U.S. patent application number 13/863322 was filed with the patent office on 2013-10-17 for instrumenting high reliability electric submersible pumps.
This patent application is currently assigned to Schlumberger Technology Corporation. The applicant listed for this patent is SCHLUMBERGER TECHNOLOGY CORPORATION. Invention is credited to Jostein Engeseth Fonneland, Yi Sin Loh, Kelvin Chee Tiong Neo, Varun Vinaykumar Nyayadhish, Min Shi, Kok Onn Toh.
Application Number | 20130272898 13/863322 |
Document ID | / |
Family ID | 49325263 |
Filed Date | 2013-10-17 |
United States Patent
Application |
20130272898 |
Kind Code |
A1 |
Toh; Kok Onn ; et
al. |
October 17, 2013 |
Instrumenting High Reliability Electric Submersible Pumps
Abstract
Instrumentation for high reliability electric submersible pumps
(ESPs) is provided. Comprehensive sensors placed throughout ESP
components enable monitoring, analysis, and intervention to improve
performance of ESP components and provide high reliability and long
life for components. Example ESP sensors used to protectively
monitor an ESP string may include electrical current leakage
detectors, temperature sensors at the pothead, fiber optics used as
distributed temperature sensors in the motor stator and windings of
the motor, water cut sensors to determine quality of hydrocarbon
being produced, tachometer and torque sensors to detect the speed
of rotating shafts of the motors and pumps, temperature and
vibration sensors for rotor bearings and thrust members, and
wye-point imbalance detectors for balancing electrical loads on the
three phases in a wye system. Interpretation and control modules
analyze the sensor input and apply actions that improve performance
and lengthen lifespan of components.
Inventors: |
Toh; Kok Onn; (Singapore,
SG) ; Fonneland; Jostein Engeseth; (Oslo, NO)
; Shi; Min; (Singapore, SG) ; Loh; Yi Sin;
(Singapore, SG) ; Neo; Kelvin Chee Tiong;
(Singapore, SG) ; Nyayadhish; Varun Vinaykumar;
(Singapore, SG) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
SCHLUMBERGER TECHNOLOGY CORPORATION |
Sugar Land |
TX |
US |
|
|
Assignee: |
Schlumberger Technology
Corporation
Sugar Land
TX
|
Family ID: |
49325263 |
Appl. No.: |
13/863322 |
Filed: |
April 15, 2013 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
61625651 |
Apr 17, 2012 |
|
|
|
Current U.S.
Class: |
417/44.1 |
Current CPC
Class: |
F04D 13/10 20130101;
F04D 15/00 20130101; E21B 43/128 20130101; F04D 15/0088
20130101 |
Class at
Publication: |
417/44.1 |
International
Class: |
F04D 15/00 20060101
F04D015/00 |
Claims
1. A system, comprising: an electric submersible pump (ESP) string,
including at least one ESP motor; a sensor associated with at least
a shaft bearing or a rotor bearing of each section of the ESP
string; a monitoring module for dynamically tracking data of each
sensor; and a control module for changing an operating parameter of
a component of the ESP string based on the dynamic tracking of the
sensor data.
2. The system of claim 1, further comprising a fiber optic strand
to perform distributed sensing of temperatures along the ESP
string, the control module changing an operating parameter of at
least one component of the ESP string based on the distributed
sensing of the temperatures.
3. The system of claim 2, wherein the fiber optic strand runs
internally in at least one motor stator of the ESP string.
4. The system of claim 2, wherein the distributed sensing of
temperature using the fiber optic strand includes sensing a
temperature associated with at least a shaft bearing or a rotor
bearing of the ESP string.
5. The system of claim 4, further comprising a vibration sensor to
dynamically track vibrations generated by the ESP string.
6. The system of claim 5, wherein a vibration module obtains
vibration spectral data up to 1 kHz for a select component along
the ESP string.
7. The system of claim 5, wherein each vibration sensor dynamically
tracks a vibration associated with a pump bearing or a motor
bearing of the ESP string.
8. The system of claim 7, wherein the control module changes an
operating parameter of at least one component of the ESP string
based on analysis of at least one temperature and at least one
vibration in the ESP string.
9. The system of claim 1, further comprising a fiber optic strand
to measure a distributed temperature profile or a platinum
resistive thermocouple device (RTD) to measure a temperature of a
power cable of the ESP string or along a motor lead extension (MLE)
cable of the ESP string.
10. The system of claim 1, further comprising a tachometer (RPM)
sensor or a torque sensor packaged around at least a shaft for
monitoring a rotational speed and a torque of the shaft.
11. The system of claim 1, further comprising at least a water cut
sensor or at least a chemical sensor located along the ESP string
to perform oil purity measurements or chemical measurements.
12. The system of claim 1, further comprising a pressure sensor
located in the ESP string to perform a pressure measurement.
13. The system of claim 12, wherein at least one pressure sensor
measures a differential pressure inside and outside of a bellows in
the ESP string.
14. The system of claim 13, further comprising an electrical relief
valve in tandem with a mechanical relief valve for relieving a
pressure in the bellows.
15. The system of claim 1, further comprising an electrical current
leakage sensor.
16. The system of claim 1, further comprising a wye-point imbalance
detector for detecting an unbalanced phase in a wye system.
17. The system of claim 1, further comprising a thrust member
sensor to measure one of a temperature, a strain, or a proximity of
a thrust member to a thrust member runner in the ESP string.
18. A system, comprising: an electric submersible pump (ESP); a
control module to change an operating parameter of a component of
the ESP based on dynamic tracking of data from multiple types of
sensors arrayed along the ESP; a sensor associated with at least a
bearing of each component of the ESP; and a sensor selected from
the group of sensors consisting of bearing temperature sensors,
bearing vibration sensors, stator temperature sensors, distributed
temperature profile sensors, power cable temperature profile
sensors, motor lead temperature profile sensors, shaft RPM sensors,
shaft torque sensors, water cut sensors, water ingress sensors,
chemical sensors, bellows pressure sensors, thrust bearing
temperature sensors, thrust bearing strain sensors, thrust bearing
proximity sensors, electrical current leakage sensors, and
wye-point imbalance sensors.
19. The system of claim 18, wherein the multiple types of sensors
arrayed along the ESP are multiplexed along the length of a fiber
optic strand by one of: assigning different wavelengths of light
for each sensor, or sensing a time delay as light passes along the
fiber through each sensor, wherein an optical time-domain
reflectometer determines the time delay.
20. The system of claim 18, wherein a control module changes an
operating characteristic of at least a segment of the ESP based on
monitoring the multiplexed sensors, by varying a power, a voltage,
an amperage, a frequency, a pump speed, a motor speed, a valve
state, a pressure, a flow, a temperature, or a vibration in a
selected spatial plane, of the at least one component of the ESP.
Description
RELATED APPLICATIONS
[0001] This patent application claims the benefit of priority to
U.S. Provisional Patent Application No. 61/625,651 filed Apr. 17,
2012 and incorporated herein by reference in its entirety.
BACKGROUND
[0002] In artificial lift for the production of hydrocarbons and
other resources, especially for subsea operations, it is important
to increase the reliability of electric submersible pumps (ESPs)
and their associated components (hereinafter, "ESP strings")
because the cost of intervention and repair can be very great.
Conventional downhole monitoring to help avoid repairs is limited
to the intake location and the discharge location of a conventional
ESP string and measures only pressure, temperature, and vibration
at the intake and discharge locations of the ESP string. Data from
such conventional monitoring is sent to surface equipment for
conventional interpretation, but offers only a rudimentary view of
problems that may be occurring along the ESP string.
SUMMARY
[0003] Instrumentation for high reliability electric submersible
pumps (ESPs) is provided. An example system includes an ESP string,
a sensor associated with a shaft bearing or a rotor bearing of each
section of the ESP string, a monitoring module for dynamically
tracking data of each sensor, and a control module for changing an
operating parameter of the ESP string based on the dynamic tracking
of the sensor data. Embedded fiber optics can monitor distributed
temperatures of motor coils and can also multiplex sensor data sent
to the surface. Sensors may monitor bearing temperatures, bearing
vibration, stator temperatures, distributed temperature profiles,
power cable temperatures, shaft RPM, shaft torque, water cut, water
ingress, fluid chemistry, bellows pressure, thrust bearing
temperature, strain, and wear; electrical current leakage, and
wye-point electrical phase imbalance. This summary section is not
intended to give a full description of instrumenting high
reliability electric submersible pumps. A detailed description with
example embodiments follows.
BRIEF DESCRIPTION OF THE DRAWINGS
[0004] FIG. 1 is a diagram of an example electric submersible pump
(ESP) string, with running fiber optic strand to monitor
components.
[0005] FIG. 2 is a diagram of an example pump component of the ESP
string, with thrust member.
[0006] FIG. 3 is a diagram of an example submersible motor arrayed
with sensors for high reliability.
[0007] FIG. 4 is a diagram of an example protector arrayed with
sensors for high reliability.
[0008] FIG. 5 is a diagram of an example thrust bearing assembly
arrayed with sensors for high reliability.
[0009] FIG. 6 is a diagram of an example pump and pump intake
arrayed with sensors for high reliability.
[0010] FIG. 7 is a block diagram of an example high reliability
engine.
[0011] FIG. 8 is a block diagram of an example device for hosting
the high reliability engine.
[0012] FIG. 9 is a flow diagram of an example method of improving
performance and reliability of an ESP string.
DETAILED DESCRIPTION
[0013] This disclosure describes instrumenting high reliability
electric submersible pumps (ESPs). An example system described
herein provides high reliability ESP strings that have
comprehensive sensor features and enhanced interpretation of the
comprehensive sensors. The comprehensive sensor deployment enables
enhanced monitoring, analysis, and control of many parts of the ESP
string, not just the intake and discharge locations, and provides
extended lifespan of components. In the description below, the
terms "control" and "intervention" (or "intervene") are used
interchangeably. The example system includes new tools providing
various enhanced monitoring and intervention capabilities for an
ESP string.
[0014] Overview
[0015] An example ESP string is outfitted with numerous sensors
throughout to provide improved operation and high reliability. The
example submersible motor may include current leakage sensor(s) to
detect grounding or loss of electrical current at likely locations,
temperature sensor(s) at the pothead, fiber optics used as
distributed temperature sensor(s) in the stator, e.g., for
monitoring temperature along coil sections in the windings of the
motor; water cut sensor(s) to determine quality of a hydrocarbon
being produced, RPM and torque sensor(s) to detect the speed of
rotating shafts of the motor(s) and/or pump(s), temperature and/or
vibration sensor(s) applied to rotor bearings and thrust members,
and wye-point imbalance detector(s) for balancing electrical loads
on the three phases in a wye system.
[0016] Surface equipment measures and analyzes detected electrical
current leakage. Temperature and vibration can be measured and
monitored at multiple rotor bearing locations. One or more
temperature profiles can be obtained along motor lead extension
(MLE) cables using fiber optic or RTDs at potheads. The water cut
sensors for oil purity may be used at multiple locations to also
identify water ingress.
[0017] Example Systems
[0018] FIG. 1 shows an example submersible pumping system 20, with
example sensor leads 18 connected internally to sensors arrayed
within the pumping system 20. Submersible pumping system 20 may
include a variety of sections and components depending on the
particular application or environment in which it is used. Examples
of components utilized in pumping system 20 include at least one
submersible pump 22, at least one submersible motor 24, and one or
more motor protectors 26 that are coupled together to form stages,
sections, or segments of the submersible pumping system 20,
referred to as an electric submersible pump (ESP) string 20.
[0019] In the example system shown, submersible pumping system 20
is designed for deployment in a well 28 within a geological
formation 30 containing desirable production fluids, such as
petroleum. A wellbore 32 is drilled into formation 30, and, in at
least some applications, is lined with a wellbore casing 34.
Perforations 36 are formed through wellbore casing 34 to enable
flow of fluids between the surrounding formation 30 and the
wellbore 32.
[0020] Submersible pumping system 20 is deployed in wellbore 32 by
a deployment system 38 that may have a variety of configurations.
For example, deployment system 38 may comprise tubing 40, such as
coiled tubing or production tubing, connected to submersible pump
22 by a connector 42. Power is provided to the at least one
submersible motor 24 via a power cable 44. The submersible motor
24, in turn, powers submersible pump 22 which can be used to draw
in production fluid through a pump intake 46. Within submersible
pump 22, a plurality of impellers is rotated to pump or produce the
production fluid through, for example, tubing 40 to a desired
collection location which may be at a surface 48 of the Earth.
[0021] The illustrated submersible pumping system 20 is only one
example of many types of submersible pumping systems that can
benefit from the features described herein. For example, multiple
pump stages and other components can be added to the pumping
system, and other deployment systems may be used. Additionally, the
production fluids may be pumped to the collection location through
tubing 40 or through an annulus around the deployment system 38.
The submersible pump or pumps 22 can also utilize different types
of stages, such as mixed flow stages or radial flow stages.
[0022] FIG. 2 shows a cross-sectional view of one example
embodiment of a submersible pump 22. FIG. 2 is only one example of
submersible pump construction provided to show example sensor
placement. In this embodiment, submersible pump 22 comprises a
plurality of stages, such as stages 50 and 50'. Each stage 50
comprises an impeller 52 coupled to a shaft 54 rotatable about a
central axis 56. Rotation of shaft 54 by submersible motor 24
causes impellers 52 to rotate within an outer pump housing 58. Each
impeller 52 draws fluid in through an impeller or stage intake 60
and routes the fluid along an interior impeller passageway 62
before discharging the fluid through an impeller outlet 64 and into
an axially adjacent diffuser 66. The interior passageway 62 is
defined by the shape of an impeller housing 68, and housing 68 may
be formed to create an impeller for a floater stage, as illustrated
in FIG. 2, or for a compression stage. Additionally, the impeller
housing 68 may be designed to create a mixed flow stage, a radial
flow stage, or another suitable stage style for use in submersible
pump 22.
[0023] In FIG. 2, an inner thrust member 70, such as a thrust
washer, is positioned to resist thrust loads, i.e., to resist
downthrust loads created by the rotating impeller 52. In this
example embodiment, thrust washer 70 may be positioned in the
profile of an impeller feature 72, such as a recess formed in an
upper portion of impeller housing 68. The thrust washer 70 may be
disposed between the impeller 52 and a radially inward portion 74
of the next adjacent upstream diffuser 66. In an implementation, at
least one sensor 76 may be placed near, against, or within the
thrust member 70 and wired through stationary parts of the diffuser
housing, such as radially inward portion 74. Temperature, load, and
position or proximity sensors may be applied to a thrust bearing 70
to monitor load or strain on the thrust bearing 70 or proximity of
a runner to the a thrust bearing 70. The sensor(s) may monitor the
condition or aging of the thrust bearing, as well as load
characteristics, e.g., for purposes of adjusting the load to spare
the thrust bearing or to lengthen the lifespan of the thrust
bearing.
[0024] FIG. 3 shows an example motor 24, which may power one or
more components of an ESP string 20. For example, in one scenario,
the example motor 24 may power multiple pump stages. The example
motor 24 has various hardware components and associated sensors.
The example motor 24 may have a motor head 302, a motor base 304,
and an outer housing 306. A rotor 308, supported by rotor bearings
310, drives rotation of a shaft 312. A stator 314 with laminations
provides a rotating magnetic field to drive the rotor 308.
[0025] The stator 314 has windings 316, which create
electromagnetic fields when electricity flows. The rotor 308 may
also have windings 316, to induce electromagnetic fields that
interact with the electromagnetic fields of the stator 314.
Alternatively, the rotor 308 may have permanent magnets instead of
windings 316. The motor 24 may have other features, such as a drain
and fill valve 318 for motor oil, such as dielectric oil. A
coupling 320 at the motor head 302 connects with a pump 22 or a
protector 26. Bearings for the shaft 312 may have associated thrust
members 322 or a thrust ring to bear the axial load generated by
the thrust of one or more operating pumps 22. Electrically, the
motor 24 may have a power cable extension 324 that connects to a
terminal 326.
[0026] Various types of sensors may be included in the ESP string
20 to monitor many aspects of the above components. The rotor 308,
for example, may have a rotor temperature sensor 328. There may
also be a pothead temperature sensor 330. Each bearing, such as the
rotor bearings or a thrust bearing 322 may have a bearing
temperature sensor 332. A fiber optic strand acting as a
distributed temperature sensor 334 may be place in the stator
314.
[0027] In an implementation, the example system measures
distributed temperature 334 via fiber optics, and also includes
vibration sensors 336 at multiple locations along the ESP string
20. For example, an example system 20 may deploy distributed
temperature sensing 334 and vibration sensors 336 mainly at pump
bearings 604 & 606 and rotor bearings, such as bearing 322. In
an implementation, an example system 20 makes measurements using
fiber optics that are placed internally, e.g., in the motor stator
314, or makes measurements via electronic gauges strapped to
external housing points along the ESP string 20.
[0028] A fiber optic sensor 18 uses optical fiber either as the
intrinsic sensing element or as an extrinsic means of transmitting
signals from remote sensors to the processing unit that receives
the signals. Fibers have many uses for remote sensing in the
example ESP string 20. Fiber is employed because of its small size
and because no electrical power is required downhole. Also,
numerous sensors can be multiplexed along a length of a fiber optic
strand by assigning different wavelengths of light for each sensor,
or by sensing a corresponding time delay as light passes along the
fiber through each sensor along the line. The time delay may be
determined using an optical time-domain reflectometer or other
device.
[0029] Fiber optic sensors are immune to electromagnetic
interference, which is important downhole given the power being
supplied to the submersible motor(s) 24, and fiber optics do not
conduct electricity so can be utilized where there is high voltage
electricity. Fiber optic sensors can also be constructed with
immunity to very high temperatures.
[0030] As well as measuring distributed temperatures 334 along its
length, an optical fiber can also be used as a sensor to measure
strain, pressure and other quantities by modifying the fiber so
that the quantity being measured modulates the intensity, phase,
polarization, wavelength, or transit time of light in the fiber.
Sensors that can vary the intensity of light are the simplest to
employ in an ESP string 20, since only a simple source and detector
are required. An attractive feature of intrinsic fiber optic
sensing is that it can provide distributed sensing over very large
distances, as when a well is very deep.
[0031] Temperature can be measured by using a fiber that has
evanescent loss that varies with temperature, or by analyzing the
Raman scattering of the optical fiber. Electrical voltage in the
ESP string 20 can be sensed by nonlinear optical effects in
specially-doped fiber, which alter the polarization of light as a
function of voltage or electric field. Angle measurement sensors
can be based on the Sagnac effect.
[0032] Optical fiber sensors for distributed temperature sensing
334 and pressure sensing in downhole settings are well suited for
this environment when temperatures are too high for semiconductor
sensors.
[0033] Fiber optic sensors can be used to measure co-located
temperature and strain simultaneously, e.g., in an ESP bearing 322,
404, 406, 604, or 606, with very high accuracy using fiber Bragg
gratings. This technique is useful when acquiring information from
small complex structures.
[0034] A fiber optic AC/DC voltage sensor can be used in the
example ESP string 20 to sense AC/DC voltage in the middle and high
voltage ranges (100-2000 V). The sensor is deployed by inducing
measurable amounts of Kerr nonlinearity in single mode optical
fiber by exposing a calculated length of fiber to the external
electric field. This measurement technique is based on polarimetric
detection and high accuracy is achieved in hostile downhole
environments.
[0035] Electrical power in the ESP string 20 can be measured in a
fiber by using a structured bulk fiber ampere sensor coupled with
proper signal processing in a polarimetric detection scheme.
[0036] When used as a transmission medium for signals from
conventional sensors to the surface, extrinsic fiber optic sensors
use an optical fiber cable, normally a multimode one, to transmit
modulated light from either a non-fiber optical sensor, or an
electronic sensor connected to an optical transmitter. Using a
fiber to transmit data of extrinsic sensors provides the advantage
that the fiber can reach places that are otherwise inaccessible.
For example, a fiber can measure temperature inside a hot component
of the ESP string 20 by transmitting radiation into a radiation
pyrometer located outside the component. Extrinsic sensors can be
used in the same way to measure the internal temperature of the
submersible motor 24, where the extreme electromagnetic fields
present make other measurement techniques impossible.
[0037] Fiber optic sensors provide excellent protection of
measurement signals from noise corruption. However, some
conventional sensors produce electrical output which must be
converted into an optical signal for use with fiber. For example,
in the case of a platinum resistance thermometer, the temperature
changes are translated into resistance changes. The PRT can be
outfitted with an electrical power supply. The modulated voltage
level at the output of the PRT can then be injected into the
optical fiber via a usual type of transmitter. Low-voltage power
might need to be provided to the transducer, in this scenario.
[0038] Extrinsic sensors can also be used with fiber as the
transmission medium to the surface to measure vibration, rotation,
displacement, velocity, acceleration, torque, and twisting in the
ESP string 20.
[0039] An example electronic module can sense vibrations in various
planes or combinations of planes, for example the X and Z planes in
a 3-dimensional space. In an implementation, vibration canceling
modules 354 counteract or dampen vibrations, through vibration
canceling technology applied in specific planes.
[0040] In one implementation, a sensor of an example vibration
module can obtain vibration spectral data up to 1 kHz for a select
component along an ESP string 20, for example, for a part of a
rotating motor shaft.
[0041] In an implementation, an example vibration module can be
incorporated into WELLNET Pressure and Temperature gauges or the
WELLWATCHER Flux digital sensor array system (Schlumberger Ltd,
Houston Tex.).
[0042] The example system 20 can also measure temperature profiles
along a power cable, e.g., from surface to ESP string 20, using
fiber optics or platinum resistance temperature detector(s) (RTDs)
330, e.g., at a pothead.
[0043] A rotor vibration sensor 336 may be included to sense
relative health of the rotor 308 and its bearings. Each bearing may
also have a strain sensor 338 and a proximity sensor 340 to sense
wear, as measured by changing alignment or changing tolerances. The
rotating shaft 312 of the ESP may have an associated tachometer RPM
sensor 342 and a torque sensor 344. The torque sensors 344 may be
packaged around motor shafts 312 for monitoring torque and
rotational power. Electrically, the ESP may have an electrical
current leakage sensor 346 and a wye-point voltage or current
imbalance sensor 348. The ESP may also have associated chemical
sensors 350, and water cut sensors 352. Additional sensors, e.g.,
from Wireline Downhole Fluid Analysis tools may be employed to
detect gas-oil ratios, solids content, hydrogen sulfide and carbon
dioxide concentrations, pH, density, viscosity, and other chemical
and physical parameters. The water cut sensors 352 may also be
located at various locations in an ESP string for oil purity
measurements and for detecting water ingress.
[0044] As shown in FIG. 4, the example ESP string 20 may also
include a protector 26, which intervenes between motor 24 and pump
22, and which has various components and associated sensors. An
example protector 26 may include a shaft 400, shaft seal 402, and
shaft bearing 404. At least one shaft bearing may have an
associated thrust bearing 406 to bear an axial load of the shaft
400 generated by pump thrust. In an implementation, a thrust
bearing is instrumented by addition of temperature, strain, and
proximity sensors to monitor status. The protector 26 may also
equalize pressure between the motor 24 and pump 22, such as
equalization of oil expansion between the two components, or may
equalize pressure between the ambient well environment and the
interior of the protector 26, and may therefore include at least
one expandable bag or bellows chamber 408. The protector 26 may
also include a filter 410, when oil in the protector 26 is in
communication with motor oil, e.g., the filter 410 keeps motor
debris from the protector 26, or, in another or the same
implementation, when the interior of the protector 26 equalizes
pressure with the ambient well pressure, to keep well fluid debris
from entering the interior of the protector 26.
[0045] The protector 26 may include many types of sensors to
monitor and improve operation, to keep the protector 26 healthy,
and to provide high reliability. The protector 26 may include a
fiber optic strand 18 to sense distributed temperatures. The fiber
optic strand 18 may be the same fiber optic strand 18 running
continuously through much or all of the ESP string 20. The
protector 26 may also include, e.g., for each bearing, a
temperature sensor 328 and a vibration sensor 336. The bag or
bellows chamber 408 may have associated differential pressure
sensors 412 to measure, for comparison, pressure inside and outside
of the bag or bellows chamber 408. A protection mechanism for a
protector string employs differential pressure sensors 412 to
measure pressure inside and outside the bag or bellows 408 of the
protector 26. When a mechanical valve is not protecting the bag or
bellows chamber 408, for excessive pressure, the protector 26 may
include an electrical pressure relief valve 414 to relieve excess
pressure on a signal from a surface sensor analyzer 710, or from a
local logic circuit. The electrical relief valve 414 may be used in
tandem with conventional mechanical relief valves. Differential
pressure sensors 412 monitor stress on the bag, bellows 408,
accordion, or other means for equalizing pressure between, e.g.,
motor oil and external reservoir fluid. When pressure builds up due
to a mechanical relief valve failure, the event is detected by
differential pressure sensors 412, and the electrical relief valve
414 operates to relieve pressure and prevent protector bag failure
or bellows 408 failure.
[0046] FIG. 5 shows an exploded view of an example thrust bearing
(e.g., 322 or 406). The thrust bearing 322 may be instrumented by
addition of at least one temperature sensor 332, a strain sensor
338 (e.g., a load cell), and a proximity sensor 340, to monitor
status. The example proximity sensor 340 has high reliability and
long functional life because of an absence of mechanical parts in
the proximity sensor 340 and lack of physical contact between the
proximity sensor 340 and the sensed bearing or shaft. A suitable
proximity sensor 340 can measure the variation in distance between
the shaft and its support bearing, or between friction interface
surfaces of the thrust member 322.
[0047] FIG. 6 shows an example pump 22 and associated intake 600.
The pump 22 may be a centrifugal pump, but in alternative
implementations the example pump 22 may be another type of
submersible pump, such as a diaphragm pump or a progressing cavity
pump in another type of submersible pump string setup. The example
pump 22 has a fluid inlet or intake 600, and a fluid discharge 602.
The example pump 22 may have various bearings, such as bearing 604
and bearing 606. Each bearing 604 & 606 may have an associated
temperature sensor 332 and vibration sensor 336. The fluid intake
600 may also have at least one pressure sensor 608, a temperature
sensor 332, and a vibration sensor 336. Likewise, the fluid
discharge 602 may have a respective pressure sensor 608,
temperature sensor 332, and vibration sensor 336. The pump 22 may
have at least one associated flow sensor 610 to determine a current
flow rate of the pump 22 or other volumetric fluid data. The pump
22 may also have associated at least one chemical sensor 350 and at
least one water cut sensor 352. These sensors 350 & 352 can
detect a gas-oil ratio, solids content, H.sub.2S and CO.sub.2
concentrations, pH, fluid density, and fluid viscosity, for
example. The output of the various sensors of the pump 22 may be
multiplexed to communicate with the surface using a minimum of
communication wires, or a single fiber optic cable.
[0048] FIG. 7 shows an example high reliability engine 700 for
monitoring various sensors deployed in an ESP string 20, and for
controlling components of the ESP string 20 for longer life, high
availability, and high reliability. The illustrated high
reliability engine 700 is only one example of a
sensor-interpretation module and ESP-control module. Other
configurations of a monitor-controller could also be used. The
example high reliability engine 700 can be situated on the surface,
for example hosted by a computer, or can be associated with other
components that are on the surface and communicatively coupled with
downhole components, such as a variable-speed drive (VSD) 714 or
variable frequency drive (VFD). The high reliability engine 700 may
also be implemented in a programmable logic controller (PLC).
Alternatively, the high reliability engine 700 can be located
downhole, as a local module hosted by a computing device that is
local to the components of the ESP string 20.
[0049] In an implementation, the high reliability engine 700 is
coupled with the ESP string 20 via a multiplexer 702 that
communicates with many sensors over only a few wires or fibers 18,
and then communicates the sensor data to a sensor data input 706 of
the high reliability engine 700. In some implementations, the high
reliability engine 700 does not use an intervening multiplexer 702.
The multiplexer 702 may also include a fiber optics multiplexer
704, e.g., for wavelength-division multiplexing (WDM) so that many
sensors can be monitored over a one or a few fiber optic strands.
Likewise, the ESP string 20 may have distributed temperature
sensing 334 over one or a few fiber optic strands.
[0050] The high reliability engine 700 may include a sensor data
input 706, and sensor monitoring module 708, an interpretation
module 710, and a control module 712. The sensor data input 706
receives signals from the sensors or from the multiplexer 702. The
sensors that generate data may include temperature sensors,
distributed temperature sensors, vibration sensors, vibration
spectral data sensors, pressure sensors, differential pressure
sensors, strain sensors, proximity sensors, load cell sensors,
dirty filter sensors, bearing wear sensors, positional sensors,
rotational speed sensors, torque sensors, electrical leakage
detectors, wye-point imbalance sensors, chemical sensors, water cut
sensors, and so forth.
[0051] The sensor monitoring module 708 keeps track of the data of
each individual sensor. The sensor monitoring module 708 may track
current real-time sensor data, and also may keep a history of all
data or selected data, for a predetermined historical interval. The
interpretation module 710 analyzes the sensor data and computes
ongoing conclusions about the health of each ESP string component.
The interpretation module 710 may signal the control module 712 to
modify an operating parameter of the ESP string 20.
[0052] The control module 712 has executive control over at least
some operating parameters of the ESP string 20, and may adjust the
operating parameters to lengthen the life of the downhole hardware
components by preventing wear or keeping the operating parameters
within safe limits For example, the control module 712 may signal
the VSD 714 to change an electrical power parameter, such as
voltage, amperage, or frequency being supplied to the submersible
motor 24. The change in electrical power modifies operation of the
pump 22. For example, a slight slowing of the pump 22 may greatly
reduce wear on a bearing, e.g., 322, 404, 406, 604, 606. Or the
slight slowing may add life to a pump impeller when an abrasive
fluid is being pumped. Or, the pump speed may be adjusted to result
in a safe operating temperature of the motor 24, protector 26, or
pump 22.
[0053] Upon receiving signals from the interpretation module 710,
the control module 712 may also apply anti-vibration mechanical
waves or acoustic waves via the vibration canceling modules 354. In
an implementation, the vibration canceling modules 354 cancel out
vibrations in a selected vibration plane.
[0054] The control module 712, upon being signaled by the
interpretation module 710, may also decrease a pressure, either by
tapering off the output of the pump 22 or by actuating a valve,
such as electrical pressure relief valve 414, which can spare a
bellows/bag/chamber 408 from excessive pressure. The control module
712 may also actuate other valves to divert or rearrange a flow
path, in order to improve the operation or increase the lifespan of
the components of the ESP string 20. There are many other valves,
solenoids, actuators, coils, motors, and electrical parameters that
the control module 712 can control in order to improve the
performance of the ESP string 20 or add life to a component. For
example, on sensing wear of a thrust washer or bearing 322 or 406,
the control module 712 may adjust a thrust washer pad, moving the
worn pad closer to a contacting surface. The control module 712 can
perform many other interventions, such as adjusting pump operation
to suit the physical characteristics of the fluid being pumped, run
a self-cleaning cycle in the ESP string 20, activate additional
tests and sensors when called for, change position of parts to
compensate for wear, perform built-in maintenance measures,
dispense lubricants, clean an optical window, switch to a spare or
a reserve part (e.g., electrical), and many other remote-control
interventions, prompted by the sensors and the interpretation
module 710, that improve operation or lengthen the lifespan of a
component of the ESP string 20.
[0055] FIG. 8 shows an example computing or hardware environment,
e.g., example device 800, for hosting the high reliability engine
700 of FIG. 7. Thus, FIG. 8 illustrates an example device 800 that
can be implemented to monitor and analyze sensor data, and control
or intervene to help provide improved operation, high reliability,
and high-availability to an ESP string 20. The shown example device
800 is only one example of a computing device or programmable
device, and is not intended to suggest any limitation as to scope
of use or functionality of the example device 800 and/or its
possible architectures. Neither should example device 800 be
interpreted as having any dependency or requirement relating to any
one or a combination of components illustrated in the example
device 800.
[0056] Example device 800 includes one or more processors or
processing units 802, one or more memory components 804, one or
more input/output (I/O) devices 806, a bus 808 that allows the
various components and devices to communicate with each other, and
includes local data storage 810, among other components.
[0057] Memory 804 generally represents one or more volatile data
storage media. Memory component 804 can include volatile media
(such as random access memory (RAM)) and/or nonvolatile media (such
as read only memory (ROM), flash memory, and so forth).
[0058] Bus 808 represents one or more of any of several types of
bus structures, including a memory bus or memory controller, a
peripheral bus, an accelerated graphics port, and a processor or
local bus using any of a variety of bus architectures. Bus 808 can
include wired and/or wireless buses.
[0059] Local data storage 810 can include fixed media (e.g., RAM,
ROM, a fixed hard drive, etc.) as well as removable media (e.g., a
flash memory drive, a removable hard drive, optical disks, magnetic
disks, and so forth).
[0060] One or more input/output devices 806 can allow a user to
enter commands and information to example device 800, and also
allow information to be presented to the user and/or other
components or devices. Examples of input devices include a
keyboard, a cursor control device (e.g., a mouse), a microphone, a
scanner, and so forth. Examples of output devices include a display
device (e.g., a monitor or projector), speakers, a printer, a
network card, and so forth.
[0061] A user interface device may also communicate via a user
interface (UI) controller 812, which may connect with the UI device
either directly or through the bus 808.
[0062] A network interface 814 communicates with hardware, such as
the sensors, valves 414, multiplexer 702 and/or 704, vibration
canceling modules 354, VSD 714, VFD, and so forth.
[0063] A media drive/interface 816 accepts media 818, such as flash
drives, optical disks, removable hard drives, software products,
etc. Logic, computing instructions, or a software program
comprising elements of the high reliability engine 700 may reside
on removable media 818 readable by the media drive/interface
816.
[0064] Various techniques and the modules of the high reliability
engine 700 may be described herein in the general context of
software or program modules, or the techniques and modules may be
implemented in pure computing hardware. Software generally includes
routines, programs, objects, components, data structures, and so
forth that perform particular tasks or implement particular
abstract data types. An implementation of these modules and
techniques may be stored on or transmitted across some form of
tangible computer readable media. Computer readable media can be
any available data storage medium or media that is tangible and can
be accessed by a computing device. Computer readable media may thus
comprise computer storage media.
[0065] "Computer storage media" include volatile and non-volatile,
removable and non-removable tangible media implemented for storage
of information such as computer readable instructions, data
structures, program modules, or other data. Computer storage media
include, but are not limited to, RAM, ROM, EEPROM, flash memory or
other memory technology, CD-ROM, digital versatile disks (DVD) or
other optical storage, magnetic cassettes, magnetic tape, magnetic
disk storage or other magnetic storage devices, or any other
tangible medium which can be used to store the desired information,
and which can be accessed by a computer.
[0066] Example Method
[0067] FIG. 9 is an example method 900 of improving performance and
reliability of an ESP string. In the flow diagram, operations are
represented by individual blocks. The example method may be
performed by hardware and software elements, such as the example
high reliability engine 700.
[0068] At block 902, an electric submersible pump (ESP) string is
outfitted with at least one motor and a sensor associated with at
least a shaft bearing or a rotor bearing of each section of the ESP
string.
[0069] At block 904, sensor data is dynamically tracked by a
monitoring module.
[0070] At block 906, an operating parameter of a component of the
ESP string is changed by a control module, based on the dynamic
tracking of the sensor data.
[0071] Conclusion
[0072] Although only a few example embodiments have been described
in detail above, those skilled in the art will readily appreciate
that many modifications are possible in the example embodiments
without materially departing from the subject matter. Accordingly,
all such modifications are intended to be included within the scope
of this disclosure as defined in the following claims. In the
claims, means-plus-function clauses are intended to cover the
structures described herein as performing the recited function and
not only structural equivalents, but also equivalent structures. It
is the express intention of the applicant not to invoke 35 U.S.C.
.sctn.112, paragraph 6 for any limitations of any of the claims
herein, except for those in which the claim expressly uses the
words `means for` together with an associated function.
* * * * *