US20150159475A1 - Downhole Apparatus Using Induction Motors with Magnetic Fluid in Rotor-Stator Gap - Google Patents
Downhole Apparatus Using Induction Motors with Magnetic Fluid in Rotor-Stator Gap Download PDFInfo
- Publication number
- US20150159475A1 US20150159475A1 US14/097,992 US201314097992A US2015159475A1 US 20150159475 A1 US20150159475 A1 US 20150159475A1 US 201314097992 A US201314097992 A US 201314097992A US 2015159475 A1 US2015159475 A1 US 2015159475A1
- Authority
- US
- United States
- Prior art keywords
- fluid
- magnetic
- gap
- motor
- rotor
- Prior art date
- Legal status (The legal status 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 status listed.)
- Abandoned
Links
- 239000011553 magnetic fluid Substances 0.000 title claims abstract description 37
- 230000006698 induction Effects 0.000 title description 14
- 239000012530 fluid Substances 0.000 claims abstract description 47
- 239000002122 magnetic nanoparticle Substances 0.000 claims abstract description 30
- 238000004519 manufacturing process Methods 0.000 claims description 18
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims description 14
- 238000000034 method Methods 0.000 claims description 12
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 claims description 10
- 230000035699 permeability Effects 0.000 claims description 10
- 229910052742 iron Inorganic materials 0.000 claims description 7
- 239000002245 particle Substances 0.000 claims description 6
- 229910017052 cobalt Inorganic materials 0.000 claims description 5
- 239000010941 cobalt Substances 0.000 claims description 5
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 claims description 5
- 229910052759 nickel Inorganic materials 0.000 claims description 5
- 239000000203 mixture Substances 0.000 claims description 4
- HCHKCACWOHOZIP-UHFFFAOYSA-N Zinc Chemical compound [Zn] HCHKCACWOHOZIP-UHFFFAOYSA-N 0.000 claims description 3
- WPBNNNQJVZRUHP-UHFFFAOYSA-L manganese(2+);methyl n-[[2-(methoxycarbonylcarbamothioylamino)phenyl]carbamothioyl]carbamate;n-[2-(sulfidocarbothioylamino)ethyl]carbamodithioate Chemical compound [Mn+2].[S-]C(=S)NCCNC([S-])=S.COC(=O)NC(=S)NC1=CC=CC=C1NC(=S)NC(=O)OC WPBNNNQJVZRUHP-UHFFFAOYSA-L 0.000 claims description 3
- 229910052725 zinc Inorganic materials 0.000 claims description 3
- 239000011701 zinc Substances 0.000 claims description 3
- 230000007246 mechanism Effects 0.000 claims description 2
- 239000000463 material Substances 0.000 claims 3
- 239000000696 magnetic material Substances 0.000 claims 1
- 229910052751 metal Inorganic materials 0.000 claims 1
- 239000002184 metal Substances 0.000 claims 1
- 239000012811 non-conductive material Substances 0.000 claims 1
- 230000015572 biosynthetic process Effects 0.000 description 12
- 238000005755 formation reaction Methods 0.000 description 12
- 229930195733 hydrocarbon Natural products 0.000 description 8
- 150000002430 hydrocarbons Chemical class 0.000 description 6
- SZVJSHCCFOBDDC-UHFFFAOYSA-N ferrosoferric oxide Chemical compound O=[Fe]O[Fe]O[Fe]=O SZVJSHCCFOBDDC-UHFFFAOYSA-N 0.000 description 4
- 239000004215 Carbon black (E152) Substances 0.000 description 2
- 125000001183 hydrocarbyl group Chemical group 0.000 description 2
- 230000001939 inductive effect Effects 0.000 description 2
- 238000003475 lamination Methods 0.000 description 2
- 230000001050 lubricating effect Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 239000002105 nanoparticle Substances 0.000 description 2
- 238000004804 winding Methods 0.000 description 2
- 239000000956 alloy Substances 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 230000004907 flux Effects 0.000 description 1
- 239000006249 magnetic particle Substances 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 239000004576 sand Substances 0.000 description 1
- 238000010008 shearing Methods 0.000 description 1
- 238000004088 simulation Methods 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Images
Classifications
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B43/00—Methods or apparatus for obtaining oil, gas, water, soluble or meltable materials or a slurry of minerals from wells
- E21B43/12—Methods or apparatus for controlling the flow of the obtained fluid to or in wells
- E21B43/121—Lifting well fluids
- E21B43/128—Adaptation of pump systems with down-hole electric drives
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02K—DYNAMO-ELECTRIC MACHINES
- H02K9/00—Arrangements for cooling or ventilating
- H02K9/19—Arrangements for cooling or ventilating for machines with closed casing and closed-circuit cooling using a liquid cooling medium, e.g. oil
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02K—DYNAMO-ELECTRIC MACHINES
- H02K5/00—Casings; Enclosures; Supports
- H02K5/04—Casings or enclosures characterised by the shape, form or construction thereof
- H02K5/12—Casings or enclosures characterised by the shape, form or construction thereof specially adapted for operating in liquid or gas
- H02K5/132—Submersible electric motors
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02K—DYNAMO-ELECTRIC MACHINES
- H02K2201/00—Specific aspects not provided for in the other groups of this subclass relating to the magnetic circuits
- H02K2201/03—Machines characterised by aspects of the air-gap between rotor and stator
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02K—DYNAMO-ELECTRIC MACHINES
- H02K7/00—Arrangements for handling mechanical energy structurally associated with dynamo-electric machines, e.g. structural association with mechanical driving motors or auxiliary dynamo-electric machines
- H02K7/14—Structural association with mechanical loads, e.g. with hand-held machine tools or fans
Definitions
- This disclosure relates generally to AC induction motors and to downhole apparatus that utilizes such motors, wherein a magnetic fluid is utilized between the rotor and stator to increase the efficiency of such motors.
- Wells also referred to as “wellbores” or “boreholes” are drilled in subsurface formations for the production of hydrocarbons (oil and gas). Wellbores often extend to depths of more than 5000 meters (over 15,000 ft.). Many such wellbores are deviated or horizontal.
- a casing is typically installed in the wellbore, which is perforated at hydrocarbon-bearing formation zones to allow the hydrocarbons to flow from the formation into the casing.
- a production string is typically installed inside the casing.
- the production string includes a variety of flow control devices and a production tubular that extends from the surface to each of the perforated zones.
- ESPs electrical submersible pumps
- An ESP includes a pump driven by an AC induction motor.
- the rotor and stator of an AC Induction motor are separated by a gap that creates a magnetic field disconnect between the rotor and the stator, which generates a reluctance load within the motor and causes the stator to pull additional current. Additional current pulled by the stator makes the motor inefficient and also generates heat that increases the already high temperature of the motor in the wellbore, which temperature can exceed 300° F.
- the highest reluctance and thus greatest loss of the magnetic field between the stator and the rotor is due to the gap between the rotor and stator because the medium in the gap (air in most AC induction motors with dielectric oil in most ESP AC induction motors) has low magnetic permeability. Therefore, increasing the magnetic permeability (i.e. reducing the reluctance) of the medium in the gap can improve the overall efficiency of an AC induction motor, reduce the heat generated by the motor and increase the overall efficiency and the operating life of the motor.
- the disclosure herein provides apparatus and methods that in general improve the overall performance of AC induction motors, and particularly motors utilized in ESP pumps for downhole applications.
- an apparatus for use in a wellbore in one non-limiting embodiment includes an electric motor with a gap between a rotor and a stator and a magnetic fluid in the gap that contains an electrically nonconductive fluid and magnetic nanoparticles that increase the magnetic permeability of the gap.
- a method of producing a fluid from a wellbore may include: deploying a string in the wellbore that includes a pump driven by an electric motor that includes a magnetic fluid in a gap between a stator and rotor of the electric motor; and operating the pump with the electric motor to produce the fluid from the wellbore.
- FIG. 1 is a schematic diagram of an exemplary production wellbore with an ESP deployed therein, which ESP is made according to one non-limiting embodiment of the disclosure;
- FIG. 2 shows an exemplary motor of an ESP that includes an electrically nonconductive magnetic fluid according to one non-limiting embodiment of the disclosure
- FIG. 3 shows a cut-view of the motor section “A” of the induction motor of FIG. 2 showing a magnetic fluid in the gap between the stator and rotor;
- FIG. 4 shows a cut-view of the motor section “B” shown in FIG. 2 ;
- FIG. 5 shows a non-limiting embodiment of a heat-exchange fluid reservoir and a device that mixes magnetic nanoparticles with a base fluid in the heat-exchange reservoir for circulating the magnetic fluid in the motor of FIG. 2 .
- FIG. 1 shows an exemplary wellbore system 100 that includes a wellbore 110 drilled from the surface 104 through the earth formation 102 .
- the wellbore 110 is shown formed through a production zone 120 that contains hydrocarbons (oil and/or gas) therein.
- the fluid 150 in the production zone 120 is referred to as the “formation fluid” and typically contains hydrocarbons and water.
- System 100 includes a string that includes an electrical submersible pump (ESP) 160 that contains a pump 184 driven by an electric motor 180 , typically an AC induction motor). Seals 186 separate the motor 180 and the pump 184 .
- the formation fluid 150 enters the wellbore 110 from the production zone 120 via perforations 116 and control equipment 130 , such as sand screens, valves, etc. known in the art.
- the formation fluid 150 enters the pump 184 as shown by arrows 162 .
- the production zone 120 is shown isolated from the wellbore 110 above and below perforations 116 by packers 122 a and 122 b .
- the wellbore section between the packers 122 a and 122 b is filled with the formation fluid 150 .
- the ESP 160 is shown deployed on a production tubing 140 for lifting the formation fluid 150 from the production zone 120 to the surface 104 via the production tubing 140 .
- the fluid level in the wellbore 110 is maintained a certain level above the ESP 160 to provide a fluid head to the ESP.
- Power to the ESP 160 is supplied from a power source 162 at the surface and a controller 164 may be utilized to control the operations of the ESP 160 .
- a fluid processing unit 170 at the surface 104 processes the formation fluid 150 received at the surface 104 .
- Various sensors 188 may be utilized for determining information about one or more parameters relating to the ESP 160 , including
- FIG. 2 shows an exemplary motor 180 of an ESP that includes a magnetic fluid 270 in the gap between the rotor and the stator of the motor 180 , according to one non-limiting embodiment of the disclosure.
- the motor 180 includes a housing 210 , a base 212 and an upper threaded end 214 for connection to the seals 186 .
- the motor 180 includes a stator (laminations) 220 and a rotor 230 that rotates a shaft 240 .
- Bearings 250 support the rotor 230 and the shaft 240 .
- the motor 180 further includes a reservoir or chamber 260 that includes the magnetic fluid 270 .
- the magnetic fluid 270 may include any electrically nonconductive fluid 272 , such as oil, for lubricating the various components of the motor 230 and a selected amount (by weight or volume) of magnetic nanoparticles 280 .
- the magnetic nanoparticles 280 increase the magnetic permeability of the fluid 272 in the gap and thus reduce the magnetic reluctance of the gap, which reduces the reluctance of the gap between the stator 220 and the rotor 230 .
- the rotor 230 rotates the shaft 240 at a relatively high rotational speed, which speed may exceed 3000 rpm.
- the magnetic fluid 270 moves up the shaft 240 and passes around the bearings 250 and in the gap between the stator 220 and the rotor 230 , which in aspects may provide relatively high magnetic permeability in the gap compared to the base fluid 272 .
- FIG. 3 shows a cut-view of the motor section “A” shown in FIG. 2 .
- View 300 shows stator 220 with windings 320 and rotor 230 with shaped rotor bars 330 .
- the gap 380 between the stator 220 and the rotor 230 is filled with the magnetic fluid 270 .
- the magnetic fluid 270 circulates in the gap 380 due to the movement of the fluid 270 from the reservoir ( 260 , FIG. 2 ) to the various components of the motor 180 , including the gap 380 .
- Commercially available AC induction motors do not have the various components described herein.
- Such motors include a stator and a motor separated by ab air gap.
- the gap may filled with a sealed magnetic fluid that includes a base fluid, such as oil or another suitable electrically non-conductive fluid, and magnetic nanoparticles to increase the magnetic permeability of the gap 380 .
- FIG. 4 shows a cut-view 400 of motor section “B” shown in FIG. 2 .
- View 400 shows the housing 210 containing stator laminations 220 , rotor 230 with end rings 332 , and shaft 240 supported by bearings 250 a .
- the magnetic fluid 270 moves along the path 445 as shown by arrow 370 .
- the magnetic fluid 270 circulates around the bearing 250 a via fluid passages 420 as shown by arrow 475 and returns to the reservoir 260 ( FIG. 1 ) via fluid passages 480 as shown by arrow 485 respectively.
- the magnetic fluid 270 also circulates around bearings that are uphole of the bearing 250 a and such fluid returns to the reservoir 260 via a passage, such as passage 488 .
- FIG. 5 shows a non-limiting embodiment of a reservoir that includes or has associated therewith a device that mixes the nanoparticles 280 with the base fluid 272 in the reservoir.
- the shaft 240 may be extended, as shown by extension 510 and a mixer 520 attached to the shaft extension 510 .
- the mixer 520 may include any type of mixing mechanism, including, but not limited to, propellers and fins that continuously churn the magnetic fluid 270 in the reservoir 260 .
- the magnetic fluid may comprise any or more suitable electrically nonconductive fluids and selected amounts of one or more suitable magnetic nanoparticles.
- the term “nano” includes nano-meter size particles and/or micro-meter size particles.
- the size of the magnetic nano particles may be less than about 12 nm and in another non-limiting embodiment the size of the magnetic nanoparticles may be less than 100 nm.
- the nanoparticles may be of the form AB 2 O 4 , in one embodiment, A may be iron, cobalt, manganese, zinc, nickel and combinations thereof and B is iron. In one aspect the size of the AB 2 O 4 particles is less than 100 nm.
- the magnetic nanoparticles include Fe 3 O 4 .
- the size of the Fe 3 O 4 particles may be less than 12 nm.
- magnetic nanoparticles may include electrically and magnetically conductive elements with an electrically non-conductive coating.
- the conductive elements may include, but are not limited to, iron, cobalt, nickel, and their alloys.
- the magnetic nanoparticles are electrically nonconductive and magnetically permeable.
- the magnetic nanoparticles are suspended in the base fluid during circulation of the fluid through the gap.
- the amount of the magnetic nanoparticles in the magnetic fluid is selected to maintain an operating viscosity of the magnetic fluid in the gap between a desired range. In one aspect, the viscosity range of the magnetic fluid at the operating temperature is between 3 and 6 cP.
- reducing the reluctance of the gap 380 by providing higher magnetic permeability gap, such as by filling the gap with a magnetic fluid increases the power factor of the motor because of the reduced inductive loads within the motor.
- the reduced inductive load causes the motor to draw (consume) less current for the same amount of motor break horsepower (BHP) as of a motor with a lower magnetic permeability gap, such as motor with an air gap or filled with an oil.
- BHP motor break horsepower
- utilizing a magnetic fluid in the gap increases the efficiency of the motor.
- the reduced amount of the current used by the motor results in lower heat generated by the stator windings and further improves the overall efficiency of the motor.
- providing a magnetic fluid in the gap between the stator and the rotor of an ESP may increase the power factor of the ESP motor by about 15 percent and decrease the internal temperature in the motor by about 10° F. Additionally, reduced use of the current increases the reliability of the motor because the internal temperature of the motor is reduced. Additionally, simulations demonstrate that suspended magnetic nanoparticles within the base fluid 272 in the gap 380 follow the rotating magnetic field flux lines in the motor, accelerating the fluid 270 around the gap 380 until it reaches a steady state velocity. Such a phenomenon can reduce the friction losses within the motor as shearing losses are reduced.
- incorporating electrically nonconductive magnetic particles in a lubricating fluid in the gap between the rotor and the stator of an AC induction motor increases the overall performance of the AC induction motor.
- use of a magnetic fluid, such as mixture of oil and magnetic nanoparticles may increase the efficiency of the motor to an extent that offsets the reduction in the efficiency due to the friction losses created by the magnetic fluid in the gap when the rotor rotates in the stator.
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Life Sciences & Earth Sciences (AREA)
- Geology (AREA)
- Mining & Mineral Resources (AREA)
- Physics & Mathematics (AREA)
- Environmental & Geological Engineering (AREA)
- Fluid Mechanics (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Geochemistry & Mineralogy (AREA)
- Iron Core Of Rotating Electric Machines (AREA)
- Connection Of Motors, Electrical Generators, Mechanical Devices, And The Like (AREA)
Abstract
In one aspect, an apparatus for use in a wellbore is disclosed that in one non-limiting embodiment includes an AC motor having a rotor and a stator with a gap between the rotor and the stator and a magnetic fluid in the gap that contains an electrically nonconductive fluid and magnetic nanoparticles.
Description
- 1. Field of the Disclosure
- This disclosure relates generally to AC induction motors and to downhole apparatus that utilizes such motors, wherein a magnetic fluid is utilized between the rotor and stator to increase the efficiency of such motors.
- 2. Background of the Art
- Wells (also referred to as “wellbores” or “boreholes”) are drilled in subsurface formations for the production of hydrocarbons (oil and gas). Wellbores often extend to depths of more than 5000 meters (over 15,000 ft.). Many such wellbores are deviated or horizontal. After a wellbore is formed, a casing is typically installed in the wellbore, which is perforated at hydrocarbon-bearing formation zones to allow the hydrocarbons to flow from the formation into the casing. A production string is typically installed inside the casing. The production string includes a variety of flow control devices and a production tubular that extends from the surface to each of the perforated zones. Some wellbores are not cased and in such cases the production string is installed in the open hole. Often, the pressure in the hydrocarbon-bearing subsurface formations is not sufficient to cause the hydrocarbons to flow from the formation to the surface via the production tubing. In such cases, one or more electrical submersible pumps (ESPs) are often deployed in production string to lift the hydrocarbons to the surface.
- An ESP includes a pump driven by an AC induction motor. The rotor and stator of an AC Induction motor are separated by a gap that creates a magnetic field disconnect between the rotor and the stator, which generates a reluctance load within the motor and causes the stator to pull additional current. Additional current pulled by the stator makes the motor inefficient and also generates heat that increases the already high temperature of the motor in the wellbore, which temperature can exceed 300° F. In an AC induction motor, the highest reluctance and thus greatest loss of the magnetic field between the stator and the rotor is due to the gap between the rotor and stator because the medium in the gap (air in most AC induction motors with dielectric oil in most ESP AC induction motors) has low magnetic permeability. Therefore, increasing the magnetic permeability (i.e. reducing the reluctance) of the medium in the gap can improve the overall efficiency of an AC induction motor, reduce the heat generated by the motor and increase the overall efficiency and the operating life of the motor.
- The disclosure herein provides apparatus and methods that in general improve the overall performance of AC induction motors, and particularly motors utilized in ESP pumps for downhole applications.
- In one aspect, an apparatus for use in a wellbore is disclosed that in one non-limiting embodiment includes an electric motor with a gap between a rotor and a stator and a magnetic fluid in the gap that contains an electrically nonconductive fluid and magnetic nanoparticles that increase the magnetic permeability of the gap.
- In another aspect, a method of producing a fluid from a wellbore is disclosed that in one non-limiting embodiment may include: deploying a string in the wellbore that includes a pump driven by an electric motor that includes a magnetic fluid in a gap between a stator and rotor of the electric motor; and operating the pump with the electric motor to produce the fluid from the wellbore.
- Examples of the more important features of the apparatus and methods of the disclosure have been summarized rather broadly in order that the detailed description thereof that follows may be better understood, and in order that the contributions to the art may be appreciated. There are, of course, additional features that will be described hereinafter and which will form the subject of the claims.
- For a detailed understanding of the apparatus and methods disclosed herein, reference should be made to the accompanying drawings and the detailed description thereof, wherein like elements have generally been given like numerals and wherein:
-
FIG. 1 is a schematic diagram of an exemplary production wellbore with an ESP deployed therein, which ESP is made according to one non-limiting embodiment of the disclosure; -
FIG. 2 shows an exemplary motor of an ESP that includes an electrically nonconductive magnetic fluid according to one non-limiting embodiment of the disclosure; -
FIG. 3 shows a cut-view of the motor section “A” of the induction motor ofFIG. 2 showing a magnetic fluid in the gap between the stator and rotor; -
FIG. 4 shows a cut-view of the motor section “B” shown inFIG. 2 ; and -
FIG. 5 shows a non-limiting embodiment of a heat-exchange fluid reservoir and a device that mixes magnetic nanoparticles with a base fluid in the heat-exchange reservoir for circulating the magnetic fluid in the motor ofFIG. 2 . -
FIG. 1 shows anexemplary wellbore system 100 that includes awellbore 110 drilled from thesurface 104 through theearth formation 102. Thewellbore 110 is shown formed through a production zone 120 that contains hydrocarbons (oil and/or gas) therein. Thefluid 150 in the production zone 120 is referred to as the “formation fluid” and typically contains hydrocarbons and water.System 100 includes a string that includes an electrical submersible pump (ESP) 160 that contains apump 184 driven by anelectric motor 180, typically an AC induction motor).Seals 186 separate themotor 180 and thepump 184. Theformation fluid 150 enters thewellbore 110 from the production zone 120 viaperforations 116 andcontrol equipment 130, such as sand screens, valves, etc. known in the art. Theformation fluid 150 enters thepump 184 as shown byarrows 162. The production zone 120 is shown isolated from thewellbore 110 above and belowperforations 116 bypackers packers formation fluid 150. TheESP 160 is shown deployed on aproduction tubing 140 for lifting theformation fluid 150 from the production zone 120 to thesurface 104 via theproduction tubing 140. The fluid level in thewellbore 110 is maintained a certain level above theESP 160 to provide a fluid head to the ESP. Power to theESP 160 is supplied from apower source 162 at the surface and acontroller 164 may be utilized to control the operations of theESP 160. Afluid processing unit 170 at thesurface 104 processes theformation fluid 150 received at thesurface 104.Various sensors 188 may be utilized for determining information about one or more parameters relating to theESP 160, including, but not limited to, temperature, pressure and vibration. -
FIG. 2 shows anexemplary motor 180 of an ESP that includes amagnetic fluid 270 in the gap between the rotor and the stator of themotor 180, according to one non-limiting embodiment of the disclosure. Referring toFIGS. 1 and 2 , themotor 180 includes ahousing 210, abase 212 and an upper threadedend 214 for connection to theseals 186. Themotor 180 includes a stator (laminations) 220 and arotor 230 that rotates ashaft 240.Bearings 250 support therotor 230 and theshaft 240. Themotor 180 further includes a reservoir orchamber 260 that includes themagnetic fluid 270. In one non-limiting embodiment, themagnetic fluid 270 may include any electrically nonconductive fluid 272, such as oil, for lubricating the various components of themotor 230 and a selected amount (by weight or volume) of magnetic nanoparticles 280. The magnetic nanoparticles 280 increase the magnetic permeability of the fluid 272 in the gap and thus reduce the magnetic reluctance of the gap, which reduces the reluctance of the gap between thestator 220 and therotor 230. In operations, therotor 230 rotates theshaft 240 at a relatively high rotational speed, which speed may exceed 3000 rpm. Themagnetic fluid 270 moves up theshaft 240 and passes around thebearings 250 and in the gap between thestator 220 and therotor 230, which in aspects may provide relatively high magnetic permeability in the gap compared to the base fluid 272. -
FIG. 3 shows a cut-view of the motor section “A” shown inFIG. 2 . View 300shows stator 220 withwindings 320 androtor 230 withshaped rotor bars 330. Thegap 380 between thestator 220 and therotor 230 is filled with themagnetic fluid 270. Themagnetic fluid 270 circulates in thegap 380 due to the movement of thefluid 270 from the reservoir (260,FIG. 2 ) to the various components of themotor 180, including thegap 380. Typically, commercially available AC induction motors do not have the various components described herein. Such motors include a stator and a motor separated by ab air gap. In such motors, the gap may filled with a sealed magnetic fluid that includes a base fluid, such as oil or another suitable electrically non-conductive fluid, and magnetic nanoparticles to increase the magnetic permeability of thegap 380. -
FIG. 4 shows a cut-view 400 of motor section “B” shown inFIG. 2 . View 400 shows thehousing 210 containingstator laminations 220,rotor 230 with end rings 332, andshaft 240 supported bybearings 250 a. Themagnetic fluid 270 moves along thepath 445 as shown byarrow 370. Themagnetic fluid 270 circulates around the bearing 250 a viafluid passages 420 as shown byarrow 475 and returns to the reservoir 260 (FIG. 1 ) viafluid passages 480 as shown byarrow 485 respectively. Typically, there is more than one set of bearings. Themagnetic fluid 270 also circulates around bearings that are uphole of the bearing 250 a and such fluid returns to thereservoir 260 via a passage, such aspassage 488. -
FIG. 5 shows a non-limiting embodiment of a reservoir that includes or has associated therewith a device that mixes the nanoparticles 280 with the base fluid 272 in the reservoir. In one aspect, theshaft 240 may be extended, as shown byextension 510 and amixer 520 attached to theshaft extension 510. In one non-limiting embodiment, themixer 520 may include any type of mixing mechanism, including, but not limited to, propellers and fins that continuously churn themagnetic fluid 270 in thereservoir 260. - In aspects, the magnetic fluid (270,
FIGS. 2-4 ) may comprise any or more suitable electrically nonconductive fluids and selected amounts of one or more suitable magnetic nanoparticles. For the purpose of this disclosure, the term “nano” includes nano-meter size particles and/or micro-meter size particles. In one non-limiting embodiment, the size of the magnetic nano particles may be less than about 12 nm and in another non-limiting embodiment the size of the magnetic nanoparticles may be less than 100 nm. In other aspects, the nanoparticles may be of the form AB2O4, in one embodiment, A may be iron, cobalt, manganese, zinc, nickel and combinations thereof and B is iron. In one aspect the size of the AB2O4 particles is less than 100 nm. In another non-limiting embodiment, the magnetic nanoparticles include Fe3O4. In one aspect, the size of the Fe3O4 particles may be less than 12 nm. In other embodiments, magnetic nanoparticles may include electrically and magnetically conductive elements with an electrically non-conductive coating. In aspects, the conductive elements may include, but are not limited to, iron, cobalt, nickel, and their alloys. In each embodiment, the magnetic nanoparticles are electrically nonconductive and magnetically permeable. In aspects, the magnetic nanoparticles are suspended in the base fluid during circulation of the fluid through the gap. In another aspect, the amount of the magnetic nanoparticles in the magnetic fluid is selected to maintain an operating viscosity of the magnetic fluid in the gap between a desired range. In one aspect, the viscosity range of the magnetic fluid at the operating temperature is between 3 and 6 cP. - Referring to
FIGS. 1-4 , in general, reducing the reluctance of thegap 380 by providing higher magnetic permeability gap, such as by filling the gap with a magnetic fluid, increases the power factor of the motor because of the reduced inductive loads within the motor. The reduced inductive load causes the motor to draw (consume) less current for the same amount of motor break horsepower (BHP) as of a motor with a lower magnetic permeability gap, such as motor with an air gap or filled with an oil. Thus, utilizing a magnetic fluid in the gap increases the efficiency of the motor. Additionally, the reduced amount of the current used by the motor results in lower heat generated by the stator windings and further improves the overall efficiency of the motor. In one aspect, providing a magnetic fluid in the gap between the stator and the rotor of an ESP may increase the power factor of the ESP motor by about 15 percent and decrease the internal temperature in the motor by about 10° F. Additionally, reduced use of the current increases the reliability of the motor because the internal temperature of the motor is reduced. Additionally, simulations demonstrate that suspended magnetic nanoparticles within the base fluid 272 in thegap 380 follow the rotating magnetic field flux lines in the motor, accelerating the fluid 270 around thegap 380 until it reaches a steady state velocity. Such a phenomenon can reduce the friction losses within the motor as shearing losses are reduced. Thus, incorporating electrically nonconductive magnetic particles in a lubricating fluid in the gap between the rotor and the stator of an AC induction motor increases the overall performance of the AC induction motor. In motors that typically include an air gap, use of a magnetic fluid, such as mixture of oil and magnetic nanoparticles, may increase the efficiency of the motor to an extent that offsets the reduction in the efficiency due to the friction losses created by the magnetic fluid in the gap when the rotor rotates in the stator. - The foregoing disclosure is directed to certain exemplary embodiments and methods. Various modifications will be apparent to those skilled in the art. It is intended that all such modifications within the scope of the appended claims be embraced by the foregoing disclosure. The words “comprising” and “comprises” as used in the claims are to be interpreted to mean “including but not limited to”. Also, the abstract is not to be used to limit the scope of the claims.
Claims (20)
1. An apparatus for use in a wellbore, comprising:
a motor having a rotor and a stator with a gap between the rotor and the stator; and
a magnetic fluid in the gap that contains an electrically nonconductive fluid and magnetic nanoparticles that increase magnetic permeability of the electrically nonconductive fluid.
2. The apparatus of claim 1 further comprising a pump driven by the motor.
3. The apparatus of claim 1 , wherein the magnetic nanoparticles are electrically nonconductive.
4. The apparatus of claim 1 , wherein the magnetic nanoparticles comprise a composition of AB2O4, wherein A is chosen from a group consisting of iron, manganese, cobalt, zinc, nickel and a combination thereof and B is iron.
5. The apparatus of claim 1 , wherein the magnetic nanoparticles include a core having an electrically-conductive magnetic material and a shell made from an electrically nonconductive material.
6. The apparatus of claim 5 , wherein the core includes a material selected from a group consisting of: a metal; nickel; iron; cobalt; and a combination thereof.
7. The apparatus of claim 1 , wherein the magnetic nanoparticles are suspended or substantially suspended in the electrically nonconductive fluid.
8. The apparatus of claim 1 , wherein size of the magnetic nanoparticles is selected from a group consisting of: less than 12 nm; and between 12 nm and 100 nm.
9. The apparatus of claim 1 , wherein amount of the magnetic nanoparticles in the magnetic fluid is selected to maintain an operating viscosity of the fluid in the gap between a desired range.
10. The apparatus of claim 1 , wherein the magnetic nanoparticles cause the magnetic fluid in the gap to move with magnetic field lines between the stator and the rotor to reduce friction loss caused by the electrically nonconductive fluid.
11. The apparatus of claim 1 further comprising:
a reservoir that contains the magnetic fluid; and
a fluid circulation device that circulates the magnetic fluid in the motor.
12. The apparatus of claim 11 , wherein the circulation mechanism includes fins that cause the magnetic nanoparticles to mix with the electrically nonconductive fluid in the reservoir.
13. A production system comprising:
a production string in a wellbore including a tubing;
an electrical submersible pump that supplies a fluid from the wellbore to the tubing, wherein the electrical submersible pump includes:
a pump;
a motor having a gap between a stator and a rotor; and
a fluid in the gap that contains an electrically nonconductive fluid and magnetic nanoparticles that increase magnetic permeability of the nonmagnetic fluid.
14. The apparatus of claim 13 , wherein the magnetic nanoparticles are selected from a group consisting of: a material having composition of AB2O4, wherein A is selected from a group consisting of iron, manganese, zinc, cobalt, nickel and a combination thereof; and particles having an electrically-conductive core and an electrically nonconductive shell.
15. A method of making an apparatus, comprising:
providing a rotor inside a stator, with a gap between the rotor and the stator; and
filling the gap with a magnetic fluid.
16. The method of claim 15 , wherein the magnetic fluid includes an electrically nonconductive fluid and magnetic nanoparticles.
17. A method of producing a fluid from a wellbore, the method comprising:
deploying a string in the wellbore, the string including a pump driven by an motor, wherein the motor includes a rotor and a stator with a gap between the rotor and the stator and a magnetic fluid in the gap; and
operating the pump with the motor to produce the fluid from the wellbore.
18. The method of claim 17 , wherein the motor includes a fluid reservoir configured to circulate the magnetic fluid through the gap.
19. The method of claim 17 , wherein the magnetic nanoparticles are selected from a group consisting of: a material having composition of AB2O4, and particles having an electrically and magnetically-conductive core and an electrically nonconductive outer surface.
20. The method of claim 17 , wherein size of the magnetic nanoparticles is selected from a group consisting of: less than 12 nm; and between 12 nm and 100 nm.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US14/097,992 US20150159475A1 (en) | 2013-12-05 | 2013-12-05 | Downhole Apparatus Using Induction Motors with Magnetic Fluid in Rotor-Stator Gap |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US14/097,992 US20150159475A1 (en) | 2013-12-05 | 2013-12-05 | Downhole Apparatus Using Induction Motors with Magnetic Fluid in Rotor-Stator Gap |
Publications (1)
Publication Number | Publication Date |
---|---|
US20150159475A1 true US20150159475A1 (en) | 2015-06-11 |
Family
ID=53270637
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US14/097,992 Abandoned US20150159475A1 (en) | 2013-12-05 | 2013-12-05 | Downhole Apparatus Using Induction Motors with Magnetic Fluid in Rotor-Stator Gap |
Country Status (1)
Country | Link |
---|---|
US (1) | US20150159475A1 (en) |
Cited By (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2016204784A1 (en) * | 2015-06-19 | 2016-12-22 | Schlumberger Canada Limited | Electric submersible pump motor monitoring using magnets |
US20170113773A1 (en) * | 2014-06-25 | 2017-04-27 | Wood Hole Oceanographic Institution | Improved-Efficiency Submersible Thruster |
WO2018057169A1 (en) * | 2016-09-21 | 2018-03-29 | Baker Hughes, A Ge Company, Llc | Magnetic pulse actuation arrangement having a reluctance reduction configuration and method |
US10596655B2 (en) | 2016-08-12 | 2020-03-24 | Baker Hughes, A Ge Company, Llc | Magnetic pulse actuation arrangement for downhole tools and method |
US10626705B2 (en) | 2018-02-09 | 2020-04-21 | Baer Hughes, A Ge Company, Llc | Magnetic pulse actuation arrangement having layer and method |
DE102019100938A1 (en) | 2019-01-15 | 2020-07-16 | Volkswagen Aktiengesellschaft | Electric machine with fluid chamber and motor vehicle |
US10801283B2 (en) | 2016-08-12 | 2020-10-13 | Baker Hughes, A Ge Company, Llc | Magnetic pulse actuation arrangement for downhole tools and method |
US20230184069A1 (en) * | 2021-12-14 | 2023-06-15 | Saudi Arabian Oil Company | Electrical submersible pump lubricant and coolant |
Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4570507A (en) * | 1983-08-19 | 1986-02-18 | The United States Of America As Represented By The Secretary Of The Army | Magnetic fluid gyro bearing and caging mechanism |
US20060087393A1 (en) * | 2000-04-03 | 2006-04-27 | Abb Ab | Multiphase induction device |
US20110001370A1 (en) * | 2008-03-03 | 2011-01-06 | Kabushiki Kaisha Kawasaki Precision Machinery | Electric motor integrated hydraulic motor |
US20120282120A1 (en) * | 2011-05-02 | 2012-11-08 | General Electric Company | Electric cable, electric motor and electric submersible pump |
US20130009089A1 (en) * | 2009-12-14 | 2013-01-10 | Teknologian Tutkimuskeskus Vtt | Method of Surfacing Metallic Nanoparticles With Carbon |
US20130148301A1 (en) * | 2011-12-12 | 2013-06-13 | Toyota Motor Engineering & Manufacturing North America | Magnetic fluid cooling devices and power electronics assemblies |
-
2013
- 2013-12-05 US US14/097,992 patent/US20150159475A1/en not_active Abandoned
Patent Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4570507A (en) * | 1983-08-19 | 1986-02-18 | The United States Of America As Represented By The Secretary Of The Army | Magnetic fluid gyro bearing and caging mechanism |
US20060087393A1 (en) * | 2000-04-03 | 2006-04-27 | Abb Ab | Multiphase induction device |
US20110001370A1 (en) * | 2008-03-03 | 2011-01-06 | Kabushiki Kaisha Kawasaki Precision Machinery | Electric motor integrated hydraulic motor |
US20130009089A1 (en) * | 2009-12-14 | 2013-01-10 | Teknologian Tutkimuskeskus Vtt | Method of Surfacing Metallic Nanoparticles With Carbon |
US20120282120A1 (en) * | 2011-05-02 | 2012-11-08 | General Electric Company | Electric cable, electric motor and electric submersible pump |
US20130148301A1 (en) * | 2011-12-12 | 2013-06-13 | Toyota Motor Engineering & Manufacturing North America | Magnetic fluid cooling devices and power electronics assemblies |
Cited By (13)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US10106237B2 (en) * | 2014-06-25 | 2018-10-23 | Woods Hole Oceanographic Institution | Efficiency submersible thruster |
US20170113773A1 (en) * | 2014-06-25 | 2017-04-27 | Wood Hole Oceanographic Institution | Improved-Efficiency Submersible Thruster |
WO2016204784A1 (en) * | 2015-06-19 | 2016-12-22 | Schlumberger Canada Limited | Electric submersible pump motor monitoring using magnets |
US11014191B2 (en) | 2016-08-12 | 2021-05-25 | Baker Hughes, A Ge Company, Llc | Frequency modulation for magnetic pressure pulse tool |
US10596655B2 (en) | 2016-08-12 | 2020-03-24 | Baker Hughes, A Ge Company, Llc | Magnetic pulse actuation arrangement for downhole tools and method |
US10801283B2 (en) | 2016-08-12 | 2020-10-13 | Baker Hughes, A Ge Company, Llc | Magnetic pulse actuation arrangement for downhole tools and method |
US11465229B2 (en) | 2016-08-12 | 2022-10-11 | Baker Hughes, LLC | Frequency modulation for magnetic pressure pulse tool |
GB2569722A (en) * | 2016-09-21 | 2019-06-26 | Baker Hughes A Ge Co Llc | Magnetic pulse actuation arrangement having a reluctance reduction configuration and method |
WO2018057169A1 (en) * | 2016-09-21 | 2018-03-29 | Baker Hughes, A Ge Company, Llc | Magnetic pulse actuation arrangement having a reluctance reduction configuration and method |
US10626705B2 (en) | 2018-02-09 | 2020-04-21 | Baer Hughes, A Ge Company, Llc | Magnetic pulse actuation arrangement having layer and method |
DE102019100938A1 (en) | 2019-01-15 | 2020-07-16 | Volkswagen Aktiengesellschaft | Electric machine with fluid chamber and motor vehicle |
US20230184069A1 (en) * | 2021-12-14 | 2023-06-15 | Saudi Arabian Oil Company | Electrical submersible pump lubricant and coolant |
US11952874B2 (en) * | 2021-12-14 | 2024-04-09 | Saudi Arabian Oil Company | Electrical submersible pump lubricant and coolant |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US20150159475A1 (en) | Downhole Apparatus Using Induction Motors with Magnetic Fluid in Rotor-Stator Gap | |
Takacs | Electrical submersible pumps manual: design, operations, and maintenance | |
US11643911B2 (en) | Integrated electric submersible pumping system with electromagnetically driven impeller | |
US20150114632A1 (en) | High-Speed, Multi-Power Submersible Pumps and Compressors | |
CN105556053A (en) | Submersible electrical machine and method | |
US10253606B1 (en) | Artificial lift | |
EP3427368B1 (en) | Esp motor with sealed stator windings | |
US5465789A (en) | Apparatus and method of magnetic well stimulation | |
US10989027B2 (en) | Artificial lift | |
US10697276B2 (en) | Downhole power generation | |
CN101826760A (en) | Submersible motor with ferrofluid gap | |
WO2014001331A1 (en) | Diffuser for cable suspended dewatering pumping system | |
US10370947B1 (en) | Artificial lift | |
US10196885B2 (en) | Downhole induction heater for oil and gas wells | |
EP3844369B1 (en) | Artificial lift | |
US9885226B2 (en) | Heat exchange in downhole apparatus using core-shell nanoparticles | |
US10280721B1 (en) | Artificial lift | |
US10837268B2 (en) | Methods and apparatus for producing fluids from a well | |
Xiao et al. | Induction vs. permanent-magnet motors for ESP applications | |
US20150091306A1 (en) | System and method for downhole power generation using a direct drive permanent magnet machine | |
Albori et al. | Comparative Simulation Studies of ESP Permanent Magnet and Induction Current Motors in ESP Selective Applications | |
Yashin et al. | Characteristics Analysis of Linear Submersible Electric Motors for Oil Production | |
US11125059B2 (en) | Downhole-type tool for artificial lift | |
US11952874B2 (en) | Electrical submersible pump lubricant and coolant | |
US12031415B2 (en) | Drilling fluid through-flow axial flux turbine generator |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: BAKER HUGHES INCORPORATED, TEXAS Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:PRIETO, CARLOS A.;KUMAR, DEEPAK;RICHARD, BENNETT M.;AND OTHERS;REEL/FRAME:031811/0074 Effective date: 20131206 |
|
STCB | Information on status: application discontinuation |
Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION |