A submersible asynchronous electric motor is used to drive an electric centrifugal pump; the electric motor rotates the pump shaft on which the stages are located.
The principle of operation of the pump can be represented as follows: the liquid sucked through the receiving filter enters the blades of the rotating impeller, under the influence of which it acquires speed and pressure. To convert kinetic energy into pressure energy, the liquid leaving the impeller is directed into fixed channels of variable cross-section of the working apparatus connected to the pump body, then the liquid leaving the working apparatus enters the impeller of the next stage and the cycle is repeated. Centrifugal pumps are designed for high shaft rotation speed.
The pump is usually started with the valve on the discharge pipe closed (the pump consumes the least power). After the pump starts, the valve is opened.
When designing submersible pumps for oil production their stages are subject to special requirements: despite their limited dimensions, they must develop high pressures, be easy to assemble, and have high reliability.
In multi-stage submersible pumps, a stage design is adopted with a “floating” impeller, freely moving along the shaft, secured only with a key to absorb torque. The axial force generated in each impeller is transmitted to the corresponding guide vane and is further absorbed by the pump housing. This stage design allows you to assemble a large number of impellers on a very thin shaft (17 - 22 mm).
To reduce the friction force, the guide vane is equipped with an annular shoulder the required height and width, and the impeller - a support washer (usually made of textolite). The latter, being also a kind of seal, helps reduce the flow of liquid into the stages. Considering that in some operating modes of the pump (for example, during startup with an open valve, with Hst close to zero) axial forces can be directed upward and the wheels can float up, to reduce the friction force between the upper disk of the impeller and the guide vane, an intermediate a washer made of textolite, but of smaller thickness.
Depending on the working conditions, various materials are used for the manufacture of steps. Typically, the impellers and guide vanes of submersible electric pumps are made by casting from special alloy cast iron followed by machining. The condition of the surfaces and the geometry of the flow channels of the impeller and guide vane significantly affect the characteristics of the stage. With an increase in roughness, the pressure and efficiency of the stage decrease significantly, therefore, when casting the working parts of an ESP, it is necessary to achieve the required quality of the surfaces of the flow channels.
ESPs, depending on the transverse diameter of the engine, are conventionally divided into 3 groups: ESP5 (103 mm), ESP5A (117 mm), ESP6 (123 mm). The outer diameter of the ESP allows them to be lowered into wells with a minimum internal diameter of the production casing: ESP5 - 121.7 mm; UETSN5A – 130 mm; ESP6 - 144.3 mm.
The symbol of the pump (standard version) is ETsNM5 50-1300, where
E-drive from a submersible motor; C-centrifugal; H-pump; M-modular; 5 - pump group (nominal well diameter in inches); 50 - supply, m3/day; 1300 - head, m.
For corrosion-resistant pumps, the letter “K” is added before the designation of the pump group. For wear-resistant pumps, the letter “I” is added before the designation of the pump group.
Designation of the engine PEDU 45(117), where P – submersible; ED – electric motor; U – universal; 45 - power in kW; 117 - outer diameter, in mm.
For two-section engines, the letter “C” is added after the letter “U”
Symbol of hydraulic protection: Protector 1G-51, compensator GD-51, where
G – water protection; D – diaphragm.
Designation of ESP "REDA"
Symbol of the pump (standard version) DN-440 (268 stages).
Series 387, where DN is working bodies made of NI-RESIST (an alloy of iron and nickel); 440 - supply in barrels/day; 268 - number of working stages; 387 is the outer diameter of the case in inches.
For wear-resistant pumps after the ARZ flow rate (abrasion-resistant zirconium).
Symbol of the electric motor 42 HP - power in horsepower; 1129 - Rated voltage in volts; 23 - rated current in amperes; series 456 - outer diameter of the case in inches.
Hydraulic protection symbol: LSLSL and BSL. L – labyrinth; B – reservoir; P - parallel connection; S - serial connection.
Reasons for failures of domestic ESPs.
In NGDU Nizhnesortymskneft, more than half (52%) of the operating stock and 54.7% of the producing well stock with ESP are in the Bitemskoye field.
In NGDU, including Kamynskoye, Ulyanovskoye, Bitemskoye, Muryaunskoye, North-Labatyuganskoye and other fields, in 2013 there were 989 failures of domestically produced ESPs.
MTBF percentage is:
from 30 to 180 days - 331 ESP failures (91%)
over 180 days - 20 ESP failures (5.5%)
over a year - 12 ESP failures (3.5%).
Table 2. Causes of failures of domestic ESPs expressed as a percentage.
| Rejection reason | Number of failures | Percentage |
| violation of operating conditions leakage of tubing, lack of release of ESP insufficient inflow poor-quality repair of the main protection system poor-quality repair of the motor motor poor-quality start-up poor-quality equipment of the ESP poor-quality installation of the ESP poor-quality preparation of wells poor-quality operation of wells unreasonable lifting unstable power supply defects in the manufacture of the cable coupling high gas factor poor-quality repair of the main protection device design flaw of the ESP mechanical damage cable mechanical impurities poor-quality killing solution poor-quality operation in periodic mode salt deposition increased EHF content decrease in cable insulation excess curvature poor-quality repair of civil protection decreased insulation of motor drives | 0.64 3.8 2.3 5.7 2.8 0.31 7.32 0.64 0.31 0.95 2.54 0.64 0.64 2.8 1.2 0.64 2.22 1.91 8.7 0.64 6.59 9.55 7.32 23.3 0.95 2.3 |
At the Kamynskoye, Ulyanovskoye, Bitemskoye, Muryaunskoye, Severo-Labatyuganskoye and other fields, REDA submersible electric centrifugal pumps began to be introduced in May 1995. Currently, as of 01/01/2013, the stock of oil wells equipped with ESP “REDA” in the Kamynskoye, Ulyanovskoye, Bitemskoye, Muryaunskoye, Severo-Labatyuganskoye and other fields is:
Operating stock - 735 wells
Operating stock - 558 wells
Product-producing fund - 473 wells
Idle stock - 2 wells
Inactive fund - 2 wells
In percentage terms it looks like this:
non-performing fund - 0.85%
idle fund - 0.85%
dormant fund - 0.85%
The depth of the pumps is from 1700 to 2500 meters. DN-1750 are operated with flow rates of 155...250 m 3 /day, with dynamic levels of 1700...2000 meters, DN-1300 are operated with flow rates of 127...220 m 3 /day, with dynamic levels of 1750...2000 meters , DN-1000 are operated with flow rates of 77...150 m 3 /day, with dynamic levels of 1800...2100 meters,
DN-800 with flow rates of 52...120 m 3 /day, with dynamic levels of 1850...2110 meters, DN-675 with flow rates of 42...100 m 3 /day, with dynamic levels of 1900...2150 meters, DN-610 with flow rates of 45...100 m 3 /day, with dynamic levels of 1900...2100 meters, DN-440 with flow rates of 17...37 m 3 /day, with dynamic levels of 1900...2200 meters.
The temperature in the ESP suspension area is 90...125 degrees Celsius. Water cut of well production is 0...70%.
Causes of failures of the REDA ESP.
Table 3. Causes of failures of the REDA ESP expressed as a percentage.
Brief Analysis reasons for failures of the REDA ESP.
The first place among the reasons for repeated repairs of the REDA ESP is jamming due to salt deposits, which accounts for 35% of all repairs. Greater sensitivity to salt clogging of installations is due to their design features. Obviously, the impellers have less clearance and greater centrifugal curvature. This appears to promote and accelerate the scale deposition process.
Mechanical damage to the cable can only be explained by faulty work of the control crews during hoisting operations. All refusals for this reason are premature.
Leakage of the tubing due to poor quality delivery of the pipe by the manufacturer.
Reduced cable insulation resistance - in the cable splice (burnout), where an unleaded REDALENE cable was used.
The decrease in inflow is explained by a decrease in reservoir pressure.
In sixth place are failures due to increased EHF, but this does not mean that REDA ESPs are not afraid of mechanical impurities. This is explained by the fact that such ESP installations are operated in wells with an acceptable concentration of mechanical impurities, in other words, they operate in “greenhouse conditions”, because the cost of REDA installations is very high (more than 5 times higher than domestic installations).
A decrease in motor insulation resistance is an electrical breakdown of the stator winding due to motor overheating or formation fluid entering the motor cavity.
Stops for geological and technical geological and technical measures (transfer to pressure maintenance, for hydraulic fracturing, etc.)
High-pressure installations operating at low dynamic levels identified the problem of gas release practically under reservoir conditions, which negatively affected the operation of the ESP (by the way, which is confirmed by the operation of high-pressure domestic ESPs), therefore, in the future, they refuse to launch high-pressure ESPs at the oil and gas production department "NSN" fields. Work is currently underway to test return flow casings. It is too early to talk about test results. Technological services have begun to make wider use of fittings.
In conclusion, I would like to note that imported ESPs are much more stable for operation in difficult conditions. This is clearly expressed by the results of comparison of ESPs of domestic and imported production. Moreover, both have their advantages and disadvantages.
Rod deep pumping units. Shsnu diagrams, new plunger pump drives. Operation of wells by other methods: GPN, EDP, EVN, ShVNU, etc. Composition of equipment. Advantages and disadvantages of these extraction methods.
One of the most common methods of mechanized oil production today is the rod pumping method, which is based on the use of a well rod pumping unit(USSHN) for lifting liquid from oil wells.
USSHN (Fig. 13) consists of a pumping machine, wellhead equipment, a tubing string suspended on a faceplate, a sucker rod string, a sucker rod pump (SRP) of an inserted or non-inserted type.
The borehole pump is driven by a pumping machine. Rotational movement, received from the engine using a gearbox, crank mechanism and balancer, is converted into reciprocating motion transmitted to the plunger well pump suspended on rods. This ensures that fluid rises from the well to the surface.
Principle of operation
Conventional deep-well pumps, according to their operating principle, are classified as single-action plunger pumps. Below is a diagram of the pumping process with a deep-well pump (Fig. 14). Initial situation: the pump and tubing are filled with liquid. The plunger is at top dead center O.T.; plunger valve is closed. The load of the liquid column above the pump is taken by the sucker rods. When the flow of liquid from below, through the suction valve, stops, this valve closes under the influence of gravity. The cylinder is completely or partially filled with liquid. When the plunger is immersed in this liquid, the plunger valve opens and the entire liquid load falls on the suction valve and, consequently, on the tubing (Fig. 14a).
With the further downward stroke of the plunger (Fig. 14b), the upper rod is immersed in the liquid column, displacing its corresponding volume, which is fed into the pipeline. In the case of using plungers whose diameter is equal to or less than the diameter of the upper rod, liquid is supplied into the pipeline only during the downward stroke of the plunger, while when the plunger moves upward, a column of liquid is again collected. As soon as the plunger begins to move upward, the plunger valve closes; The fluid load is again transferred to the sucker rods. If the reservoir pressure exceeds the cylinder pressure, the suction valve opens as the plunger moves away from bottom dead center U.T. (Fig. 14c). The flow of fluid from the formation into the pressure-free cylinder continues until the upward stroke of the plunger ends in the O.T. position. (Fig. 14d). Simultaneously with the rise of the liquid column above the plunger, an equal amount of liquid is sucked in. In practice, however, the pump duty cycle is usually more complex than indicated in this simplified diagram. The operation of the pump depends to a large extent on the size of the harmful space, the gas-liquid ratio and the viscosity of the pumped medium.
In addition, vibrations of the tubing string and sucker rods, resulting from the continuous change in the load of the liquid column, and vibrations of the valves also affect the pumping cycle.
Purpose and technical data of ESP.
Submersible centrifugal pump installations are designed for pumping out reservoir fluid containing oil, water and gas, and mechanical impurities from oil wells, including inclined ones. Depending on the number of different components contained in the pumped-out liquid, the pumps of the installations have a standard design and a version with increased corrosion and wear resistance. When operating an ESP, where the concentration of solids in the pumped-out liquid exceeds the permissible 0.1 gram/liter, the pumps become clogged and the working units wear out intensively. As a result, vibration increases, water enters the motor through the mechanical seals, and the engine overheats, which leads to failure of the ESP.
Symbol of installations:
ESP K 5-180-1200, U 2 ESP I 6-350-1100,
Where U - installation, 2 - second modification, E - driven by a submersible electric motor, C - centrifugal, N - pump, K - increased corrosion resistance, I - increased wear resistance, M - modular design, 6 - groups of pumps, 180, 350 - supply m/day, 1200, 1100 – pressure, m.w.st.
Depending on the diameter of the production string, the maximum transverse dimension submersible unit, ESPs of various groups are used - 5.5, and 6. Installation of group 5 with a transverse diameter of at least 121.7 mm. Group 5a installations with a transverse dimension of 124 mm - in wells with an internal diameter of at least 148.3 mm. Pumps are also divided into three conditional groups - 5.5 a, 6. The diameters of the housings of group 5 are 92 mm, group 5 a - 103 mm, group 6 - 114 mm. Technical characteristics of pumps of the ETsNM and ETsNMK types are given in Appendix 1.
Composition and completeness of the ESP
The ESP installation consists of a submersible pumping unit (an electric motor with hydraulic protection and a pump), a cable line (a round flat cable with a cable entry coupling), a tubing string, wellhead equipment and surface electrical equipment: a transformer and a control station (complete device) (see Figure 1.1 .). The transformer substation converts the field network voltage to a sub-optimal value at the electric motor terminals, taking into account voltage losses in the cable. The control station provides control of the operation of pumping units and its protection under optimal conditions.
A submersible pumping unit, consisting of a pump and an electric motor with hydraulic protection and a compensator, is lowered into the well along the tubing. The cable line provides power supply to the electric motor. The cable is attached to the tubing with metal wheels. Along the length of the pump and protector, the cable is flat, attached to them with metal wheels and protected from damage by casings and clamps. Check and drain valves are installed above the pump sections. The pump pumps out fluid from the well and delivers it to the surface through the tubing string (see Figure 1.2.)
Wellhead equipment provides flange suspension casing Tubing with an electric pump and cable, sealing of pipes and cables, as well as drainage of the produced fluid into the outlet pipeline.
A submersible, centrifugal, sectional, multistage pump does not differ in operating principle from conventional centrifugal pumps.
Its difference is that it is sectional, multi-stage, with a small diameter of working stages - impellers and guide vanes. Submersible pumps produced for the oil industry contain from 1300 to 415 stages.
The pump sections, connected by flange connections, are made of a metal casing. Made from steel pipe 5500 mm long. The length of the pump is determined by the number of operating stages, the number of which, in turn, is determined by the main parameters of the pump. - feed and pressure. The flow and pressure of the stages depend on the cross-section and design of the flow part (blades), as well as on the rotation speed. A package of stages is inserted into the body of the pump sections, which is an assembly of impellers and guide vanes on a shaft.
The impellers are mounted on the shaft on a feather key along a running fit and can move in the axial direction. The guide vanes are secured against rotation in the nipple body, located in the upper part of the pump. From below, a pump base with receiving holes and a filter is screwed into the housing, through which liquid from the well flows to the first stage of the pump.
The upper end of the pump shaft rotates in the oil seal bearings and ends with a special heel that takes the load on the shaft and its weight through a spring ring. Radial forces in the pump are absorbed by plain bearings installed at the base of the nipple and on the pump shaft.
At the top of the pump there is a fishing head in which a check valve is installed and to which the tubing is attached.
Submersible electric motor, three-phase, asynchronous, oil-filled with a squirrel-cage rotor in a conventional version and a corrosion-resistant version PEDU (TU 16-652-029-86). Climatic modification - B, placement category - 5 according to GOST 15150 - 69. At the base of the electric motor there is a valve for pumping oil and draining it, as well as a filter for cleaning the oil from mechanical impurities.
The hydraulic protection of the motor motor consists of a protector and a compensator. It is designed to protect the internal cavity of the electric motor from formation fluid, as well as to compensate for temperature changes in oil volumes and its consumption. (See Figure 1.3.)
The protector is two-chamber, with a rubber diaphragm and mechanical shaft seals, and a compensator with a rubber diaphragm.
Three-core cable with polyethylene insulation, armored. Cable line, i.e. a cable wound on a drum, to the base of which an extension is attached - a flat cable with a cable entry coupling. Each cable core has an insulation layer and a sheath, cushions made of rubberized fabric and armor. Three insulated cores of a flat cable are laid parallel in a row, and a round cable is twisted along a helical line. The cable assembly has a unified cable entry coupling K 38, K 46 round type. In a metal casing, the couplings are hermetically sealed using a rubber seal, and tips are attached to the conductive conductors.
The design of ESP installations, ESPNM with a pump having a shaft and stages made of corrosion-resistant materials, and ESP with a pump having plastic impellers and rubber-metal bearings is similar to the design of ESP installations.
When the gas factor is high, pump modules are used - gas separators, designed to reduce the volumetric content of free gas at the pump intake. Gas separators correspond to product group 5, type 1 (repairable) according to RD 50-650-87, climatic version - B, placement category - 5 according to GOST 15150-69.
Modules can be supplied in two versions:
Gas separators: 1 MNG 5, 1 MNG5a, 1 MNG6 – standard design;
Gas separators 1 MNGK5, MNG5a - increased corrosion resistance.
Pumping modules are installed between the input module and the submersible pump section module.
The submersible pump, electric motor, and hydraulic protection are connected to each other by flanges and studs. The pump, motor and protector shafts have splines at the ends and are connected by splined couplings.
Accessories for lifts and equipment for ESP installations are given in Appendix 2.
Technical characteristics of the motor
The drive of submersible centrifugal pumps is a special oil-filled submersible asynchronous three-phase alternating current electric motor with a vertical squirrel-cage rotor of the PED type. Electric motors have housing diameters of 103, 117, 123, 130, 138 mm. Since the diameter of the electric motor is limited, at high powers the motor is longer, and in some cases it is made sectional. Since the electric motor operates immersed in liquid and often under high hydrostatic pressure, the main condition for reliable operation is its tightness (see Figure 1.3).
The PED is filled with a special low-viscosity, high dielectric strength oil, which serves both for cooling and lubrication of parts.
A submersible electric motor consists of a stator, rotor, head, and base. The stator housing is made of steel pipe, the ends of which are threaded for connecting the head and base of the motor. The stator magnetic circuit is assembled from active and non-magnetic laminated sheets having grooves in which the windings are located. The stator winding can be single-layer, continuous, coil or double-layer, rod, loop. The winding phases are connected.
The active part of the magnetic circuit, together with the winding, creates a rotating magnetic field in electric motors, and the non-magnetic part serves as supports for the intermediate rotor bearings. Lead ends made of stranded wire are soldered to the ends of the stator winding. copper wire with insulation, having high electrical and mechanical strength. Plug sleeves are soldered to the ends, into which the cable lugs fit. The output ends of the winding are connected to the cable through a special plug block (coupler) of the cable entry. The motor current lead can also be a knife type. The motor rotor is squirrel-cage, multi-section. It consists of a shaft, cores (rotor packages), radial supports (sliding bearings). The rotor shaft is made of hollow calibrated steel, the cores are made of sheet electrical steel. The cores are assembled onto the shaft, alternating with radial bearings, and are connected to the shaft with keys. Tighten the set of cores on the shaft axially with nuts or a turbine. The turbine serves for forced circulation of oil to equalize the engine temperature along the length of the stator. To ensure oil circulation, there are longitudinal grooves on the immersed surface of the magnetic circuit. The oil circulates through these grooves, a filter at the bottom of the engine where it is cleaned, and through a hole in the shaft. The engine head contains a heel and a bearing. The adapter at the bottom of the engine is used to accommodate the filter, bypass valve and valve for pumping oil into the engine. The sectional electric motor consists of upper and lower sections. Each section has the same main components. Technical characteristics of the SEM are given in Appendix 3.
Basic technical data of the cable
The supply of electricity to the electric motor of the submersible pump installation is carried out through a cable line consisting of a power cable and a cable entry coupling for coupling with the electric motor.
Depending on the purpose, the cable line may include:
Cable brands KPBK or KPPBPS - as the main cable.
Cable brand KPBP (flat)
The cable entry sleeve is round or flat.
The KPBK cable consists of single-wire or multi-wire copper cores, insulated in two layers of high-strength polyethylene and twisted together, as well as a cushion and armor.
Cables of the KPBP and KPPBPS brands in a common hose sheath consist of single-wire and multi-wire copper conductors, insulated with high-density polyethylene and laid in the same plane, as well as a common hose sheath, cushion and armor.
Cables of the KPPBPS brand with separately hosed conductors consist of single- and multi-wire copper conductors, insulated in two layers of high-density polyethylene and laid in the same plane.
The KPBK brand cable has:
Operating voltage V – 3300
The KPBP brand cable has:
Operating voltage, V - 2500
Allowable formation fluid pressure, MPa – 19.6
Permissible gas factor, m/t – 180
KPBK and KBPP brand cables have permissible temperatures environment from 60 to 45 C air, 90 C – reservoir fluid.
Cable line temperatures are given in Appendix 4.
1.2. Brief overview of domestic schemes and installations.
Submersible centrifugal pump installations are designed for pumping oil wells, including inclined ones, formation fluid containing oil and gas, and mechanical impurities.
The units are available in two types – modular and non-modular; three versions: normal, corrosion-resistant and increased wear resistance. The pumped medium of domestic pumps must have the following indicators:
· reservoir wildness – a mixture of oil, associated water and oil gas;
· maximum kinematic viscosity of formation fluid 1 mm/s;
· pH value of produced water pH 6.0-8.3;
· maximum content of obtained water 99%;
· free gas at intake up to 25%, for installations with modules - separators up to 55%;
· maximum temperature of extracted products up to 90C.
Depending on the transverse dimensions of the submersible centrifugal electric pumps, electric motors and cable lines used in the set of installations, the installations are conventionally divided into 2 groups 5 and 5 a. With casing diameters of 121.7 mm; 130 mm; 144.3 mm respectively.
The UEC installation consists of a submersible pumping unit, a cable assembly, ground electrical equipment - a transformer commutation substation. The pumping unit consists of a submersible centrifugal pump and a motor with hydraulic protection, and is lowered into the well on a tubing string. Submersible pump, three-phase, asynchronous, oil-filled with a rotor.
The hydraulic protection consists of a protector and a compensator. Three-core cable with polyethylene insulation, armored.
The submersible pump, electric motor and hydraulic protection are connected to each other by flanges and studs. The pump, motor and protector shafts have splines at the ends and are connected by splined couplings.
1.2.2. Submersible centrifugal pump.
The operating principle of a submersible centrifugal pump is no different from conventional centrifugal pumps used for pumping liquids. The difference is that it is multi-sectional with a small diameter of working stages - impellers and guide vanes. The impellers and guide vanes of conventional pumps are made of modified gray cast iron, corrosion-resistant pumps are made of niresist cast iron, and wear-resistant wheels are made of polyamide resins.
The pump consists of sections, the number of which depends on the main parameters of the pump - pressure, but not more than four. Section length up to 5500 meters. For modular pumps it consists of an input module, a module - section. Module - heads, check valves and drain valves. Connection of modules to each other and the input module to the motor - flange connection (except for the input module, motor or separator) is sealed rubber cuffs. The connection of the shafts of the module sections with each other, the module section with the input module shaft, and the input module shaft with the engine hydraulic protection shaft is carried out using splined couplings. The shafts of module sections of all groups of pumps with the same body lengths are unified in length.
The module section consists of a housing, a shaft, a package of stages (impellers and guide vanes), upper and lower bearings, an upper axial support, a head, a base, two ribs and rubber rings. The ribs are designed to protect the flat cable with coupling from mechanical damage.
The inlet module consists of a base with holes for the passage of formation fluid, bearing bushings and a grid, a shaft with protective bushings and a splined coupling designed to connect the module shaft with the hydraulic protection shaft.
The head module consists of a housing, on one side of which there is an internal tapered thread for connecting a check valve, on the other side there is a flange for connecting to the module section, two ribs and a rubber ring.
There is a fishing head at the top of the pump.
The domestic industry produces pumps with a flow rate (m/day):
Modular – 50,80,125,200.160,250,400,500,320,800,1000.1250.
Non-modular – 40.80,130.160,100,200,250,360,350,500,700,1000.
The following heads (m) - 700, 800, 900, 1000, 1400, 1700, 1800, 950, 1250, 1050, 1600, 1100, 750, 1150, 1450, 1750, 1800, 1700, 1550, 130 0.
1.2.3. Submersible motors
Submersible electric motors consist of an electric motor and hydraulic protection.
Motors are three-phase, asynchronous, squirrel-cage, two-pole, submersible, unified series. SEMs in normal and corrosive versions, climatic version B, location category 5, operate from an alternating current network with a frequency of 50 Hz and are used as a drive for submersible centrifugal pumps.
The engines are designed to operate in formation fluid (a mixture of oil and produced water in any proportions) with temperatures up to 110 C containing:
· mechanical impurities no more than 0.5 g/l;
· free gas no more than 50%;
· hydrogen sulfide for normal, no more than 0.01 g/l, corrosion-resistant up to 1.25 g/l;
The hydraulic pressure in the engine operating area is no more than 20 MPa. Electric motors are filled with oil with a breakdown voltage of at least 30 kV. The maximum long-term permissible temperature of the stator winding of an electric motor (for a motor with a housing diameter of 103 mm) is 170 C, for other electric motors it is 160 C.
The engine consists of one or more electric motors (upper, middle and lower, power from 63 to 630 kW) and a protector. An electric motor consists of a stator, a rotor, a head with a current input, and a housing.
1.2.4. Hydraulic protection of the electric motor.
The hydraulic protection is designed to prevent formation fluid from penetrating into the internal cavity of the electric motor, compensating the volume of oil in the internal cavity from the temperature of the electric motor and transmitting torque from the electric motor shaft to the pump shaft. There are several options for water protection: P, PD, G.
Hydroprotection is available in standard and corrosion-resistant versions. The main type of hydraulic protection for the SED configuration is the open type hydraulic protection. Open type hydroprotection requires the use of a special barrier liquid with a density of up to 21 g/cm, which has physical and chemical properties with formation fluid and oil.
The hydraulic protection consists of two chambers connected by a tube. Changes in the volume of liquid dielectric in the engine are compensated by the flow of barrier liquid from one chamber to another. In water protection closed type rubber diaphragms are used. Their elasticity compensates for changes in oil volume.
24. Conditions for well flow, determination of energy and specific gas consumption during operation of a gas-liquid lift.
Well flow conditions.
Well flowing occurs if the pressure difference between the reservoir and the bottom hole is sufficient to overcome the back pressure of the liquid column and pressure loss due to friction, that is, flowing occurs under the influence of hydrostatic pressure of the liquid or the energy of the expanding gas. Most wells flow due to gas energy and hydrostatic pressure simultaneously.
The gas contained in oil has lifting force, which manifests itself in the form of pressure on oil. The more gas is dissolved in oil, the lower the density of the mixture and the higher the liquid level rises. Having reached the mouth, the liquid overflows and the well begins to gush. The general mandatory condition for the operation of any flowing well will be the following basic equality:
Рс = Рг+Рtr+ Ру; Where
Рс - bottomhole pressure, RG, Рtr, Ру - hydrostatic pressure of the liquid column in the well, calculated vertically, pressure loss due to friction in the tubing and back pressure at the wellhead, respectively.
There are two types of well flowing:
· Gouting of a liquid that does not contain gas bubbles - artesian gushing.
· Gouting of a liquid containing gas bubbles that facilitate gushing is the most common method of gushing.
Submersible centrifugal pump installations in modular design UECNM And UETsNMK designed for pumping from oil wells, including inclined ones, formation fluid containing oil, water, gas, mechanical impurities.
The units have two versions -
Installation symbol example
where U is the setting; E - drive from a submersible motor; C - centrifugal; N - pump; M - modular; 5 - pump group; 125 - supply, m 3 / day: 1200 - pressure, m; VK - configuration option; 02 - serial number of the configuration option according to the specifications.
For corrosion-resistant installations, the letter “K” is added before the designation of the pump group.
The destination indicators for pumped media are as follows::
maximum concentration of hydrogen sulfide: for conventional installations - 0.001% (0.01 g/l); for corrosion-resistant installations - 0.125% (1.25 g/l);
temperature of the pumped liquid in the operating area of the submersible unit- no more than 90 °C.
For installations equipped with K43 cable lines, in which instead of an extension cord with a heat-resistant cable of the KFSB brand, an extension cord with a cable of the KFSB brand is used, the temperatures should be no more than:
Lithofacies model of formation Yu13 of the Krapivinskoye field Note . The internal diameter of the casing string is not less than and the transverse dimension of the pumping unit with cable is not more, respectively: for UETsNM5 installations - 121.7 and 112 mm: for UETsNM5A - 130 and 124 mm; for UECNM6 with feed up to 500 m 3 /day (inclusive) - 144.3 and 137 mm, with a feed over 500 m 3 day - 148.3 and 140.5 mm.
Installations UETsNM and UETsNMK (Fig. 1) consist of
Instead of a substation, you can use a transformer and a complete device.
A pumping unit, consisting of a submersible centrifugal pump 7 and an engine 8 (an electric motor with hydraulic protection), is lowered into the well on a tubing string 4. The pumping unit pumps out formation fluid from the well and supplies it to the surface through the tubing string.
The cable that supplies electricity to the electric motor is attached to the hydraulic protection, the pump and the pump-compressor pipes with metal belts (clamps) 3, which are part of the pump.
Complete transformer substation (transformer and complete device) converts the field network voltage to the value of the optimal voltage at the electric motor terminals, taking into account voltage losses in the cable and ensures control of the operation of the pumping unit of the installation and its protection in abnormal conditions.
Check valve 1 is designed to prevent reverse rotation (turbine mode) of the pump rotor under the influence of the liquid column in the tubing string during stops and thereby facilitate the restart of the pumping unit. The check valve is screwed into the module - the pump head, and the drain valve - into the check valve body.
Drain valve 2 is used to drain liquid from the tubing string when lifting the pumping unit from the well.
It is allowed to install valves above the pump depending on the gas content at the grid of the pump inlet module. In this case, the valves must be located below the splice of the main cable with the extension cord, since otherwise the transverse dimension of the pump unit will exceed the permissible limit.
To pump out formation fluid containing more than 25 - up to 55% (by volume) of free gas at the receiving grid of the input module, a pumping unit is connected to the pump module - gas separator .
The motor is an asynchronous submersible, three-phase, squirrel-cage, two-pole, oil-filled.
The units can be completed motors type 1PED according to TU 16-652.031 - 87, equipped with a system for monitoring the temperature and pressure of the formation fluid.
In this case, the installations must be equipped with a complete device ShGS 5805-49TZU1.
The connection of the assembly units of the pump unit is flanged (on bolts and studs), the shafts of the assembly units are connected using splined couplings.
The cable assembly is connected to the motor using a cable entry coupling.
The remote connection point is designed to prevent the passage of gas through the cable into the KTPPN (KTPPNKS) or complete device.
The wellhead equipment ensures suspension of the tubing string with the pumping unit and cable assembly on the casing flange, sealing of the annulus, and drainage of formation fluid into the flowline.
The pump is a submersible centrifugal modular pump. Figure 2.
Submersible centrifugal modular pump (hereinafter referred to as “pump”) - multistage vertical design. The pump is manufactured in two versions: conventional ETsNMK and corrosion-resistant ETsNMK.
The pump consists of an inlet module, a section module (section modules), a head module, a check valve and a drain valve (Fig. 2). It is possible to reduce the number of module sections in the pump if the submersible unit is equipped with an engine of the required power.
To pump out formation fluid containing more than 25% (by volume) of free gas at the pump inlet module grid, a pump module - gas separator (Fig..3) should be connected to the pump. installed between the input module and the section module.
The most famous are two designs of gas separators:
gas separators with counterflow;
§ centrifugal or rotary gas separators.
For the first type, used in some Reda pumps, when liquid enters the gas separator, it is forced to sharply change the direction of movement. Some gas bubbles are separated already at the pump inlet. The other part, entering the gas separator, rises inside it and leaves the housing. domestic installations, as well as pumps from Centrilift and Reda, use rotary gas separators that operate similarly to a centrifuge. The centrifuge blades, rotating at a frequency of 3500 rpm, displace heavier liquids to the periphery, and then through the transition channel up into the pump, while the lighter liquid (steam) remains near the center and exits through the transition channel and outlet channels back into the well.
Fig.3. Gas separator:
1 - head; 2 - radial bearing bushing; 3 - shaft: 4 - separator; 5 - guide vanes: 6 - impeller; 7 - body; 8 - auger; 9 - base
The connection between the modules and the input module to the motor is flanged. Connections (except for connections of the input module to the engine and the input module to the gas separator) are sealed with rubber rings.
The connection of the shafts of the module sections with each other, the module section with the input module shaft, and the input module shaft with the engine hydraulic protection shaft is carried out using splined couplings.
The connection of the gas separator shafts, the section module and the input module to each other is also carried out using splined couplings.
The shafts of module sections of all groups of pumps having the same body lengths (2, 3 and 5 m) are unified in length. The shafts of module sections and input modules for pumps of standard design are made of calibrated corrosion-resistant high-strength steel grade OZKH14N7V and are marked “NZh” at the end; for pumps with increased corrosion resistance - from calibrated rods made of N65D29YUT-ISH alloy K-monel and are marked at the ends marked "M".
The impellers and guide vanes of conventional pumps are made of modified gray cast iron, while corrosion-resistant pumps are made of modified cast iron ChN16D7GKhSh of the “niresist” type. Impellers of conventional pumps can be made from radiation-modified polyamide.
The head module consists of a body, on one side of which there is an internal conical thread for connecting a check valve (pump-compressor pipe), on the other side there is a flange for connecting two ribs and a rubber ring to the module-section. The fins are attached to the body of the head module with a bolt, nut and spring washer. A rubber ring seals the connection between the head module and the section module.
Module heads of pumps of groups 5 and 5A have a smooth pipe coupling thread 73 GOST 633 - 80.
The module head of group 6 pumps has two versions: with coupling threads 73 and 89 GOST 633 - 80.
The head module with thread 73 is used in pumps with a nominal flow of up to 800 m 3 /day. with thread 89 - more than 800 m 3 days.
Module section consists of a housing, a shaft, a package of stages (impellers and guide vanes), an upper bearing, a lower bearing, an upper axial support, a head, a base, two ribs and rubber rings. Connecting module sections to each other, as well as threaded connections and the gap between the body and the stage package is sealed with rubber rings.
The ribs are designed to protect the flat cable with coupling from mechanical damage against the casing wall during lowering and lifting of the pumping unit. The ribs are attached to the base of the module section with a bolt with a nut and a spring washer.
The face of the module-section head, which has a minimum angular displacement relative to the base surface between the ribs, is marked with a spot of paint for orientation relative to the ribs of another module-section during installation in the well.
Module sections are supplied sealed with warranty seals and the manufacturer's mark on the soldered seams.
Input module consists of a base with holes for the passage of formation fluid, bearing bushings and a grid, a shaft with protective bushings and a splined coupling for connecting the module shaft with the hydraulic protection shaft.
Using pins, the upper end of the module is connected to the section module. The lower end of the input module is connected to the engine hydraulic protection.
The input module for pumps of group 6 has two versions: one - with a shaft with a diameter of 25 mm - for pumps with flows of 250, 320, 500 and 800 m 3 /day, the other - with a shaft with a diameter of 28 mm - for pumps with flows of 1000, 1250 m 3 /day
Check valves for pumps of groups 5 and 5A, designed for any flow, and group 6 with a flow of up to 800 m 3 /day inclusive, are structurally the same and have smooth tubing coupling threads 73 GOST 633 - 80. Check valve for pumps of group 6 with flow over 800 m 3 /day has smooth tubing coupling threads 89 GOST 633 - 80.
Bleed valves have the same thread designs as check valves.
The cable fastening belt consists of a steel buckle and a steel strip attached to it.
SUBMERSIBLE MOTORS
Submersible motors consist of an electric motor (Fig. 4) and water protection (Fig. 5).
Three-phase asynchronous squirrel-cage two-pole submersible motors of the unified series PED in normal and corrosion-resistant versions, climatic version B, location category 5, operate from an alternating current network with a frequency of 50 Hz and are used as a drive for submersible centrifugal pumps in a modular design for pumping formation fluid from oil wells.
The engines are designed to operate in formation fluid (a mixture of oil and produced water in any proportions) with temperatures up to 110 °C, containing:
mechanical impurities with a relative particle hardness of no more than 5 points on the Mohs scale - no more than 0.5 g/l;
hydrogen sulfide: for normal execution - no more than 0.01 g/l; for corrosion-resistant performance - no more. 1.25 g/l;
free gas(by volume) - no more than 55%. Hydrostatic pressure in the engine operating area is no more than 25 MPa.
Permissible deviations from the nominal values of the supply network:
by voltage- from minus 5% to plus 10%; AC frequency - ±0.2 Hz; by current- not higher than nominal in all operating modes, including bringing the well into operation.
The following designations are adopted in the engine code PEDUSK-125-117DV5 TU 16-652.029 - 86: PEDU - unified submersible electric motor; C - sectional (absence of a letter - non-sectional); K - corrosion-resistant (no letter - normal); 125 - power, kW; 117 - body diameter, mm; D - code for modernizing hydraulic protection (no letter - main model); B5 - climatic version and placement category.
Rice. 4.
1 - cover: 2 - head; 3 - heel: 4 - thrust pad; 5 - plug: 6 - stator winding; 7 - bushing; 8 - rotor; 9 - stator; 10 - magnet; 11 - filter; I2 - block; 13 - cable with tip; 14 - ring; 15 - sealing ring; 16 - body: 17, 18 - plug
The code for the EDK45-117V electric motor uses the following designations: ED - electric motor; K - corrosion-resistant (no letter - normal version); 45 - power, kW; 117 - body diameter, mm; B - upper section (absence of letter - non-sectional, C - middle section, H - lower section).
The PK92D hydraulic protection code uses the following designations: P - protector; K - corrosion-resistant (no letter - normal performance); 92 - body diameter in mm; D - modernization with a diaphragm (no letter - basic model with a barrier liquid).
Starting, controlling the operation of engines and protecting them in emergency modes are carried out by special complete devices.
Starting, operation control and protection of a 360 kW motor with a housing diameter of 130 mm is carried out by a complete thyristor converter.
Electric motors are filled with MA-PED oil with a breakdown voltage of at least 30 kV.
The maximum long-term permissible temperature of the stator winding of electric motors (in terms of resistance for electric motors with a housing diameter of 103 mm) is 170 °C, and for other electric motors - 160 °C.
The engine consists of one or more electric motors (upper, middle and lower with power from 63 to 360 kW) and a protector.
An electric motor (see Fig. 4) consists of a stator, a rotor, a head with a current lead, and a housing.
The stator is made of a pipe into which a magnetic circuit made of sheet electrical steel is pressed.
The stator winding is a single-layer continuous coil. The winding phases are connected in a star.
The rotor is squirrel-cage, multi-section. The rotor consists of a shaft, cores, radial supports (sliding bearings), and a bushing. The shaft is hollow, made of high-strength steel, with a special surface finish. Two special nuts are screwed into the central hole of the rotor shaft of the upper and middle electric motors, between which a ball is placed that blocks the drainage of oil from the electric motor during installation.
The cores are made of sheet electrical steel. Copper rods are placed in the grooves of the cores, welded at the ends with short-circuiting rings. The cores are mounted on the shaft, alternating with radial bearings. A set of cores on the shaft is fixed on one side by a split liner, and on the other by a spring ring.
The bushing is used to displace the radial bearings of the rotor when repairing the electric motor.
The head is an assembly unit mounted in the upper part of the electric motor (above the stator). The head contains a thrust bearing assembly, consisting of a heel and a thrust bearing, outer radial bearings of the rotor, a current input assembly (for non-sectional electric motors) or an assembly electrical connection electric motors (for sectional electric motors).
A current lead is an insulating block into the grooves of which cables with lugs are inserted.
The electrical connection unit for the windings of the upper, middle and lower electric motors consists of output cables with lugs and insulators fixed in the heads and housings of the sectioning ends.
The hole under the plug is used to pump oil into the protector when installing the engine.
The housing, located at the bottom of the electric motor (under the stator), contains a radial rotor bearing and plugs. Through the holes under the plug, oil is pumped and drained into the electric motor.
This motor housing has an oil filter.
Thermomanometric system TMS-Z designed to control certain technological parameters of wells equipped with ESP (pressure, temperature, vibration) and protect submersible units from abnormal operating conditions (overheating of the electric motor or a decrease in fluid pressure at the pump intake below the permissible level).
The TMS-Z system consists of a downhole transducer that transforms pressure and temperature into a frequency-manipulated electrical signal, and a surface device that performs the functions of a power supply, an amplifier-signal conditioner and a device for controlling the operating mode of a submersible electric pump in terms of pressure and temperature.
The downhole pressure and temperature transducer (PDT) is made in the form of a sealed cylindrical container placed in the lower part of the electric motor and connected to the zero point of its stator winding.
A ground-based device installed in the ShGS complete device provides the generation of signals to turn it off and turn off the pump based on pressure and temperature.
The power supply network of the submersible electric motor is used as a communication line and power supply for the PDT.
HYDRAULIC PROTECTION OF SUBMERSIBLE ELECTRIC MOTORS
The hydraulic protection is designed to prevent formation fluid from penetrating into the internal cavity of the electric motor, compensating for changes in the volume of oil in the internal cavity from the temperature of the electric motor and transmitting torque from the electric motor shaft to the pump shaft.
Two design options for hydraulic protection have been developed for engines of the unified series:
Hydroprotection is released
In the usual version, the hydraulic protection is coated with FL-OZ-K GOST 9109 - 81 primer. In the corrosion-resistant version, the hydraulic protection has a K-Monel shaft and is coated with EP-525, IV, 7/2 110 °C enamel.
The main type of hydraulic protection for the SED configuration is the open type hydraulic protection. Open-type hydraulic protection requires the use of a special barrier liquid with a density of up to 2 g/cm 3, which has physical and chemical properties that prevent its mixing with the formation fluid of the well and oil in the cavity of the electric motor.
Rice. 5. Water protection of open (a) and closed (b) types:
A - upper chamber; B - lower chamber; 1 - head; 2 - upper nipple: 3 - body; 4 - middle nipple; 5 - lower nipple; 6 - base; 7 - shaft; 8 - mechanical seal; 9 - connecting tube; 10 - aperture
The design of the open type hydraulic protection is shown in Fig. 5, a, closed type - in Fig. 5 B.
The upper chamber is filled with barrier liquid, the lower chamber with dielectric oil. The cameras are connected by a tube. Changes in the volume of liquid dielectric in the engine are compensated by the flow of barrier liquid in the hydraulic protection from one chamber to another.
In closed-type hydraulic protections, rubber diaphragms are used; their elasticity compensates for changes in the volume of liquid dielectric in the engine.
Currently, the functions of the control station are performed by complete devices of the ELECTON family.
COMPLETE DEVICES “ELECTON 04” SERIES
The station provides the following protections and regulation of their settings:
The station provides the following functions:
In addition, the station provides display of the following information on the alphanumeric display:
The BSI-01 device (information reading unit) is designed for retrieving and storing information from the Elekton controller, as well as for transferring it to a desktop computer. The memory capacity allows you to store information from 63 controllers. BSI-01 is powered from the network adapter (in controllers with serial number 1000 and higher, the unit is powered via the RS-232 connector).
Frequency converters of the IF-TTPT-ХХХ-380-50-1-УХЛ1 “Elekton 05” family designed to regulate the rotation speed of three-phase asynchronous motors(IM) with a squirrel-cage or wound-wound rotor of common general industrial series.
The control system ensures the drive operates in several modes:
Output frequency - 1...75 Hz ±0.1%.
Overload current - 125% of the rated current for 5 minutes with an averaging time of 10 minutes (mode No. 2 in accordance with GOST 24607-88).
Reliability indicators.
The mean time between failures of the control system must be at least 8000 hours.
The display of the frequency converter is shown in Figure 6.
Figure No. 6.
The power part of all control systems is built according to a single circuit and is a two-stage energy converter of three-phase network current into three-phase current energy, with adjustable voltage and frequency.
The mains voltage is converted to DC using a rectifier (thyristor-controlled or diode-controlled) and filtered using an LC filter. The direct voltage is converted by an autonomous voltage inverter (AVI) into three-phase to power the asynchronous motor.
The autonomous voltage inverter is made on the basis of insulated gate bipolar transistors - IGBT, which allows the use of a fairly flexible three-phase bridge control algorithm - pulse width modulation (PWM). By controlling the voltage on the IGBT gates of the AIN bridge, it is possible to obtain a three-phase system of sinusoidal currents with adjustable frequency and amplitude at the outputs U, V, W.
IGBT control pulses are generated by the control system and sent to the driver board, where bipolar powerful signals are generated to control the gates of the transistors.
COMPLETE TRANSFORMER SUBSTATIONS KTPPNKS SERIES.
KTPPNKS are designed for power supply, control and protection of four centrifugal electric pumps (ECP) with electric motors with a power of 16 - 125 kW for oil production from well pads, powering up to four electric motors of pumping machines and mobile current collectors when performing repair work.
Submersible cable line.
To supply electricity to the electric motor of a submersible pump installation, a cable line is used, consisting of a main power cable and an extension cord spliced with it with a cable entry coupling, which ensures a hermetically sealed connection of the cable line to the electric motor. The composition of the cable line and methods of splicing with an extension cord are presented in Figures No. 7, 8 and 9.
Depending on the purpose, the cable line may include:
as the main cable - round cables of the KPBK, KTEBK, KFSBK brands or flat cables of the KBPBP, KTEB, KFSB brands;
as an extension cord - flat cables of the KPBP or KFSB brands;
round type cable entry coupling. Cables of the KPBK and KBPP brands with polyethylene insulation are intended for operation at ambient temperatures up to +90 °C.
KPBK and KBPP cables consist of copper conductors, insulated in two layers of high-density polyethylene and twisted together (in KPBK cables) or laid in the same plane (in KBPBP cables), as well as from a cushion and armor.
Cables of the KTEBK and KTEB brands with thermoplastic elastomer insulation are designed for operation at ambient temperatures up to +110 °C. KTEBK and KTEB cables consist of copper conductors insulated with polyamide-fluoroplastic film, insulated and sheathed with thermoplastic elastomer and twisted together (in KTEBK cables) or laid in the same plane (in KTEB cables), as well as from a cushion and armor.
Cables of the KFSKB and KFSB brands with fluoroplastic insulation are intended for operation at ambient temperatures up to +160 °C.
KFSBK and KFSB cables consist of copper conductors insulated with polyamide-fluoroplastic film, insulated with fluoroplastic and sheathed with lead and twisted together (in KFSBK cables) or laid in the same plane (in KFSB cables), as well as from a cushion and armor.
Figures No. 8 and 9.
Application area ESP- these are high-yield, water-flooded, deep and inclined wells with a flow rate of 10 ¸ 1300 m 3 / day and a lift height of 500 ¸ 2000 m. Overhaul period ESP up to 320 days or more.
Installations of submersible centrifugal pumps in modular design types UECNM and UECNMK are designed for pumping out oil well products containing oil, water, gas and mechanical impurities. Installation type UECNM have a standard design, but type UETsNMK- corrosion-resistant.
The installation (Fig. 24) consists of a submersible pumping unit, a cable line lowered into the well on pump and compressor pipes, and surface electrical equipment (transformer substation).
The submersible pumping unit includes a motor (an electric motor with hydraulic protection) and a pump, above which a check valve and drain valve are installed.
Depending on the maximum transverse dimensions of the submersible unit, the installations are divided into three conditional groups - 5; 5A and 6:
— Group 5 units with a transverse dimension of 112 mm are used in wells with a casing string with an internal diameter of at least 121.7 mm;
— installations of group 5A with a transverse dimension of 124 mm — in wells with an internal diameter of at least 130 mm;
- installations of group 6 with a transverse dimension of 140.5 mm - in wells with an internal diameter of at least 148.3 mm.
Conditions of applicability ESP for pumped media: liquid with a mechanical impurity content of no more than 0.5 g/l, free gas at the pump intake no more than 25%; hydrogen sulfide no more than 1.25 g/l; water no more than 99%; pH value of formation water is within 6¸8.5. The temperature in the area where the electric motor is located is no more than +90°C (special heat-resistant version up to +140°C).
An example of a settings code - UETsNMK 5-125-1300 means: UETsNMK— installation of an electric centrifugal pump of modular and corrosion-resistant design; 5 - pump group; 125 — supply, m 3 / day; 1300 — developed pressure, m of water. Art.
In Fig. Figure 24 shows a diagram of the installation of submersible centrifugal pumps in a modular design, representing a new generation of equipment of this type, which allows you to individually select the optimal installation layout for wells in accordance with their parameters from a small number of interchangeable modules.
The installations (in Fig. 24 there is a diagram of NPO Borets, Moscow) provide optimal selection of the pump to the well, which is achieved by the presence of a large number of pressures for each supply. The pressure pitch of the installations ranges from 50¸100 to 200¸250 m, depending on the supply in the intervals specified in the table. 7 basic settings data.
Table 7
|
Name of installations |
Minimum (internal) diameter of the exploitation column, mm |
Transverse installation dimensions, mm |
Supply m3/day |
Engine power, kW |
Gas separator type |
|
|
UETsNMK5-80 |
||||||
|
UETsNMK5-125 |
||||||
|
UETsNM5A-160 |
||||||
|
UETsNM5A-250 |
||||||
|
UETsNMK5-250 |
||||||
|
UETsNM5A-400 |
||||||
|
UETsNMK5A-400 |
||||||
|
144.3 or 148.3 |
137 or 140.5 |
|||||
|
UETsNM6-1000 |
Mass-produced ESP have a length from 15.5 to 39.2 m and a weight from 626 to 2541 kg, depending on the number of modules (sections) and their parameters.
IN modern installations 2 to 4 module sections can be included. A package of steps is inserted into the section body, which consists of impellers and guide vanes assembled on a shaft. The number of steps ranges from 152¸393. The inlet module represents the base of the pump with inlet holes and a mesh filter through which liquid from the well enters the pump. At the top of the pump there is a fishing head with check valve, to which the tubing is attached.
Pump ( ECNM)— submersible centrifugal modular multistage vertical design.
Pumps are also divided into three conditional groups - 5; 5A and 6. The diameters of the housings of group 5¸92 mm, group 5A - 103 mm, group 6 - 114 mm.
The pump section module (Fig. 25) consists of a housing 1 , shaft 2 , stage packages (impellers - 3 and guide vanes - 4 ), upper bearing 5 , lower bearing 6 , upper axial support 7 , heads 8 , grounds 9 , two ribs 10 (serve to protect the cable from mechanical damage) and rubber rings 11 , 12 , 13 .
The impellers move freely along the shaft in the axial direction and are limited in movement by the lower and upper guide vanes. The axial force from the impeller is transmitted to the lower textolite ring and then to the guide vane shoulder. Partial axial force is transferred to the shaft due to friction of the wheel on the shaft or sticking of the wheel to the shaft due to the deposition of salts in the gap or corrosion of metals. Torque is transmitted from the shaft to the wheels by a brass (L62) key that fits into the groove of the impeller. The key is located along the entire length of the wheel assembly and consists of segments 400-1000 mm long.
The guide vanes are articulated with each other along their peripheral parts; in the lower part of the housing they all rest on the lower bearing 6 (Fig. 25) and base 9 , and from above through the upper bearing housing are clamped in the housing.
The impellers and guide vanes of standard pumps are made of modified gray cast iron and radiation-modified polyamide; corrosion-resistant pumps are made of modified cast iron TsN16D71KhSh of the “niresist” type.
The shafts of section modules and input modules for pumps of standard design are made of combined corrosion-resistant high-strength steel OZH14N7V and are marked “NZh” at the end; for pumps with increased corrosion resistance - from calibrated rods made of N65D29YUT-ISH-K-Monel alloy and are marked at the ends "M".
The shafts of the module sections of all groups of pumps, which have the same body lengths of 3, 4 and 5 m, are unified.
The connection of the shafts of the section modules with each other, the section module with the input module shaft (or gas separator shaft), and the input module shaft with the engine hydraulic protection shaft is carried out using splined couplings.
The connection between the modules and the input module to the motor is flanged. The connections (except for the connection of the input module to the engine and the input module to the gas separator) are sealed with rubber rings.
To pump out formation fluid containing more than 25% (up to 55%) by volume of free gas at the pump inlet module grid, a pumping-gas separator module is connected to the pump (Fig. 26).
Rice. 26. Gas separator:
1 – head; 2 – adapter; 3 – separator; 4 - frame; 5 – shaft; 6 – grate; 7 - guide vane; 8 - Working wheel; 9 – auger; 10 – bearing; 11 ‑ base
The gas separator is installed between the input module and the section module. The most effective gas separators are of the centrifugal type, in which the phases are separated in a field of centrifugal forces. In this case, the liquid is concentrated in the peripheral part, and the gas is concentrated in the central part of the gas separator and is released into the annulus. Gas separators of the MNG series have a maximum flow rate of 250¸500 m 3 /day, a separation coefficient of 90%, and a weight of 26 to 42 kg.
The engine of a submersible pumping unit consists of an electric motor and hydraulic protection. Electric motors (Fig. 27) are submersible three-phase, short-circuited, two-pole, oil-filled, conventional and corrosion-resistant designs of the unified PEDU series and in the conventional design of the PED modernization series L. Hydrostatic pressure in the operating area is no more than 20 MPa. Rated power from 16 to 360 kW, rated voltage 530¸2300 V, rated current 26¸122.5 A.
Rice. 27. Electric motor of the PEDU series:
1 - coupling; 2 - lid; 3 – head; 4 – heel; 5 – thrust bearing; 6 - cable entry cover; 7 - cork; 8 – cable entry block; 9 – rotor; 10 – stator; 11 – filter; 12 – base
Hydraulic protection (Fig. 28) of SEM motors is designed to prevent formation fluid from penetrating into the internal cavity of the electric motor, compensating for changes in the volume of oil in the internal cavity from the temperature of the electric motor and transmitting torque from the electric motor shaft to the pump shaft.
Rice. 28. Water protection:
A– open type; b– closed type
A– upper chamber; B- down Cam;
1 – head; 2 – mechanical seal; 3 – upper nipple; 4 - frame; 5 – middle nipple; 6 – shaft; 7 – lower nipple; 8 – base; 9 - connecting tube; 10 – aperture
The hydraulic protection consists of either one protector or a protector and a compensator. There may be three options for hydraulic protection.
The first consists of protectors P92, PK92 and P114 (open type) from two chambers. The upper chamber is filled with a heavy barrier liquid (density up to 2 g/cm 3 , immiscible with formation fluid and oil), the lower chamber is filled with MA-PED oil, the same as the cavity of the electric motor. The cameras are connected by a tube. Changes in the volume of liquid dielectric in the engine are compensated by transferring the barrier liquid in the hydraulic protection from one chamber to another.
The second consists of protectors P92D, PK92D and P114D (closed type), which use rubber diaphragms; their elasticity compensates for changes in the volume of liquid dielectric in the engine.
The third - hydraulic protection 1G51M and 1G62 consists of a protector located above the electric motor and a compensator attached to the lower part of the electric motor. The mechanical seal system provides protection against formation fluid ingress along the shaft into the electric motor. The transmitted power of the hydraulic protection is 125¸250 kW, weight is 53¸59 kg.
The thermomanometric system TMS - 3 is intended for automatic control over the operation of a submersible centrifugal pump and its protection from abnormal operating conditions (at low pressure at the pump intake and elevated temperature of the submersible electric motor) during well operation. There are underground and above ground parts. Controlled pressure range from 0 to 20 MPa. Operating temperature range from 25 to 105 o C.
Total weight 10.2 kg (see Fig. 24).
The cable line is a cable assembly wound on a cable drum.
The cable assembly consists of a main cable - a round PKBK (cable, polyethylene insulation, armored, round) or a flat cable - KBPP (Fig. 29), connected to it by a flat cable with a cable entry coupling (extension cord with a coupling).
Rice. 29. Cables:
A– round; b– flat; 1 - lived; 2 – insulation; 3 – shell; 4 - pillow; 5 - armor
The cable consists of three cores, each of which has an insulation layer and a sheath; cushions made of rubberized fabric and armor. Three insulated cores of a round cable are twisted along a helix, and the cores of a flat cable are laid parallel in one row.
The KFSB cable with fluoroplastic insulation is designed for operation at ambient temperatures up to +160 o C.
The cable assembly has a unified cable entry coupling K38 (K46) of the round type. The insulated conductors of the flat cable are hermetically sealed in the metal housing of the coupling using a rubber seal.
Plug lugs are attached to the conductive conductors.
The round cable has a diameter from 25 to 44 mm. Flat cable sizes from 10.1x25.7 to 19.7x52.3 mm. Nominal construction length 850, 1000¸1800m.
Complete devices type ShGS5805 provide switching on and off of submersible motors, remote control from the control center and program control, operation in manual and automatic modes, shutdown in case of overload and deviation of the mains voltage above 10% or below 15% of the nominal, current and voltage control, as well as external light signaling of emergency shutdown (including built-in thermometric system).
The integrated transformer substation for submersible pumps - KTPPN is designed to supply electricity and protect electric motors of submersible pumps from single wells with a power of 16-125 kW inclusive. Nominal high voltage 6 or 10 kV, medium voltage regulation limits from 1208 to 444 V (transformer TMPN100) and from 2406 to 1652 V (TMPN160). Weight with transformer 2705 kg.
The complete transformer substation KTPPNKS is designed for power supply, control and protection of four centrifugal electric pumps with 16¸125 kW electric motors for oil production in well pads, powering up to four electric motors of pumping machines and mobile pantographs when performing repair work. KTPPNKS is designed for use in the conditions of the Far North and Western Siberia.
The installation package includes: pump, cable assembly, motor, transformer, complete transformer substation, complete device, gas separator and tool kit.
