WO2011159166A1 - Pompe à moteur annulaire - Google Patents

Pompe à moteur annulaire Download PDF

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Publication number
WO2011159166A1
WO2011159166A1 PCT/NO2011/000168 NO2011000168W WO2011159166A1 WO 2011159166 A1 WO2011159166 A1 WO 2011159166A1 NO 2011000168 W NO2011000168 W NO 2011000168W WO 2011159166 A1 WO2011159166 A1 WO 2011159166A1
Authority
WO
WIPO (PCT)
Prior art keywords
motor
pump
liquid
impeller
pump according
Prior art date
Application number
PCT/NO2011/000168
Other languages
English (en)
Inventor
Gunnar Andersen
Petter Arlehed
Leif Vartdal
Original Assignee
Norali As
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from NO20100871A external-priority patent/NO333616B1/no
Application filed by Norali As filed Critical Norali As
Publication of WO2011159166A1 publication Critical patent/WO2011159166A1/fr

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Classifications

    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04DNON-POSITIVE-DISPLACEMENT PUMPS
    • F04D13/00Pumping installations or systems
    • F04D13/02Units comprising pumps and their driving means
    • F04D13/06Units comprising pumps and their driving means the pump being electrically driven
    • F04D13/0646Units comprising pumps and their driving means the pump being electrically driven the hollow pump or motor shaft being the conduit for the working fluid
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04DNON-POSITIVE-DISPLACEMENT PUMPS
    • F04D1/00Radial-flow pumps, e.g. centrifugal pumps; Helico-centrifugal pumps
    • F04D1/06Multi-stage pumps
    • F04D1/063Multi-stage pumps of the vertically split casing type
    • F04D1/066Multi-stage pumps of the vertically split casing type the casing consisting of a plurality of annuli bolted together
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04DNON-POSITIVE-DISPLACEMENT PUMPS
    • F04D13/00Pumping installations or systems
    • F04D13/02Units comprising pumps and their driving means
    • F04D13/06Units comprising pumps and their driving means the pump being electrically driven
    • F04D13/08Units comprising pumps and their driving means the pump being electrically driven for submerged use
    • F04D13/10Units comprising pumps and their driving means the pump being electrically driven for submerged use adapted for use in mining bore holes
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04DNON-POSITIVE-DISPLACEMENT PUMPS
    • F04D13/00Pumping installations or systems
    • F04D13/12Combinations of two or more pumps
    • F04D13/14Combinations of two or more pumps the pumps being all of centrifugal type

Definitions

  • the invention relates to a rotor-dynamic, centrifugal pump for use in pumping hydrocarbons and water in a downhole application.
  • Centrifugal pumps for use in downhole applications are previously known. These pumps employ a so-called multi-stage principle, where the pump consists of a plurality of vertically arranged stages. One stage consists primarily of an impeller and a diffuser. The impeller is attached to a common shaft which runs through all stages, and this shaft is driven by an electric motor.
  • An example of this technique is the ESP pump (Electrical Submersible Pump) which can be found on the market today. The reason a plurality of stages is used is that a stage has a limited capacity for supplying a pressure increase.
  • pumps of this type must use several stages, coupled in series, one on top of the other.
  • the existing structures are long as the motor is mounted below the pump stages. This is a problem in connection with well deviation.
  • Today's pumps are moreover subject to problems associated with bearing lifetime and wear due to cavitation.
  • the vertical distance from the surface down to the reservoirs may vary from several hundred metres to several thousand metres.
  • the actual production takes place either by using artificial lifting or in that the reservoir liquids, which may contain dissolved or free gas, flow to the surface through a borehole/well because the pressure in the reservoir is higher than at the surface.
  • Artificial lifting is a generic term for different methods and techniques which can be used for this production.
  • This invention comprises equipment for improving the lifting of hydrocarbons (with or without gas) and/or water to the surface.
  • Choice of method for artificial lifting is made on the basis of conditions in the reservoirs, the nature of the oil, and the depth and path of the borehole/well. In addition, importance is given to the location of the field (onshore or offshore) and the infrastructure of the area, such as access to electric power and gas at the location in question. On the basis of these parameters, the field operator can, with the aid of the invention, construct a plant which gives optimal total economy based on the production properties of the reservoir, investment in equipment and operating costs.
  • a system known as a sucker rod pump is often chosen.
  • the actual driving apparatus is located on the surface, connected to a pump unit down in the well via a pump rod.
  • the challenges of this system are a relatively large driving apparatus that is located above and close to the wellhead, friction between pump rod and the pipe wall in the well, production of sand from the reservoir and a system efficiency factor of 0.4.
  • the systems have limited lifting capacity, and are therefore used at low production rates.
  • the design of the system per se, together with operating conditions, such as sand production, means that they suffer frequent operational interruptions.
  • the stroke length of the actual pump unit in a sucker rod pump is two to three metres, and the frequency is from one to ten strokes per minute.
  • US Patent 5, 179,306 describes a principle in which the pump unit in a sucker rod pump is run by a double-acting DC linear motor that is located downhole together with the pump unit, which is done to avoid the challenges associated with the actual pump rod.
  • j ESPCP and PCP are also systems that are used for artificial lifting. In principle, these are two similar pumps with the difference that the ESPCP (Electrical
  • Submersible Progressive Cavity Pump is driven by an electric motor which is located downhole, whilst the PCP (Progressive Cavity Pump) is driven by a motor that is located on the surface.
  • the power for a PCP is transmitted from the surface to the pump down in the well via a pump rod, in the same way as for a sucker rod pump.
  • the pumping principle employed in these pumps is that often termed a screw pump inasmuch as a rotor moves in a circular path within a specially designed pump housing.
  • the ESPCP may be used in both offshore and onshore installations, whilst the PCP is used only on onshore fields. Pumps of this type are regarded as being highly suitable for production of heavy (viscous) oils, and they are generally considered to have an efficiency factor that is better than the ESP which is described in the next paragraph.
  • the Electrical Submersible Pump is a pump type that is frequently used for artificial lifting in both onshore and offshore installations.
  • the pump is mounted down towards the bottom of the well as an integral part of the production tubing, and this means that if it fails, the whole tubing must be pulled out of the well.
  • the pump itself consists primarily of an electric motor in the bottom, out from which there runs a shaft on which impellers and diffusers are mounted in several stages. The number of stages is determined by the necessary lifting height. The liquid is sucked into the bottom of the pump and for each stage the pressure increases, and large pumps may have more than 250 - 300 stages. To reduce the number of stages, the rotational speed can be increased, which gives a reduction in the total length of the pump.
  • US Patent 4,278,399 describes a solution for a more efficient pump stage in an ESP. This is done in principle by reducing the thickness of the material of the pump housing so as to allow the impellers to have a larger radius.
  • the efficiency factor of such pumps is reckoned to be about 0.3, and the volume flow may vary from a few hundred barrels a day to 20-30,000 bbl/d.
  • the electric motor in the pump receives power supplied from the surface through a special cable which is fastened to the outside of the production tubing, and the system is controlled from the surface with the aid of a system known as VSD (Variable Speed Drive). VSD converts AC to DC and back to AC with different frequencies. This causes wear on the electric cables and connections and may lead to earthing problems.
  • VSD Very Speed Drive
  • induction motors are used to drive the actual pump and, owing to the need for a large amount of power at high rates and deep wells, they are relatively long. These motors have little clearing between stator and rotor, which means that small bends (dog legs) in the well path may create contact between rotor and stator and result in breakage. The same may happen as a result of vibrations in the motor when long motors are involved (a motor of 250 HP is 20 m long). Due to these conditions, the industry has developed Permanent Magnet (PM) motors which have a more robust design. The mechanical challenges associated with ESP are wear and overheating of the electric motor, which PM is presumed to handle in a better manner. At the same time, large axial forces are generated in the pump itself.
  • PM Permanent Magnet
  • ESP systems have problems in handling production of large amounts of sand and other solid particles such as scale.
  • cavitation occurs when free gas is produced. Both these situations cause wear of the impellers.
  • Free gas is also a problem for the electric motor itself since the gas has a poorer capacity for conducting away inherent heat generated by the electric motor. All these conditions mean that an ESP system is presumed to have an average lifetime of about 1.5 years. The costs involved in replacing an ESP will vary with the depth of the well since the whole production tubing must be pulled out. In addition to the direct costs of the operation, which involves the use of a drilling rig, there are the costs of delayed production.
  • Gas lifting is frequently used as artificial lifting on offshore installations where there is access to produced gas from the separator plant.
  • the principle is based on reinjecting produced gas into the annulus between the production tubing and the casing (production annulus) and down towards the production packer at the bottom of the well.
  • Gas lift valves are mounted at different levels in the production tubing. These are one way valves that allow the gas in the annulus to flow into the production tubing so that the weight of the hydrostatic column inside the tubing is reduced, thereby also reducing the counter-pressure on the reservoir so that the reservoir pressure itself can force the produced liquids to the surface.
  • gas lifting is an efficient system, but it requires investment in own gas compressors, surface flow pipes, annulus safety valves (ASV), gas lift valves (GLV) and gas-tight pipe threads in the casing.
  • ASV annulus safety valves
  • GLV gas lift valves
  • the system may be difficult to operate optimally because the mixture ratio between oil, water and possible gas produced from the reservoir will vary with shorter and longer time intervals.
  • reinjected gas in the production annulus may leak out into the outer annulus through the casings.
  • a number of oil companies now wish to develop a V0 version of GLV so that they can remove ASV, as it has been found that these valves are vulnerable to leakages. This change is contributing to an increase in the investment costs for gas lifting.
  • Single and double-acting piston pumps for use in artificial lifting are previously known. Apart from different designs of the actual pump housing (the pistons) and inlet and outlet valves, there are several different drive mechanisms for the pumps. These may be anything from electromagnetic motor solutions to solutions involving linear motors.
  • a single-acting piston pump is known that is driven by an induction motor which in turn drives a hydraulic unit, which in its turn drives the piston and valves. This particular solution is designed for operation of more than one single-acting piston in the pump.
  • a common feature of all the pumps is that they are designed to be installed at the bottom of the well.
  • US Patent 1 ,740,003 teaches an electrically driven double-acting piston pump. To turn the piston movement, the phase of the motor must be changed so that it turns in the opposite direction.
  • the pump according to the invention comprises several steps, which in turn are divided into one or more pump stages.
  • a pump stage comprises an impeller and a diffuser.
  • a step is defined as comprising a motor which drives one or more pump stages in the step, and according to an aspect of the invention, the pump includes several steps in order for the apparatus to have sufficient lifting capacity.
  • the pump according to the invention overcomes the disadvantages associated with the situation where only one electric motor is to drive all the pump stages inasmuch as the invention is characterised in that it uses a motor in each step.
  • the motor may also drive two or more pump stages in a step via one shaft.
  • the pump is equipped with motors which are configured as ring motors (i.e., liquid can flow in the centre of the motors) at each step - and that there are several steps in the pump in order to obtain sufficient lifting capacity.
  • motors which are configured as ring motors (i.e., liquid can flow in the centre of the motors) at each step - and that there are several steps in the pump in order to obtain sufficient lifting capacity.
  • the pump according to the invention consists of up to about three pump stages in a step in order to obtain sufficient lifting, but more pump stages are possible. It is an advantage that the pump has "redundancy" - i.e., if the motor in a step stops, all the other steps will be able to continue to pump.
  • the motors in the pump are preferably permanent magnet motors with a stationary part attached to the diffuser and a movable part attached to the impeller.
  • the motors may be an electric motor with a stationary part and a rotating part.
  • the motors will have a cavity in the centre for flow of liquid, and the rotating part of the motor is attached to the impeller for operation thereof.
  • the motors may be hydraulic motors with a stationary part and a rotating part. In this case too, the motor will have a cavity in the centre for flow of liquid, and where the rotating part of the motor is attached to an impeller for operation thereof.
  • the pump may use bearings, preferably magnetic bearings, to take up the forces in the apparatus.
  • a permanent magnet motor is per se highly efficient with a high efficiency factor.
  • the pump has a redundancy by still being capable of delivering a pressure increase even if one or more motors (steps) come to a standstill.
  • Each motor can, if the conditions in the well so require, be run at an individual rotational speed so as to avoid cavitation. Since the motor is no longer supplied as a long unit, but is divided into different steps, the pump handles well deviation far better than existing pumps. Service on the pump is easier as the steps are not connected to a common shaft.
  • the pump is characterised in that it essentially consists of permanent magnet motors which individually drive the impellers in the pump stages and that it uses magnetic bearings to take up the forces in the apparatus.
  • Fig. 1 shows the principle of a plurality of steps in the pump
  • Fig. 2 shows the principle of a permanent magnet motor
  • Fig. 3 shows a section of a permanent magnet motor
  • Fig. 4 shows a section of a step including impeller, diffuser and permanent magnet motor
  • Fig. 5 shows the principle of an axial permanent magnet motor
  • Fig. 6 shows a section of an axial permanent magnet motor
  • Fig. 7 shows a section of a step including impeller, diffuser and axial permanent magnet motor
  • Fig. 8 shows a section of two steps including the principle of a bearing
  • Fig. 9 shows a section of an axially positioned motor including the principle of a bearing arrangement
  • Fig. 10 shows a section of two steps with axially positioned motor including a bearing arrangement
  • Fig. 1 1 is a rough outline of the connection of power
  • Fig. 12 shows an embodiment where the pump is used together with a plug/packer
  • Fig. 13 shows an embodiment where the rotating part of the motor drives a shaft which in turn drives a plurality of pumps stages in a step.
  • a step (1 ) consists, as in conventional centrifugal pumps, of an impeller (2) and a diffuser (3).
  • the number of steps (1 ) the pump consists of may vary according to the requirements of the well.
  • the impeller (2) is driven by a permanent magnet motor (the PM motor) (4) as shown in Fig. 2, which includes a rotating part (6) that is an integral part of the impeller (2) and a stationary part (5) that is an integral part of the diffuser (3).
  • Fig. 13 shows an embodiment where the rotating part (6) of the motor drives a shaft (25) which in turn drives three pump stages in a step.
  • FIG. 4 shows a radially positioned PM motor (4) mounted in the impeller (2) and the diffuser (3).
  • the diffuser (3) stands still together with the stationary part of the PM motor (5).
  • the impeller (2) is arranged so that it can rotate within the diffuser (3).
  • the impeller when the PM motor starts to rotate, the impeller also rotates.
  • the impeller rotates within the stationary diffuser.
  • the method of attachment of the parts of the PM motor may vary.
  • the rotating part of the PM motor is made of the same blank as the impeller.
  • the output and the capacity an impeller has to supply an increase in pressure are determined by impeller diameter and internal flow design of the impeller and diffuser.
  • Figure 4 shows how the PM motor can be positioned without affecting the impeller diameter.
  • the internal flow optimisation of the impeller and diffuser is not affected by the invention owing to the position of the PM motor, which means that the pump solution according to the invention can be used with known impeller and diffuser design.
  • several steps can be mounted one above the other so as to enable the pumping capacity to be modified according to need.
  • the steps are constructed with a mechanical control so that they cannot rotate in relation to one another.
  • all steps are located within a casing.
  • the length of the casing varies according to the number of steps used to obtain desired capacity of the system. In the bottom of the casing is a conventionally used base and at the top a head. These two are screwed into the casing so that the steps are compressed.
  • the impeller In conventional centrifugal pumps, the impeller is fixed to a shaft such that the radial motion is controlled. In the invention, this is done with the aid of a radial bearing (12).
  • the position of the radial bearing may vary.
  • Figure 8 shows a radial bearing (12) placed in the centre above the impeller (2).
  • the radial bearing ( 12) in this case is fastened to the diffuser (3), and, during mounting, the shaft on the impeller is inserted into bearings so that the impeller is radially supported against the diffuser. Mounted in this way, the impeller is given radial support like that which other conventional centrifugal pumps with a common shaft have.
  • the radial bearing ( 12) may be of the passive magnetic bearing type, in another embodiment it may be of the active magnetic bearing type, whilst in a third embodiment it may be of the standard radial sliding bearing or roller bearing type.
  • the support of axial forces is effected by one axial bearing ( 1 1 ) located between the impeller in the overlying pump stage and the diffuser in the underlying pump stage, as shown in Figure 8.
  • the position of the bearing may vary.
  • the axial bearing is mounted in a conventionally known way.
  • the rotating part of the bearing is mounted on the impeller.
  • the stationary part is mounted in the diffuser.
  • the bearing may be of the passive magnetic bearing type, whilst in another embodiment it may be of the active magnetic bearing type. This type of bearing is in theory friction-free with increased lifetime for the bearings as a result.
  • the bearing arrangement does not preclude the use of ordinary axial sliding bearings or roller bearings. These may be of the conventional axial bearing type.
  • the motor may be of such a type that it eliminates the need for radial and axial support.
  • the PM motor has current applied in a conventionally known way via a power cable. Redundancy is vital so that the pump does not stop if a step stops.
  • the diffuser is constructed so that power supply is possible.
  • Figure 1 1 shows an embodiment of power supply at the bottom left-hand side of the figure.
  • Figure 5 and Figure 6 show a basic drawing of an axial PM motor (7). This also consists of a rotating part (8) and a stationary part (9). This type of motor is also known in the market.
  • Figure 7 shows an embodiment where the motor is positioned axially in a stage. The stationary part of the motor (9) is mounted in the underlying diffuser and the rotating part (8) in the overlying impeller.
  • the pump according to the invention is installed in the well with the aid of a remote-controlled plug or packer, as shown in Fig. 12.
  • the plug consists of an electric motor ( 13) for setting and pulling the plug.
  • the electric motor is, through planet gear (14), in connection with hollow shaft ( 15) that is rotated to set one or more slips ( 16) which lock the packer to the production tubing (17), and hollow shaft (18) that is rotated to set a packer element ( 19).
  • the packer element (19) separates the inlet side from the exhaust side as shown in the figure.
  • a hollow shaft (20) controls a ball valve (21 ).
  • the apparatus includes pipe (22) that leads the liquid through the plug and into the pump.
  • a valve (23) ensures that, when needed, hydraulic contact can be formed between the inlet side and the exhaust side of the pump.
  • the valve may, for example, be a magnetic valve.
  • the pump and the remote-controlled plug can be set together to form a unit that can be run downhole and pulled up with the aid of a cable (24).

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Mining & Mineral Resources (AREA)
  • Structures Of Non-Positive Displacement Pumps (AREA)
  • Transition And Organic Metals Composition Catalysts For Addition Polymerization (AREA)
  • Lubrication Of Internal Combustion Engines (AREA)

Abstract

L'invention concerne une pompe centrifuge rotodynamique destinée à être utilisée dans le pompage d'hydrocarbures et d'eau dans une application en fond de trou. La pompe est conçue avec une pluralité de segments disposés dans la direction longitudinale et prévue pour être placée dans un puits, chaque segment étant constitué d'un moteur et d'un ou plusieurs étages de pompe comprenant notamment un diffuseur et une roue à aubes pouvant tourner pour accélérer radialement un liquide, ledit diffuseur étant disposé de façon à amener le liquide à un niveau supérieur et à pomper ainsi le liquide vers le haut dans le puits. Les roues à aubes de chaque segment sont entraînées par un moteur commun, ledit moteur étant configuré comme un moteur annulaire, de telle sorte que le liquide puisse s'écouler au centre du moteur.
PCT/NO2011/000168 2010-06-17 2011-06-09 Pompe à moteur annulaire WO2011159166A1 (fr)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
NO20100871A NO333616B1 (no) 2010-06-17 2010-06-17 Magnetpumpe
NO20100871 2010-06-17
NO20101569A NO20101569A1 (no) 2010-06-17 2010-11-08 Ringmotorpumpe
NO20101569 2010-11-08

Publications (1)

Publication Number Publication Date
WO2011159166A1 true WO2011159166A1 (fr) 2011-12-22

Family

ID=44511442

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/NO2011/000168 WO2011159166A1 (fr) 2010-06-17 2011-06-09 Pompe à moteur annulaire

Country Status (2)

Country Link
NO (1) NO20101569A1 (fr)
WO (1) WO2011159166A1 (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2501352B (en) * 2012-03-12 2017-11-15 Norali As Pump having an enclosed annular volume

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1740003A (en) 1926-05-24 1929-12-17 Kobe Inc Electrically-driven oil-well pump
GB909550A (en) * 1959-12-14 1962-10-31 Hans Moser Improvements in or relating to glandless centrifugal pumps with built in electric motor
US4278399A (en) 1979-06-21 1981-07-14 Kobe, Inc. Pumping stage for multi-stage centrifugal pump
US5179306A (en) 1990-01-10 1993-01-12 Escue Research And Development Company Small diameter brushless direct current linear motor and method of using same
US5201848A (en) 1991-10-01 1993-04-13 Conoco Inc. Deep well electrical submersible pump with uplift generating impeller means
US5209650A (en) * 1991-02-28 1993-05-11 Lemieux Guy B Integral motor and pump
US20020066568A1 (en) * 2000-10-18 2002-06-06 Buchanan Steven E. Integrated pumping system for use in pumping a variety of fluids

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1740003A (en) 1926-05-24 1929-12-17 Kobe Inc Electrically-driven oil-well pump
GB909550A (en) * 1959-12-14 1962-10-31 Hans Moser Improvements in or relating to glandless centrifugal pumps with built in electric motor
US4278399A (en) 1979-06-21 1981-07-14 Kobe, Inc. Pumping stage for multi-stage centrifugal pump
US5179306A (en) 1990-01-10 1993-01-12 Escue Research And Development Company Small diameter brushless direct current linear motor and method of using same
US5209650A (en) * 1991-02-28 1993-05-11 Lemieux Guy B Integral motor and pump
US5201848A (en) 1991-10-01 1993-04-13 Conoco Inc. Deep well electrical submersible pump with uplift generating impeller means
US20020066568A1 (en) * 2000-10-18 2002-06-06 Buchanan Steven E. Integrated pumping system for use in pumping a variety of fluids

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2501352B (en) * 2012-03-12 2017-11-15 Norali As Pump having an enclosed annular volume

Also Published As

Publication number Publication date
NO20101569A1 (no) 2011-12-19

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