RU2620626C1 - Unit of compression type submersible impeller pump - Google Patents

Abstract

FIELD: oil and gas industry.

SUBSTANCE: unit of a compression-type submersible impeller pump includes a motor, a protector with an axial shaft support, a pump section. The pump section includes a shaft, a body, a base, a head, a package assembly of centrifugal stages. Each stage contains a guiding device and an impeller with blades between the drive and cover plates and the hub. The impellers and guiding devices are made in the form of solid cast iron structures. There is a blade ring at the drive plate of each impeller. There are fillets between the lateral faces of each blade of the blade ring and the drive disc; the height of the blade ring does not exceed the minimum distance between the drive and the cover plates of the impeller, and the radius of the fillet is from 0.2 to 0.8 of this value. The impellers are compressed by a nut on the hubs, the guiding devices are fixed relative to the body, the shafts of the pump sections are supported by each other. The shaft of the lower section rests on the shaft in the protector, which axial bearing is made in the form of a hydrodynamic bearing.

EFFECT: increased reliability of work, wear and corrosion resistance, optimisation of the properties of stages.

7 cl, 7 dwg

Description

FIELD OF THE INVENTION

The invention relates to petroleum engineering, in particular to multistage submersible pumps for pumping formation fluid from wells.

State of the art

A pump installation is known according to US Pat. No. 5,885,058 (priority date 12/28/1995, publication date 03/23/1999), including pump sections that contain many functional components and bushings mounted on the shaft to form a substantially continuous pipe around the shaft; at the same time, fittings are provided at the top and bottom of the shaft to hold the components and bushings forming the pipe in a compressed state. The disadvantage of this installation is that the installed stages cannot reliably work in wells with small and medium flow rates, due to the high axial force acting on each impeller.

Also known installation with a section of the upstream device for processing a gas-liquid mixture, RU 136503 U1 from 05.25.2012. The section includes a housing, a shaft, impellers, guides, bearings, etc. Impellers, bearings and bushings mounted on the shaft form a substantially continuous pipe around the shaft. The disadvantage is that the installed stages cannot reliably work in wells with small and medium flow rates due to the high axial force acting on each impeller.

The closest analogue is an electric submersible pump RU 2476726 C2 from 05.16.2008 for use in a well, comprising: a motor section; pump section; a protective section located between the motor section and the pump section, and a rotating shaft passing through the motor, protective and pump sections; wherein the motor, protective and pump sections comprise each of a plurality of functional components and bushings mounted on the shaft to form a substantially continuous pipe around the shaft; at the same time, fittings are provided at the top and bottom of the shaft to hold the components and bushings forming the pipe in a compressed state. The disadvantage is that the multitude of functional components and bushings mounted on the shaft with the formation of a substantially continuous pipe around the shaft of the protective and motor sections reduces the reliability of the installation, since this significantly increases the dimensional chain from the axial support of the upper stage of the pump to the axial support, which with this design should be installed in the lower part of the engine. In addition, the disadvantage is that the installed stages cannot reliably work in wells with small and medium flow rates due to the high axial force acting on each impeller.

For the sake of clarity, the descriptions of this application make a reservation that there are batch type pumps or batch type pumps, that is, pumps in which several impellers and guide vanes (from 3 or more pairs) are assembled into packages (subassemblies). Typically, in an actual product, an average of about ten pairs of impellers and guide vanes are used.

Compression type pumps are understood to be pumps with a compression type of assembly, that is, those pumps in which, due to the exact adjustment of the height of the impeller hubs, they are in contact with each other (such a “comb” of wheels is fixed on the shaft).

Packet-compression type pumps are understood as pumps that combine the features of both types of assemblies: compression and batch.

In a batch pump, the entire wheel force is perceived by the separate axial bearing of each section (for each package). In a batch-compression pump, the power of the wheels is transferred to the hydraulic protection support, which avoids the use of additional bearings and reduces or eliminates wear of parts.

The technical task of the invention is the creation of the design of an electric submersible pump, which reduces to an optimal value the axial force acting on the impellers and, therefore, on the axial support of the pump rotor.

Technical results include increasing the reliability of work in wells with low and medium flow rates, ensuring the optimal plant life in terms of corrosion resistance and wear resistance, optimization of the mechanical and physicochemical properties of the steps.

SUMMARY OF THE INVENTION

The technical problem is solved, and the technical results are ensured by the fact that the installation of a submersible vane pump of the compression type includes an engine, a tread with axial shaft support, at least one pump section, which includes: a shaft, a housing, a base, a head, an assembly of a package of stages, each step contains a guiding apparatus and an impeller, the impellers contain a drive and cover discs between which the blades are located, and the hub, impellers on the shaft are compressed with a special nut on the hubs, the guides the apparatuses are fixed relative to the housing, the shafts of the pump sections in working condition are supported by each other, while centrifugal steps are installed in the pump, the impellers are made in the form of solid cast iron structures, the guide vanes are made in the form of solid cast iron structures, on the drive wheel drive disk scapular crown, between the side faces of each scapular blade of the scapular crown and the leading disk rounding; the height of the blade rim does not exceed the minimum distance between the driving and cover disks of the impeller, and the radius of rounding is from 0.2 to 0.8 of this value, the shaft of the lower section rests on the shaft in the tread, in which the axial bearing is made in the form of a hydrodynamic bearing.

With this installation, the axial force acting on the shaft and wheels through the hubs, bushings and support rings is perceived as a support in hydraulic protection, which works in oil and has a significantly lower coefficient of friction. This eliminates wear in the axial bearings of the stage and increases the installation life.

In addition, in the particular case of the invention, cast iron, in addition to iron and impurities, contains, in particular, carbon, silicon, manganese, chromium, cerium, phosphorus, boron and sulfur, with the following content of these elements, wt. %:

carbon 3,5-3,9 silicon 2.1-2.7 manganese 0.4-0.6 chromium <0.12 sulfur 0.05-0.07 phosphorus <0.3 cerium <0.03 boron <0.01

In addition, in the particular case of the invention, cast iron, in addition to iron and impurities, contains, in particular, carbon, silicon, manganese, chromium, nickel, copper, phosphorus, sulfur, aluminum and magnesium in the following contents of these elements, wt.%:

carbon 2.7-3.1 silicon 1.2-1.9 manganese 0.85-1.5 chromium 0.7-3.0 nickel 15-17 copper 6.1-8 sulfur <0.03 phosphorus <0.25 aluminum 0.01-0.3 magnesium 0.01-0.07

In addition, in the particular case of the invention, cast iron, in addition to iron and impurities, contains, in particular, carbon, silicon, manganese, chromium, nickel, copper, phosphorus and sulfur with the following content of these elements, wt.%:

carbon 2.7-3.1 silicon 1.2-2.2 manganese 1.3-1.9 chromium 2.0-2.9 nickel 15.0-17.0 copper 5.0-8.0 sulfur <0.05 phosphorus <0.25

In addition, in the particular case of the invention, the shafts of the pump sections are provided with splines, an axial threaded hole at the end, an adjusting bolt, a spline coupling, locks in the form of radial protrusions mating with splines of the coupling mounted on the shaft are made on the bolt.

Centrifugal steps are used for efficient operation of formations with low and medium flow rates. Impellers and guide vanes are made in the form of cast-iron cast iron structures: this allows to provide an optimal resource in terms of the combination of corrosion resistance and wear resistance and this is a condition for creating compression pumps, since cast iron has the necessary mechanical properties (elasticity) for compressing steps. A blade rim is made on the driving wheel of the impellers, this allows to significantly reduce the axial force acting on each impeller. Between the lateral faces of each blade of the scapular crown and the leading disk, roundings are made; the height of the blade rim does not exceed the minimum distance between the driving and covering disks of the impeller, and the radius of rounding is from 0.2 to 0.8 of this value, design features allow optimizing the value of axial force. The shaft of the lower section rests on the axial support in the tread, which is made in the form of a hydrodynamic bearing. The hydrodynamic bearing has a higher resource in comparison with traditional plain bearings.

The above composition of cast iron allows you to optimize the mechanical and physico-chemical properties of the steps.

If the shafts of the pump sections are equipped with splines, an axial threaded hole at the end, an adjusting bolt, a splined coupling, the bolts have latches in the form of radial protrusions that mate with the splines of the coupling mounted on the shaft, this allows for more accurate joining of the shafts during assembly, which is necessary for reliable operation of the compression pump.

In addition, in the particular case of the invention, the installation motor of the submersible vane pump of the compression type is a valve electric motor.

In addition, it is possible to perform the installation of a submersible vane pump of the compression type, in which this installation includes an engine, a tread with an axial shaft support, at least one pump section, which includes: a shaft, a housing, a base, a head, an assembly of a package steps, each step contains a guide apparatus and an impeller, the impellers contain a drive and cover discs between which the blades are located, and the hub, guide apparatuses are fixed relative to the housing, the shafts of the pump sections in they are supported by each other in operation, the installation is equipped with a valve electric motor, and differs in that it contains centrifugal steps, and the impellers and guide vanes are made in the form of solid cast iron structures, while the shaft of the lower section rests on the shaft in the tread, which has axial support made in the form of a hydrodynamic bearing, the transverse installation size does not exceed 86 mm.

In this embodiment, the best size range for the transverse dimension of the installation is from 84.60 mm to 85.00 mm.

A brief description of the graphic materials explaining the invention.

FIG. 1 - section of a submersible pump in a section;

FIG. 2 - sectional stages of a submersible pump;

FIG. 3.1, 3.2, 3.3 - embodiments of the scapular crown;

FIG. 4 - view "A" of the blades of the scapular crown;

FIG. 5 is an embodiment of an adjustment bolt; connection of shafts with a spline coupling (in section).

Ways to implement the invention

Installation of a compression type submersible vane pump, including: an engine (not shown), a tread with an axial shaft support (not shown), at least one pump section 1, which includes: shaft 2, housing 3, base 4, head 5, assembly package steps, each step contains a guide apparatus 6 and the impeller 7. The impellers on the shaft are compressed with a special nut 8, the guide devices are fixed relative to the housing. Each impeller contains a drive 9 and a cover disk 10, between which the blades 11 are located, and the hub 12. The shafts of the pump sections 2 in the working state rest on each other. A blade rim 13 is made on the driving disk of the impellers, rounded with R roundings between the side faces of each blade of the blade rim and the driving disk; the shaft of the lower section rests on the shaft in the tread, in which the axial support is made in the form of a hydrodynamic bearing (not shown).

The shafts of the pump sections 2 are provided with splines 14, an axial threaded hole at the end 15, an adjustment bolt 16, a spline coupling 17, the bolts 18 are made in the form of radial protrusions mating with the splines of the coupling mounted on the shaft.

Installation works as follows. When the shaft 2 of the submersible multistage centrifugal pump 1 is rotated, the torque is transmitted through the hubs 12 to the impellers 7. The formation fluid enters the section through the base 4 and swirls in the area that is formed between the main 9, the covering 10 discs and blades 11. In series, the fluid passes through impellers 7, guiding devices 6, exit through the head 5. In this case, the pressure of the reservoir fluid increases.

When the impeller 7 rotates due to the presence of a blade rim 13 on the drive disk 9, the fluid in the sinus between this disk and the guide device 8 rotates at a greater angular speed than in the absence of a blade rim. A toroidal vortex arises, due to which the liquid passes from the impeller 7 to the guide apparatus 6. In this case, thanks to the blade rim 13, the pressure in this sinus decreases and the axial force acting on the impellers 7 decreases. The axial force acting on the shaft 2 and wheels 7 through hubs 12, bushings and support rings, it is perceived as a support in hydroprotection, which works in oil and has a significantly lower coefficient of friction. This eliminates wear in the axial bearings of the stage and increases the installation life. For the exact joining of the shafts 2 with the splines 14, axial threaded holes 15 are made in each shaft, an adjusting bolt 16 is installed. On each bolt, the clamps 18 are made in the form of radial protrusions mating with the splines of the coupling 17 mounted on the shaft.

Claims (10)

1. Installation of a submersible vane pump of compression type, comprising an engine, a tread with an axial shaft support, at least one pump section, which includes: a shaft, a housing, a base, a head, an assembly of a package of stages, each stage contains a guide apparatus and the impeller, the impellers contain a drive and cover discs between which the blades are located, and the hub, the impellers on the shaft are compressed by a nut on the hubs, the guiding devices are fixed relative to the housing, the shafts of the pump sections in the working section the thawings are supported by each other, characterized in that it contains centrifugal steps, the impellers and guide vanes are made of cast-iron solid structures, a blade rim is made on the driving disk of the impellers, roundings are made between the lateral faces of each blade of the blade rim and the drive disk; the height of the blade rim does not exceed the minimum distance between the driving and covering disks of the impeller, and the radius of rounding is from 0.2 to 0.8 of this value, the shaft of the lower pump section rests on the shaft in the tread, in which the axial bearing is made in the form of a hydrodynamic bearing . 2. Installation according to claim 1, characterized in that the cast iron, in addition to iron and impurities, contains, in particular, carbon, silicon, manganese, chromium, cerium, phosphorus, boron and sulfur, with the following content of these elements, wt. %: carbon 3,5-3,9 silicon 2.1-2.7 manganese 0.4-0.6 chromium <0.12 sulfur 0.05-0.07 phosphorus <0.3 cerium <0.03 boron <0.01 3. Installation according to claim 1, characterized in that the cast iron, in addition to iron and impurities, contains, in particular, carbon, silicon, manganese, chromium, nickel, copper, phosphorus, aluminum, magnesium and sulfur, with the following contents of these elements, wt. %: carbon 2.7-3.1 silicon 1.2-1.9 manganese 0.85-1.5 chromium 0.7-3.0 nickel 15-17 copper 6.1-8 sulfur <0.03 phosphorus <0.25 aluminum 0.01-0.3 magnesium 0.01-0.07 4. Installation according to claim 1, characterized in that the cast iron, in addition to iron and impurities, contains, in particular, carbon, silicon, manganese, chromium, nickel, copper, phosphorus and sulfur, with the following content of these elements, wt. %: carbon 2.7-3.1 silicon 1.2-2.2 manganese 1.3-1.9 chromium 2.0-2.9 nickel 15.0-17.0 copper 5.0-8.0 sulfur <0.05 phosphorus <0.25 5. Installation according to claim 1, characterized in that the shafts of the pump sections are provided with splines, an axial threaded hole at the end, an adjusting bolt, a spline coupling, and the bolts have latches in the form of radial projections mating with splines of the coupling mounted on the shaft. 6. Installation according to claim 1, characterized in that its engine is a valve electric motor. 7. Installation of a submersible vane pump of compression type, including a valve motor, a protector with an axial shaft support, at least one pump section, which includes: a shaft, a housing, an assembly of a package of stages, each stage contains a guide apparatus and an impeller, the impellers contain a drive and cover discs, between which the blades are located, and the hub, the impellers on the shaft are compressed by a special nut on the hubs, the guiding devices are fixed relative to the housing, the shafts of the pump sections in in working condition, they are supported by each other, characterized in that centrifugal stages are installed in the pump, the impellers and guide vanes are made in the form of cast-iron structures made of cast iron, the shaft of the lower section rests on the shaft in the tread, in which the axial bearing is made in the form of a hydrodynamic bearing, and the transverse installation size does not exceed 86 mm.

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