Electric submersible pump with reduced vibration

Patent metadata

Field	Value
Publication number	US-2016222984-A1
Application number	US-201414917563-A
Country	US
Kind code	A1
Filing date	Sep 15, 2014
Priority date	Sep 15, 2013
Publication date	Aug 4, 2016
Grant date	—

Abstract

An electric submersible pump (ESP) with reduced vibration is provided. In an implementation, an ESP section has radial bearings placed at shaft locations of reduced vibration to reduce wear. The locations of reduced vibration are selected to avoid areas of high vibration and vibrational waves that reinforce each other due to structure resonance and natural excitation frequencies. In an implementation, a radial bearing is positioned at a node of reduced vibration of a standing vibrational wave. In an implementation, a succession of multiple radial bearings are spaced at different intervals from each other to avoid conventional even spacing of the bearings that causes standing waves, resonance waves, and vibrational waves at natural excitation frequencies. In an implementation, a span between adjacent radial bearings is selected to spare other adjacent bearings at different spans the effects of vibrations that may extend over a range of excitation frequencies in the ESP section.

First claim

1 . An apparatus, comprising:
at least one electric submersible pump (ESP) section; at least a shaft for rotation in the at least one ESP section; locations of increased vibration and locations of reduced vibration along the shaft due to at least one natural frequency of vibration of the at least one ESP section and shaft; and a bearing for radial support of the shaft, positioned at one of the locations of reduced vibration along the shaft.

2 . The apparatus of claim 1 , further comprising a bearing support in the ESP section disposed along the shaft to position the bearing at the location of reduced vibration along the shaft.

3 . The apparatus of claim 1 , wherein the bearing is positioned at a vibrational node of a standing wave, the vibrational node having reduced vibration.

4 . The apparatus of claim 1 , wherein the bearing is positioned along the shaft to avoid a vibrational antinode of a standing wave, the vibrational antinode having increased vibration.

5 . The apparatus of claim 1 , further comprising multiple bearings, wherein the multiple bearings are spaced at different intervals from each other along the shaft to reduce vibrational wear on the multiple bearings.

6 . The apparatus of claim 5 , wherein neighboring or adjacent bearings are spaced at intervals calculated to reduce or defeat wave and vibration phenomena that increase wear on the bearings and shaft.

7 . The apparatus of claim 5 , wherein the bearings are located to reduce an effect of a destructive resonance or to reduce an effect of vibrational waves reinforcing each other.

8 . The apparatus of claim 5 , wherein a span between two bearings of the multiple bearings is selected to possess a natural vibrational frequency that does not coincide with a natural frequency, an excitation frequency, or a resonance of the at least one ESP section.

9 . The apparatus of claim 5 , wherein a first span between two bearings of the multiple bearings has a length that cancels out natural vibrational frequencies of one or more nearby spans between bearings of the multiple bearings.

10 . The apparatus of claim 5 , wherein when the ESP is operated over a wide range of excitation frequencies, a span between two bearings of the multiple bearings along the shaft has a length that prevents a nearby span between bearings of the multiple bearings from being excited at an excitation frequency in the range of excitation frequencies.

11 . The apparatus of claim 10 , wherein spacings between the multiple bearings along the shaft are arranged to minimize or reduce the number of bearings at or near an antinode of increased vibrational energy over the range of excitation frequencies.

12 . The apparatus of claim 5 , wherein at least two adjacent bearings of the multiple bearings have a distance between each other that varies from a distance between another two adjacent bearings of the multiple bearings by approximately one-twentieth or five percent of the distance between the other two adjacent bearings.

13 . The apparatus of claim 5 , wherein each distance between adjacent bearings of the multiple bearings is unique.

14 . The apparatus of claim 5 , wherein each distance between two adjacent bearings of the multiple bearings varies by at least one-twentieth or 5 percent of the distance between two bearings on either adjacent side of the two adjacent bearings.

15 . An electric submersible pump (ESP) section, comprising:
at least one shaft section capable of rotation; at least four successive radial bearings along the at least one shaft section; and a first bearing span between two adjacent radial bearings of the at least four successive radial bearings having a length at least 5% different then at least a second bearing span between two other adjacent radial bearings of the at least four successive radial bearings.

16 . The ESP section of claim 15 , wherein the first bearing span prevents the second bearing span from vibrating at a resonance frequency of the ESP section; and
wherein the first bearing span prevents the second bearing span from vibrating at a natural excitation frequency of the at least one shaft section.

17 . The ESP section of claim 15 , wherein the ESP section is selected from the group consisting of a pump, a motor, and a protector.

18 . The ESP of claim 15 , wherein a second radial bearing and a third radial bearing of the at least four successive radial bearings are spaced with at least a 5% difference in distance between each other than a spacing between either the first and second bearings or the third and fourth bearings.

19 . A method, comprising:
detecting a location of reduced vibration along a shaft of an electric submersible pump (ESP) component; and positioning a radial bearing to support the shaft at the location of reduced vibration.

20 . The method of claim 19 , further comprising determining a first span between radial bearings along the shaft; and
varying an adjacent span between radial bearings along the shaft by at least 5% from the first span.

Assignees

• Schlumberger Technology Corp

Inventors

• Lam Hao
• Watson Arthur I
• Orban Jacques
• De Camargo Lauro

Classifications

• F04D29/666

  by means of rotor construction or layout, e.g. unequal distribution of blades or vanes · CPC title

• F04D29/046

  Bearings · CPC title

• F04D13/06

  the pump being electrically driven · CPC title

• F04D13/10 Primary

  adapted for use in mining bore holes · CPC title

• F04D13/08

  for submerged use · CPC title