under compression instead that under traction, as in usual pumps, the pressure resulting from each stage being as much lesser as we become farther away from the drafting body, and avoiding, thus, the bursting thereof.

The fluid conduction wires are directly connected to the engine, without needing pass along the pump body, thereby needing a lesser piping diameter.

In order to complement the following description, and for a better comprehension of the characteristics of the invention, the present specificaiton has an attached drawing, the single figure of which represents a sectional view of a well with the pumping multistage pump-and-engine according to the invention.

In view of the aforementioned figure, and according to the adopted numeration, it can be seen how for the embodiment of the well, the drill 1 of said well must be first made, positioning inside it the filter 2, over which the well coating pipe 3 will be positioned, the latter working too as driving pipe, both the filter 2 and said pipes 3 being of a lesser diameter than the drili, so that the gravel 4 is positioned at the space between both. The whole assembly constituting the pump-and-engine set 5 will be finally positioned.

The drive will be carried out by the engine 6, generally an hydraulic one, which, revolving at high revolutions (up to 8000 variable r.p.m.), allows the development of submerged pumps with great differences with respect to the classical ones in the market, which, being generally driven by an electric engine, work at 2950 and 1450 fix r.p.m.. These high revolutions minimize the number and diameter of the pump bodies, with the consequent constructive saving. On the other hand, it allows the construction of pump-and-engine sets of high specific Ns speeds (between 200 and 250), thereby improving noticeably the outputs.

The use of runners 7 with little diameter and of axes 9 not working under compression (therefore without shafts produced by the bulging), allows the material to be submitted to peripheral speeds very inferior to those of chassic pumps, with the consequent improvement in the P x V factor of the bearings 10, and the use of injection-manufactured plastic materials.

The fact that the pump is supported by the drafting body without being suspended by the driving pipes, allows the use of the coating pipe 3 of the well as driving pipe, thereby making the pressure resulting from the last stage to be transmitted by the outside of the pump, the pump bodies working under compression instead that under traction, as in the pumps existing up to now, which, together with the little diameter thereof, allows the use of plastic materials in the own pump bodies.

In the checkings and maintenance of the pump-and-engine set, and in the arrangement thereof in the well, it is raised and descended suspended on the own small whips or cables connected to the engine drills 8. The engine 6 stands in the water-driving body 11, which works as engine frame, having the metallic closure 12 at the revolving engine side and the mechanical closure 13, likewise, at the fix engine side, whilst it has, at the pump side, another mechanical closure 14 and 15, comprising a fix and a revolving part, respectively.

The driving body 11 and said four closures constitute the watertightness and fluid (water, oil and others) separation system; special catchers can also be used for low depths.

The attached design shows that the driving runners 16 are provided with the compensating drills 17 in order to reduce the axial load of the runner 7, having the wedge socket 18 for fixing the runner to the axis.

The diffusing cell or pump body 19 is between the driving runners 16. The pump axis 9 is provided with the special dry bearing 20 and with the rubber bearer 21 as damper.

By means of the watertightness joint 22 the under-pressure driving zone is separated, this zone being supported by the drafting body 23, which, in its turn, stands on the socket 24 for the support thereof by the filter 2.

The whole pump-and-engine set can be easily removed by pulling the small whips or cables on which it is suspended and which are connected to the engine 6 drills 8, this not being possible in conventional systems.

Claims (8)

1. A MULTISTAGE PUMP-AND-ENGINE SET FOR THE PUMPING OF DEEP WELLS WITH FLOODED ENGINE, essentially characterized in that the engine, being generally of a lesser diameter than the pump body, is arranged at the driving zone, all the pumped water being in direct contact thereto, thereby producing a cooling thereof, so that the driving axis of the runners works at a torsion-andtraction combined load.

2. A MULTISTAGE PUMP-AND-ENGINE SET FOR THE PUMPING OF DEEP WELLS WITH FLOODED ENGINE, according to the previous claim, characterized in that the watertightness between the pipe and the pump is performed at the drafting body, thereby resulting that the pressure of the last driving body is transmitted between the pipe and the pump, making the driving bodies work under compression and the pressure resulting from each stage being much lesser as it becomes farther away from the drafting body.

3. A MULTISTAGE PUMP-AND-ENGINE SET FOR THE PUMPING OF DEEP WELLS WITH FLOODED ENGINE, according to the previous claims, characterized in that the fluid connection wires are directly connected to the engine without passing along the pump body, thereby reducing the piping diameter.

4. A multistage pump-and-engine set for the pumping of deep wells, comprising a driv ing zone having a plurality of drive runners, fixed to and located along the length of a drive shaft for driving liquid through the driving zone, and an engine for driving the drive runners via the drive shaft, wherein the engine is located generally downstream of the drive runners so that the drive shaft works at a torsion-and-traction combined load when the pump-and-engine set is in use.

5. A multistage pump-and-engine set according to claim 4, wherein the drive runners include apertures or compensating drills for re- ducing axial load on the drive runners.

6. A multistage pump-and-engine set according to claim 4 or 5, wherein the engine is positioned so that pumped liquid comes into contact with the engine thereby to produce cooling of the engine.

7. A multistage pump-and-engine set for the pumping of deep wells, comprising a driving zone having a pump which includes a plurality of pump bodies surrounded by a pipe member, the pump being supported by a drafting body, wherein a seal is provided between the pipe member and the drafting body, upstream of the pump, so that the liquid pressure in the region of the most downstream pump body is transmitted between the pipe and the pump thereby making the pump bodies work under compression.

8. A multistage pump-and-engine substantially as hereinbefore described with reference to the accompanying drawing.