Pumps for oil: screw, submersible, semi-submersible, centrifugal for the oil industry. Application features and description of oil pumps

I can't think of something interesting topic tell you, and for this case I always have your help in the form of . Let's go there and listen to the friend skolik : " I really want to understand the principle of operation of oil pumps, you know, such hammers that drive a pipe into the ground here and there.”

Now we will learn more about how everything happens there.

The pumping unit is one of the main, basic elements of the operation of oil wells with a pump. On the professional language this equipment is called: “Individual balancing mechanical drive of the rod pump”.

A pumping unit is used for a mechanical drive to oil well pumps, called rod or plunger pumps. The design consists of a gearbox and a double four-link articulated mechanism, a balancing drive of rod pumps. The photo shows the basic principle of operation of such a machine:

In 1712, Thomas Newcomen created an apparatus for pumping water out of coal mines.

In 1705, the Englishman Thomas Newcomen, together with the tinker J. Cowley, built a steam pump, which continued to be improved for about ten years, until it began to work properly in 1712. Thomas Newcomen never received a patent for his invention. However, he created an installation externally and according to the principle of operation reminiscent of modern oil pumping chairs.

Thomas Newcomen was an ironmonger. While supplying his products to the mines, he was well aware of the problems associated with the flooding of mines with water, and to solve them, he built his steam pump.

Newcomen's machine, like all its predecessors, worked intermittently - there was a pause between two strokes of the piston, writes spiraxsarco.com. She was the height of a four or five-story building and, therefore, exceptionally "gluttonous": fifty horses barely had time to deliver fuel to her. The attendants consisted of two people: the stoker continuously threw coal into the furnace, and the mechanic operated the taps that let steam and cold water into the cylinder.

In his setup, the motor was connected to a pump. This steam-atmospheric machine, quite effective for its time, was used to pump water in mines and became widespread in the 18th century. This technology is currently used by concrete pumps at construction sites.

However, Newcomen was unable to obtain a patent for his invention, since the steam water lift was patented back in 1698 by T. Severi, with whom Newcomen later collaborated.

The Newcomen steam engine was not a universal engine and could only work as a pump. Newcomen's attempts to use the reciprocating motion of a piston to turn a paddle wheel on ships were unsuccessful. However, Newcomen's merit is that he was one of the first to implement the idea of ​​using steam to obtain mechanical work, informs wikipedia. His car became the forerunner of J. Watt's universal engine.

All drives drives

The time of flowing wells, referring to the period of development of deposits in Western Siberia, has long ended. We are not in a hurry to get new fountains to Eastern Siberia and other regions with proven oil reserves - this is too expensive and not always profitable. Now oil is extracted almost everywhere using pumps: screw, piston, centrifugal, jet, etc. At the same time, more and more new technologies and equipment are being created for hard-to-recover reserves of raw materials and residual oil.

Nevertheless, the leading role in the extraction of "black gold" still belongs to pumping units, which have been used in the oil fields of Russia and abroad for more than 80 years. These machines in the specialized literature are often referred to as sucker-rod pump drives, but the abbreviation PShGN has not really taken root, and they are still referred to as pumping units. In the opinion of many oilmen, no other more reliable and easy-to-maintain equipment has been created so far than these drives.

After the collapse of the USSR, the production of pumping units in Russia was mastered by 7-8 enterprises, but they are steadily produced by three or four, of which the leading positions are occupied by JSC Izhneftemash, JSC Motovilikhinskiye Zavody, FSUE Uraltransmash. It is important that these enterprises survived in a fierce competition with both domestic and foreign manufacturers of similar products from Azerbaijan, Romania, and the USA. The first pumping units of Russian enterprises were produced on the basis of the documentation of the Azerbaijan Institute of Petroleum Engineering (AzINMash) and the only manufacturer of these machines in the USSR - the Baku Rabochiy plant. In the future, the machines have been improved in accordance with the world's leading trends in oil engineering, they have API certificates.

1 - frame; 2 - rack; 3 - balancer head; 4 - balancer; 5 - lock of the head of the balancer; 6 - traverse; 7 - connecting rod; 8 - gearbox; 9 - crank; 10 - counterweights; 11 - the lower head of the connecting rod; 12 - stuffing box suspension; 13 - fence; 14 - belt drive casing: 15 - lower platform; 16 - top platform; 17 - control station; 29 - balancer support; 30 - foundation of the pumping unit; 35 - gear platform

For the first rocking chairs, towers were used for percussion cable drilling after completion of drilling, while the rocker of the drilling machine was used to drive the downhole pump. The bearing elements of these installations were made of wood with metal bearings and accessories. The drive was steam engines or single-cylinder low-speed internal combustion engines equipped with a belt drive. Sometimes a drive from an electric motor was added later. In these installations, the derrick remained above the well and the power plant and main flywheel were used to service the well. The same equipment was used for drilling, production and maintenance. These rigs, with some modifications, were used until about 1930. By this time, deeper wells had been drilled, pump loads increased, and the use of wireline drilling rigs as pumps had become obsolete. An old rocking chair is depicted, converted from a tower for shock-rope drilling.

The pumping unit is one of the elements of operating wells with a rod pump. In fact, the pumping unit is a drive rod pump located at the bottom of the well. This device is very similar in principle to a bicycle hand pump, converting reciprocating movements into air flow. The oil pump converts reciprocating movements from the pumping unit into a fluid flow, which enters the surface through tubing pipes (tubing).

A modern rocker pump, mostly developed in the 1920s, is shown in fig. The advent of efficient mobile well service equipment has eliminated the need for built-in hoists on every well, and the development of durable, efficient gearboxes has provided the basis for higher speed pumps and lighter weight prime movers.

Counterweight. The counterweight located on the arm of the rocker crank is an important component of the system. It can also be placed on a balancer for this purpose, you can use a pneumatic cylinder. Pumping units are divided into units with rocker, crank and pneumatic balancing.

The purpose of balancing becomes clear if we consider the movement of the string of sucker rods and rocking chairs on the example of the idealized operation of the pump shown. In this simplified case, the upward load on the packing rod consists of the weight of the rods plus the weight of the well fluids. In the reverse stroke, this is only the weight of the rods. Without any balance, the load on the gear reducer and the prime mover are directed in the same direction during the upward movement. When moving down, the load is directed in the opposite direction. This type of load is highly undesirable. It causes unnecessary wear, operation and wasted fuel (energy). In practice, a counterweight is used equal to the weight of the sucker rod string plus about half the weight of the fluid being lifted. Correct selection The counterweight creates the least possible stress on the gearbox and prime mover, reduces breakdowns and downtime, and reduces fuel or power requirements. It is estimated that up to 25% of all rockers in service are not properly balanced.

Demand: high potential

The state of the sucker rod pump drive market can be judged both by its estimates by experts and by statistical data. Experts' conclusions are confirmed by the data of the State Statistics Committee of the Russian Federation: in 2001, the production of pumping units increased by 1.5 times in comparison with 2000 and outstripped other types of oil equipment in terms of growth rates.
The proclamation by the state of the task of promoting domestic products to foreign markets as one of the priorities of economic policy has played a positive role. At present, the quality level of pumping units and traditionally low prices create opportunities for the return of Russian products to countries that previously purchased Soviet equipment: Vietnam, India, Iraq, Libya, Syria and others, as well as to neighboring countries.

It is also interesting that VO Stankoimport, together with the Union of Oil and Gas Equipment Manufacturers, organized a Consortium of leading Russian enterprises. The main purpose of the association is to assist in the promotion of oil and gas equipment to the traditional markets of Russian exports, primarily the countries of the Near and Middle East. One of the tasks of the Consortium is the coordination of foreign economic activity related to the placement of orders on the basis of centralized information support.

Market: competition is growing

Competition in the well pump drive market has been around for a long time. It can be viewed from various perspectives.
Firstly, it is competition between domestic and foreign manufacturers. It is worth noting here that the overwhelming market share in the segment of pumping units is occupied by the products of domestic enterprises. It fully meets the needs in terms of price-quality.

Secondly, competition between Russian enterprises themselves, seeking to occupy their niche in the oil and gas equipment market. In addition to the pumping units already mentioned, other enterprises are also engaged in the production of pumping units in our country.

Thirdly, as an alternative to balancing pumping units, hydraulic drives of sucker-rod pumps are being promoted in the oil fields. It is worth noting here that a number of enterprises are ready for this type of competition and their factories can produce both types of drives. The latter include JSC Motovilikhinskiye Zavody, which manufactures drives, sucker rods, and pumps. For example, the MZ-02 hydraulic rod pump drive is mounted on the upper flange of the well fittings and does not require a foundation, which is very important for permafrost conditions. Stepless adjustment of the stroke length and the number of double strokes in a wide range allows you to choose the optimal operating mode. The advantages of a hydroficated drive are also in weight and dimensions. They are 1600 kg and 6650x880x800 mm respectively. For comparison, balancing pumping units weigh approximately 12 tons and have dimensions (OM-2001) of 7960x2282x6415 mm.

The hydraulic drive is designed for long-term operation at ambient temperature from -50 to plus 45°С. However, the design parameters (this applies not only to temperature and not only to the hydraulic drive) are not always maintained in real oilfield conditions. It is known that one of the reasons for this is an imperfect system of maintenance and repair of equipment.

It is also known that operators are wary of purchasing new, less common equipment. Balancing pumping units are well studied, highly reliable, able to work for a long time under open sky without the presence of people.

In addition, new equipment requires retraining of personnel, and the personnel problem is far from the last problem of oilmen, which, however, deserves an independent discussion.

However, competition is growing, and the rod pump drive market is developing and maintaining a positive trend.

And I will remind you about The original article is on the website InfoGlaz.rf Link to the article from which this copy is made -

Vladimir Khomutko

Reading time: 6 minutes

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Types of pumps for oil production and their characteristics

The oil industry is the most important branch of the Russian industry. The importance of this natural energy resource for the domestic economy cannot be overestimated. Every year, millions of tons of "black gold" are mined in Russia, and this volume not only meets the needs of the domestic market, but also brings the country a significant share of export earnings.

The modern extraction of this mineral is carried out by means of wells drilled in the rock mass. If there is not enough pressure in the reservoir, as a rule, oil is extracted using special mechanisms that allow you to raise the raw material to the surface, and are also used to pump water into the reservoirs, move the pumped products through field pipelines, and so on.

These mechanisms are called oil pumps. Oil production pumps are used to lift oil to the surface, transfer pumps are used to provide the necessary pressure in the main and field pipeline systems. Next, we will consider the main types of such equipment.

Pumps for oil. Main types

Oil pumps are of the following types:

1. rod deep pumps (SHR);
2. rod screw;
3. electrocentrifugal (ETsN);
4. screw;
5. diaphragmatic;
6. hydropiston;
7. trunk;
8. multiphase;
9. jet;
10. lamellar.

Deep rod pumps for oil production (SRP)

These mechanisms are three-dimensional devices. They are used to lift the extracted raw materials from the well by creating the so-called depression (pressure drop between the productive formation and the bottom of the mine working). Many of you have seen such pumps in films and on television (the famous oil pumps).

The rod pump includes a cylinder block, plungers, valves, special fasteners, rods, a rod, adapters, and so on. Such pumping units are used in more than half of the oil fields currently in operation.

Such a wide popularity of this type of oil pump is due to the following undoubted quality and performance characteristics:

• high coefficient of efficiency during operation;
• ease, convenience and simplicity of repair work;
• the ability to use a variety of types of drives;
• the possibility of using even under extreme conditions (for example, in the case of a high concentration of mechanical impurities; an increased content of gases in the extracted product; when pumping out raw materials with high corrosive aggressiveness).

Rod screw pumps for oil production

This variety rod installations, as a rule, are used in the mechanized operation of production wells in cases of production of heavy grades of petroleum feedstock, as well as grinding and viscous fluids.

The main advantages of such installations include: isolated gases and quite affordable for such units cost.

Electric submersible pumps (ESP)

Despite the fact that the number of wells equipped with installations of this type is much less compared to SRP, in terms of the volume of raw materials extracted with the help of centrifugal electric pumps, they are much superior to rod pumps. Suffice it to say that about 80 percent of all Russian "black gold" is mined with the help of ESP in our country.

Briefly describe this device, it is a conventional pumping mechanism equipped with electric drive(unless, unlike the rod, it does not have a ground part, it is long and thin). ESPs have proven themselves well when working in environments characterized by increased corrosiveness. These pumping units includes:

1. submersible pumping unit, consisting of the pump itself and an electric drive with hydraulic protection;
2. cable line connecting the electric motor with the transformer substation;
3. station for controlling and regulating the operation of the installation.

Submersible pumps of electric centrifugal type have significant advantages compared to deep-well pumps, namely:

• simple ground equipment;
• the possibility of producing large volumes of raw materials (up to 15 thousand cubic meters per day);
• the possibility of their use in wells, the depth of which exceeds 3 thousand meters;
• long (from 500 days to two or three years or more) time period of operation of the unit without repair work;
• the ability to perform the necessary research work in wells without the need to raise the pumping unit to the surface;
• simpler and less labor-intensive ways to remove paraffin deposits formed on the walls of tubing (tubing pipes).

In addition, electric centrifugal pumping units can be used at great depths and in inclined production wells (up to horizontal wells), as well as in mine workings with a high degree of water cut, in environments with a high content of iodine-bromine water, with a high degree of formation water salinity. and for lifting acidic and salt solutions to the surface.

In addition, there are ESP modifications for simultaneous-separate operation at several productive horizons within one well. In some cases, such units are also used to pump mineralized formation water into the oil reservoir in order to maintain the required reservoir pressure.

Such a pump design is used, as a rule, for the production of heavy and high-viscosity oils with a large amount of mechanical impurities (for example, sand), as well as for pumping liquids with high level viscosity.

This kind of oil pumping unit has the following advantages:

Screw pumps

Diaphragm oil pumps

Also, like rod, they belong to volumetric devices. The basis of the design of such a unit is a special diaphragm that protects the extracted products from getting into other parts of the pumping mechanism. The diaphragm pump consists of oil supply column, delivery valve, axial passage, helical spring, cylinder, piston, supports, electric cable and so on.

Such pumping units, as a rule, are used in fields where the extracted oil contains a large number of mechanical impurities. The main advantages of this design include ease of installation and subsequent operation.

Hydro piston pumps

They are designed to pump formation fluid from the well. Hydraulic reciprocating units are used in cases where there are no mechanical impurities in the extracted raw materials.

These settings include: borehole pump, a submersible engine, a channel through which oil and water are lifted, a surface power plant and a system for preparing the working environment. In the process of extraction with the help of such units, the surface comes out onto the oil along with the extracted water.

The main advantages of hydraulic piston pumps are:

• the opportunity largely makes changes to their basic characteristics;
• simplicity and ease of use;
• the ability to carry out underground repair work without much labor;
• they can be used in wells with an inclined borehole.

Main oil pumps

Their main purpose is to pump extracted raw materials or oil products through field, technical and main pipelines.

Such units are able to provide high pressure to ensure the pumping of the transported raw materials. Their main distinctive characteristics– cost-effectiveness of the operation process and a high degree of reliability.

Such installations consist of two main components - a housing and a system of rotors, and are used for pumping oil and oil products through a system of main pipelines.

The use of this type of installation allows:

• reduce the load on the mouth of the opening;
• reduce the amount of equipment used;
• increase the efficiency of the use of emitted gases;
• increase the profitability of exploitation of remote fields.

Multiphase pumps for oil and oil products

Jet Oil Pumping Units

They are the most modern and promising installations for the oil industry. Their application will help bring the technology of oil field exploitation to a higher level.

The structure of such installations includes: a mechanism for summing up the working environment. Active nozzle, injection fluid supply channel, displacement chamber and diffuser.

Currently, pumping units of this type are becoming increasingly popular due to the simplicity of their design, the absence of moving elements in it, the high degree of strength and reliability of operation even under extreme operating conditions, such as a high concentration of mechanical impurities in the working medium, a high content of free gases in the extracted raw material. elevated temperatures environment and the aggressiveness of the working fluid.

Jet installations pump type able to provide:

• stability of the device;
• freedom to regulate downhole pressure;
• optimal functioning of the unit in cases of uncontrolled changes in such parameters as the degree of water cut, in-situ pressure, and the like;
• easier and faster inflow of extracted raw materials;
• quick access to the optimal operating mode after the suspension of the well;
• efficient use of released free gases;
• prevention of flowing in the annulus;
• the process of rapid cooling of electric motors of submersible type;
• stability in the current load device;
• increase in the efficiency of an oil-producing installation.

The use of such pumping units makes it possible to provide better and faster oil production.

These pumps include:

• case equipped with a lid;
• drive shaft with bearings;
• working set, which consists of distribution discs, rotor, stator and plate.

Rotary vane (vane) pumps PN

The main advantages of plate aggregates include:

• high strength;
• good reliability;
• high degree of oil production efficiency;
• good performance;
• high wear resistance of mechanism parts.

Pumping units are one of the main components of the oil producing and processing industry. Oil depots cannot do without pumping equipment, technological installations, tank farms, tankers. The difficulty in selecting a pump lies in the peculiarities of the chemical properties of petroleum products. Combustible, flammable, with high viscosity, a large amount of suspended particles and various impurities, they require a special approach.

1. Pumps are made of melt-resistant materials, and the casing is covered with additional protective layer made of metal for better cooling of the unit during operation.
2. The level of vibration during operation should be minimal, and mechanical impurities should not clog the equipment.
3. It is necessary to achieve zero current conduction due to the increased risk of ignition.
4. The equipment must be designed to be used in a wide range of external temperatures and in a variety of climatic conditions: from the desert to the regions of the Far North.

We offer pumps for the oil industry that meet all of the above requirements. The best options are represented by the brands Mouvex and Blackmer. When it is necessary to work with dark oil products: fuel oil, bitumen, oil, gas turbine fuel or tar, Blackmer S-series vane or screw pumps and Mouvex A-series pumps will do the best.

New for 2016, Blackmer S-Series pumps are quickly gaining popularity due to their wide range of applications, ATEX Hazardous Approval and unique design features.

The Blackmer vane pump - the ancestor of all vane pumps - was introduced into mass production back in 1903. Manufacturability, high quality and the benefits of its use are confirmed by many years of testing in real operating conditions.

Another novelty recent years- Mouvex A series eccentric disc pumps, improved to meet the characteristics of the oil and gas and oil industry. The French concern PSG Dover with its Mouvex division is one of the leading European suppliers of pumping equipment for the oil, food, pharmaceutical and cosmetic industries.

The design features and technical characteristics of Mouvex and Blackmer pumps allow them to be used in any area related to petroleum products:

• in the production of crude oil and secondary production;
• for transportation and unloading of raw materials;
• for capturing vapors and gases;
• for pumping asphalt, bitumen, kerosene, propane, gasoline, diesel fuel and other fuels and lubricants;
• for pumping oil sludge, fuel oil and crude oil;
• for injection of drilling fluid in the process of drilling wells or supplying media to the reservoir to improve the intensity of oil production;
• for transportation of chemical reagents, saline solutions, liquefied gases, gas condensate;
• in pressure generation systems and booster systems;
• for pumping non-aggressive media, such as flooded oil.

In addition, pumping units of this type are used in any production where it is necessary to work with substances that have properties similar to petroleum products: viscosity, aggressiveness, flammability, etc. Pumps for the oil industry can be used both indoors and outdoors when there is a possibility of formation of explosive gases or vapours, as well as mixtures of dust with air.

One of the benefits of using Mouvex and Blackmer pumps is their versatility. Equipment of the corresponding series for the oil industry is also used in other areas:

• in the chemical industry - when working with caustic liquids, acids, polymers, adhesives;
• in the food and pharmaceutical industry - for pumping honey, molasses, creams, liquid soap, glycerin;
• in the paper industry and shipbuilding - for working with caustic liquids, solvents, varnishes, paints, mastic.

The military and firefighting industries also need Mouvex universal eccentric pumps and Blackmer screw units.

The principle of operation of Mouvex and Blackmer pumps allows them to cope with the most difficult pumping conditions and contact aggressive and viscous media without problems.

Mouvex eccentric disc pumps consist of a cylinder and a pump element mounted on an eccentric shaft. As the eccentric shaft rotates, the pumping element forms a chamber within the cylinder which increases in size at the inlet, transferring fluid to the pumping chamber. The fluid is transported to the outlet where the size of the pumping chamber is reduced. Under pressure, the liquid enters the outlet pipeline.

Blackmer rotary vane pumps, used to supply and transfer fluids of various viscosities, are versatile. Gate devices easily cope with gas turbine fuel, fuel oil, refined products and oil compositions, due to which they are used in the oil, food, pharmaceutical, cellulose industries.

When pumping, several forces are involved:

• mechanical stabilizes and presses the blades to the cylinder, advancing the viscous liquid to the pump outlet valve;
• hydraulic ensures that the pressure of the pumped composition on the base of all blades is constant and stable;
• centrifugal ensures the rotation of the rotor gates, which push the liquid up.

Blackmer Twin Prop Units are positive displacement pumps that convey any liquid without solids. The device consists of a pair of screws located opposite each other, which, when rotated, form a sealed cavity with the pump housing. The hydraulic drive creates a stable hydraulic axial stress on the shafts of the unit. The pumped medium is transported by the movement of the screws to the outlet valve located in the center of the pump.

Features and Benefits

All pumping units used in the oil industry have common design features. The equipment necessarily has a hydraulic part and a mechanical seal, is made of specific materials for installation outdoors and in any climatic conditions, and the electric motor is equipped with explosion protection. The flow part of the unit is made of carbon, nickel-containing or chrome-plated steel.

Oil installations are usually represented by two types: screw or centrifugal pumps. The former are more versatile because they are designed for use in harsh environments. And due to the pumping of liquids without contact with the screw part, they are suitable for working with contaminated substances with a high density. It is these pumps for the oil industry that are offered by Blackmer and Mouvex.

Mouvex pumps for the oil industry

Mouvex A-series pumps are known for their reliability and high performance, which are provided by innovative developments from the company's engineers.

1. The unique design of the A-Series pump allows the unit to operate continuously in reverse and provide reverse pumping of products.
2. The unique operating principle of the eccentric discs ensures smooth pumping (at low RPM) and also guarantees excellent efficiency.
3. The A-Series pumps are designed to be self-priming even when running dry and during pipeline cleaning.
4. Mouvex A-series maintain their original level of performance for extended periods without adjustment due to the automatic cleaning of the recharge system.
5. Even with a significant change in the viscosity of the pumped product, the pumps maintain a regular and constant output, regardless of the supply pressure.

In addition, Mouvex A-series pumps are equipped with a double bypass for protection in both directions, as well as a heating or cooling jacket for transporting products that can solidify at low ambient temperatures.

Blackmer pumps for the oil industry

Both vane and screw pumps of this manufacturer provide high performance, reliability and durability of the equipment.

1. Blackmer vane and screw pumps handle highly corrosive liquids and perform well in abrasive environments.
2. Both types of pumps can run dry, which saves energy and improves productivity.
3. S series screw pumps feature low noise, no product agitation and no emulsified shear.
4. Viscosity level does not matter when Blackmer screw or vane pumps are put into service.
5. The ability to operate at low shaft speeds (for sliding gate units) or screws guarantees an increased service life of the equipment.

Low power consumption and easy repair - additional benefits working with Blackmer pumps.

Key features of Mouvex and Blackmer pumps for the oil industry

To cope with all the requirements and harsh conditions of working with petroleum products, equipment must meet certain characteristics. Mouvex and Blackmer provide pumping units that not only meet the most stringent requirements, but also help optimize energy and financial costs.

The Mouvex A-Series pumps pump liquids up to 10 bar differential pressure, have a maximum speed of 600 rpm and a maximum flow of up to 55 m3/h. A constant flow rate is maintained regardless of changes in product viscosity or density. And the maximum possible liquid temperature for the uninterrupted operation of pumping equipment is +80 0 С. In potentially explosive conditions, A-series units can run dry for up to six minutes.

Blackmer vane pumps demonstrate excellent performance (up to 500 cubic meters per hour) at a speed of 640 rpm and temperatures from -50 0 C to +260 0 C. The pumps of this series are capable of withstanding pressures up to 17 bar. S series screw pumps show even more impressive results. The maximum medium temperature (depending on the pump model) can vary from -80 to +350 0 C. The maximum pressure drop reaches 60 bar, and the viscosity is 200,000 cSt.

With resource savings, high efficiency, ease of maintenance and operation, Mouvex and Blackmer pumps for the oil industry will bring maximum value to your business!

The process involves the use of special deep-seated equipment, which is based on the so-called pumping units. This is a type of surface drive mechanism that is controlled by operators during the operation of wells. As a rule, an oil pump is based on the work of those providing the function of the production infrastructure.

Appointment of oil pumps

The most common rod pump drive is designed for pile mining. With the help of this unit, users develop wells in permafrost conditions. Oil and gas equipment in the form of rocking chairs with one-arm balancers is also popular. Such machines are used as an individual drive in oil production.

In essence, any oil-producing infrastructure is focused on the implementation of raising the resource. The general principle of operation of the equipment can be compared with the function of the syringe, which in this case is provided by rod pumps. Also, as an obligatory element, the oil rocker is equipped with columns of compression pipes. Through these channels, the rise and transfer of oil is realized.

oil extraction process

The technological organization of the mining process is divided into several stages. Work begins with a depth of which can reach several kilometers. As a rule, 1,500-meter holes are developed, and wells of 4,000 meters are the champions. Then pipelines are installed, which become the basis of the oil production infrastructure. The activator in this system will be the pump. To understand the principle of its operation, it is necessary to understand how the oil pump works in overall structure pipeline. It performs the function of a drive mechanism, due to which reciprocating actions are performed. Pumps operate in a cyclic manner, allowing oil to concentrate around the well for efficient pumping. In addition, this maintenance principle minimizes the wear of plant parts.

Oil pumping device

The machine is mounted on a special concrete base in the form of a foundation. There is also a rack, platform and control station for the operator. After completion of work on the organization of the platform, a balancer is placed, balanced by a special head, to which a rope suspension is also connected. To ensure the force impact, the oil rocker is equipped with a gearbox and an electric motor. The latter can be located under the platform, but due to the high risk of operating this configuration, such placement is extremely rare.

As for the gearbox, it is connected to the balancer by means of a crank mechanism. This bundle is designed to convert the rotational action of the shaft into a reciprocating function. The task of the control station is also noteworthy. As a rule, its basis is formed by a box complex with electrical stuffing. AT without fail a manual mechanical brake is also installed next to the control relay.

Varieties

Despite the similar principle of working with an oil resource, the family of pumping units includes various modifications. As already noted, the most popular is the classic balanced machine, which provides for rear fixation of the connecting rod, as well as a gearbox connected to the frame with a balancer. But there is an alternative to this equipment. This is a hydraulic rod pump, which is mounted on the upper flange of the borehole fittings. Its features and advantages include the elimination of the need to install a foundation pillow. This difference is of great importance when it comes to permafrost zones. There are other features of hydraulic installations. In particular, they involve the implementation of stepless length adjustment, which makes it possible to more accurately select the operating modes of the equipment.

Characteristics of pumping units

Technologists analyze a wide range of technical and operational parameters that give grounds for choosing one or another machine. In particular, the load on the rod, stroke length, gearbox dimensions, torque, swing frequency range, etc. are evaluated.

One of the main characteristics of pumping units is the power of the electric motor. So, typical oil pumps cope with their functions, provided that a force of 20-25 kW is applied. A deeper analysis of the parameters also takes into account the type of belt, pulley diameters and features of the brake system. At the same time, in addition to operational operating capabilities, one should also keep in mind the overall parameters that make it possible to fundamentally install a particular machine in certain conditions. Again, a typical installation can be 7 m long and 2-2.5 m wide. The mass usually exceeds 10 tons.

How is an oil pump serviced?

To work with pumping units, designers provide special mechanisms. For example, to service a traverse with a balancer, a special platform with drive systems is mounted. Operators can control the parameters of a detachable balancing head support integrated into the machine body. of the drive system ensures optimum movement of the head and, if necessary, can be set to a fast downward movement. At the same time, it is important to separate directly the functions of operators and personnel who technically service oil pumps during operation. If the former are engaged in the regulation of the rise of oil, then the latter monitor the performance of the mechanisms in terms of maintaining their function within the tolerance of peak loads.

Conclusion

Manufacturers of pumping units regularly offer new technological solutions to ensure the oil production process, however, there is no need to talk about serious revisions of existing concepts so far. The fact is that oil and gas equipment is expensive and many customers are reluctant to change the existing fleet of equipment. Nevertheless, a partial update of significantly outdated components still occurs. There is also a trend of transition from balancing machines to more advanced hydraulic ones. This is due precisely to the desire to optimize the operation of the existing infrastructure. As a result, oil companies reduce the cost of organizing and operating equipment, but at the same time do not lower the quality of the target product.

Introduction

1. Operation of wells with centrifugal submersible pumps

1.1. Submersible installations centrifugal pumps(ESP) for oil production from wells

1.3 MNGB type gas separators

2. Operation of wells with submersible centrifugal electric pumps

2.1 General layout of the installation of a submersible centrifugal electric pump

4. Labor protection

Conclusion

Bibliography

Introduction

The composition of any well includes two types of machines: machines - tools (pumps) and machines - engines (turbines).

Pumps in a broad sense are called machines for communicating energy to the working environment. Depending on the type of working fluid, there are pumps for dripping liquids (pumps in the narrow sense) and pumps for gases (blowers and compressors). There is a slight change in blowers static pressure, and the change in the density of the medium can be neglected. In compressors, with significant changes in static pressure, the compressibility of the medium is manifested.

Let us dwell in more detail on pumps in the narrow sense of the word - liquid pumps. By converting the mechanical energy of the drive motor into the mechanical energy of a moving fluid, the pumps raise the fluid to a certain height, deliver it to the required distance in the horizontal plane, or force it to circulate in a closed system. According to the principle of operation, pumps are divided into dynamic and volumetric.

In dynamic pumps, the liquid moves under force in a chamber of constant volume, which communicates with the inlet and outlet devices.

In volumetric pumps, the movement of liquid occurs by suction and displacement of liquid due to a cyclic change in volume in the working cavities during the movement of pistons, diaphragms, and plates.

The main elements of a centrifugal pump are the impeller (RK) and the outlet. The task of the RC is to increase the kinetic and potential energy of the fluid flow by accelerating it in the vane apparatus of the centrifugal pump wheel and increasing the pressure. The main function of the outlet is to take fluid from the impeller, reduce the fluid flow rate with the simultaneous conversion of kinetic energy into potential energy (increase in pressure), transfer the fluid flow to the next impeller or to the discharge pipe.

Due to the small overall dimensions in installations of centrifugal pumps for oil production, the outlets are always made in the form of vane guide vanes (HA). The design of RK and NA, as well as the characteristics of the pump, depend on the planned flow and stage head. In turn, the flow and head of the stage depend on dimensionless coefficients: head coefficient, feed coefficient, speed coefficient (used most often).

Depending on the speed coefficient, the design and geometric parameters of the impeller and guide vane, as well as the characteristics of the pump itself, change.

For low-speed centrifugal pumps (small values ​​of the coefficient of speed - up to 60-90), a characteristic feature is a monotonically decreasing line of the pressure characteristic and a constantly increasing pump power with an increase in flow. With an increase in the speed factor (diagonal impellers, the speed factor is more than 250-300), the pump characteristic loses its monotony and gets dips and humps (pressure and power lines). Because of this, for high-speed centrifugal pumps, flow control by means of throttling (nozzle installation) is usually not used.

Well operation with centrifugal submersible pumps

1.1. Installations of submersible centrifugal pumps (ESP) for oil production from wells

The company "Borets" produces complete installations of submersible electric submersible pumps (ESP) for oil production:

In size 5" - pump with an outer diameter of the casing 92 mm, for casing strings with an inner diameter of 121.7 mm

In size 5A - a pump with an outer casing diameter of 103 mm, for casing strings with an inner diameter of 130 mm

In size 6" - pump with an outer diameter of the casing 114 mm, for casing strings with an inner diameter of 144.3 mm

Borets offers various options for completing the ESP depending on the operating conditions and customer requirements.

Highly qualified specialists of the Borets plant will make for you the selection of the ESP configuration for each specific well, which ensures the optimal functioning of the “well-pump” system.

ESP standard equipment:

Submersible centrifugal pump;

Input module or gas stabilizing module (gas separator, disperser, gas separator-disperser);

Submersible motor with hydraulic protection (2,3,4) cable and extension cable;

Submersible motor control station.

These products are produced in a wide range of parameters and have versions for normal and complicated operating conditions.

The Borets company produces submersible centrifugal pumps for delivery from 15 to 1000 m 3 / day, head from 500 to 3500 m, of the following types:

Submersible centrifugal double-bearing pumps with working stages made of high-strength niresist (ETsND type) are designed for operation in any conditions, including complicated ones: with a high content of mechanical impurities, gas content and temperature of the pumped liquid.

Submersible centrifugal pumps in a modular design (ETsNM type) - designed primarily for normal operating conditions.

Submersible centrifugal double-bearing pumps with working stages made of high-strength corrosion-resistant powder materials (ECNDP type) - are recommended for wells with high GOR and unstable dynamic level, successfully resist salt deposition.

1.2 Submersible centrifugal pumps, type ETsND

ETsNM type pumps are designed primarily for normal operating conditions. The steps are of a single-support design, the material of the steps is high-strength alloyed modified gray pearlitic cast iron, which has increased wear and corrosion resistance in formation media with a mechanical impurities content of up to 0.2 g/l and a relatively low intensity of the aggressiveness of the working medium.

The main difference between the ETsND pumps is the two-support stage made of Niresist cast iron. The resistance of niresist to corrosion, wear in friction pairs, hydroabrasive wear makes it possible to use ELP pumps in wells with complicated operating conditions.

The use of two-bearing stages significantly improves the performance of the pump, increases the longitudinal and transverse stability of the shaft and reduces vibration loads. Increases the reliability of the pump and its resource.

Advantages of steps of a two-support design:

Increased resource of the lower axial bearings of the impeller

More reliable shaft isolation from abrasive and corrosive liquids

Increased service life and radial stability of the pump shaft due to the increased length of the interstage seals

For difficult operating conditions in these pumps, as a rule, intermediate radial and axial ceramic bearings are installed.

ETsNM pumps have a pressure characteristic of a constantly falling shape, which excludes the occurrence of unstable operating modes, leading to increased pump vibration and reducing the likelihood of equipment failures.

The use of two-bearing stages, the manufacture of shaft supports from silicon carbide, the connection of pump sections according to the "body-flange" type with bolts with fine threads of strength class 10.9 increase the reliability of the ESP and reduce the likelihood of equipment failures.

Operating conditions are shown in table 1.

Table 1. Operating conditions

In the place of suspension of the pump with a gas separator, protector, electric motor and compensator, the curvature of the wellbore should not exceed the numerical values ​​of a, determined by the formula:

a \u003d 2 arcsin * 40S / (4S 2 + L 2), degrees per 10 m

where S is the gap between the internal diameter of the casing string and the maximum diametrical dimension of the submersible unit, m,

L - length of the submersible unit, m.

The allowable rate of curvature of the wellbore should not exceed 2° per 10 m.

The angle of deviation of the wellbore axis from the vertical in the area of ​​operation of the submersible unit should not exceed 60°. Specifications are shown in table 2.

Table 2. Specifications

Pump group	Nominal supply, m3/day	Pump head, m		efficiency %
		min	max
5	30	1000	2800	33,0
	50	1000		43,0
	80	900		51,0
	125	750		52,0
5.1 1	200	850	2000	48,5
5A	35	100	2700	35,0
	60	1250	2700	50,0
	100	1100	2650	54,0
	160	1250	2100	58,0
	250	1000	2450	57,0
	320	800	2200	55,0
	400	850	2000	61,0
	500 2	800	1200	54,5
	700 3	800	1600	64,0

1 - pumps with shaft D20 mm.

2 - stages made of "niresist" single-support design with an extended impeller hub

3 - stages made of "ni-resist" single-support design with an elongated impeller hub, unloaded

The structure of the symbol for pumps of the ETsND type according to TU 3665-004-00217780-98 is shown in Figure 1.

Figure 1. The structure of the symbol for pumps of the ETsND type according to TU 3665-004-00217780-98:

X - Design of pumps

ESP - electric centrifugal pump

D - two-support

(K) - pumps in corrosion-resistant design

(I) - wear-resistant pumps

(IR) - pumps in wear and corrosion resistant design

(P) - working bodies are made by powder metallurgy

5(5А,6) - overall group of the pump

XXX - nominal supply, m 3 / day

ХХХХ - nominal head, m

where X: - the figure is not affixed for modular design without intermediate bearings

1 - modular design with intermediate bearings

2 - built-in input module and without intermediate bearings

3 - built-in input module and with intermediate bearings

4 - built-in gas separator and without intermediate bearings

5 - built-in gas separator and with intermediate bearings

6 - single-section pumps with casing length over 5 m

8 - pumps with compression-dispersion stages and without intermediate bearings

9 - pumps with compression-dispersion stages and with intermediate bearings

10 - pumps without axial shaft support, with hydraulic protection shaft supported

10.1 - pumps without axial shaft support, with hydroprotection shaft support and with intermediate bearings

Examples of symbols for pumps of various designs:

ETsND5A-35-1450 according to TU 3665-004-00217780-98

Electric centrifugal double-support pump 5A-size without intermediate bearings, capacity 35 m 3 / day, head 1450 m

1ETsND5-80-1450 according to TU 3665-004-00217780-98

Electrocentrifugal two-bearing pump of the 5th size in a modular design with intermediate bearings, capacity 80 m 3 / day, head 1450 m

6ETsND5A-35-1100 according to TU 3665-004-00217780-98

Electric centrifugal double-support pump 5A - dimensions in single-section design with a capacity of 35 m 3 / day, head 1100 m

1.3 MNGB type gas separators

Gas separators are installed at the pump inlet instead of the inlet module and are designed to reduce the amount of free gas in the reservoir fluid entering the inlet of the submersible centrifugal pump. The gas separators are equipped with a protective sleeve that protects the gas separator body from hydroabrasive wear.

All gas separators, except for the ZMNGB version, are produced with ceramic axial shaft bearings.

Figure 2. Gas separator type MNGB

In gas separators of ZMNGB version, the axial shaft support is not installed, and the gas separator shaft rests on the hydraulic protection shaft.

Gas separators with the letter "K" in the designation are produced in a corrosion-resistant design. Technical characteristics of gas separators are given in table 3.

Table 3 Specifications

Without intermediate shaft supports
Pump size	Supply max, single-phase liquid m3/day.	Max, add. power on the shaft, kW
MNG B5	250	76	92	17	27,5	717
	300				27	848
ZMNGB5-02		95		20	27,5	848
	500	135(180 with soft start and shaft	103	22	28,5	752
					33	848
With intermediate shaft supports
	250	76	92	17	28	717

Well operation by submersible centrifugal electric pumps

2.1 General installation diagram of a submersible centrifugal electric pump

Centrifugal pumps for pumping liquid from a well are not fundamentally different from conventional centrifugal pumps used to pump liquids on the surface of the earth. However, small radial dimensions due to the diameter of the casing strings into which centrifugal pumps are lowered, practically unlimited axial dimensions, the need to overcome high heads and the operation of the pump in a submerged state led to the creation of centrifugal pumping units of a specific design. Outwardly, they are no different from a pipe, but the inner cavity of such a pipe contains a large number of complex parts that require perfect manufacturing technology.

Submersible centrifugal electric pumps (GGTsEN) are multistage centrifugal pumps with up to 120 stages in one block, driven by a submersible electric motor of a special design (SEM). The electric motor is fed from the surface with electricity supplied via a cable from a step-up autotransformer or transformer through a control station, in which all instrumentation and automation are concentrated. The PTSEN is lowered into the well under the calculated dynamic level, usually by 150 - 300 m. The fluid is supplied through the tubing, to the outer side of which an electric cable is attached with special belts. In the pump unit between the pump itself and the electric motor there is an intermediate link called a protector or hydraulic protection. The PTSEN installation (Figure 3) includes an oil-filled electric motor SEM 1; hydraulic protection link or protector 2; intake grid of the pump for fluid intake 3; multistage centrifugal pump ПЦЭН 4; tubing 5; armored three-core electric cable 6; belts for attaching the cable to the tubing 7; wellhead fittings 8; a drum for winding a cable during tripping and storing a certain supply of cable 9; transformer or autotransformer 10; control station with automation 11 and compensator 12.

Figure 3. General scheme of well equipment with installation of a submersible centrifugal pump

The pump, protector and electric motor are separate units connected by bolted studs. The ends of the shafts have splined connections, which are joined when assembling the entire installation.

If it is necessary to lift liquid from great depths, the PTSEN sections are connected to each other so that the total number of stages reaches 400. The liquid sucked in by the pump sequentially passes through all the stages and leaves the pump with a pressure equal to the external hydraulic resistance. UTSEN are distinguished by low metal consumption, a wide range of performance characteristics, both in terms of pressure and flow, a sufficiently high efficiency, the possibility of pumping large amounts of liquid and a long overhaul period. It should be recalled that the average liquid supply for Russia of one UPTsEN is 114.7 t/day, and USSSN - 14.1 t/day.

All pumps are divided into two main groups; conventional and wear-resistant design. The vast majority of the operating stock of pumps (about 95%) is of conventional design (Figure 4).

Wear-resistant pumps are designed to work in wells, in the production of which there is a small amount of sand and other mechanical impurities (up to 1% by weight). According to the transverse dimensions, all pumps are divided into 3 conditional groups: 5; 5A and 6, which is the nominal casing diameter, in inches, into which the pump can be run.

Figure 4. Typical characteristic of a submersible centrifugal pump

Group 5 has an outer case diameter of 92 mm, group 5A - 103 mm and group b - 114 mm.

The speed of the pump shaft corresponds to the frequency of the alternating current in the mains. In Russia, this frequency is 50 Hz, which gives a synchronous speed (for a two-pole machine) of 3000 min. "The PTSEN code contains their main nominal parameters, such as flow and pressure when operating in the optimal mode. For example, ESP5-40-950 means centrifugal group 5 electric pump with a flow rate of 40 m 3 /day (by water) and a head of 950 m.

In the code of wear-resistant pumps, there is the letter I, which means wear resistance. In them, impellers are made not from metal, but from polyamide resin (P-68). In the pump housing, approximately every 20 stages, intermediate rubber-metal shaft centering bearings are installed, as a result of which the wear-resistant pump has fewer stages and, accordingly, a head.

The end bearings of the impellers are not cast iron, but in the form of pressed rings made of hardened steel 40X. Instead of textolite support washers between the impellers and guide vanes, washers made of oil-resistant rubber are used.

All types of pumps have a passport operating characteristic in the form of dependence curves H(Q) (head, flow), η(Q) (efficiency, flow), N(Q) (power consumption, flow). Typically, these dependencies are given in the range of operating flow rates or in a slightly larger interval (Figure 4).

Any centrifugal pump, including the PTSEN, can operate with a closed outlet valve (point A: Q = 0; H = H max) and without counterpressure at the outlet (point B: Q = Q max ; H = 0). Since the useful work of the pump is proportional to the product of the supply to the pressure, then for these two extreme modes of operation of the pump, the useful work will be equal to zero, and, consequently, the efficiency will be equal to zero. At a certain ratio (Q and H), due to the minimum internal losses of the pump, the efficiency reaches a maximum value of approximately 0.5 - 0.6. Typically, pumps with low flow and small diameter impellers, as well as with a large number stages have a reduced efficiency. The flow and pressure corresponding to the maximum efficiency are called the optimal mode of operation of the pump. The dependence η (Q) near its maximum decreases smoothly, therefore, the operation of the PTSEN is quite acceptable in modes that differ from the optimal the limits of these deviations will depend on the specific characteristics of the PTSEN and should correspond to a reasonable decrease in the efficiency of the pump (by 3 - 5%) This determines a whole range of possible modes of operation of the PTSEN, which is called the recommended area.

The selection of a pump for wells essentially boils down to choosing such a standard size of the PTSEN so that, when lowered into wells, it operates under conditions of the optimal or recommended mode when pumping a given well flow rate from a given depth.

The pumps currently produced are designed for nominal flow rates from 40 (ETsN5-40-950) to 500 m 3 /day (ETsN6-50 1 750) and heads from 450 m -1500). In addition, there are pumps for special purposes, for example, for pumping water into reservoirs. These pumps have flow rates up to 3000 m3/day and heads up to 1200 m.

The head that a pump can overcome is directly proportional to the number of stages. Developed by one stage at the optimum operating mode, it depends, in particular, on the dimensions of the impeller, which in turn depend on the radial dimensions of the pump. With an outer diameter of the pump casing of 92 mm, the average head developed by one stage (when operating on water) is 3.86 m with fluctuations from 3.69 to 4.2 m. With an outer diameter of 114 mm, the average head is 5.76 m with fluctuations from 5.03 to 6.84 m.

2.2 Submersible pump unit

The pumping unit (Figure 5) consists of a pump, a hydraulic protection unit, a SEM submersible motor, a compensator attached to the bottom of the SEM.

The pump consists of the following parts: head 1 with a ball check valve to prevent fluid and tubing from draining during shutdowns; the upper sliding foot 2, which partially perceives the axial load due to the pressure difference at the inlet and outlet of the pump; upper plain bearing 3 centering the upper end of the shaft; pump housing 4 guide vanes 5, which are supported on each other and kept from rotation by a common coupler in the housing 4; impellers 6; pump shaft 7, which has a longitudinal key on which impellers are mounted with a sliding fit. The shaft also passes through the guide vanes of each stage and is centered in it by the impeller bushing, as in the bearing of the lower sliding bearing 8; base 9, closed with a receiving grid and having round inclined holes in the upper part for supplying liquid to the lower impeller; end plain bearing 10. In pumps of early designs that are still in operation, the device of the lower part is different. On the entire length of the base 9 there is an oil seal and: lead-graphite rings separating the receiving part of the pump and the internal cavities of the engine and hydraulic protection. A three-row angular contact ball bearing is mounted below the stuffing box, lubricated with thick oil, which is under some excess pressure (0.01 - 0.2 MPa) relative to the external one.

Figure 5. The device of the submersible centrifugal unit

a - centrifugal pump; b - hydraulic protection unit; c - submersible motor; g - compensator.

In modern ESP designs, there is no excess pressure in the hydroprotection unit, therefore, there is less leakage of liquid transformer oil, with which the SEM is filled, and the need for a lead-graphite gland has disappeared.

The cavities of the engine and the receiving part are separated by a simple mechanical seal, the pressures on both sides of which are the same. The length of the pump casing usually does not exceed 5.5 m. When the required number of stages (in pumps developing high pressures) cannot be placed in one casing, they are placed in two or three separate casings that make up independent sections of one pump, which are docked together when lowering the pump into the well.

The hydraulic protection unit is an independent unit attached to the PTSEN by a bolted connection (in the figure, the unit, like the PTSEN itself, is shown with transport plugs sealing the ends of the units).

The upper end of shaft 1 is connected by a splined coupling to the lower end of the pump shaft. Light mechanical seal 2 separates the upper cavity, which can contain well fluid, from the cavity below the seal, which is filled with transformer oil, which, like the well fluid, is under pressure equal to the pressure at the pump immersion depth. Below the mechanical seal 2 there is a sliding friction bearing, and even lower - node 3 - a bearing foot that perceives the axial force of the pump shaft. The sliding foot 3 operates in liquid transformer oil.

Below is the second mechanical seal 4 for more reliable sealing of the engine. It is not structurally different from the first. Below it is a rubber bag 5 in the body 6. The bag hermetically separates two cavities: the inner cavity of the bag filled with transformer oil, and the cavity between the body 6 and the bag itself, into which the external well fluid has access through check valve 7.

The downhole fluid through the valve 7 penetrates into the cavity of the housing 6 and compresses the rubber bag with oil to a pressure equal to the external one. Liquid oil penetrates through the gaps along the shaft to the mechanical seals and down to the PED.

Two designs of hydraulic protection devices have been developed. The hydroprotection of the main engine differs from the described hydroprotection T by the presence of a small turbine on the shaft, which creates an increased pressure of liquid oil in the internal cavity of the rubber bag 5.

The outer cavity between the housing 6 and the bag 5 is filled with thick oil, which feeds the ball angular contact bearing PTSEN of the previous design. Thus, the hydraulic protection unit of the main engine of an improved design is suitable for use in conjunction with the PTSEN of the previous types that are widely used in the fields. Previously, hydraulic protection was used, the so-called piston-type protector, in which excess pressure on the oil was created by a spring-loaded piston. New designs of the main engine and the main engine proved to be more reliable and durable. Temperature changes in the volume of oil during its heating or cooling are compensated by attaching a rubber bag - compensator to the bottom of the PED (Figure 5).

To drive the PTSEN, special vertical asynchronous oil-filled bipolar electric motors (SEMs) are used. Pump motors are divided into 3 groups: 5; 5A and 6.

Since, unlike the pump, the electric cable does not pass along the motor housing, the diametrical dimensions of the SEMs of these groups are slightly larger than those of the pumps, namely: group 5 has a maximum diameter of 103 mm, group 5A - 117 mm and group 6 - 123 mm.

The marking of the SEM includes the rated power (kW) and diameter; for example, PED65-117 means: a submersible electric motor with a power of 65 kW with a housing diameter of 117 mm, i.e. included in group 5A.

Small allowable diameters and high power (up to 125 kW) make it necessary to make engines of great length - up to 8 m, and sometimes more. The top of the PED is connected to bottom hydraulic protection unit using bolted studs. Shafts are joined by spline couplings.

The upper end of the PED shaft (figure) is suspended on the sliding heel 1, operating in oil. Below is the cable entry assembly 2. This assembly is usually a male cable connector. This is one of the most vulnerable places in the pump, due to the violation of the insulation of which the installations fail and require lifting; 3 - lead wires of the stator winding; 4 - upper radial sliding friction bearing; 5 - section of the end ends of the stator winding; 6 - stator section, assembled from stamped transformer iron plates with grooves for pulling stator wires. The stator sections are separated from each other by non-magnetic packages, in which the radial bearings 7 of the motor shaft 8 are strengthened. The lower end of the shaft 8 is centered by the lower radial sliding friction bearing 9. The SEM rotor also consists of sections assembled on the motor shaft from stamped plates of transformer iron. Aluminum rods are inserted into the slots of the squirrel-wheel type rotor, shorted by conductive rings, on both sides of the section. Between the sections, the motor shaft is centered in bearings 7. A hole with a diameter of 6–8 mm passes through the entire length of the motor shaft for oil to pass from the lower cavity to the upper one. Along the entire stator there is also a groove through which oil can circulate. The rotor rotates in liquid transformer oil with high insulating properties. In the lower part of the PED there is a mesh oil filter 10. The head 1 of the compensator (see figure, d) is attached to the lower end of the PED; bypass valve 2 serves to fill the system with oil. The protective casing 4 in the lower part has holes for transferring the external fluid pressure to the elastic element 3. When the oil cools, its volume decreases and the well fluid through the holes enters the space between the bag 3 and the casing 4. When heated, the bag expands, and the fluid through the same holes comes out of the casing.

PEDs used for the operation of oil wells usually have capacities from 10 to 125 kW.

To maintain reservoir pressure, special submersible pumping units are used, equipped with 500 kW PEDs. The supply voltage in the SEM ranges from 350 to 2000 V. At high voltages, it is possible to proportionally reduce the current when transmitting the same power, and this allows you to reduce the cross section of the cable conductors, and therefore the transverse dimensions of the installation. This is especially important for high power motors. SEM rotor slip nominal - from 4 to 8.5%, efficiency - from 73 to 84%, allowable temperatures environment - up to 100 °C.

A lot of heat is generated during the operation of the PED, so cooling is required for the normal operation of the engine. Such cooling is created due to the continuous flow of formation fluid through the annular gap between the motor housing and the casing string. For this reason, wax deposits in the tubing during pump operation are always significantly less than during other methods of operation.

Under production conditions, there is a temporary blackout of power lines due to a thunderstorm, wire breakage, due to icing, etc. This causes a stop of the UTSEN. In this case, under the influence of the liquid column flowing from the tubing through the pump, the pump shaft and the stator begin to rotate in the opposite direction. If at this moment the power supply is restored, the SEM will begin to rotate in the forward direction, overcoming the force of inertia of the liquid column and the rotating masses.

Starting currents in this case may exceed the permissible limits, and the installation will fail. To prevent this from happening, a ball check valve is installed in the discharge part of the PTSEN, which prevents the liquid from draining from the tubing.

The check valve is usually located in the pump head. The presence of a check valve complicates the lifting of the tubing during repair work, since in this case the pipes are lifted and unscrewed with liquid. In addition, it is dangerous in terms of fire. To prevent such phenomena, a drain valve is made in a special coupling above the check valve. In principle, the drain valve is a coupling, in the side wall of which a short bronze tube is inserted horizontally, sealed from the inner end. Before lifting, a short metal dart is thrown into the tubing. The blow of the dart breaks off the bronze tube, as a result of which the side hole in the sleeve opens and the liquid from the tubing drains.

Other devices have also been developed for draining the liquid, which are installed above the PTSEN check valve. These include the so-called prompters, which make it possible to measure the annulus pressure at the pump descent depth with a downhole pressure gauge lowered into the tubing, and establish communication between the annular space and the measuring cavity of the pressure gauge.

It should be noted that the engines are sensitive to the cooling system, which is created by the fluid flow between the casing string and the SEM body. The speed of this flow and the quality of the liquid affect the temperature regime of the SEM. It is known that water has a heat capacity of 4.1868 kJ/kg-°C, while pure oil is 1.675 kJ/kg-°C. Therefore, when pumping out watered well production, the conditions for cooling the SEM are better than when pumping clean oil, and its overheating leads to insulation failure and engine failure. Therefore, the insulating qualities of the materials used affect the duration of the installation. It is known that the heat resistance of some insulation used for motor windings has already been brought up to 180 °C, and operating temperatures up to 150 °C. To control the temperature, simple electrical temperature sensors have been developed that transmit information about the temperature of the SEM to the control station via a power electric cable without the use of an additional core. Similar devices are available for transmitting constant information about the pressure at the pump intake to the surface. At emergency conditions the control station automatically turns off the SEM.

2.3 Elements of the electrical equipment of the installation

The SEM is powered by electricity through a three-core cable, which is lowered into the well in parallel with the tubing. The cable is attached to the outer surface of the tubing with metal belts, two for each pipe. The cable works in difficult conditions. Its upper part is in a gaseous environment, sometimes under significant pressure, the lower part is in oil and is subjected to even greater pressure. When lowering and raising the pump, especially in deviated wells, the cable is subjected to strong mechanical stresses (clamps, friction, jamming between the string and tubing, etc.). The cable transmits electricity at high voltages. The use of high voltage motors makes it possible to reduce the current and hence the cable diameter. However, the cable for powering a high-voltage motor must also have a more reliable, and sometimes thicker, insulation. All cables used for UPTsEN are covered with an elastic galvanized steel tape on top to protect against mechanical damage. The need to place the cable along the outer surface of the PTSEN reduces the dimensions of the latter. Therefore, a flat cable is laid along the pump, having a thickness of about 2 times less than the diameter of a round one, with the same sections of conductive cores.

All cables used for UTSEN are divided into round and flat. Round cables have rubber (oil-resistant rubber) or polyethylene insulation, which is displayed in the code: KRBK means armored rubber round cable or KRBP - rubber armored flat cable. When using polyethylene insulation in the cipher, instead of a letter, P is written: KPBK - for a round cable and KPBP - for a flat one.

The round cable is attached to the tubing, and the flat cable is attached only to the lower pipes of the tubing string and to the pump. The transition from a round cable to a flat cable is spliced ​​by hot vulcanization in special molds, and if such splicing is of poor quality, it can serve as a source of insulation failure and failures. Recently, only flat cables running from the SEM along the tubing string to the control station have been switched. However, the manufacture of such cables is more difficult than round ones (Table 3).

There are some other types of polyethylene insulated cables not mentioned in the table. Cables with polyethylene insulation are 26 - 35% lighter than cables with rubber insulation. Cables with rubber insulation are intended for use at a rated voltage of electric current not exceeding 1100 V, at ambient temperatures up to 90 ° C and pressure up to 1 MPa. Cables with polyethylene insulation can operate at voltages up to 2300 V, temperatures up to 120 °C and pressures up to 2 MPa. These cables are more resistant to gas and high pressure.

All cables are armored with corrugated galvanized steel tape for strength. Characteristics of cables are given in table 4.

Cables have active and reactive resistance. The active resistance depends on the cable section and partly on the temperature.

Section, mm .......................................... 16 25 35

Active resistance, Ohm/km.......... 1.32 0.84 0.6

The reactance depends on cos 9 and with its value of 0.86 - 0.9 (as is the case with SEMs) is approximately 0.1 Ohm / km.

Table 4. Characteristics of cables used for UTSEN

Cable	Number of cores and cross-sectional area, mm 2	Outer diameter, mm	External dimensions of the flat part, mm	Weight, kg/km
NRB K	3 x 10	27,5	-	1280
	3 x 16	29,3	-	1650
	3x25	32,1	-	2140
	3x35	34,7	-	2680
CRBP	3 x 10	-	12.6 x 30.7	1050
	3 x 16	-	13.6 x 33.8	1250
	3x25	-	14.9 x 37.7	1600
CPBC	3 x 10	27,0	1016
	3 x 16	29,6	-	1269
	32,4	-	1622
	3x35	34,8	-	1961
CPBP	3x4	-	8.8 x 17.3	380
	3x6	-	9.5 x 18.4	466
	3 x 10	-	12.4 x 26.0	738
	3 x 16	-	13.6 x 29.6	958
	3x25	-	14.9 x 33.6	1282

There is a loss of electrical power in the cable, typically 3 to 15% total losses in installation. The power loss is related to the loss of voltage in the cable. These voltage losses, depending on the current, cable temperature, its cross section, etc., are calculated using the usual formulas of electrical engineering. They range from about 25 to 125 V/km. Therefore, at the wellhead, the voltage supplied to the cable must always be higher by the amount of losses compared to the rated voltage of the SEM. The possibilities for such an increase in voltage are provided in autotransformers or transformers that have several additional taps in the windings for this purpose.

The primary windings of three-phase transformers and autotransformers are always designed for the voltage of the commercial power supply, i.e. 380 V, to which they are connected through control stations. The secondary windings are designed for the operating voltage of the respective motor to which they are connected by cable. These operating voltages in various PEDs vary from 350V (PED10-103) to 2000V (PED65-117; PED125-138). To compensate for the voltage drop in the cable from the secondary winding, 6 taps are made (in one type of transformer there are 8 taps), which allow you to adjust the voltage at the ends of the secondary winding by changing the jumpers. Changing the jumper by one step increases the voltage by 30 - 60 V, depending on the type of transformer.

All non-oil-filled, air-cooled transformers and autotransformers are covered with a metal casing and are designed for installation in a sheltered place. They are equipped with an underground installation, so their parameters correspond to this SEM.

Recently, transformers have become more widespread, as this allows you to continuously control the resistance of the secondary winding of the transformer, cable and stator winding of the SEM. When the insulation resistance drops to the set value (30 kOhm), the unit automatically switches off.

With autotransformers having a direct electrical connection between the primary and secondary windings, such insulation control cannot be carried out.

Transformers and autotransformers have an efficiency of about 98 - 98.5%. Their mass, depending on the power, ranges from 280 to 1240 kg, dimensions from 1060 x 420 x 800 to 1550 x 690 x 1200 mm.

The operation of the UPTsEN is controlled by the control station PGH5071 or PGH5072. Moreover, the control station PGH5071 is used for autotransformer power supply of the SEM, and PGH5072 - for transformer. Stations PGH5071 provide instant shutdown of the installation when the current-carrying elements are shorted to the ground. Both control stations provide the following possibilities for monitoring and controlling the operation of the UTSEN.

1. Manual and automatic (remote) switching on and off of the unit.

2. Automatic switching on of the installation in the self-start mode after the restoration of the voltage supply in the field network.

3. Automatic operation of the installation in a periodic mode (pumping out, accumulation) according to the established program with a total time of 24 hours.

4. Automatic switching on and off of the unit depending on the pressure in the discharge manifold when automated systems group collection of oil and gas.

5. Instantaneous shutdown of the installation in case of short circuits and overloads in current strength by 40% exceeding the normal operating current.

6. Short-term shutdown for up to 20 s when the SEM is overloaded by 20% of the nominal value.

7. Short-term (20 s) shutdown in case of failure of the fluid supply to the pump.

The doors of the control station cabinet are mechanically interlocked with a switch block. There is a trend towards switching to non-contact, hermetically sealed control stations with semiconductor elements, which, as experience has shown, are more reliable, not affected by dust, moisture and precipitation.

Control stations are designed for installation in shed-type rooms or under a canopy (in the southern regions) at an ambient temperature of -35 to +40 °C.

The mass of the station is about 160 kg. Dimensions 1300 x 850 x 400 mm. The UPTsEN delivery set includes a drum with a cable, the length of which is determined by the customer.

During the operation of the well, for technological reasons, the depth of the pump suspension has to be changed. In order not to cut or build up the cable with such suspension changes, the cable length is taken according to the maximum suspension depth of a given pump and, at shallower depths, its excess is left on the drum. The same drum is used for winding the cable when lifting the PTSEN from the wells.

With a constant suspension depth and stable pumping conditions, the end of the cable is tucked into the junction box, and there is no need for a drum. In such cases, during repairs, a special drum is used on a transport trolley or on a metal sledge with a mechanical drive for constant and uniform pulling of the cable extracted from the well and winding it onto the drum. When the pump is lowered from such a drum, the cable is evenly fed. The drum is electrically driven with reverse and friction to prevent dangerous tensions. At oil producing enterprises with a large number of ESPs, a special transport unit ATE-6 based on the KaAZ-255B cargo all-terrain vehicle is used to transport a cable drum and other electrical equipment, including a transformer, pump, engine and hydraulic protection unit.

For loading and unloading the drum, the unit is equipped with folding directions for rolling the drum onto the platform and a winch with a pulling force on the rope of 70 kN. The platform also has a hydraulic crane with a lifting capacity of 7.5 kN with an outreach of 2.5 m. Typical wellhead fittings equipped for PTSEN operation (Figure 6) consist of a crosspiece 1, which is screwed onto the casing string.

Figure 6—Wellhead fittings equipped with PTSEN

The cross has a detachable insert 2, which takes the load from the tubing. A seal made of oil-resistant rubber 3 is applied to the liner, which is pressed by a split flange 5. Flange 5 is pressed by bolts to the flange of the cross and seals the cable outlet 4.

The fittings provide for the removal of annular gas through the pipe 6 and the check valve 7. The fittings are assembled from unified units and stopcocks. It is relatively easy to rebuild for wellhead equipment when operating with sucker rod pumps.

2.4 Installation of a special-purpose PTSEN

Submersible centrifugal pumps are used not only for the operation of production wells. They find a use.

1. In water intake and artesian wells for supply industrial water PPD systems and for household purposes. Usually these are pumps with high flows, but with low pressures.

2. In reservoir pressure maintenance systems, when using reservoir high-pressure waters (Albian-Cenomanian reservoir waters in the Tyumen region) when equipping water wells with direct injection of water into neighboring injection wells (underground cluster pumping stations). For these purposes, pumps with an outer diameter of 375 mm, a flow rate of up to 3000 m 3 / day and a head of up to 2000 m are used.

3. For in-situ reservoir pressure maintenance systems when pumping water from the lower aquifer, the upper oil reservoir or from the upper aquifer to the lower oil reservoir through one well. For this purpose, the so-called inverted pumping units are used, which have an engine in the upper part, then a hydraulic protection and a centrifugal pump at the very bottom of the sag. This arrangement leads to significant design changes, but it turns out to be necessary for m technological reasons.

4. Special arrangements of the pump in housings and with overflow channels for simultaneous, but separate operation of two or more layers by one well. Such designs are essentially adaptations of known elements of a standard installation of a submersible pump for operation in a well in combination with other equipment (gas lift, SHSN, PTSEN fountain, etc.).

5. Special installations of submersible centrifugal pumps on a cable-rope. The desire to increase the radial dimensions of the ESP and improve its technical characteristics, as well as the desire to simplify tripping when replacing the ESP, led to the creation of installations lowered into the well on a special cable-rope. The cable-rope withstands a load of 100 kN. It has a continuous two-layer (crosswise) outer braid of strong steel wires wrapped around a three-core electric cable, which is used to power the SEM.

The scope of PTSEN on a cable-rope, both in terms of pressure and flow, is wider than pumps lowered on pipes, since an increase in the radial dimensions of the engine and pump due to the elimination of the side cable with the same column sizes can significantly improve the technical characteristics of the units. At the same time, the use of PTSEN on a cable-rope according to the scheme of pipeless operation also causes some difficulties associated with paraffin deposits on the walls of the casing string.

The advantages of these pumps, which have the code ETsNB, which means tubeless (B) (for example, ETsNB5-160-1100; ETsNB5A-250-1050; ETsNB6-250-800, etc.) should include the following.

1. Better use of casing cross section.

2. Almost complete elimination of hydraulic pressure losses due to friction in the lifting pipes due to their absence.

3. The increased diameter of the pump and electric motor allows you to increase the pressure, flow and efficiency of the unit.

4. Possibility of complete mechanization and reduction in the cost of work on underground well repair when changing the pump.

5. Reducing the metal consumption of the installation and the cost of equipment due to the exclusion of tubing, due to which the mass of equipment lowered into the well is reduced from 14 - 18 to 6 - 6.5 tons.

6. Reducing the likelihood of damage to the cable during tripping operations.

Along with this, it is necessary to note the disadvantages of pipeless PTSEN installations.

1. More difficult conditions operation of equipment under pump discharge pressure.

2. The cable-rope along its entire length is in the liquid pumped out of the well.

3. The hydraulic protection unit, the motor and the cable-rope are not subject to the intake pressure, as in conventional installations, but to the pump discharge pressure, which significantly exceeds the intake pressure.

4. Since the liquid rises to the surface along the casing string, when paraffin is deposited on the walls of the string and on the cable, it is difficult to eliminate these deposits.

Figure 7. Installation of a submersible centrifugal pump on a cable-rope: 1 - slip packer; 2 - receiving grid; 3 - valve; 4 - landing rings; 5 - check valve, 6 - pump; 7 - SED; 8 - plug; 9 - nut; 10 - cable; 11 - cable braid; 12 - hole

Despite this, cable-rope installations are used, and there are several sizes of such pumps (figure 7).

To the estimated depth, the slip packer 1 is first lowered and fixed on the inner walls of the column, which perceives the weight of the liquid column above it and the weight of the submersible unit. The pumping unit assembled on a cable-rope is lowered into the well, put on the packer and compacted in it. At the same time, the nozzle with the receiving screen 2 passes through the packer and opens the check valve 3 of the poppet type, which is located in the lower part of the packer.

When planting the unit on the packer, sealing is achieved by touching the landing rings 4. Above the landing rings, in the upper part of the suction pipe, there is a check valve 5. Above the valve, a pump 6 is placed, then a hydraulic protection unit and a SEM 7. There is a special three-pole coaxial plug in the upper part of the engine 8, on which the connecting lug of the cable 10 is tightly fitted and fixed with a union nut 9. The load-bearing wire braid of the cable 11 and electric conductors connected to the slip rings of the docking plug device are loaded in the lug.

The liquid supplied by the PTSEN is ejected through holes 12 into the annular space, partially cooling the SEM.

At the wellhead, the cable-rope is sealed in the wellhead gland of the valve and its end is connected through a conventional control station to the transformer.

The installation is lowered and raised using a cable drum located on the chassis of a specially equipped heavy all-terrain vehicle (unit APBE-1.2 / 8A).

Time of descent of installation on depth of 1000 m - 30 min., rise - 45 min.

When lifting the pumping unit out of the well, the suction pipe comes out of the packer and allows the poppet valve to slam shut. This allows lowering and raising the pumping unit in flowing and semi-flowing wells without first killing the well.

The number of stages in the pumps is 123 (UETsNB5A-250-1050), 95 (UETsNB6-250-800) and 165 (UETsNB5-160-1100).

Thus, by increasing the diameter of the impellers, the pressure developed by one stage is 8.54; 8.42 and 6.7 m. This is almost twice as much as conventional pumps. Engine power 46 kW. The maximum efficiency of pumps is 0.65.

As an example, Figure 8 shows the operating characteristics of the UETsNB5A-250-1050 pump. For this pump, the working area is recommended: flow Q \u003d 180 - 300 m 3 / day, head H \u003d 1150 - 780 m. The mass of the pump assembly (without cable) is 860 kg.

Figure 8. Operating characteristics of the ETsNB5A 250-1050 submersible centrifugal pump, lowered on a cable rope: H - head characteristic; N - power consumption; η - efficiency factor

2.5 Determining the depth of the PTSEN suspension

The pump suspension depth is determined by:

1) the depth of the dynamic level of the liquid in the well H d during the selection of a given amount of liquid;

2) the depth of immersion of the PTSEN under the dynamic level H p, the minimum necessary to ensure the normal operation of the pump;

3) backpressure at the wellhead Р y, which must be overcome;

4) head loss to overcome the friction forces in the tubing when the flow h tr;

5) the work of the gas released from the liquid H g, which reduces the required total pressure. Thus, one can write:

(1)

Essentially, all terms in (1) depend on the selection of fluid from the well.

The depth of the dynamic level is determined from the inflow equation or from the indicator curve.

If the inflow equation is known

(2)

then, solving it with respect to the pressure at the bottomhole P c and bringing this pressure into a liquid column, we get:

(3)

(4)

Or. (5)

Where. (6)

where p cf - the average density of the liquid column in the well from the bottom to the level; h is the height of the liquid column from the bottom to the dynamic level vertically.

Subtracting h from the depth of the well (to the middle of the perforation interval) H s, we obtain the depth of the dynamic level H d from the mouth

If the wells are inclined and φ 1 is the average angle of inclination relative to the vertical in the section from the bottom to the level, and φ 2 is the average angle of inclination relative to the vertical in the section from the level to the mouth, then corrections must be made for the curvature of the well.

Taking into account the curvature, the desired H d will be equal to

(8)

Here H c is the depth of the well, measured along its axis.

The value of H p - immersion under the dynamic level, in the presence of gas is difficult to determine. This will be discussed a little further. As a rule, H p is taken such that at the inlet of the PTSEN, due to the pressure of the liquid column, the gas content β of the flow does not exceed 0.15 - 0.25. In most cases, this corresponds to 150 - 300 m.

The value of P y /ρg is the wellhead pressure expressed in meters of liquid column with density ρ. If the well production is flooded and n is the proportion of water per unit volume of well production, then the fluid density is determined as the weighted average

Here ρ n, ρ n are the densities of oil and water.

The value of P y depends on the oil and gas gathering system, the remoteness of a given well from separation points, and in some cases can be a significant value.

The value of h tr is calculated using the usual formula for pipe hydraulics

(10)

where C is the linear flow velocity, m/s,

(11)

Here Q H and Q B - the flow rate of marketable oil and water, m 3 /day; b H and b B - volumetric coefficients of oil and water for the average thermodynamic conditions existing in the tubing; f - cross-sectional area of ​​tubing.

As a rule, h tr is a small value and is approximately 20 - 40 m.

The value of Hg can be determined quite accurately. However, such a calculation is complex and, as a rule, is carried out on a computer.

Let's give a simplified calculation of the process of movement of GZhS in the tubing. At the pump outlet, the liquid contains dissolved gas. When the pressure decreases, the gas is released and contributes to the rise of the liquid, thereby reducing the required pressure by the value H g. For this reason, H g enters the equation with a negative sign.

The value of Hg can be approximately determined by the formula following from the thermodynamics of ideal gases, similarly to how it can be done when taking into account the work of gas in the tubing in a well equipped with SSN.

However, during the operation of the PTSEN, in order to take into account the higher productivity compared to the SSN and lower slip losses, higher values ​​of the efficiency factor can be recommended to assess the efficiency of the gas.

When extracting pure oil, η = 0.8;

With watered oil 0.2< n < 0,5 η = 0,65;

With heavily watered oil 0.5< n < 0,9 η = 0,5;

In the presence of actual pressure measurements at the ESP outlet, the value of η can be refined.

To match the H(Q) characteristics of the ESP with the conditions of the well, the so-called pressure characteristic of the well is built (Figure 9) depending on its flow rate.

(12)

Figure 9 shows the curves of the terms in the equation from the flow rate of the well and determining the resulting pressure characteristic of the well H well (2).

Figure 9—Head characteristics of the well:

1 - depth (from the mouth) of the dynamic level, 2 - the required head, taking into account the pressure on the wellhead, 3 - the necessary head, taking into account friction forces, 4 - the resulting head, taking into account the "gas-lift effect"

Line 1 is the dependence of H d (2), determined by the formulas given above and is plotted from points for various arbitrarily chosen Q. Obviously, at Q = 0, H D = H ST, i.e., the dynamic level coincides with the static level. Adding to N d the value of the buffer pressure, expressed in m of the liquid column (P y /ρg), we get line 2 - the dependence of these two terms on the flow rate of the well. Calculating the value of h TP by the formula for different Q and adding the calculated h TP to the ordinates of line 2, we get line 3 - the dependence of the first three terms on the well flow rate. Calculating the value of H g by the formula and subtracting its value from the ordinates of line 3, we obtain the resulting line 4, called the pressure characteristic of the well. H(Q) is superimposed on the pressure characteristic of the well - the characteristic of the pump to find the point of their intersection, which determines such a flow rate of the well, which will be equal to the flow. PTSEN during the combined operation of the pump and the well (Figure 10).

Point A - the intersection of the characteristics of the well (Figure 11, curve 1) and PTSEN (Figure 11, curve 2). The abscissa of point A gives the flow rate of the well when the well and the pump are working together, and the ordinate is the head H developed by the pump.

Figure 10—Coordination of the pressure characteristic of the well (1) with H(Q), characteristic of the PTSEN (2), 3 - efficiency line.

Figure 11—Coordination of the pressure characteristic of the well and PTSEN by removing steps

In some cases, to match the characteristics of the well and the PTSEN, the back pressure at the wellhead is increased using a choke or the extra working stages in the pump are removed and replaced with guide inserts (Figure 12).

As you can see, the point A of the intersection of the characteristics turned out in this case outside the shaded area. Wanting to ensure the operation of the pump in the mode η max (point D), we find the pump flow (well flow rate) Q CKB corresponding to this mode. The head developed by the pump when supplying Q CKB in the mode η max is determined by point B. In fact, under these operating conditions, the required head is determined by point C.

The difference BC = ΔH is the excess head. In this case, it is possible to increase the pressure at the wellhead by ΔР = ΔH p g by installing a choke or remove part of the pump operating stages and replace them with liners. The number of pump stages to be removed is determined from a simple ratio:

Here Z o - the total number of stages in the pump; H o is the pressure developed by the pump at the full number of stages.

From an energy point of view, drilling at the wellhead to match the characteristics is unfavorable, since it leads to a proportional decrease in the efficiency of the installation. Removing steps allows you to keep the efficiency at the same level or even slightly increase it. However, it is possible to disassemble the pump and replace the working stages with liners only in specialized workshops.

With the above-described matching of the characteristics of the pump well, it is necessary that the H(Q) characteristic of the PTSEN correspond to the actual characteristic when it operates on a well fluid of a certain viscosity and at a certain gas content at the intake. The passport characteristic H(Q) is determined when the pump is running on water and, as a rule, is overestimated. Therefore, it is important to have an actual PTSEN characterization before matching it with the well characterization. The most reliable method of obtaining actual characteristic pump - this is its bench tests on the well fluid at a given percentage of water cut.

Determining the depth of the PTSEN suspension using pressure distribution curves.

The depth of the pump suspension and the operating conditions of the ESP both at the intake and at its discharge are quite simply determined using the pressure distribution curves along the wellbore and tubing. It is assumed that the methods for constructing pressure distribution curves P(x) are already known from the general theory of the movement of gas-liquid mixtures in tubing.

If the flow rate is set, then from the formula (or by the indicator line) the bottom hole pressure P c corresponding to this flow rate is determined. From the point P = P c, a graph of the pressure distribution (in steps) P (x) is plotted according to the “bottom-up” scheme. The P(x) curve is constructed for a given flow rate Q, gas factor G o and other data, such as the density of liquid, gas, gas solubility, temperature, liquid viscosity, etc., taking into account that the gas-liquid mixture moves from the bottom over the entire section casing string.

Figure 12. Determining the depth of the PTSEN suspension and its operating conditions by plotting pressure distribution curves: 1 - P(x) - built from the point Pc; 2 - p(x) - gas content distribution curve; 3 - P(x), built from the point Ru; ΔР - pressure difference developed by PTSEN

Figure 12 shows the pressure distribution line P(x) (line 7), built from the bottom up from the point with coordinates P c, H.

In the process of calculating the values ​​of P and x in steps, the values ​​of the consumption gas saturation p are obtained as an intermediate value for each step. Based on these data, starting from the bottomhole, it is possible to construct a new p(x) curve (Figure 12, curve 2). When the bottomhole pressure exceeds the saturation pressure P c > P us, the line β (x) will have as its origin a point lying on the y-axis above the bottom, i.e. at the depth where the pressure in the wellbore will be equal to or less than P us .

At R s< Р нас свободный газ будет присутствовать на забое и поэтому функция β(х) при х = Н уже будет иметь некоторое положительное значение. Абсцисса точки А будет соответствовать начальной газонасыщенности β на забое (х = Н).

With a decrease in x, β will increase as a result of a decrease in pressure.

The construction of the P(x) curve should be continued until this line 1 intersects with the y-axis (point b).

Having completed the described constructions, i.e., having built lines 1 and 2 from the bottom of the well, they begin to plot the pressure distribution curve P(x) in the tubing from the wellhead, starting from the point x = 0 P = P y, according to the “top-down” scheme step by step according to any method and in particular according to the method described in the general theory of the movement of gas-liquid mixtures in pipes (Chapter 7) The calculation is performed for a given flow rate Q, the same gas factor G o and other data necessary for the calculation.

However, in this case, the P(x) curve is calculated for the movement of the hydraulic fluid along the tubing, and not along the casing, as in the previous case.

In Figure 12, the function P(x) for the tubing, built from top to bottom, is shown by line 3. Line 3 should be continued down either to the bottomhole, or to such values ​​of x at which the gas saturation β becomes sufficiently small (4 - 5%) or even equal to zero.

The field lying between lines 1 and 3 and limited by horizontal lines I - I and II - II determines the area of ​​possible operating conditions for the PTSEN and the depth of its suspension. The horizontal distance between lines 1 and 3 on a certain scale determines the pressure drop ΔР, which the pump must inform the flow in order for the well to work with a given flow rate Q, bottom hole pressure Р c and wellhead pressure Р у.

The curves in Figure 12 can be supplemented by temperature distribution curves t(x) from the bottom to the depth of the pump suspension and from the wellhead also to the pump, taking into account the temperature jump (distance in - e) at the depth of the PTSEN suspension, which comes from the thermal energy released by the engine and pump . This temperature jump can be determined by equating the loss of mechanical energy in the pump and the electric motor to the increment in the thermal energy of the flow. Assuming that the transition of mechanical energy into thermal energy occurs without loss to the environment, it is possible to determine the increment in the temperature of the liquid in the pumping unit.

(14)

Here c is the specific mass heat capacity of the liquid, J/kg-°C; η n and η d - k.p.d. pump and motor, respectively. Then the temperature of the liquid leaving the pump will be equal to

t \u003d t pr + ΔР (15)

where t pr is the temperature of the liquid at the pump intake.

If the PTSEN operating mode deviates from the optimal efficiency, the efficiency will decrease and the heating of the liquid will increase.

In order to choose the standard size of the PTSEN, it is necessary to know the flow rate and pressure.

When plotting P(x) curves (figure), the flow rate must be specified. The pressure drop at the outlet and intake of the pump at any depth of its descent is defined as the horizontal distance from line 1 to line 3. This pressure drop must be converted into a head, knowing average density liquid ρ in the pump. Then the pressure will

Fluid density ρ at watered well production is determined as a weighted average taking into account the densities of oil and water under the thermodynamic conditions of the pump.

According to the test data of the PTSEN, when operating on a carbonated liquid, it was found that when the gas content at the pump intake is 0< β пр < 5 - 7% напорная характеристика практически не изменяется. При β пр >5 - 7% head characteristics deteriorate and the calculated head must be corrected. When β pr, reaching up to 25 - 30%, there is a failure of the pump supply. The auxiliary curve P(x) (Figure 12, line 2) allows you to immediately determine the gas content at the pump intake at different depths of its descent.

The flow and the required pressure determined from the graphs must correspond to the selected size of the PTSEN when it is operating at the optimal or recommended modes.

3. Selection of a submersible centrifugal pump

Select a submersible centrifugal pump for forced liquid withdrawal.

Well depth H well = 450 m.

The static level is considered from the mouth h s = 195 m.

Permissible pressure period ΔР = 15 atm.

Productivity coefficient K = 80 m 2 / day atm.

The liquid consists of water with 27% oil γ w = 1.

The exponent in the fluid inflow equation is n = 1.

The diameter of the bypass column is 300 mm.

There is no free gas in the pumped well, as it is taken from the annular space by vacuum.

Let us determine the distance from the wellhead to the dynamic level. Pressure drop expressed in meters of liquid column

ΔР \u003d 15 atm \u003d 15 x 10 \u003d 150 m.

Dynamic level distance:

h α \u003d h s + ΔР \u003d 195 + 150 \u003d 345 m (17)

Find the required pump capacity from the inflow pressure:

Q \u003d KΔP \u003d 80 x 15 - 1200 m 3 / day (18)

For better operation of the pump, we will operate it with a certain period of pump selection by 20 m under the dynamic liquid level.

In view of the significant flow rate, we accept the diameter of the lifting pipes and the flow line as 100 mm (4"").

The pump head in the working area of ​​the characteristic must provide the following condition:

H N ≥ H O + h T + h "T (19)

where: N N - the required pump head in m;

H O is the distance from the wellhead to the dynamic level, i.e. height of liquid rise in m;

h T - friction head loss in pump pipes, in m;

h "T - the head required to overcome the resistance in the flow line on the surface, in m.

The conclusion of the diameter of the pipeline is considered correct if the pressure along its entire length from the pump to the receiving tank does not exceed 6-8% of the total pressure. Total pipeline length

L \u003d H 0 +1 \u003d 345 + 55 \u003d 400 m (20)

The pressure loss for the pipeline is calculated by the formula:

h T + h "T \u003d λ / dv 2 / 2g (21)

where: λ ≈ 0.035 – drag coefficient

g \u003d 9.81 m / s - acceleration of gravity

V \u003d Q / F \u003d 1200 x 4 / 86400 x 3.14 x 0.105 2 \u003d 1.61 m / s fluid velocity

F \u003d π / 4 x d 2 \u003d 3.14 / 4 x 0.105 2 - cross-sectional area of ​​\u200b\u200b100 mm pipe.

h T + h "T \u003d 0.035 x 400 / 0.105 x 1.61 / 2 x 9.8 \u003d 17.6 m. (22)

Required pump head

H H \u003d H O + h T + h "T \u003d 345 + 17.6 \u003d 363 m (23)

Let's check the correct choice of 100 mm (4 "") pipes.

h T + h "T / N H x 100 = 17.6 x 100/363 = 48%< 6 % (24)

The condition regarding the diameter of the pipeline is observed, therefore, 100 mm pipes are chosen correctly.

By pressure and performance, we select the appropriate pump. The most satisfying is the unit under the brand name 18-K-10, which means: the pump consists of 18 stages, its motor has a power of 10x20 = 200 hp. = 135.4 kW.

When powered by current (60 periods per second), the motor rotor on the stand gives n 1 = 3600 rpm and the pump develops a capacity of up to Q = 1420 m 3 / day.

We recalculate the parameters of the selected unit 18-K-10 for a non-standard AC frequency - 50 periods per minute: n \u003d 3600 x 50/60 \u003d 300 rpm.

For centrifugal pumps, performance is referred as the number of revolutions Q \u003d n / n 1, Q \u003d 3000/3600 x 1420 \u003d 1183 m 3 / day.

Since the pressures are related as the squares of the revolutions, then at n = 3000 rpm the pump will provide a pressure.

H "H \u003d n 2 / n 1 x 427 \u003d 3000/3600 x 427 \u003d 297 m (25)

To obtain the required number H H = 363 m, it is necessary to increase the number of pump stages.

The head developed by one pump stage is n = 297/18 = 16.5 m. With a small margin, we take 23 steps, then the brand of our pump will be 23-K-10.

The pressure of adapting pumps to individual conditions in each well is recommended by the instruction.

The working lobe with a capacity of 1200 m 3 /day is located at the intersection of the outer curve and the pipeline characteristic curve. Continuing the perpendicular upwards, we find the value of the efficiency of the unit η = 0.44: cosφ = 0.83 of the electric motor. Using these values, we will check the power consumed by the electric motor of the unit from the AC network N = Q LV x 1000/86400 x 102 η x cosφ = 1200 x 363 x 1000/86400 x 102 x 0.44 x 0.83 = 135.4 kW. In other words, the electric motor of the unit will be loaded with power.

4. Labor protection

At the enterprises, a schedule for checking the tightness of flange joints, fittings and other sources of possible hydrogen sulfide emissions is drawn up and approved by the chief engineer.

Pumps with double mechanical seals or with electromagnetic couplings should be used for pumping hydrogen sulfide-containing media.

Waste water from oil, gas and gas condensate treatment plants must be treated, and if the content of hydrogen sulfide and other harmful substances is higher than the MPC, neutralization.

Prior to opening and depressurization of process equipment, it is necessary to take measures to decontaminate pyrophoric deposits.

Before inspection and repair, containers and apparatus must be steamed and washed with water to prevent spontaneous combustion of natural deposits. For the deactivation of pyrophoric compounds, measures should be taken using foam systems based on surfactants or other methods that wash the apparatus systems from these compounds.

In order to avoid spontaneous combustion of natural deposits, during repair work, all components and parts of process equipment must be moistened with technical detergent compositions (TMS).

If there is a gas and product with a large geometric volume at the production facilities, it is necessary to section them by automatic valves, ensuring the presence in each section under normal operating conditions of no more than 2000 - 4000 m 3 of hydrogen sulfide.

In indoor installations and industrial sites where hydrogen sulfide can be released into the air working area, constant monitoring of the air environment and signaling dangerous concentrations of hydrogen sulfide should be carried out.

The installation location of the sensors of stationary automatic gas detectors is determined by the field development project, taking into account the density of gases, the parameters of the variable equipment, its location and the recommendations of suppliers.

Control over the state of the air environment on the territory of field facilities should be automatic with the output of sensors to the control room.

Measurements of the concentration of hydrogen sulfide by gas analyzers at the facility should be carried out according to the schedule of the enterprise, and in emergency situations- gas rescue service with the results recorded in a log.

Conclusion

Installations of submersible centrifugal pumps (ESPs) for oil production from wells are widely used in wells with a large flow rate, so it is not difficult to choose a pump and an electric motor for any large capacity.

The Russian industry produces pumps with a wide range of performance, especially since the performance and height of the liquid from the bottom to the surface can be adjusted by changing the number of pump sections.

The use of centrifugal pumps is possible at different flow rates and pressures due to the “flexibility” of the characteristic, however, in practice, the pump flow should be inside the “working part” or “working zone” of the pump characteristic. These working parts of the characteristic should provide the most economical modes of operation of installations and minimal wear of pump parts.

The Borets company manufactures complete sets of submersible electric centrifugal pumps of various configurations that meet world standards, designed for operation in any conditions, including those complicated with a high content of mechanical impurities, gas content and temperature of the pumped liquid, it is recommended for wells with a high GOR and unstable dynamic level, successfully resist the deposition of salts.

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