US20160273324A1 - Downhole Compressor - Google Patents

Downhole Compressor Download PDF

Info

Publication number
US20160273324A1
US20160273324A1 US15/053,274 US201615053274A US2016273324A1 US 20160273324 A1 US20160273324 A1 US 20160273324A1 US 201615053274 A US201615053274 A US 201615053274A US 2016273324 A1 US2016273324 A1 US 2016273324A1
Authority
US
United States
Prior art keywords
rotor
impeller
downhole compressor
compressor according
downhole
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
Application number
US15/053,274
Other languages
English (en)
Inventor
Kazuyuki Yamaguchi
Yohei MAGARA
Toyomi Yoshida
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Hitachi Ltd
Original Assignee
Hitachi Ltd
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
Application filed by Hitachi Ltd filed Critical Hitachi Ltd
Assigned to HITACHI, LTD. reassignment HITACHI, LTD. ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: Magara, Yohei, YOSHIDA, TOYOMI, YAMAGUCHI, KAZUYUKI
Publication of US20160273324A1 publication Critical patent/US20160273324A1/en
Abandoned legal-status Critical Current

Links

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
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
    • F04D25/00—Pumping installations or systems
    • F04D25/02—Units comprising pumps and their driving means
    • F04D25/06—Units comprising pumps and their driving means the pump being electrically driven
    • F04D25/0606—Units comprising pumps and their driving means the pump being electrically driven the electric motor being specially adapted for integration in the pump
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
    • F04D29/00—Details, component parts, or accessories
    • F04D29/05—Shafts or bearings, or assemblies thereof, specially adapted for elastic fluid pumps
    • F04D29/051—Axial thrust balancing
    • F04D29/0516—Axial thrust balancing balancing pistons
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
    • F04D29/00—Details, component parts, or accessories
    • F04D29/05—Shafts or bearings, or assemblies thereof, specially adapted for elastic fluid pumps
    • F04D29/056—Bearings
    • F04D29/058—Bearings magnetic; electromagnetic

Definitions

  • the present invention relates to a downhole compressor, and particularly relates to a downhole compressor suitable for securing reliability at the time of high-speed rotation.
  • a downhole compressor installed inside a natural gas well and adapted to assist production of natural gas is installed inside a borehole having a diameter of approximately several centimeters, size reduction of the device is needed.
  • a gas production amount may be reduced because a flow passage cross-sectional area is reduced.
  • centrifugal force used for gas compression is reduced due to reduction of an outer diameter size of an impeller due to size reduction of the compressor. Therefore, there may be possibility that a pressure ratio is reduced and sufficient pressure cannot be obtained for gas production.
  • a rotational speed of a rotor is required to be accelerated in the downhole compressor in order to compensate such a reduced flow rate and reduced pressure ratio caused by size reduction.
  • a gas flow rate is increased because a flow speed is increased by accelerating rotation of the rotor.
  • the pressure ratio is increased because the centrifugal force is increased by acceleration.
  • a downhole compressor disclosed in U.S. Pat. No. 7,338,262 is operated at a high rotational speed of 20,000 rpm to 50,000 rpm.
  • a thrust load acting on the impeller may be increased due to mixture of the foreign matters inside the natural gas.
  • load capacity is generally small compared to an oil bearing and the like. Therefore, it is difficult to design a bearing that can handle a large thrust load caused by mixture of the foreign matters.
  • the present invention is directed to providing a downhole compressor in which reliability can be secured at the time of high-speed rotation even when natural gas properties are changed due to mixture of foreign matters and the like.
  • the present invention provides a downhole compressor, including: a casing disposed inside a well; a rotor built inside the casing; and an impeller disposed at the rotor, wherein an electromagnetic control unit configured to electromagnetically control a relative position of the rotor inside the casing is provided.
  • the present invention is the downhole compressor characterized in including a bearingless motor as an electromagnetic control unit.
  • the present invention is the downhole compressor characterized in that the electromagnetic control unit includes a magnetic bearing.
  • the present invention is the downhole compressor characterized in that a pressure regulating chamber is provided at a back surface portion of the impeller, a shaft sealing device is provided between an outlet portion of the impeller and the pressure regulating chamber, and a communication unit is provided between the pressure regulating chamber and an inlet portion of the impeller.
  • the present invention is the downhole compressor characterized in that a displacement meter to measure axial displacement of the rotor is provided, and the displacement meter is disposed at the back surface portion of the impeller.
  • the present invention is the downhole compressor characterized in that a leakage amount at the shaft sealing device is reduced when the rotor is displaced to an axial upstream side.
  • the present invention is the downhole compressor characterized in that the shaft sealing device includes axial clearance, and the axial clearance is reduced when the rotor is displaced to the axial upstream side.
  • the present invention is the downhole compressor characterized in that a control device for the electromagnetic control unit is disposed on the ground.
  • the present invention is the downhole compressor characterized in that an operating condition is determined by using a control signal of the electromagnetic control unit.
  • the rotor can be supported by electromagnetically controlling a position of the rotor without using lubricant such as natural gas. Therefore, deterioration of reliability of the bearing caused by heat generation of the lubricant can be prevented. Further, reliability of the device can be stably secured because there is no effect on supporting characteristics from change of the natural gas properties.
  • FIG. 1 is a cross-sectional view illustrating a main portion of a downhole compressor according to a first embodiment of the present invention
  • FIG. 2 is a cross-sectional view illustrating an installation state of the downhole compressor according to the first embodiment of the present invention
  • FIG. 3 is a cross-sectional view illustrating a main portion of a downhole compressor according to a second embodiment of the present invention
  • FIG. 4 is a cross-sectional view illustrating a main portion of a downhole compressor according to a third embodiment of the present invention.
  • FIG. 5 is a cross-sectional view illustrating a main portion of a downhole compressor according to a fourth embodiment of the present invention.
  • FIG. 1 is a cross-sectional view illustrating a main portion of a downhole compressor according to a first embodiment of the present invention.
  • An impeller 3 is disposed at an end portion of a rotor 2 , and natural gas is pressurized by rotation of the rotor 2 .
  • a thrust load generated at the impeller 3 is supported by a thrust bearing not illustrated.
  • a bearingless motor 4 disposed at center of the rotor 2 generates drive torque at the rotor 2 and simultaneously supports the rotor 2 by generating electromagnetic force such that relative positions between the rotor 2 and a casing not illustrated is kept substantially constant. Since the position of the rotor 2 is electromagnetically controlled, supporting characteristics of the rotor 2 do not change even when the natural gas properties are changed, and the rotor 2 can be stably supported.
  • FIG. 2 is a cross-sectional view illustrating an installation state of the downhole compressor 1 according to the present embodiment.
  • the downhole compressor 1 is installed inside a natural gas well 5 .
  • a controller 6 of the bearingless motor 4 is disposed on the ground 15 , and the downhole compressor 1 and the controller 6 are connected via a cable 7 . Since the controller 6 is disposed on the ground 15 , a control signal of the bearingless motor 4 can be easily extracted and used for setting an operating condition of the downhole compressor 1 .
  • Electromagnetic control force to control the position of the rotor 2 inside the casing of the downhole compressor 1 is proportional to the square of control current. Therefore, dynamic fluid force that acts on the rotor 2 can be grasped by monitoring the control current.
  • the natural gas properties and unsteadiness thereof can be estimated by collating the fluid force, operating characteristics of the impeller 3 , drive torque, rotational speed, and so on.
  • An operating condition such as the rotational speed can be appropriately set by collating the estimated gas properties and operating characteristics of the impeller 3 , and excessive fluid force that may act on the impeller 3 and unstable phenomena of the fluid can be prevented. For example, in the case where the fluid force is increased by increased liquid content inside the gas, the fluid force can be decreased by reducing the rotational speed of the rotor 2 , and reliability of the device can be secured.
  • FIG. 3 is a cross-sectional view illustrating a main portion of a downhole compressor 1 according to the present embodiment.
  • a component denoted by a reference sign same as a first embodiment has the same structure and effects. Therefore, a description therefor will be omitted and only a different point from the above-described first embodiment will be described.
  • a motor 8 is disposed as a unit to generate drive torque at a rotor 2 instead of a bearingless motor 4 .
  • a magnetic bearing 9 disposed at a casing not illustrated is used instead of the bearingless motor 4 .
  • radial magnetic bearings 9 a to support a load in an axial orthogonal direction are disposed.
  • a thrust collar 10 to transmit a thrust load is disposed between the motor 8 and the impeller 3 , and thrust magnetic bearings 9 b are disposed on both sides of the thrust collar 10 .
  • a displacement sensor and an electromagnetic actuator are built inside the magnetic bearing 9 , and electromagnetic force is controlled such the position of the rotor 2 inside the casing is kept substantially constant. Load capacity can be increased by using the magnetic bearing 9 independent from the motor 8 , and reliability can be improved.
  • FIG. 4 Next, a third embodiment of the present invention will be described using FIG. 4 .
  • FIG. 4 is a cross-sectional view illustrating a main portion of a downhole compressor 1 according to the present embodiment.
  • a component denoted by a reference sign same as above-described embodiments has the same structure and effects. Therefore, a description therefor will be omitted and only a different point from the above-described embodiments will be described.
  • pressure in a flow passage portion of an impeller 3 is increased from an inlet portion 3 b to an outlet portion 3 a , but pressure on a back surface of the impeller 3 is substantially equal to the pressure at the outlet portion 3 a of the impeller 3 .
  • a thrust load is generated at the impeller 3 in a direction from the back surface side to a flow passage side.
  • Load capacity of a magnetic bearing 9 is small compared with a general oil lubrication bearing. Therefore, in the case of applying the magnetic bearing 9 in the downhole compressor 1 , the thrust load is preferably reduced as much as possible.
  • a shaft sealing device 12 is disposed at a back surface portion of the impeller 3 and forms a pressure regulating chamber 11 . Further, a communication unit 13 is provided between the pressure regulating chamber 11 and the inlet portion 3 b of the impeller 3 and decreases pressure at the pressure regulating chamber 11 . As a result, the thrust load can be reduced by decreasing the pressure at the back surface of the impeller 3 , and reliability of a thrust magnetic bearing 9 b can be improved.
  • axial clearance of the shaft sealing device 12 is preferably kept constant. Therefore, a position sensor 14 for an axial rotor 2 used to control the thrust magnetic bearing 9 b is provided at the back surface portion of the impeller 3 , and the thrust magnetic bearing 9 b is controlled so as to keep the clearance of shaft sealing device 12 constant.
  • an axial groove is provided as the communication unit 13 at a fixing portion of the impeller 3 of the rotor 2 .
  • the axial groove may also be provided on the impeller 3 side and a communication hole may be provided at the rotor 2 and the impeller 3 .
  • FIG. 5 is a cross-sectional view illustrating a main portion of a downhole compressor 1 according to the present embodiment.
  • a component denoted by a reference sign same as above-described embodiments has the same structure and effects. Therefore, a description therefor will be omitted and only a different point from the above-described embodiments will be described.
  • a shaft sealing device 12 is disposed at an outer diameter portion of an impeller 3 .
  • the shaft sealing device 12 includes a so-called labyrinth seal 12 a opposing to an outer periphery of the impeller 3 and an axial clearance 12 b projecting to a flow passage side of the impeller 3 .
  • a leakage amount at the shaft sealing device 12 is increased, back pressure of the impeller 3 is increased and a thrust load is increased, thereby moving a rotor 2 to an axial upstream side.
  • the axial clearance 12 b at the shaft sealing device 12 becomes small, and the leakage amount is reduced at the shaft sealing device 12 . Therefore, the thrust load is reduced and the rotor 2 is pushed back to an axial downstream side. Since the thrust load is thus automatically adjusted in accordance with movement of the rotor 2 , the thrust load that acts on a thrust magnetic bearing 9 b can be properly adjusted and reliability of the device can be improved.
  • the thrust magnetic bearing 9 b can be controlled so as to keep the clearance at the shaft sealing device 12 constant by providing a position sensor 14 at an axial rotor 2 illustrated in the third embodiment.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Mining & Mineral Resources (AREA)
  • Geology (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • General Life Sciences & Earth Sciences (AREA)
  • Geochemistry & Mineralogy (AREA)
  • Environmental & Geological Engineering (AREA)
  • Electromagnetism (AREA)
  • Structures Of Non-Positive Displacement Pumps (AREA)
  • Magnetic Bearings And Hydrostatic Bearings (AREA)
  • Sealing Of Bearings (AREA)
US15/053,274 2015-03-18 2016-02-25 Downhole Compressor Abandoned US20160273324A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2015-054152 2015-03-18
JP2015054152A JP6389785B2 (ja) 2015-03-18 2015-03-18 ダウンホール圧縮機

Publications (1)

Publication Number Publication Date
US20160273324A1 true US20160273324A1 (en) 2016-09-22

Family

ID=55640526

Family Applications (1)

Application Number Title Priority Date Filing Date
US15/053,274 Abandoned US20160273324A1 (en) 2015-03-18 2016-02-25 Downhole Compressor

Country Status (3)

Country Link
US (1) US20160273324A1 (ja)
EP (1) EP3088656B1 (ja)
JP (1) JP6389785B2 (ja)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2018125781A1 (en) * 2016-12-28 2018-07-05 Upwing Energy, LLC Downhole blower system with passive radial bearings
CN111188778A (zh) * 2018-11-14 2020-05-22 财团法人工业技术研究院 磁浮离心式压缩机及其控制方法
US11300131B2 (en) * 2017-05-09 2022-04-12 Daikin Industries, Ltd. Electric motor system and turbo compressor provided therewith
WO2022222563A1 (zh) * 2021-04-19 2022-10-27 青岛海尔生物医疗科技有限公司 离心机

Family Cites Families (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS56113101U (ja) * 1980-02-01 1981-09-01
US5355042A (en) * 1988-09-09 1994-10-11 University Of Virginia Patent Foundation Magnetic bearings for pumps, compressors and other rotating machinery
US5605193A (en) * 1995-06-30 1997-02-25 Baker Hughes Incorporated Downhole gas compressor
JP2001254693A (ja) * 2000-03-09 2001-09-21 Tokyo Buhin Kogyo Co Ltd 磁気浮上式シールレスポンプ
GB2362901B (en) * 2000-06-03 2004-03-31 Weir Pumps Ltd Downhole gas compression
GB2384274A (en) 2002-01-16 2003-07-23 Corac Group Plc Downhole compressor with electric motor and gas bearings
EP1895180A2 (en) * 2006-08-30 2008-03-05 Ebara Corporation Magnetic bearing device, rotating system therewith and method of identification of the model of the main unit in a rotating system
EP2677177B1 (en) * 2012-06-22 2020-10-14 Skf Magnetic Mechatronics Electric centrifugal compressor for vehicles
US20140271270A1 (en) * 2013-03-12 2014-09-18 Geotek Energy, Llc Magnetically coupled expander pump with axial flow path

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2018125781A1 (en) * 2016-12-28 2018-07-05 Upwing Energy, LLC Downhole blower system with passive radial bearings
US10465489B2 (en) * 2016-12-28 2019-11-05 Upwing Energy, LLC Downhole blower system with passive radial bearings
US20200072030A1 (en) * 2016-12-28 2020-03-05 Upwing Energy, LLC Downhole blower system with passive radial bearings
US11686319B2 (en) * 2016-12-28 2023-06-27 Upwing Energy, Inc. Downhole blower system with a passive magnetic radial bearing assembly
AU2017387014B2 (en) * 2016-12-28 2023-11-23 Upwing Energy, Inc. Downhole blower system with passive radial bearings
US11300131B2 (en) * 2017-05-09 2022-04-12 Daikin Industries, Ltd. Electric motor system and turbo compressor provided therewith
CN111188778A (zh) * 2018-11-14 2020-05-22 财团法人工业技术研究院 磁浮离心式压缩机及其控制方法
US10920784B2 (en) 2018-11-14 2021-02-16 Industrial Technology Research Institute Magnetic bearing centrifugal compressor and controlling method thereof
WO2022222563A1 (zh) * 2021-04-19 2022-10-27 青岛海尔生物医疗科技有限公司 离心机

Also Published As

Publication number Publication date
EP3088656B1 (en) 2018-01-17
JP6389785B2 (ja) 2018-09-12
JP2016173084A (ja) 2016-09-29
EP3088656A1 (en) 2016-11-02

Similar Documents

Publication Publication Date Title
EP3088656B1 (en) Downhole compressor
KR100999015B1 (ko) 터보 기계
JP5928827B2 (ja) 遠心圧縮機の動的スラストバランス調整
CN109185387B (zh) 弹性支承主动液压减振装置及其转子试验台
JP5650372B2 (ja) 受動軸方向平衡システムを含む回転機
WO1991014853A1 (en) Control system for regulating the axial loading of a rotor of a fluid machine
US6851862B2 (en) Gas lubricated thrust bearing
US10107298B2 (en) Turbo machine
CZ20021454A3 (cs) Zařízení pro kompenzaci axiálního posunu u turbostrojů
Bidaut et al. The challenge for the accurate determination of the axial rotor thrust in centrifugal compressors
JP2008215107A (ja) 圧縮機
WO2014168488A1 (en) Subsea turbomachine assembly with magnetic lift and magnetic coupling
Childs et al. Static performance of smooth liquid annular seals in the transition and turbulent regimes
CN109723674B (zh) 一种用于压气机转子的可转动内端壁机匣
KR100616153B1 (ko) 축추력 제어부재가 설치된 원심형 터보기계
EP3857072B1 (en) A multistage pump with axial thrust optimization
US10634152B2 (en) Multi-bearing design for shaft stabilization
US3692373A (en) Slipper bearing lubrication and seal
JP4376021B2 (ja) 流体軸受
JPH04351318A (ja) 気体軸受の給気制御方法及び装置
KR20150012912A (ko) 축하중 저감 수단이 구비되는 터보발전기
KR102197850B1 (ko) 회전장치 및 그 제동방법
RU2314436C1 (ru) Шнекоцентробежный насос
Yang et al. Research on nonlinear fluid-solid interaction dynamic lubrication in floating ring bearings
Preuss Application of Hydrostatic Bearings in sCO

Legal Events

Date Code Title Description
AS Assignment

Owner name: HITACHI, LTD., JAPAN

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:YAMAGUCHI, KAZUYUKI;MAGARA, YOHEI;YOSHIDA, TOYOMI;SIGNING DATES FROM 20160107 TO 20160108;REEL/FRAME:037830/0254

STCB Information on status: application discontinuation

Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION