U.S. patent application number 14/449775 was filed with the patent office on 2015-02-05 for electric submersible pump having a plurality of motors operatively coupled thereto and methods of using.
This patent application is currently assigned to Chevron U.S.A. Inc.. The applicant listed for this patent is Gopikrishna Chava, Jose A. Gamboa, Yamila Antonieta Orrego, Ben Partington. Invention is credited to Gopikrishna Chava, Jose A. Gamboa, Yamila Antonieta Orrego, Ben Partington.
Application Number | 20150037171 14/449775 |
Document ID | / |
Family ID | 52427827 |
Filed Date | 2015-02-05 |
United States Patent
Application |
20150037171 |
Kind Code |
A1 |
Orrego; Yamila Antonieta ;
et al. |
February 5, 2015 |
ELECTRIC SUBMERSIBLE PUMP HAVING A PLURALITY OF MOTORS OPERATIVELY
COUPLED THERETO AND METHODS OF USING
Abstract
A downhole electric submersible pump system includes a plurality
of motors operatively coupled on a common shaft with an electric
submersible pump and a downhole switch mechanism for providing an
electrical circuit to each motor of the plurality of motors,
wherein the downhole switch mechanism allows power to be delivered
to at least one motor. A downhole switch mechanism located in a
wellbore, the downhole switch mechanism including an electrical
power input for receiving power from an electrical cable and at
least two electrical power outputs connected to at least two motors
operatively coupled with one or more electric submersible pumps,
wherein the downhole switch mechanism is actuated from the surface
via the electrical cable and allows power to be delivered to at
least one motor of the at least two motors coupled with the one or
more electric submersible pumps. A method is also provided.
Inventors: |
Orrego; Yamila Antonieta;
(Houston, TX) ; Chava; Gopikrishna; (Perth,
AU) ; Partington; Ben; (Houston, TX) ; Gamboa;
Jose A.; (Katy, TX) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Orrego; Yamila Antonieta
Chava; Gopikrishna
Partington; Ben
Gamboa; Jose A. |
Houston
Perth
Houston
Katy |
TX
TX
TX |
US
AU
US
US |
|
|
Assignee: |
Chevron U.S.A. Inc.
San Ramon
CA
|
Family ID: |
52427827 |
Appl. No.: |
14/449775 |
Filed: |
August 1, 2014 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61861269 |
Aug 1, 2013 |
|
|
|
Current U.S.
Class: |
417/45 ; 417/319;
417/423.3 |
Current CPC
Class: |
F04D 13/021 20130101;
F04D 13/0693 20130101; F04D 13/10 20130101; E21B 43/128
20130101 |
Class at
Publication: |
417/45 ;
417/423.3; 417/319 |
International
Class: |
F04D 13/06 20060101
F04D013/06; F04D 13/10 20060101 F04D013/10 |
Claims
1. A downhole electric submersible pump system comprising: a
plurality of motors operatively coupled on a common shaft with an
electric submersible pump; and a downhole switch mechanism for
providing an electrical circuit to each motor of the plurality of
motors; wherein the downhole switch mechanism allows power to be
delivered to at least one motor of the plurality of motors coupled
with the electric submersible pump.
2. The electric submersible pump system of claim 1, wherein the
downhole switch mechanism is electrically actuated.
3. The electric submersible pump system of claim 1, further
comprising an electrical cable providing electrical power to the
downhole switch mechanism.
4. The electric submersible pump system of claim 1, wherein the
downhole switch mechanism comprises an electrical power input
connected to an electrical cable, and a plurality of electrical
outputs.
5. The electric submersible pump system of claim 4, further
comprising respective motor lead extensions extending from the
plurality of electrical outputs to each motor of the plurality of
motors.
6. The electric submersible pump system of claim 1, wherein the
plurality of motors includes an upper motor and a lower motor,
wherein the lower motor is downhole of the upper motor, further
comprising a clutch mechanism disposed between the lower motor and
the upper motor.
7. The electric submersible pump system of claim 6, wherein the
clutch mechanism is configured to disengage at least a portion of
the common shaft corresponding to the lower motor and at least a
portion of the common shaft corresponding to the upper motor when
the upper motor is operating.
8. The electric submersible pump system of claim 6, wherein the
clutch mechanism is configured to engage at least a portion of the
common shaft corresponding to the lower motor and at least a
portion of the common shaft corresponding to the upper motor when
the lower motor is operating.
9. The electric submersible pump system of claim 6, wherein the
clutch mechanism is electro-magnetic, mechanical, or hydraulic.
10. The electric submersible pump system of claim 6, wherein the
downhole switch mechanism allows power to be delivered to the lower
motor, and wherein the clutch mechanism receives power from the
lower motor.
11. The electric submersible pump system of claim 1, wherein the
plurality of motors are disposed downhole from the electric
submersible pump.
12. The electric submersible pump system of claim 1, wherein the
plurality of motors are disposed up hole from the electric
submersible pump.
13. The electric submersible pump system of claim 1, wherein the
plurality of motors are disposed up hole and downhole from the
electric submersible pump.
14. The electric submersible pump system of claim 1, wherein one
motor of the plurality of motors is electrically powered while
remaining motors are idle.
15. A method of powering a plurality of motors operatively coupled
with an electric submersible pump located downhole in a wellbore,
the method comprising: providing a downhole switch mechanism in the
wellbore, the downhole switch mechanism being supplied with
electrical power, the downhole switch mechanism further being
connected to two or more motors operatively coupled on a common
shaft with the electric submersible pump; providing electrical
power through the downhole switch mechanism to a first motor of the
two or more motors; and actuating the downhole switch mechanism to
break electrical power through the downhole switch mechanism to the
first motor and to provide electrical power through the downhole
switch mechanism to a second motor of the two or more motors.
16. The method of claim 15, further comprising electrically
actuating the downhole switch mechanism.
17. The method of claim 15, wherein the second motor is downhole of
the first motor, further comprising disengaging at least a portion
of the common shaft corresponding to the second motor and at least
a portion of the common shaft corresponding to the first motor when
the first motor is operating.
18. The method of claim 15, wherein the second motor is downhole of
the first motor, further comprising engaging at least a portion of
the common shaft corresponding to the second motor and at least a
portion of the common shaft corresponding to the first motor when
the second motor is operating.
19. A downhole switch mechanism located in a wellbore, the downhole
switch mechanism comprising: an electrical power input for
receiving power from an electrical cable; and at least two
electrical power outputs connected to at least two motors
operatively coupled with one or more electric submersible pumps;
wherein the downhole switch mechanism is actuated from the surface
via the electrical cable and allows power to be delivered to at
least one motor of the at least two motors coupled with the one or
more electric submersible pumps.
20. The downhole switch mechanism of claim 19, wherein the downhole
switch mechanism breaks electrical power through the downhole
switch mechanism to a first motor and delivers electrical power
through the downhole switch mechanism to a second motor.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims priority from U.S.
Provisional Application No. 61/861,269, filed on Aug. 1, 2013,
(Attorney Docket No. T-9438-P/210715-CVN067P), the disclosure of
which is hereby incorporated by reference in its entirety.
TECHNICAL FIELD
[0002] One or more embodiments of the present disclosure relate to,
for example, electric submersible pumps having a plurality of
motors operatively coupled thereto and an electrical switch
mechanism allowing selection among one or more of the plurality of
motors.
BACKGROUND
[0003] Many oil and gas wells must be provided with artificial lift
in order to extract hydrocarbons in an effective manner, otherwise
the relatively low natural reservoir pressure (particularly in the
middle and later years of some wells) is not sufficient to flow the
well. Conventionally, the artificial lift may be provided by a
variety of methods including injection of CO.sub.2 into the well to
force the hydrocarbons up to the surface and by providing downhole
pumps to suck in the hydrocarbons and pump them up production
tubing to the surface. An electrical submersible pump (or "ESP") is
a form of artificial lift pump designed to draw fluid from a well
in the absence of pressure to suit the production rate required.
Typically, ESPs in the oilfield have been run as single units on
the end of the production tubing (or coiled tubing) within a
wellbore. A power cable, attached to the electrical motor unit of
the ESP, extends to the surface of the well alongside the
production tubing (or coiled tubing) and terminates at the
wellhead.
[0004] ESP motor failure is a significant contributor to ESP system
failure during artificial lift operations. ESP motors typically
fail over time due to one or more factors (e.g., high temperatures,
short circuits, fluid contamination, etc.). ESP motor and system
failure is tremendously expensive, not only due to equipment costs
(i.e., motors represent a substantial part of the total cost of the
ESP system used in artificial lift operations), but even more so
due to production time lost during workovers and other well
interventions.
SUMMARY
[0005] Embodiments disclosed herein provide electric submersible
pumps having a plurality of motors operatively coupled thereto so
that one or more backup motors are operated when a first motor
fails, thereby postponing or eliminating costly workovers in the
event of motor failure downhole.
[0006] In one aspect, embodiments disclosed herein relate to a
downhole electric submersible pump system including a plurality of
motors operatively coupled on a common shaft with an electric
submersible pump and a downhole switch mechanism for providing an
electrical circuit to each motor of the plurality of motors,
wherein the downhole switch mechanism allows power to be delivered
to at least one motor of the plurality of motors coupled with the
electric submersible pump.
[0007] In other aspects, embodiments disclosed herein relate to a
method of powering a plurality of motors operatively coupled with
an electric submersible pump located downhole in a wellbore, the
method including providing a downhole switch mechanism in the
wellbore, the downhole switch mechanism being supplied with
electrical power, the downhole switch mechanism further being
connected to two or more motors operatively coupled on a common
shaft with an electric submersible pump, providing electrical power
through the downhole switch mechanism to a first motor of the two
or more motors, actuating the downhole switch mechanism to break
electrical power through the downhole switch mechanism to the first
motor and to provide electrical power through the downhole switch
mechanism to a second motor of the two or more motors.
[0008] In yet other aspects, embodiments disclosed herein relate to
a downhole switch mechanism located in a wellbore. The downhole
switch mechanism includes an electrical power input for receiving
power from an electrical cable and at least two electrical power
outputs connected to at least two motors operatively coupled with
one or more electric submersible pumps, wherein the downhole switch
mechanism is actuated from the surface via the electrical cable and
allows power to be delivered to at least one motor of the at least
two motors coupled with the one or more electric submersible
pumps.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 illustrates a particular embodiment of an electric
submersible pump and a plurality of motors operatively coupled
thereto, as well as a downhole switch mechanism, in accordance with
one or more embodiments of the present disclosure.
[0010] FIG. 2 illustrates an alternative embodiment of an electric
submersible pump and a plurality of motors operatively coupled
thereto, as well as a downhole switch mechanism, in accordance with
one or more embodiments of the present disclosure.
[0011] FIG. 3 illustrates, in flowchart form, an embodiment of a
method of powering a plurality of motors operatively coupled with
an electric submersible pump located downhole in a wellbore in
accordance with one or more embodiments of the present
disclosure.
DETAILED DESCRIPTION
[0012] The aspects, features, and advantages of the present
disclosure mentioned above are described in more detail by
reference to the drawings, wherein like reference numerals
represent like elements. Also, for simplicity, the terminology a
first (or upper) motor 106a is utilized throughout. Similarly, the
terminology a second (or lower) motor 106b I used throughout.
[0013] Embodiments of a downhole completion and/or production
system for artificial lift operations are disclosed. The downhole
system includes a production (or coiled) tubing having an intake
into which fluid (e.g., hydrocarbons, water, brine) from the
wellbore may be drawn and pumped to the surface. Alternatively, the
downhole system may be arranged for injecting fluid into a
formation adjacent to the wellbore (e.g., waterflooding, polymer
flooding). The downhole system may comprises one or more pumps
(e.g., disposed at a lower end of the production tubing). The pumps
may comprise electrical submersible pumps having two or more (e.g.,
hermetically sealed) motors coupled to the pump body.
[0014] Two or more motors may be coupled with the pump. The motors
may be disposed downhole from the pump or up hole from the pump.
Alternatively, one or more motors may be disposed downhole from the
pump and one or more motors disposed up hole from the pump. The
motors may be located directly adjacent to the pump, or may be
indirectly coupled to the pump if other components (e.g., gas
separators, sensors, protectors/isolators, thrust bearings, seals)
are located therebetween. The motors may range in horsepower (HP)
from at least about 100 HP, or 200 HP, or 500 HP, up to about 1000
HP, or 1500 HP, or greater. One skilled in the art will recognize
that the horsepower of the motor may be configured based on the
wellbore casing size (e.g., use of different sized motors in 5.5
inch casing compared to 7 inch casing). The motors may be installed
in tandem having a common longitudinal shaft so that when a first
motor is operating the additional motors run idle, generating no
significant electrical output. Thus, the common shaft may be a
one-piece shaft that may not separate, but in an alternative
embodiment of the common shaft, the common shaft may comprise or
include separate shafts (e.g., discussed in the context of FIGS.
1-2). The downhole system further comprises an electrical cable
that travels from the surface and powers the motors, and a downhole
(e.g., electrical) switch mechanism disposed at or near an end of
the electrical cable. The downhole electrical switch mechanism may
include an electrical input connected to the electrical cable, and
two or more electrical outputs connected, by way of motor lead
extensions, to the motors to operate each of the motors.
[0015] FIG. 1 illustrates a particular embodiment of an electric
submersible pump and a plurality of motors operatively coupled
thereto, as well as a downhole switch mechanism, in accordance with
one or more embodiments of the present disclosure. More
particularly, FIG. 1 illustrates a particular embodiment of a
downhole completion and production system or string 100 in
accordance with one or more embodiments of the present disclosure.
A production tubing or string 102 extends along a length of a
wellbore from a wellhead (not shown) at the surface. One or more
pumps 104 may be disposed along a length of the production tubing
102 having an intake (not shown) into which fluid from the wellbore
may be drawn and pumped to the surface. Only one pump 104 is
illustrated, however multiple pumps may be included in the
production string 102, and each pump may be coupled or associated
with one or more motors. The pumps 104 may be any type of
electrical submersible pump having two or more (e.g., hermetically
sealed) motors 106 coupled to the pump body. For example, the pumps
104 may be multistage centrifugal pumps operating in a vertical
position and available from any number of pump manufacturers and/or
service companies, as will be understood by one of ordinary skill
in the art. For example, the pumps 104 may be ESP pumps available
from the General Electric Company.
[0016] In certain embodiments, one or more pumps 104 (e.g., at the
lower end of the production string 102) may be operated in a manner
for performing artificial lift operations in a wellbore. In other
embodiments, one or more pumps 104 (e.g., at the lower end of the
production string 102) may be operated in a manner for injecting
fluids (e.g., water, brine, acids, polymers, surfactants, etc.)
into a formation adjacent the wellbore. One of ordinary skill in
the art will further understand additional modes in which one or
more pumps may be operated or used.
[0017] As shown, downhole ESP motors 106a and 106b may be coupled
with the pump 104 (e.g., at the lower end of the production string
102). While two motors 106a and 106b are shown, more than two
motors may be coupled with the pump 104. As shown, the motors 106a
and 106b may be disposed downhole of the pump 104. Alternatively,
the motors may be disposed up hole of the pump 104. In yet other
embodiments, one or more motors may be disposed up hole of the pump
104, and one or more motors may be disposed downhole of the pump
104. The motors 106a and 106b may be located directly adjacent to
the pump 104, or the motors 106a and 106b may be indirectly coupled
to the pump 104 such that other components (e.g., gas separators,
sensors, protectors/isolators, thrust bearings, seals) are located
therebetween. The motors 106a and 106b may be electric motors
available from any number of suppliers as will be understood by one
of ordinary skill in the art. For example, the motors 106a and 106b
may be ESP motors available from the General Electric Company, such
as (i) the TR-series motors, (ii) E-series motors, (iii) the
three-phase two-pole induction motors, and/or (iv) any combination
thereof. Motors used in accordance with one or more embodiments
disclosed herein may be 100 horsepower (HP) motors up to 1500 HP
motors, or greater, as will be understood by one of ordinary skill
in the art. It will be understood that the motors having different
HP ratings may be used (i.e., motor 106a can have a different HP
rating from motor 106b), or motors having all the same HP ratings
may be used.
[0018] In certain embodiments, the motors 106a and 106b may be
installed in tandem (series) and having a common longitudinal motor
shaft 107 so that when a first motor is operating the second motor
runs idle. As used herein, idle means that the motor produces an
insufficient output to operate pump 104. In embodiments, the motor
shaft of the idle motor rotates although no significant electrical
output is generated. In certain embodiments, the motors 106a and
106b may be located adjacent one another. In other embodiments, the
motors 106a and 106b may be spaced apart and other components
(e.g., gas separators, sensors, protectors/isolators, thrust
bearings, seals) located therebetween. Moreover, when the second
motor is operating the first motor may run idle.
[0019] In other embodiments, a clutch mechanism may be disposed
between the motors 106a and 106b that provides or transmits power
from one motor to another when engaged, but can be disengaged
(e.g., the clutch mechanism can disengage the shaft of the lower
motor when the upper motor is operating). In yet other embodiments,
the motors 106a and 106b may have separate motor shafts. For
example, FIG. 2 illustrates an alternative embodiment of an
electric submersible pump and a plurality of motors operatively
coupled thereto, as well as a downhole switch mechanism, in
accordance with one or more embodiments of the present disclosure.
More particularly, FIG. 2 illustrates an embodiment of a clutch
mechanism 202 and an embodiment of the ESP shaft 107 of FIG. 1
comprising separate motor shafts for use with the clutch mechanism
202.
[0020] With reference to both FIGS. 1 and 2, a production string
200 is similar to the production string 100, but may include the
clutch mechanism 202. The clutch mechanism 202 may be a clutch.
Alternatively, the clutch mechanism may include a clutch as well as
one or more other components. The clutch mechanism 202 may
disengage at least a portion of the common shaft corresponding to
the lower motor 106b and at least a portion of the common shaft
corresponding to the upper motor 106a when the upper motor 106a is
operating. For example, the clutch mechanism 202 may be disposed
between the upper motor 106a and lower motor 106b, and the clutch
mechanism 202 may disengage the shaft of the lower motor 106b and
the shaft of the upper motor 106a when the upper motor 106a is
operating. In other words, the common shaft (e.g., shaft 107 of
FIG. 1) may include separate motor shafts such as (i) an ESP shaft
207a corresponding to the upper motor 106a, (ii) an ESP shaft 207b
corresponding to the lower motor 106b, and so on with an ESP shaft
corresponding to each motor. The clutch mechanism 202 may be
disposed between the motors 106a and may disengage or decouple the
ESP shaft 207b corresponding to the lower motor 106b from the ESP
shaft 207a corresponding to the upper motor 106a, or vice versa, or
decouple in some other manner. By disengaging the ESP shaft 207b of
the lower motor 106b, the lower motor 106b and its components may
experience less wear and tear, may not run idle, and may even
remain unused until the upper motor 106a experiences a failure.
[0021] The clutch mechanism 202 may also provide or transmit power
from one motor to another when engaged. Thus, the clutch mechanism
202 may serve as a link between various ESP shafts. For example,
the clutch mechanism 202 may be disengaged which may in turn
disengage or decouple an ESP shaft from another ESP shaft, or the
clutch mechanism 202 may be engaged which may in turn engage or
couple an ESP shaft with another ESP shaft.
[0022] Turning more specifically to engagement, in a particular
embodiment, a downhole electrical switch mechanism 110 (described
further hereinbelow) may deliver electrical power through the
downhole electrical switch mechanism 110 to the upper motor 106a
while the clutch mechanism 202 and the lower motor 106b may remain
inactive. Also, the lower motor 106b may not be engaged or coupled
to the upper motor 106a at this point. The lower motor 106b may be
downhole of the upper motor 106a, and the clutch mechanism 202 may
be disposed between the lower motor 106b and the upper motor
106a.
[0023] In response to a failure of the upper motor 106a, for
example, the downhole electrical switch mechanism 110 may break
electrical power through the downhole electrical switch mechanism
110 to the upper motor 106a and deliver electrical power through
the downhole electrical switch mechanism 110 to the lower motor
106b (e.g., so that the lower motor 106b begins operating and not
the upper motor 106a). At least a portion of the electrical power
to the lower motor 106b may be provided from the lower motor 106b
to the clutch mechanism 202.
[0024] In response to electrical power to the clutch mechanism 202,
the clutch mechanism 202 may engage at least a portion of the
common shaft corresponding to the lower motor 106b and at least a
portion of the common shaft corresponding to the upper motor 106a
when the lower motor 106b is operating. For example, in response to
receiving electrical power from the lower motor 106b, the clutch
mechanism 202 may engage or couple the ESP shaft 207b of the lower
motor 106b and the ESP shaft 207a of the upper motor 106a, or vice
versa, or couple in some other manner. The clutch mechanism 202 may
continue to engage or couple the ESP shaft 207b of the lower motor
106b and the ESP shaft 207a of the upper motor 106a during
operation of the lower motor 106b. Thus, the clutch mechanism 202
may engage (e.g., engage or couple the ESP shaft 207b and the ESP
shaft 207a) once the lower motor 106b is activated, in other words,
the clutch mechanism 202 may engage in response to activation of
the lower motor 106b. Indeed, the downhole electrical switch
mechanism 110 may allow power to be delivered to the lower motor
106b, and the clutch mechanism 202 may receive power from the lower
motor 106b. The clutch engagement may depend on whether the clutch
mechanism 202 is either electro-magnetic or mechanical or
hydraulic. Thus, the clutch mechanism 202 may be at least one of
electro-magnetic, mechanical, or hydraulic.
[0025] As an example, if the clutch mechanism 202 is
electro-magnetic, electrical power may be utilized for its
operation. This power could be supplied once the lower motor 106b
is energized. The clutch mechanism 202 may then utilize electrical
communication with the lower motor 106b's power so that part of the
electrical power can be utilized for the clutch mechanism 202's
operation.
[0026] As another example, if the clutch mechanism 202 is
mechanical (e.g., friction disk) or hydraulic, an electronic signal
may be used for its engagement. This signal can be modulated over
the lower motor 106b's supplied cable. An electronic circuit,
external or integrated to the lower motor 106b, may receive this
signal and may activate the clutch mechanism 202. The clutch
mechanism 202 may utilize electrical communication with the lower
motor 106b. An alternative may be to transmit the signal through a
cable that connects the downhole electrical switch mechanism 110
and the clutch mechanism 202. This could be a downhole
instrumentation cable or a fiber optic cable. The fiber optic cable
may occupy less space in the annular space.
[0027] As another example, if the clutch mechanism 202 is
hydraulic, the engagement may also be made using the internal motor
oil. For instance, a small pump or turbine may be installed between
the clutch mechanism 202 and the lower motor 106b. This pump or
turbine may be coupled to the lower motor 106b. Once the lower
motor 106b is activated, the pump or turbine may boost motor oil
toward the clutch mechanism 202's internals, which may cause the
clutch engagement. An alternative may be to use motor oil thermal
expansion for engaging the clutch mechanism 202. Once the lower
motor 106b is activated, the internal temperature of this motor may
increase (as well as the upper motor 106a may decrease). The
increment of temperature may cause the thermal expansion of the
motor oil increasing the internal pressure of the oil inside the
lower motor 106b. The increase of internal pressure may be used for
creating an up-thrust force against the clutch mechanism 202
causing its engagement.
[0028] Those of ordinary skill in the art will appreciate that the
examples in this disclosure are not exhaustive. Moreover,
terminology such as "at least a portion of the common shaft
corresponding to the lower motor" may include, for example, an end
of the separate motor shaft illustrated as ESP shaft 207b
corresponding to the lower motor 106b, the entire separate motor
shaft illustrated as ESP shaft 207b corresponding to the lower
motor 106b, etc. Similarly, terminology such as "at least a portion
of the common shaft corresponding to the upper motor" may include,
for example, an end of the separate motor shaft illustrated as ESP
shaft 207a corresponding to the upper motor 106a, the entire
separate motor shaft illustrated as ESP shaft 207a corresponding to
the upper motor 106a, etc.
[0029] Terminology such as "when the lower motor is operating" may
include, for example, the lower motor 106b begins operating, during
operation of the lower motor 106b, etc. Similarly, terminology such
as "when the upper motor is operating" may include, for example,
the upper motor 106a begins operating, during operation of the
upper motor 106a, etc.
[0030] Furthermore, the order of disengaging at least a portion of
the common shaft corresponding to the lower motor and at least a
portion of the common shaft corresponding to the upper motor may
depend on the specific implementation, and may include, for
example: (i) the at least a portion of the common shaft
corresponding to the lower motor may be disengaged from the at
least a portion of the common shaft corresponding to the upper
motor, (ii) the at least a portion of the common shaft
corresponding to the upper motor may be disengaged from the at
least a portion of the common shaft corresponding to the lower
motor, etc. Similarly, the order of engaging at least a portion of
the common shaft corresponding to the lower motor and at least a
portion of the common shaft corresponding to the upper motor may
depend on the specific implementation, and may include, for
example: (i) the at least a portion of the common shaft
corresponding to the lower motor may be engaged to the at least a
portion of the common shaft corresponding to the upper motor, (ii)
the at least a portion of the common shaft corresponding to the
upper motor may be engaged to the at least a portion of the common
shaft corresponding to the lower motor, etc.
[0031] With reference to FIGS. 1 and 2, an electrical cable 108
that travels from the surface (which may be several hundred or
thousand feet) powers the motors 106a and 106b through a downhole
electrical switch mechanism 110. In embodiments, the electrical
cable 108 may be secured to the production string 102 by way of
practically any attachment mechanism used in the context of ESP's
(illustrated as an attachment mechanism 204), standard clamps or
cable protectors (not shown) as will be understood by one of
ordinary skill in the art. For example, clamps or cable protectors
may be disposed at about every 30 feet or each joint of the
production tubing 102. In embodiments, the electrical cable 108 is
encapsulated within a coiled tubing umbilical. The submersible
electrical cable 108 may be used for submersible electrical pumps
in a deep well and is capable of withstanding harsh conditions used
in both fresh and salt water. Further, the submersible electrical
cable 108 may be a single or multiple conductor type, and may be
flat or round in cross section. In certain instances, the
submersible electrical cable 108 is color-coded for identification
and may include an overall cable jacket that is also
color-coded.
[0032] In embodiments, the electrical cable 108 may be a
three-phase (3-phase) or four-phase (4-phase) cable, in which plain
copper and/or tinned copper are used as a conductor. For example,
the electrical cable 108 may comprise a PVC 3-phase or 4-phase
cable, either flat or round. Alternatively, the electrical cable
108 may comprise a rubber 3-phase or 4-phase cable, either flat or
round. Still further, the electrical cable 108 may comprise a flat
drincable, or HO7RN-F cable, which will be understood by one of
ordinary skill in the art. For example, the electrical cable 108
may be an ESP cable available from the General Electric Company or
available from any number of suppliers as will be understood by one
of ordinary skill in the art. The electrical cable 108 may be
General Electric Company's Powerline.TM. cable.
[0033] The downhole electrical switch mechanism 110 may be disposed
at or near an end of the electrical cable 108. The downhole
electrical switch mechanism 110 may be a downhole electrical
switch. The downhole electrical switch mechanism 110 may include a
downhole electrical switch as well as other components. Of note,
although a downhole switch mechanism may be the downhole electrical
switch mechanism 110, such need not be the case in some
embodiments. For example, the downhole switch mechanism may be a
downhole electrical switch or simply a downhole switch.
[0034] Nonetheless, the downhole electrical switch mechanism 110
may be separate from, or it may be integral with or incorporated
into the ESP housing. The downhole electrical switch mechanism 110
may be any type of electrical component that can switch an
electrical circuit, interrupting or diverting it from one conductor
to another. For example, the downhole electrical switch mechanism
110 may include an electrical power input 212 connected to the
electrical cable 108 and at least two electrical power outputs 214a
and 214b connected to motor lead extensions 112a and 112b. The
downhole electrical switch mechanism 110 includes internal
conductive pieces or contacts (not shown), which may be metal, that
touch to complete (make) a circuit or separate to open (break) the
circuit between the electrical cable 108 and the motor lead
extensions 112a and 112b to operate either of the motors 106a and
106b, respectively. For example, the motor lead extensions 112a and
112b may be lead extensions available from the General Electric
Company or available from any number of suppliers as will be
understood by one of ordinary skill in the art. While two motor
lead extensions 112a and 112b are shown, there may be more than two
motor lead extensions depending upon the number of motors. The
downhole electrical switch mechanism 110 may utilize an electrical
signal to make and break the circuit to the motors 106a and 106b,
through respective motor lead extensions 112a and 112b, to operate
motors 106a and 106b, respectively. Each motor 106a and 106b has a
motor lead extension 112a and 112b, respectively, that extends from
each respective motor to the downhole electrical switch mechanism
110 (which may extend up to 100 feet or more).
[0035] FIG. 3 illustrates, in flowchart form, an embodiment of a
method of powering a plurality of motors operatively coupled with
an electric submersible pump located downhole in a wellbore in
accordance with one or more embodiments of the present disclosure.
With reference to FIGS. 1, 2, and 3, a method 300 of powering a
plurality of motors may be utilized for operating the electrical
submersible pump 104 (e.g., at the lower end of the production
string 102).
[0036] Turning to the method 300, the method 300 may include, at
302, providing a downhole switch mechanism in the wellbore, the
downhole switch mechanism being supplied with electrical power, the
downhole switch mechanism further being connected to two or more
motors operatively coupled on a common shaft with an electric
submersible pump. For example, a downhole electrical switch
mechanism 110 may be provided, the downhole electrical switch
mechanism 110 being supplied electrical power through an electrical
cable 108 running from the surface, or alternatively through a
separate electrical cable. The downhole electrical switch mechanism
110 is connected by way of motor lead extensions 112a and 112b to
motors 106a and 106b, respectively, coupled to the pump 104 (e.g.,
at the lower end of the production string 102) by the ESP shaft 107
(FIG. 1) or the ESP shafts 207a and 207b (FIG. 2).
[0037] The method 300 may include, at 304, providing electrical
power through the downhole switch mechanism to a first motor of the
two or more motors. The method 300 may also include, at 306,
disengaging at least a portion of the common shaft corresponding to
the second motor and at least a portion of the common shaft
corresponding to the first motor when the first motor is operating.
For example, in embodiments, when the production string 102 is run,
the downhole electrical switch mechanism 110 is set in a first
position to make a circuit between the electrical cable 108 and the
first or upper motor 106a, thereby powering the first motor 106a.
The circuit between the electrical cable 108 and the second (or
lower) motor 106b is broken at this time, and thus the second motor
106b receives no power at this time and runs idle. An alternative
to the second motor 106b running idle was discussed hereinabove in
connection with FIG. 2, namely, the clutch mechanism 202 may be
utilized to disengage at least a portion of the common shaft
corresponding to the second (or lower) motor 106b, such as
disengage the ESP shaft 207b from ESP shaft 207a, when the first
(or upper) motor 106a is operating.
[0038] The method 300 may include, at 308, actuating the downhole
switch mechanism to break electrical power through the downhole
switch mechanism to the first motor and to provide electrical power
through the downhole switch mechanism to a second motor of the two
or more motors. For example, subsequently, the downhole electrical
switch mechanism 110 may be moved to a second position to make a
circuit between the electrical cable 108 and the second motor 106b,
thereby powering the second motor 106b. The circuit between the
electrical cable 108 and the first motor 106a is broken at this
time, and thus the first motor 106a receives no power at this time
and runs idle. At any particular instant, the downhole electrical
switch mechanism 110 may be activated to break the circuit with the
first motor 106a and make the circuit with the second motor 106b,
thereby delivering power to the second motor 106b while the first
motor 106a runs idle. For example, if the upper motor 106a fails
due to any reason, the downhole electrical switch mechanism 110
allows selection of the lower motor 106b to continue operating the
pump. In embodiments, the downhole electrical switch mechanism 110
may switch between motors 106a and 106b based on downhole reservoir
or motor conditions (e.g., information such as motor winding
temperature, motor load, power supply, downhole sensor data).
Alternatively, in certain embodiments, the second motor 106b may be
operated before the first motor 106a. Still further, more than the
two motors 106a and 106b shown may be included with a single
electric submersible pump 104, such that the downhole electrical
switch mechanism 110 is configured to make and break circuits with
each individual motor coupled with the electric submersible pump
104. In certain embodiments, only one motor at a time may operate
the electric submersible pump 104 while any other motors coupled
therewith to the electric submersible pump 104 remain idle.
Alternatively, more than one motor at a time may operate the
electric submersible pump 104 to provide extra power and pumping
and/or injecting capabilities. One of ordinary skill in the art
will understand that one or more motors at a time can be operated
while any additional motors can remain idle.
[0039] Furthermore, if the clutch mechanism 202 was utilized at 306
to disengage the ESP shaft 207b of the second (or lower) motor
106b, the disengagement of the ESP shaft 207b may be reversed at
308. For example, the method 300, at 309, may include engaging at
least a portion of the common shaft corresponding to the second
motor and at least a portion of the common shaft corresponding to
the first motor when the second motor is operating. For example, as
described hereinabove in connection with FIG. 2, the clutch
mechanism 202 may be utilized to engage at least a portion of the
common shaft corresponding to the second (or lower) motor 106b,
such as engage the ESP shaft 207b with the ESP shaft 207a, when the
second (or lower) motor 106b is operating.
[0040] The method 300 may include, at 310, performing artificial
lift operations in the wellbore. The method 300 may also include,
at 312, injecting fluids into a formation adjacent the wellbore.
For example, the electric submersible pump or pumps 104 may be
utilized to perform artificial lift operations and/or to inject
fluids depending on the particular implementation and/or needs of
the users.
[0041] The claimed subject matter is not to be limited in scope by
the specific embodiments described herein. Indeed, various
modifications of one or more embodiments disclosed herein in
addition to those described herein will become apparent to those
skilled in the art from the foregoing descriptions. Such
modifications are intended to fall within the scope of the appended
claims. For example, although one pump is illustrated in FIGS. 1
and 2, those of ordinary skill in the art will appreciate that more
than one pump may be utilized. For example, a single downhole
electrical switch mechanism 110 may provide power to separate
motors corresponding to separate pump completions. Moreover, the
use of multiple separate cables may be avoided, and instead, the
single cable 108 coupled to the single downhole electrical switch
mechanism 110 may be utilized to power motors in various pump
completions.
[0042] Furthermore, for example, sensors may be included on the
surface or downhole in additional embodiments. Furthermore, the
surface may include entities configured to receive data from
downhole, process data, compare data, send data downhole, etc. The
entities may include computing apparatuses, wherein a particular
computing apparatus includes at least one processor and/or at least
one memory bearing program code (e.g., data and instructions) that
when executed by the processor cause the computing apparatus to
perform actions, methods, etc. User input may or may not be needed
depending on the task.
[0043] As used in this specification and the following claims, the
terms "comprise" (as well as forms, derivatives, or variations
thereof, such as "comprising" and "comprises") and "include" (as
well as forms, derivatives, or variations thereof, such as
"including" and "includes") are inclusive (i.e., open-ended) and do
not exclude additional elements or steps. Accordingly, these terms
are intended to not only cover the recited element(s) or step(s),
but may also include other elements or steps not expressly recited.
Furthermore, as used herein, the use of the terms "a" or "an" when
used in conjunction with an element may mean "one," but it is also
consistent with the meaning of "one or more," "at least one," and
"one or more than one." Therefore, an element preceded by "a" or
"an" does not, without more constraints, preclude the existence of
additional identical elements. Furthermore, the use of the
terminology "lower end of the production string" and the like is
meant to provide an example and should not limit the scope of the
claims.
[0044] The use of the term "about" applies to all numeric values,
whether or not explicitly indicated. This term generally refers to
a range of numbers that one of ordinary skill in the art would
consider as a reasonable amount of deviation to the recited numeric
values (i.e., having the equivalent function or result). For
example, this term can be construed as including a deviation of
.+-.10 percent of the given numeric value provided such a deviation
does not alter the end function or result of the value. Therefore,
a value of about 1% can be construed to be a range from 0.9% to
1.1%.
* * * * *