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Patent 2221463 Summary

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(12) Patent: (11) CA 2221463
(54) English Title: DOWNHOLE APPARATUS FOR GENERATING ELECTRICAL POWER IN A WELL
(54) French Title: APPAREIL DE FOND PLACE DANS UN PUITS POUR LA PRODUCTION D'ENERGIE ELECTRIQUE
Status: Expired
Bibliographic Data
(51) International Patent Classification (IPC):
  • E21B 41/00 (2006.01)
(72) Inventors :
  • TUBEL, PAULO (United States of America)
  • HOLCOMBE, MICHAEL WAYNE (United States of America)
  • BAUGH, JOHN L. (United States of America)
  • MULLINS, ALBERT A., II (United States of America)
  • ROSS, ROBERT CHAPMAN (United States of America)
(73) Owners :
  • BAKER HUGHES INCORPORATED (United States of America)
(71) Applicants :
  • BAKER HUGHES INCORPORATED (United States of America)
(74) Agent: SIM & MCBURNEY
(74) Associate agent:
(45) Issued: 2006-10-31
(86) PCT Filing Date: 1996-06-19
(87) Open to Public Inspection: 1997-01-09
Examination requested: 2003-05-29
Availability of licence: N/A
(25) Language of filing: English

Patent Cooperation Treaty (PCT): Yes
(86) PCT Filing Number: PCT/US1996/010546
(87) International Publication Number: WO1997/001018
(85) National Entry: 1997-11-18

(30) Application Priority Data:
Application No. Country/Territory Date
60/000,469 United States of America 1995-06-23

Abstracts

English Abstract




Electrical generating apparatus is provided which connects to
the production tubing. In a preferred embodiment, this apparatus
includes a housing having a primary flow passageway in
communication with the production tubing. The housing also includes a
laterally displaced side passageway communicating with the primary
flow passageway such that production fluid passes upwardly towards
the surface through the primary and side passageways. A flow
diverter may be positioned in the housing to divert a variable amount
of production fluid from the production tubing and into the side
passageway. In accordance with an important feature of this
invention, an electrical generator is located at least partially in or along
the side passageway. The electrical generator generates electricity
through the interaction of the flowing production fluid.


French Abstract

L'invention concerne un appareil fournissant de l'énergie électrique, qui est relié à la colonne de production dans un puits. Dans un mode de réalisation préféré, cet appareil comporte une enveloppe dotée d'un conduit principal d'écoulement relié à la colonne de production. L'enveloppe comporte aussi un conduit secondaire déplacé latéralement, qui communique avec le conduit d'écoulement principal de sorte que le liquide de production circule vers le haut en direction de la surface en empruntant les conduits principal et secondaire. Un déflecteur de liquide peut être placé dans l'enveloppe afin de dévier une quantité variable de liquide de production hors de la colonne de production pour qu'il s'écoule dans le conduit secondaire. La caractéristique importante de l'invention est qu'un générateur, situé au moins en partie dans le conduit secondaire ou le long de ce conduit, produit de l'électricité sous l'effet de l'écoulement du liquide de production.

Claims

Note: Claims are shown in the official language in which they were submitted.




-25-

What is claimed is:

1. ~An electrical energy generating apparatus for generating electricity
downhole in a
well, comprising:
a primary flow passageway and side passageway laterally displaced in a side-by-

side relationship from said primary passageway; and
an electrical generating device positioned, at least in part, in said side
passageway,
said electrical generating device adapted to generate electricity in response
to fluid flowing
through said side passageway.

2. ~The apparatus of claim 1 wherein:
said primary flow passageway and said side passageway are housed in a housing.

3. ~The apparatus of claim 1 wherein:
said side passageway communicates with said primary passageway to allow fluid
from said primary passageway to flow into said side passageway.

4. ~The apparatus of claim 3 wherein:
said side passageway communicates with said primary passageway through at
least
one opening between said primary and side passageways.

5. ~The apparatus of claim 1 wherein said primary flow passageway and said
side
passageway are adapted for positioning in a borehole such that an annulus is
defined
between an inner wall of the borehole and the side passageway and wherein:
said side passageway communicates with said annulus to allow fluid from said
annulus to flow into said side passageway.

6. ~The apparatus of claim 5 wherein:
said side passageway communicates with said annulus through at least one
opening
between said side passageway and said annulus.





-26-


7. The apparatus of claim 3 wherein said primary flow passageway and said side
passageway are adapted for positioning in a borehole such that an annulus is
defined
between an inner wall of the borehole and the side passageway and wherein:

said side passageway communicates with said annulus to allow fluid from said
annulus to flow into said side passageway.

8. The apparatus of claim 1 wherein said electrical generating device
comprises:

at least one turbine operatively connected within said side passageway for
movement in response to fluid flowing through said side passageway; and

an electrical generator associated with said side passageway and operatively
connected to said turbine for generating electricity in response to movement
by said
turbine.

9. The apparatus of claim 1 wherein said electrical generating device
comprises:

a magnetic field extending across said side passageway, said magnetic field
being
created in response to fluid flowing through said side passageway; and

an electrical energy converter associated with said side passageway for
converting
magnetic flux created by said magnetic field into electrical energy.

10. The apparatus of claim 9 wherein said magnetic field comprises:

a magnetic reed located within said side passageway and moveable in response
to
flowing fluid; and

a coil spaced from and associated with said reed.

11. The apparatus of claim 9 wherein said magnetic field comprises:

a flexible bladder having an interior and an exterior, said bladder being
located
within said side passageway, said bladder including an opening for receiving
fluid to the
interior thereof;

at least one magnet on the exterior of said bladder; and

a coil spaced from and associated with said magnet wherein said magnet moves
relative to said coil when fluid flows into said bladder.




-27-


12. The apparatus of claim 11 including:

a turbulence enhancer upstream of said bladder.

13. The apparatus of claim 1 wherein said electrical generating device
comprises:

a piezoelectric device positioned within said side passageway and being
responsive
to movement caused by flowing fluid; and

a converter for converting said signals from said piezoelectric device to
electrical
energy.

14. The apparatus of claim 1 including:

a flow diverter in said housing for diverting fluid from said primary flow
passageway to said side passageway.

15. The apparatus of claim 1 including:

a rechargeable battery in said side passageway, said electrical generating
device
being operatively connected to said battery for charging said battery.

16. The apparatus of claim 15 wherein said battery comprises:

at least one polymer lithium power cell.

17. The apparatus of claim 15 wherein said battery comprises:

at least one battery which includes an integrated circuit for optimizing
battery life.

18. The apparatus of claim 1 wherein:

at least a portion of said electrical generating device is enclosed by a fluid
tight
enclosure.

19. The apparatus of claim 1 including:

an electrical device operatively connected to said electrical generating
device
wherein said electrical generating device provides electrical power to said
electrical device.




-28-


20. The apparatus of claim 19 wherein:

said electrical device comprises a computer.

21. The apparatus of claim 15, including:

an electrical device operatively connected to said battery wherein said
battery
provides electrical power to said electrical device.

22. The apparatus of claim 21 wherein:

said electrical device is selectively connected to either said battery or said
electrical
generating device.

23. A production well comprising:

a first section of production tubing;

a second section of production tubing; and

a downhole electrical energy generating apparatus positioned between and
operatively connected to said first and second sections of production tubing,
said electrical
energy generating apparatus including;

(a) a primary flow passageway and a side passageway laterally displaced in
a side-to-side relationship from said primary passageway; and

(b) an electrical generating device positioned at least in part in said side
passageway, said electrical generating device adapted to generate electricity
in response to
fluid flowing through said side passageway.

24. An electrical energy generating apparatus for generating electricity
downhole in a
well, comprising:

a movable magnetic field extending across a selected area downhole, said
movable
magnetic field being created in response to the flow of fluid, said movable
magnetic field
comprising a magnetic reed movable in response to flowing fluid and associated
with said
reed; and

an electrical energy converter for converting magnetic flux created by said
movable
magnetic field into electrical energy.




-29-


25. An electrical energy generating apparatus for generating electricity
downhole in a
well, comprising:

a movable magnetic field extending across a selected area downhole, said
movable
magnetic field being created in response to the flow of fluid; and

an electrical energy converter for converting magnetic flux created by said
movable
magnetic field into electrical energy;

wherein said movable magnetic field comprises:

a flexible bladder having an interior and an exterior, said bladder being
located within said side passageway, said bladder including an opening for
receiving fluid
to the interior thereof;

at least one magnet on the exterior of said bladder; and

a coil spaced from and associated with said magnet wherein said magnet
moves relative to said coil when fluid flows into said bladder.

26. The apparatus of claim 25 including:

a turbulence enhancer upstream of said bladder.

27. The apparatus of claim 25 including production tubing in said well for
housing the
flowing fluid and wherein:

said flexible bladder is positioned within said production tubing and is
axially
aligned with said production tubing.

28. An electrical generating apparatus for generating electricity downhole in
a
production well, comprising:

a movable magnetic field extending across a selected area downhole, said
magnetic
field being created in response to pressure pulses traveling through a fluid
pathway; and

an electrical energy converter for converting magnetic flux created by said
movable
magnetic field into electrical energy.

29. The apparatus of claim 28 wherein said electrical generating apparatus
comprises:
a spring actuated magnet; and

a coil spaced from and magnetically communicating with said spring actuated




-30-


magnet wherein said pressure pulses cause said spring actuated magnet to move
relative to
said coil.

30. The apparatus of claim 28 including tubing in said well for housing fluid
and
wherein said pressure pulses travel through said tubing.

31. The apparatus of claim 29 including tubing in said well for housing fluid
and
wherein said pressure pulses travel through said tubing.

32. The apparatus of claim 31 wherein:

said spring actuated magnet and coil are laterally offset from said tubing.

33. The apparatus of claim 28 including tubing in said well for housing fluid
and
wherein:

said pressure pulses travel through a conduit having fluid therein which is
laterally
offset from said tubing.

34. An electrical generating apparatus for generating electricity downhole in
a well,
comprising:

a piston positioned in a selected area downhole, said piston being moved in a
first
direction in response to pressure pulses traveling through a fluid pathway;
and

an electrical energy generator coupled to said piston for generating
electrical energy
in response to motion by said piston.

35. The apparatus of claim 34 further comprising:

a spring connected to said piston, said spring moving said piston in a second
direction opposite to said first direction.

36. The apparatus of claim 35 wherein said electrical energy generator
comprises:

a magnetic coil; and

a generator armature which rotates within said magnetic coil to generate said
electrical energy.



-31-


37. The apparatus of claim 36 further comprising a drive shaft connected to
said piston
and said generator armature, said drive shaft rotating said generator armature
when said
piston moves in said first direction and said second direction.

38. The apparatus of claim 34 including tubing in said well for housing fluid
and
wherein:

said pressure pulses travel through a conduit having fluid therein which is
laterally
offset from said tubing.

39. An electrical energy generating apparatus for generating electricity
downhole in a
well, comprising:

a primary flow passageway having an interior and an exterior; and

an electrical generating device positioned on said exterior of said primary
flow
passageway, said electrical generating device adapted to generate electricity
in response to
fluid flowing along said exterior of said primary passageway.

40. The apparatus of claim 39 wherein said electrical generating device
comprises:

at least one turbine being operative in response to said flowing fluid; and

an electrical generator operatively connected to said turbine for generating
electricity in response to movement by said turbine.

41. The apparatus of claim 39 wherein said electrical generating apparatus
comprises:

a rotating member for rotating about the exterior of said primary flow
passageway in alignment with the longitudinal axis of said primary flow
passageway;

at least one magnet mounted on said rotating member and being rotatable with
said
rotating member; and

a coil positioned about the exterior of the primary flow passageway, said coil
being
spaced from and associated with said magnet wherein said magnet moves relative
to said
coil when fluid flows through said turbine.




-32-


42. The apparatus of claim 41 wherein said primary flow passageway comprises
tubing
and the exterior of said primary flow passageway comprises an annulus and
wherein:

said fluid flows through said turbine and is directed into said tubing
downstream of
said turbine.

43. The apparatus of claim 42 wherein:

said fluid is directed from the interior of said tubing to said annulus
upstream of said
turbine.

44. An electrical generating apparatus for generating electricity downhole in
a well,
comprising:

a primary flow passageway and a side passageway laterally displaced from said
primary flow passageway; and

an electrical generating device positioned in said side passageway, said
electrical
generating device adapted to generate electricity in response to fluid flowing
downhole in
the well.

45. A production well comprising:

a section of production tubing having an interior flow passage and an
exterior;

a piezoelectric device positioned on said exterior of said tubing and being
responsive to movement caused by flowing fluid; and

a converter for converting signals from said piezoelectric device to
electrical
energy.

46. The well of claim 45 wherein said converter includes:

a power rectifier operatively connected to said piezoelectric device;

a voltage regulator for receiving rectified signals from said power rectifier;

at least one rechargeable battery; and

a switch operatively connected between said voltage regulator and said
battery.

47. A production well comprising:

a section of production tubing;





-33-


a downhole power generator associated with said production tubing; and

at least one rechargeable battery operatively connected to said power
generator.

48. The well of claim 47 wherein:

said battery comprises a lithium polymer battery.

49. The well of claim 48 wherein:

said battery includes an integrated circuit for optimizing performance.

50. The well of claim 47 including:

at least two rechargeable batteries wherein a first of said batteries is
recharged while
a second of said batteries is being used to provide power to a device.

51. A long-term power supply to be mounted on hydrocarbon production tubing
downhole in a wellbore for providing electrical power to equipment mounted on
the
production tubing comprising:

an electrical power generating device powered by fluid flow downhole;

a rechargeable battery for storing electrical power from the generating
device; and

a charging circuit receiving electrical power as generated from the generating
device
and producing a charging current for delivery of power to the battery;

wherein the battery is recharged on a periodic basis by the charging circuit
and
serves as a source of power for the downhole equipment.

52. The well of claim 51 wherein:

said battery comprises a lithium polymer battery.

53. The well of claim 52 wherein:

said battery includes an integrated circuit for optimizing performance.

54. The well of claim 51 including:

at least two rechargeable batteries wherein a first of said batteries is
recharged while
a second of said batteries is being used to provide power to a device.

Description

Note: Descriptions are shown in the official language in which they were submitted.



CA 02221463 1997-11-18
WO 97/01018 PCT/US96/10546
DOWNHOLE APPARATUS FOR GENERATING
ELECTRICAL POWER IN A WELL
Background of the Invention:
This invention relates to apparatus and methods for providing electrical power
to electrical circuits located in a well. More particularly, this invention
relates to
downhole apparatus and methods for producing electrical power in oil and gas
production wells wherein the primary wellbore passage is maintained free of
obstruction.
The control of oil and gas production wells constitutes an important and on-
going concern of the petroleum industry. Production well control has become
particularly important and more complex in view of the industry wide
recognition that
wells having multiple branches (i.e., multilateral wells) will be increasingly
important
and commonplace. Such multilateral wells include discrete production zones
which
produce fluid in either common or discrete production tubing. In either case,
there is a
need for controlling zone production, isolating specific zones and otherwise
monitoring
each zone in a particular well. As a result, the methods and apparatus for
controlling
wells are growing more complex and in particular, there is an ever increasing
need for
downhole control systems which include downhole computerized modules employing
downhole computers (e.g., microprocessors) for commanding downhole tools such
as
packers, sliding sleeves and valves. An example of such a sophisticated
downhole


CA 02221463 2005-08-22
wa srrrotots pc~rnrss6nns4s
-2-
control system is disclosed in U_S. Patent No. 5,732,776, which is assigned to
the
assignee hereof. This application discloses downhole sensors, downhole
electromechanical devices and downhole computerized control electronics
whereby the
control electronics automatically control thg electromechanical devices based
rnz input
g from the downhole sensors. Thus, using the dowirhole sensors, the downhole
computerized controhsystem will monitor actual downhole parameters (such as
pressure,
temperature, flow, gas influx, etc.) and automatically execute control
instructions when
the zzronitvrcd downhole parameters are outside a selected operating range
(e.g.,
indicating an unsafe condition}. 'The automatic eoxAtrol instructions will
then cause an
1 p electromechanical control device (such as a valve) to actuate a suitable
foal (for example,
actuate a sliding sleeve or packer, or close a valve or startlstop a pump or
other fluid flow
device).
It wih be appreciated that the above-described well control system as well as
othea well control systems utilize downhole devices and circuits which require
15 electrical power. However, presently known methods of supplying ar
generating
electricity downhole each suffers from a host of problems and deficiencies.
One manner of providing electricity downhale in a well includes lowering a
tool
on a wireline and conducting energizing electricity through one or store
conductozs ar
tire wireline from the surface to the tool when positioned dawnhoie. This
technique is
20 not always desirable because it is relatively complex iri that it requires
the wireline to
be passed through the wellhead closure equipment at the mouth of the weld.
"'his can
create safety problems. p'urthermore, at least in deep webs, there can be
signi$cant
energy loss caused by the resistance or impedance of a long wireline
conductor_
.~.nother way to provide electricity to downhole electrical circuits utilizes
25 batteries housed within the electrical circuits in the dowahole assembly.
1~or example,
lithium-thionyl-chloride batteries have been used with downhole tools. A
shortcoming
of batteries, however, is that they cannot provide moderate (and higher)
amounts of
electrical enemy (e.g., 3Q kilowatt hours) at the elevated temperatures
encountered in


CA 02221463 1997-11-18
WO 97/01018 PCT/US96/10546
-3-
petroleum and geothermal wells. Batteries are also extremely dangerous. Still
another
problem with batteries are their relatively short life whereupon the batteries
need to be
replaced and/or recharged.
Because of the shortcomings of power derived either from wireline or battery
sources, suggestions have been made to provide a downhole mechanism which
continuously generates and supplies electricity. For example, U.S. Patent
4,805,407 to
Buchanan discloses a downhole electrical generator/power supply which includes
a
housing in which a primary fuel source, a Stirling cycle engine, and a linear
alternator
are disposed. The primary fuel source includes a radioisotope which, by its
radioactive
decay, provides heat to operate the Stirling engine which in turn drives the
linear
alternator to provide a suitable electrical output for use by the circuit of
the downhole
tool. U.S. Patent 5,202,194 to VanBerg Jr. discloses a downhole power supply
comprised of a fuel cell.
U.S. Patent Nos. 3,970,877 ('877) and 4,518,888 ('888) both relate to the use
of
piezoelectric techniques for generating small electric currents. The '888
patent
generates electrical energy downhole (in the drillstring) by the use of a
piezoelectric
device stored in the drill collar which converts vibrational energy from the
drillstring
into electrical energy. The piezoelectric device is in the form of a stack of
piezoelectric
elements arranged in an electrically additive configuration. The '877 patent
describes a
method of power generation used in a drilling operation wherein a
piezoelectric
material is responsive to turbulence in the mud flowing past the piezoelectric
material.
The vibrations resulting from the turbulent flow of the mud past the
piezoelectric
material will be converted into an electrical output. In addition to a
piezoelectric
material, the '877 patent also discloses the use of a fixed coil with a
magnetic core
freely movable relative to the coil and attached to the inner surface of a
flexible disk
which will also be actuated by the flowing mud for generation of electrical
energy.
U.S. Patent 3,666,030 ('030) discloses a stressed spring or other form of
stored
energy which is carned downhole and is then converted to electrical energy by
causing
relative motion between a permanent magnet and coil and some other structure
which is
urged into movement by the compressed spring. In the '030 patent, the
energizing


CA 02221463 1997-11-18
WO 97/01018 PCT/US96/10546
-4-
source comprises a housing which is adapted to traverse a borehole. A magnetic
coil is
positioned within the housing and the storage means for storing energy (i.e.,
spring) is
also positioned in the housing. A release mechanism located in the housing
releases
the stored energy at the proper moment downhole so that the electrical energy
can be
generated.
U.S. Patent 3,342,267 ('267) to Cotter et al discloses downhole production
tubing including an electric generator which is energized by a turbine for
providing
electricity to a coiled heater which is also disposed in the production
tubing. The
turbine rotates upon the upward flow of fluids in the production tubing. In
FIGURE 2
of the '267 patent, a primary production tubing is shown at 12, a coiled
heater is shown
at 24 and downstream from the coiled heater is a series of rotatable turbines
26.
Disposed laterally from production turbine 12 is a side compartment 38 which
houses
the electrical generator 20. During operation, production fluid flows upwardly
through
production tubing 12 thereby rotating turbines 26 which in thin, through a
series of
Bearings, will rotate generator 20 in the side compartment 38 and thereby
generate
electricity to power the heating coil 24.
The numerous attempts at generating electricity downhole in a well as
disclosed
in the aforementioned patents all suffer from one or more drawbacks and
problems
including, for example, environmental and safety concerns (.e.g., patent
4,805,407)),
high expense and complexity (e.g., patent 5,202,194), inability to generate
high or
sustained levels of power (e.g., patents 3,666,030; 3,970,877; 4,518,888) and
causing
obstructions within the production tubing (e.g., patent 3,342,267). This
latter problem,
that of obstructing the production tubing, poses a serious drawback to many
prior art
schemes. In the '267 patent, for example, the turbine blades are positioned in
the
primary production tubing and thus would preclude unobstructed production as
is
required, particularly so as to enable entry of completion equipment and other
objects
into the production tubing. Thus, the turbo generator of the "?67 patent would
not
allow for the downhole introduction of instruments, tools and other completion
devices
due to the presence of turbines.


CA 02221463 1997-11-18
WO 97/01018 PCT/US96/10546
-5-
Such obstruction problems are also an important reason why well known turbo
generators used in generating electricity during drilling operations (e.g.,
for powering
MWD equipment) would be problematic when used in a production well. Examples
of
patents describing downhole turbo generators used during drilling include
patents
3,036,645 and 4,647,853.
Summary of the Invention:
The above-described and other drawbacks and deficiencies of the prior art are
overcome or alleviated by the downhole electrical generating apparatus and
methods of
the present invention. In accordance with the present invention, electrical
generating
apparatus is provided which connects to the production tubing. This apparatus
includes
a housing having a primary flow passageway in communication with the
production
tubing. In a first embodiment of this invention, the housing also includes a
laterally
displaced side passageway communicating with the primary flow passageway such
that
production fluid passes upwardly towards the surface through the primary and
side
passageways. A flow diverter may be positioned in the housing to divert a
variable
amount of production fluid from the production tubing and into the side
passageway.
Alternatively, production fluid may enter the side passageway from the annulus
defined
by the production tubing and the borehole wall or casing.,
In accordance with an important feature of this invention, an electrical
generating device is located in or along the side passageway. The electrical
generating
device generates electricity through the interaction of the flowing production
fluid. In a
first embodiment ofthis-invention,-a turbine or-the like is operatively
connected within
the side passageway for movement in response to fluid flowing through the side
passageway. A generator is also positioned in the side passageway and is
operatively
connected to the turbine for generating electricity in response to movement by
the
turbine. In a second embodiment of this invention, a magnetic field is
positioned in the
side passageway with the magnetic field being movable in response to fluid
flowing the


CA 02221463 1997-11-18
WO 97/01018 PCT/US96/10546
-6-
side passageway (such as an oscillating magnetic reed enclosed by a coil). An
electrical energy converter in the side passageway converts the AC power
created by
the movable magnetic field into DC electrical energy.
In a third embodiment of this invention, a movable magnetic field within the
side passageway is effected by positioning magnets on a movable bladder which
is
sandwiched between a pair of coils. Fluid is directed through the bladder such
that the
magnets move with respect to the coils thereby generating electricity.
Preferably, a
turbulence enhancer is positioned upstream of the bladder to cause a turbulent
and
constant movement of the fluid within the bladder. In a fourth embodiment, the
electrical generating device in the side passageway constitutes a
piezoelectric power
supply wherein a piezoelectric assembly generates electrical power in response
to fluid
flow.
In accordance with another embodiment of this invention, pressure waves are
delivered downhole through a column of fluid to actuate an electrical
generating device
to thereby generate electricity. In one such embodiment, the pressure waves
travel
through the production tubing and cause a laterally mounted spring actuated
magnet/coil assembly to move in a reciprocal motion and thus generate
electricity. In
another such embodiment, the pressure waves travel downwardly through a
separate
control line to actuate the laterally mounted or annulus mounted magnet/coil
assembly
to reciprocate and generate power.
In still another embodiment of this invention, various electrical energy
generating devices are positioned in the annulus adjacent the production
tubing and
generate electricity in response to fluid flowing either from the production
tubing or
within the annulus itself. In one such embodiment, the electrical generating
device
comprises a turbine rotatably mounted about the outer circumference of the
production
tubing. Attached to the turbine is one or more magnets. Also attached to the
outer
circumference of the production tubing and in spaced, facing relation to the
magnet is a
coil. During use, production fluid flowing from the annulus or from within the


CA 02221463 2005-08-22
WO 97/01018 FCTIUS96/t0546
_7_
production tubing out to the annulus, will flow past the turbine causing the
turbine and
attached magnets) to freely rotate about the tubing. Thte rotating magnet will
interact
with the coil in a known zxsdnner to generate electricity.
Preferably, in each of the foregoing embodiments, a rechargeable battery may
also be present in the side passageway with the electrical generator being
operatively
connected to the battery far electrically charging the battery. As a result,
an elee'trieaf
circuit such as a downhole computer can be provided with electricity either
directly
froze the generator or from the battery. Since many of the electrical
generator
techatiques of this invention necessitate the flow of production fluid,
provision of a
battery is particularly important for those periods where the flow of
production fluids
has halted or significantly slowed.
A particularly preferred rechargeable battery for use in the downhole power
generation appazntus of this invention is a lithium power cell (LPG') using
polymer
electrolytes. Also believed to be preferred is a rechargeable battery which
incorporates
integrated circuit technology for maximizing battery life.
The downhole electrical generating methods and apparatus of the present
invention provide many features and advantages ever prior art techniques. One
important feature is that the components which generate the electricity are
outside of
the primary passageway defined by the production tubing. As a result, the
present
invention does not in any way obstruct the production tubing (as does for
example, the
turbo generator of patent 3,342,267). This rraeans that eompietion equipment,
coiled
tubing and other objects may be freely introduced downhoIe. The present
invention
also provides envixanmentally acceptable, relatively low post processes and
apparatus
for downhole electrical generation.


CA 02221463 2005-08-22
- 7a -
Accordingly, in one aspect of the present invention there is provided an
electrical
energy generating apparatus for generating electricity dowz~hole in a well,
comprising:
a primary flow passageway and side passageway laterally displaced in a side-hy-

side relationship fx'om said primary passageway; and
an electrical generating device positioned, at least in pant, in said side
passageway,
said electrical generating device adapted to generate electricity ira response
to fluid flowing
through said side passageway.
According to another aspect of the present invention there is provided a
production
well comprising:
a ~~rst section of production tubing;
a second section ofpmduction tubing; and
a downhole electrical energy generating apparatus positioned between and
operatively connected to said first and second sections ofproduction tubing,
said electrical
energy generating apparatus including;
(a) a primary flow passageway and a side passageway laterally displaced in
a side-to~side relationship from said primary passageway; and
(b) an electrical generating device positioned at least in part iu~ said side
passageway, said electrical generating device adapted to generate electricity
in response to
fluid flowing through said side passageway.
According to yet another aspect of the present inveption there is provided an
electrical energy generating apparatus for generation electricity downhole in
a well,
comprising=
a movable magnetic field extending across a selected area downhole, said
movable
magnetic field being created in response to the flow oFfluid, said movalale
magnetic ii~ld
comprising a magnetic reed movable in response to flowing fluid and associated
with said
reed; and
an electrical energy converter for converting magnetic flux created by said
movable
magnetic field into electrical energy.
According to yet another aspect of the present invention there is provided an
electrical energy generatin; apparatus for generating electricity downhole in
a well,
comprising.


CA 02221463 2005-08-22
_7b_
a movable rrxagnetic field extending across a selected area downhole, said
~motlable
magnetic field being created in response to the flow of fluid; and
an electnicaI energy converter for converting magnetic flux created by said
movably
magnetic field into electrical energy;
wherein said movable magnetic field comprises:
a flexible bladder having an inferior end an exterior, said bladder being
located within said side passageway, said bladder including art opening for
receiving fluid
to the interior thereof;
at least one magnet on the exterior of said bladder; and
a coil spaced from and associated with said magnet wherein said magnet
moves relative to said tail when fluid flows into said bladder.
According to yet another aspect of the present invention there is provided an
electrical generating apparatus for generating electricity downhole in a
production well,
comprising_
a nrxovable magnetic i field extendi~~tg across a selected area downhole, said
malmeue
field being created in response to pressure pulses traveling through a fluid
pathway; and
an electxxcal energy converter for converting magnetic flux created by said
movable
magnetic field into electrical energy.
According tv yet another aspect of the present invention there is provided an
electrical generating apparatus for generating electricity downhole in a well,
comprising:
a piston positioned in a selected area dowrthole, said piston being moved in a
First
direction in response to pressure pulses traveling through a fluid pathway;
and
an electrical energy generator cougled to said piston for generating
electrical cxleroy
in response to motion by said piston.
According to yet another aspect of the present invention there is provided an
electrical energy generating apparatus for generating electricity downhole in
a well,
comprising:
a primary flow passageway having an interior and an exterior, and
an electrical generating device positioned on said exteriox of said primary
flew
passageway, said electrical geztexa2ing device adapted to gEnerate electricity
in respo~tse to
fluid flowing along said exterior of said primary passageway_


CA 02221463 2005-08-22
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According to still yet another aspect of the present invention there is
provided an
electrical generatizag apparahts for generating electricity downhole in a
well, comprising: a
primary flow passageway and a side passageway laterally displaced from said
primary flow
passageway, and
S an electrical gcneratixg device positioned tut said side passageway, said
electrical
generating device adapted to generate electricity in response to fluid flowing
downhole in
tlxe well.
According to still yet another aspect of the present invention there is
provided a
productivz~ well comprising:
a section of production tubing having an interior flow passage and an extcri
or;
a piezoelectric device positioned on said exterior of said tubing and being
responsive to movement caused by flowing fluid; and
a converter for converting signals from said piezoelectric device to
electrical
energy.
I S According to still yet another aspect of the present i nvention there is
provided a
production well comprising:
a sectioxt of production tubing;
a downhole power generator associated with said production tubing; and
at least one rechargeable battery operatively connected to said power
generator.
According to still yet another aspect of the present invention there is
provided a
long-term power supply to be mounted on hydrocarbon production tubing dow~ale
in a
wellbore for providing electrical power to eduipment mounted on the production
tubing
comprising:
an elecrncal power g~'n~rating device powered by fluid flow downhola;
a rechargeable battery for storing electrical power from the generatitag
device; and
a charging circuit reeeiviztg electrical power as generated from the
generating device
and producing a charging current fox delivery of power to the battery;
wherein the battery is recharged on a periodic basis by the charging circuit
and
serves as a source of power for the dvwnhole equipment.
The above-discussed and other features and advantages of the present invention
will
be appreciated and understood by those stalled iz~ the art from the following
detailed
description and drawings.


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Brief Description of the Drawinus:
Referring now to the drawings, wherein like elements are numbered alike in the
several FIGURES:
FIGURE 1 is a cross-sectional elevation view of a downhole power generating
apparatus in accordance with this invention utilizing a turbine located in a
side
passageway;
FIGURE 1 A is a cross-sectional elevation view of a downhole power generating
apparatus, similar to FIGURE 1, but utilizing an alternative fluid diverter;
FIGURE 2 is a cross-sectional elevation view of a downhole power generating
apparatus, similar to FIGURE 1, but being responsive to fluid flow from the
annulus;
FIGURE 3 is a cross-sectional elevation view of a downhole power generating
apparatus in accordance with this invention utilizing an oscillating reed;
FIGURES 4A and 4B are cross-sectional elevation views of related downhole
power generating apparatuses in accordance with this invention utilizing a
movable
bladder associated with a magnet/coil assembly for generating electrical power
downhole;
FIGURE 5 is a cross-sectional elevation view of a downhole power generating
apparatus in accordance with this invention utilizing a piezoelectric
generating device
located in a side passageway;
FIGURE 6 is an electrical schematic of the circuitry involved in the
embodiment of FIGURE 5 for converting signals from the piezoelectric device to
electricity and/or stored power;
FIGURE 7A is a cross-sectional elevation view of a downhole power generating
apparatus in accordance with this invention wherein a spring actuated
magrietic/coil
assembly generates power in response to pressure waves;
FIGURE 7B is a cross-sectional elevation view of a downhole power generating
apparatus in accordance with this invention wherein a spring actuated
gernerator
armature assembly generates power in response to pressure waves;


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FIGURE 7C is a cross-sectional view of a device for producing pressure pulses;
FIGURE 7D is a cross-sectional view of an alternative device for producing
pressure pulses;
FIGURE 8 is a cross-sectional elevation view of a downhole power generating
apparatus in accordance with this invention, similar to the power generating
device of
FIGURE 7, with the pressure waves being delivered via a separate control line;
FIGURE 9 is a cross-sectional elevation view of a downhole power generating
apparatus in accordance with this invention utilizing a turbine positioned in
the annulus
between the production tubing and the casing or borehole wall;
FIGURES l0A through l OC are cross-sectional elevation views depicting a
power generating apparatus located in the annulus between the production
tubing and
well casing which consists of a magnet/coil assembly rotatably mounted on the
production tubing;
FIGURE 11 is a cross-sectional elevation view of a downhole power generating
apparatus consisting of a piezoelectric or magnetic assembly positioned in the
annulus
between the production tubing and the casing or borehole wall; and
FIGURE 12 is a cross-sectional elevation view of a downhole power generating
apparatus, similar to the embodiments of FIGURES 4A-4B, but with the movable
bladder being positioned in the production tubing's primary passage.
Description of the Preferred Embodiment:
Referring first to FIGURE 1, a downhole electrical generating apparatus in
accordance with a first embodiment of this invention is shown. FIGURE 1 more
particularly depicts a production well 10 for producing oil, gas or the like.
Well 10 is
defined by well-known well casing 12 which is cemented or otherwise
permanently
positioned in earth 14 using an appropriate cement or the like 16. Well 10 has
been
completed in a known manner using production tubing with an upper section of
production tubing being shown at 16A and a lower section of production tubing
being
shown at 16B. Attached between production tubing 16A and 16B, at an
appropriate
location, is the electrical power generating apparatus in accordance with the
present


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invention which is shown generally at 18. Power generating apparatus 18
comprises a
housing 20 having a primary flow passageway 22 which communicates with and is
generally in alignment with production tubing 16A and 16B. Housing 20 also
includes
a side passageway 24 which is laterally displaced from primary flow passageway
22.
Side passageway 24 is defined by a laterally extending section 26 of housing
20 and an
interior dividing wall 28. Shown by the arrows, production fluids such as
petroleum
are produced from below electrical generating device 18 and travel upwardly
through
production tubing 16B into housing 20 whereupon the production fluid travels
both
through the primary passageway 22 and the side passageway 24. Upon reaching
the
upper portion of side passageway 24, the production fluid again enters the
primary
passageway 22 and then travels on upwardly into the upper section of
production
tubing 16A.
The amount of fluid traveling into side passageway 24 may be controlled using
a flow diverter 30 which is pivotally attached to wall 28. Flow diverter 30
may shut off
all fluid flow into side passageway 24 or in contrast, open up the fluid flow
into side
passageway 24 so as to divert a varying amount of fluid therethrough. Diverter
30 may
be controlled from the surface using coil tubing or other tools.
In the first embodiment of FIGURE l, the electrical generating means utilizes
one or more turbines (in this case two turbines 32 and 34). Turbines 32, 34,
are
mounted on a shaft 36. Shaft 36 is rotatably mounted in a lower mount 38 where
a
centrally located bearing 40 permits shaft 36 to freely rotate therein. The
upper section
of shaft 36 is mounted to a conventional electrical generator 42 such that
rotation of
shaft 36 will rotate so as to produce electricity in a known manner. In a
preferred
embodiment, generator 42 is positioned in a fluid tight chamber 44 so as to
preclude the
adverse effects of the pressurized and high temperature production fluids
flowing
through side passageway 24. Shaft 36 terminates within chamber 44 at a support
46
which houses an upper bearing 48. Also located in chamber 44 is a rechargeable
battery 50 and a computer or other device 52 which includes at least one
circuit which
requires electrical power. Electrical generator 42 communicates directly
through a first
wire 54 to battery 50 and through a second wire 56 to computer 52. In turn,


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rechargeable battery 50 communicates with computer 52 through a wire 58. As
will be
discussed, rechargeable battery 50 may comprise any conventional rechargeable
battery
which is adapted for high temperature operations. As mentioned, item 52 may
comprise any device or group of devices which include at least one electrical
circuit
which is powered by the present invention. For example, item 52 may comprise a
computer such as shown at 50 in FIGURE 6 of aforementioned U.S. Application
S.N.
08/385,992. In this latter example, power source 66 as shown in FIGURE 6 of
USSN.
08/385,992 could be constituted by either rechargeable battery 50 or
electrical
generator 42.
It will be appreciated that one or more of electrical generator 42, battery
50,
computer 52 and any other component associated with the turbines may be
located in
another location (such as in the annulus) so long as these components do not
block the
primary passageway 22.
It will further be appreciated that the separation between primary flow
passageway 22 and the electrical generating apparatus in side passageway 24
could be
effected using a liner for separation as opposed to the more complex housing
20.
During operation, production fluid flowing upwardly through production tubing
16B is diverted by diverter 30 into side passageway 24 whereupon the fluid
will rotate
in a known manner turbines 32 and 34. Rotating turbines 32, 34 will cause
shaft 36 to
rotate which in turn, will provide the necessary rotation for the generation
of electricity
in generator 42. Electricity generated by generator 42 (which, if necessary,
is
converted from AC to DC using a known AC/DC converter) may be used either to
directly power a circuit in item 52 and/or may be used to recharge battery 50.
If item
52 is a computer, then the computer may be programmed to receive electrical
power
either directly from generator 42 or from battery 50. In some cases, it may be
preferable that computer 52 only receive its power from battery 50. When fluid
flow in
production tubing 16B ceases, rechargeable battery 50 can supply, on a
continuous or
intermittent basis, power to computer 52. The amount of fluid flowing into
side
passageway 24 may be controlled by diverter 30 depending on the need for
electricity
and other relevant factors. It will be appreciated that computer 52 will
communicate


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with other downhole devices such as described in more detail in Application
S.N.
08/385,992.
In FIGURE lA, an alternative flow diverter means is shown wherein a flexible,
tapered restriction 3 I (which may be made from an high temperature elastomer
or other
appropriate material) is attached to the inner surface of primary passage 22
near the
opening 29 to side passage 24. This flexible restriction 31 ensures fluid flow
through
lateral passage 24 as shown by the arrows. In addition, should a tool, coiled
tubing or
other object be required to pass through primary passage 22, restriction 31
will easily
yield (deflect outwardly towards the inner walls of tubing 22) to the object.
After the
object has passed, the restriction 31 will recover to its original shape.
Refernng to FIGURE 2, an electrical power generating device utilizing a
turbine similar to FIGURE I is shown. The main difference between the
embodiments
of FIGURE 1 and FIGURE 2 is that in FIGURE 2, the turbine is actuated by
production
fluid flowing in from the annulus as opposed to flowing in from within the
production
tubing itself. More particularly, side passageway 24 is shown which includes
turbine
32, 34 mounted on a shaft 36 which in turn is mounted to a generator 42. The
generator communicates with an energy storage device 50 (battery) and
associated
electronics 52 as in FIGURE 1. Perforations 68 have been foamed through the
casing
12, cement 16 and formation 14 so as to allow production fluid (indicated by
the
arrows) to flow from the formation and into the annulus 10. These formation
fluids
travel upwardly through at least one opening 70 and into the side passageway
24
whereupon the fluid interacts with turbines 32, 34 causing the turbines to
rotate and
generate electricity in the same manner as was discussed in detail with regard
to
FIGURE 1. After passing through turbines 32, 34, the fluid continues to flow
upwardly
and into the primary flow passageway of production tubing 20. It will be
appreciated
that the alternative embodiment of FIGURE 2 may be utilized in those locations
downhole where formation fluids are being produced at or near the power
generating
location as shown in FIGURE 2. Of course, the FIGURE 2 embodiment can also
have
an opening of the type shown at 29 in FIGURE 1 (with or without a flow
diverter 30)
so that turbines 32, 34 could be actuated from production fluid which both is
flowing


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upwardly through tubing 16 and which is flowing outwardly from the formation
into
. annulus 10.
Turning now to FIGURE 3, a second embodiment of the power generating
apparatus of the present invention is shown. This second embodiment is
substantially
similar to the first embodiment of FIGURES 1 and 2 with the primary difference
being
that rather than using the turbine based generator of FIGURE l, the second
embodiment utilizes an alternative power generating source wherein the
movement of a
magnetic field is used to create a magnetic flux for electrical power
generation. This
movable magnetic field is obtained using a reed or the like 72 which is
mounted on a
shaft 74 within lateral housing 26 using mount 76. Reed 72 comprises a
permanent
magnet which isrotatable (in a manner analogous to a propeller) relative to
shaft 74.
Lower portion 26 of side passageway 24 includes a coil 78 with reed 72 being
positioned within coil 78. The north and south poles of reed 72 are positioned
transverse to the cylindrically shaped coil 78 such that when reed rotates or
oscillates, a
magnetic flux will be induced on coil 78 in a known manner. Electrically
communicating with coil 78 is a converter 80 which converts AC electrical
output to
DC electrical energy. As in the FIGURE 1 embodiment, converter 80 is connected
directly to a rechargeable battery 50 and a computer or other device which
incorporates
an electrical circuit 52.
As discussed above, the change in the magnetic field induced in the coils 78
will generate the electrical power that will be rectified and stored in the
rechargeable
battery cell 50. One of the basic equations underlying this power generation
technique
(as well as the other techniques described herein which rely on a movable
magnetic
field) is:
dW(L,X) =1*dL - FdX
where W is the system energy;
L is the magnetic flux;
X is the displacement of the armature;
1 is the electric current; and
F is the mechanical force.


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It will be appreciated that the energy is constant and the magnetic flux is
the link
between the electrical force and the mechanical force.
During operation, production fluid travels upwardly from production tubing
16B into housing 20 whereupon the fluid travels both through the primary
passageway
22 and is diverted by optional diverter 30 into the side passageway 24. The
fluid
flowing into side passageway 24 acts to oscillate or rotate reed 72 as shown
by the
arrows in FIGURE 3. The movement of reed 72 within the coil 78 creates a
magnetic
flux (e.g., a movable magnetic field) which is converted in a known manner to
electricity. As in the FIGURE 1 embodiment, converter 80 may then directly
provide
electricity either to rechargeable battery 50 or to item 52.
Turning now to FIGURES 4A and 4B, in accordance with a third embodiment
of the present invention, a movable magnetic field is created within the side
passageway 24 using an expandable bladder 82 having one or more magnets 84
attached to the outer periphery thereof. On either side of magnets 84 are a
pair of coils
1 S 86, 88. Coils 86, 88 are attached to the inner walls of side passageway
24. Preferably,
a turbulence enhancer 90 which may consist of a plurality of appropriately
spaced and
contoured vanes, is positioned upstream of bladder 82 at the inlet to side
passageway
24. Coils 86, 88 are in electrical communication with an electronics module 92
and
rechargeable battery 94.
During operation, fluid flows upwardly through production tubing 16 and a
portion of the fluid is diverted (using if desired, a diverter 30 as shown in
FIGURE 1 )
into side passageway 24 where it is directed through turbulence enhancer 90
and into
the flexible bladder 82. The turbulence enhancer 90 will cause the fluid to
undergo a
turbulent motion and thereby cause the flexible bladder 82 to undulate and
move
magnets 84 within the annular space defined between coils 86 and 88. As a
result, a
magnetic flux will be developed on coils 86 and 88 thereby producing
electrical energy
which will flow to electronics 92 and rechargeable battery 94 in a manner as
described
above with regard to the FIGURE 3 embodiment.
As mentioned, in the FIGURE 4A embodiment of this invention, the production
flow within tubing 16 causes the bladder 82 to move and undulate and thereby
produce


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electricity. Alternatively, in the FIGURE 4B embodiment, production fluid from
perforations 68 of the type described in FIGURE 2 are directed into the
annulus and
flow within side passageway 24 through an opening 70 and into bladder 82. It
will be
appreciated that the FIGURE 4B embodiment could also include an inlet to side
passageway 24 from primary flow passageway 22 as in the FIGURE 4A embodiment.
Turning now to FIGURE 5, still another embodiment of this invention wherein
an electrical generating device is positioned at least in part, within a side
passageway is
shown. In the FIGURE 5 embodiment, the electrical generating device comprises
a
stack of piezoelectric elements 90 which are connected to a power rectifier
92, voltage
regulator 94, charge/power on switch 96 and rechargeable battery 98 as
schematically
shown in FIGURE 6. Piezoelectric elements 90 are composed of a low level force
to
electrical charge piezoelectric crystal or film. A vibration amplifier will
convert the
flow turbulence from within tubing 16 into a motion (e.g., vibration or
stress) outside
the tubing. The piezoelectric wafer stack is mounted with a motion generator
to
convert the movements into electrical charges. The power rectifier circuit 92
will
process the electrical charges into an electrical direct current. The output
voltage from
rectifier 92 will be regulated via regulator 94 to create a signal compatible
with the
battery cells 98. The charge/power-on circuit 96 will determine if the battery
cell 98
should be charged or if the battery pack should deliver power to the
electronic circuit
(such as item 52 in FIGURE 1 ). A dual battery pack (identified as "1 " and
"2" in
element 98) is preferred such that one pack will deliver power to the
electronics while
the other pack is being recharged. As shown in FIGURE 5, the piezoelectric
stack 90
may be actuated by movement of fluid flowing both within production tubing 16
as
well as from the annulus 10 through the aforementioned perforation 68 and out
of the
formation. Piezoelectric stack 90 is composed of any one of several known
materials
including piezoelectric crystalline materials or polymeric films such as
polyvinyl
chloride film. Such known materials generate electrical power once a
mechanical force
such as vibration or stress is exerted onto the stack. In this case, the
vibration or stress
will be exerted onto the stack through the production fluid impacting upon the
stack via
the tubing wall 28.


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While the foregoing embodiments of the present invention shown in FIGURES
1-6 generate electricity by the positioning of an electrical generating device
in a lateral
passageway and then generating electricity through the interaction of fluid
being
produced either from the formation into the annulus or from within the
production
tubing itself, in FIGURES 7A, 7B and 8, an alternative method of generating
electricity
will be described wherein pressure waves are sent downwardly through a
suitable fluid
so as to actuate a suitable power generation device. In the FIGURE 7A
embodiment,
this power generation device is again positioned in a lateral chamber 24 which
is
positioned outside of the primary flow passage. More particularly, the power
generation device comprises a permanent magnet 100 which extends outwardly
from a
piston 102. Piston 102 sealingly engages a suitably sized cylinder 104 (via
seal I06).
A spring 107 is sandwiched between piston 106 and the interior base 108 of
cylinder
104. Spring 107 surrounds magnet 100. It will be appreciated that when a force
urges
the upper surface I 10 of piston 102 downwardly, spring 107 will be compressed
such
that when the force on surface 110 is removed, spring 107 will urge upwardly
to place
piston 102 into its normal position. Surrounding chamber 104 and positioned in
facing
alignment to the normal position of magnet 100 is a coil 1 I 2. Coil 112 in
turn
electrically communicates with an electronics and battery package 114 of the
type
described above with regard to the embodiments shown in FIGURES 1-5.
During operation, assuming that production fluid or other fluid is present
within
the primary passage 16, pressure waves indicated by the lines I 15 are
directed
downwardly from the surface or from some other position downstream of side
passageway 24 and impinge upon surface 1 I 0 of piston I 02. The pressure
waves are
delivered over a selected intermittent and timed sequence such that piston 102
will be
sequentially urged downwardly when impinged by a pressure wave. During the
time
period that the pressure wave has passed and before the next pressure wave
impinges
upon piston 102, spring 107 will urge piston 102 upwardly to its normal
position. As a
result, piston 102 will undergo a reciprocating upward and downward motion
whereby
magnet 100 will similarly reciprocate within the annular opening defined
between coil
112. The result is a magnetic flux which will generate electricity in a known
manner


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and supply the electricity to the appropriate electronics and storage battery
114 as
discussed above regarding the embodiments of FIGURES 3 and 4A-B.
FIGURE 7B depicts an embodiment similar to that shown in FIGURE 7A. In
the FIGURE 7B embodiment, the power generation device is again positioned in a
lateral chamber 24 which is positioned outside of the primary flow passage.
More
particularly, the power generation device comprises a magnetic coil 150 and a
generator armature 152. The generator armature I 52 and the magnetic coil 150
form a
conventional electrical generator. A generator drive shaft 154 couples the
generator
armature 152 to a piston body 156 and piston head 158. The drive shaft 154
converts
linear motion by the piston body 156 into rotational motion to turn the
generator
armature. Piston head 158 sealingly engages the wall of the lateral chamber
through a
seal 162. A spring 160 is sandwiched between the bottom of the piston head 158
and a
base 164. It will be appreciated that when a force urges the piston head 158
downwardly, the piston body 156 causes the shaft 154 to turn the generator
armature
152. The generator produces electricity that is supplied to electronics and
battery
package 1 I 4 of the type described above. The spring 160 will be compressed
such that
when the force on the piston head 158 is removed, spring 160 will urge
upwardly to
place piston head 158 into its normal position.
During operation, assuming that production fluid or other fluid is present
within
the primary passage 16, pressure waves indicated by the lines 115 are directed
downwardly from some position downstream of side passageway 24 and impinge
upon
the piston head 158. The pressure waves are delivered over a selected
intermittent and
timed sequence such that piston head 158 will be sequentially urged downwardly
when
impinged by a pressure wave. During the time period that the pressure wave has
passed and before the next pressure wave impinges upon piston head 158, spring
160
will urge piston head 158 upwardly to its normal position. As a result, piston
head 158
will undergo a reciprocating upward and downward motion whereby the piston
body
156 will similarly reciprocate causing the drive shaft 154 to turn the
generator armature
152. The drive shaft 154 may be spiral cut in both directions so that downhole
and
uphole motion by the piston body 156 drives the generator armature 152 in the
same


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direction. The electricity produced by the generator is supplied to the
appropriate
electronics and storage battery 114 as discussed above regarding the
embodiments of
FIGURES 3 and 4A-B.
FIGURE 8 depicts an embodiment which is similar to FIGURE 7A in its use of
a reciprocating spring actuated piston which moves a magnet with respect to a
stationary coil. The primary difference between the embodiments of FIGURES 7A
and
8 is that in the FIGURE 8 embodiment, the pressure waves used to periodically
impinge upon surface 1 10 of piston 102 are delivered by a discrete control
line 116
which is positioned in the annulus 10 between the production tubing and the
casing.
The discrete control line 116 may also be used with the embodiment shown in
FIGURE
7B.
The pressure waves 115 shown in FIGURES 7A, 7B and 8 may be generated by
injecting an energy pulse into the fluid using an external device at the
surface of the
well. Alternatively, a device may be positioned within the well to produce the
pressure
waves 115. FIGURE 7C illustrates a choke assembly shown generally as 170.
Fluid
flow in tubing 176 is sharply and momentarily stopped by the choke assembly
170.
This causes a back pressure wave that will flow the length of the well and
provide the
pressure pulses 11 S shown in FIGURES 7A, 7B and 8. The actuator 172 drives a
rod
171 having a head 173 that engages a seat assembly 175. The actuator 172
repeatedly
engages and disengages the head 173 and the seat assembly 175 to form a series
of
pressure pulses 115 shown in FIGURES 7A, 7B and 8.
FIGURE 7D is an alternative mechanism for generating the pressure pulses 1 I 5
FIGURE 7D illustrates a valve assembly shown generally at I 80. Fluid flow in
tubing
186 is stopped momentarily by a valve gate 183. The valve gate 183 is
connected to a
rod 181 which is driven by actuator 182. The actuator 182 repeatedly inserts
and
removes the valve gate 183 from the tubing 186 to form a series of pressure
pulses 115
shown in FIGURES 7A, 7B and 8. An optional side flow path 184 is also shown in
FIGURE 7D. The optional side flow path 184 allows fluid to continue to flow in
the


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tubing 186 when the valve gate 183 has sealed the primary path of the tubing
186.
Thus, it is not necessary to completely shut off the fluid flow to generate
the series of
pressure pulses.
While many of the foregoing embodiments utilize downhole electrical energy
generating apparatus which are positioned in a lateral or side passageway
adjacent the
primary fluid passageway of the production tubing, it will be appreciated that
downhole
electrical energy generating apparatus could also be positioned outside of a
lateral
passageway. That is, energy generating apparatus could simply be positioned
within
the annulus between the production tubing and the casing or borehole wall. By
placement in the annulus, the electrical energy generating apparatus would
still not be
blocking the primary flow passage of the production tubing as is prevalent
with many
prior art devices such as the device disclosed in aforementioned U.S. Patent
3,342,267.
Examples of locating the downhole energy generating apparatus in the annulus
are
shown in the following FIGURES 9-11. In FIGURE 9, a downhole electrical
generating apparatus is shown which is substantially similar to that shown in
FIGURE
2 with the difference being that no outer housing or lateral passageway
shrouds the
turbine and therefore the electrical generating apparatus is openly positioned
in the
annulus and is not surrounded by a lateral passageway. It will be appreciated
that the
turbine is actuated by fluid flowing from perforation 68 in the formation as
indicated by
the arrows and/or fluid flowing up the primary passageway 22 through opening
29. A
packer is shown at 118 downstream of turbine 32 for sealing off the selected
portion of
the annulus 10 and causing the fluid flowing past turbines 32, 34 to flow back
into the
primary passageway 22. While the generator 42, energy storage device 50, and
electronics 52 are shown enclosed by an enclosure 120, it will be appreciated
that these
units could also be exposed within the annulus to the annulus fluids. However,
it is
preferred that units 42, 50 and 52 are protected by enclosure 120 so as to
avoid any
damage from fluids and other debris within the annulus.
Referring now to FIGURES l0A-1 OC, still another embodiment of this
invention wherein the electrical generating apparatus is positioned within the
annulus is
shown. In the embodiment of FIGURE l0A-l OC, a turbine 122 is rotatably
mounted


CA 02221463 1997-11-18
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onto the outer surface of tubing 16 using a bearing assembly 124. One or more
magnets 126 is mounted to a lower surface 128 of turbine 122. As a result,
fluid
impinging over turbine 122 will rotate both turbine 122 and. magnet 126 about
the
longitudinal axis of production tubing 16. Disposed upstream and in facing
relation to
turbine 122 and more particularly magnet 126 is an electrical coil 130 which
is rigidly
mounted about the outer periphery of tubing 16. Connected to coil 130 are
appropriate
electronics 132 and rechargeable battery 134 of the type described in
connection with
aforementioned embodiments of FIGURES 3 and 4A-B. In the embodiment of
FIGURE 10A, production fluid travels upwardly through annulus 10 from
perforations
68 formed in the formation 14. This flowing fluid impinges upon turbine 122
thereby
rotating turbine 122 about the longitudinal axis of tubing 16 whereupon the
magnet 126
will move relative to the coil 130 which is stationary (i.e. fixed) to tubing
16. As a
result, the rotating turbine will generate electricity through the interaction
between
moving magnet 126 and coil 130. After the fluid has impinged upon turbine 122,
the
fluid will continue to flow through the annulus 10 and enter the primary
passageway 22
of tubing 16 through a series of openings 136 and 138. In addition, the fluid
will pass
through optional centralizes 140.
FIGURE 1 OB shows a downhole powered generation assembly which is
substantially similar to FIGURE l0A with the difference being that in FIGURE 1
OB,
the production fluid which initially impinges upon turbine I22 flows out of
the
production tubing 16 through a upstream openings 140. A packer 142 is
positioned
upstream of openings 140 to seal this portion of the annulus 10. After leaving
the
primary passageway 140, the fluid impinges upon turbine 122 and then travels
upwardly and back into the primary passageway through openings 136, 138 as
discussed with regard to FIGURE 10A.
The FIGURE l OC embodiment is again substantially identical to the FIGURES
l0A and l OB embodiments with the difference being that the fluid which
impinges
upon turbine 122 neither flows back into the production tubing 16 (as in
FIGURE l0A)
nor initially emanates from the production tubing 16 (FIGURE l OB). Instead,
the fluid
flows from the annulus via an appropriate perforation 68 in the formation,
impinges


CA 02221463 1997-11-18
WO 97/01018 PCT/US96/10546
-21-
turbine 122, and thereafter travels upwardly through the annulus. Of course,
the fluid
may be directed back into the production tubing 16 at a location downstream.
In the
embodiments shown in FIGURES l0A-l OC, the turbine 122 and magnets 126 are
positioned above the electrical coil 130. It is understood that the this
relationship may
be reversed, that is the turbine 122 and magnets 126 may be placed below the
electrical
coil 130 with the same result being achieved.
Referring now to FIGURE 1 l, still another embodiment of this invention
wherein the electrical generating apparatus is positioned in the annulus is
shown. In
the FIGURE 11 embodiment, a piezoelectric power generating unit is shown which
is
substantially similar to the piezoelectric power generating unit of FIGURE 5.
Thus, a
stack of piezoelectric elements 90 is positioned on the outer circumference of
tubing 16
and is, in turn, connected to an electronics unit 91 and rechargeable battery
98 with
electronics unit 91 including the power rectifier 92, voltage regulator 94 and
charge/power on switch 96 of FIGURE 6. FIGURE 11 also depicts downhole sensors
and/or gauges 140 of the type described in aforementioned U.S. Application
S.N.
08/385,992. Sensors 140 communicate with a computer/communications module 142.
As with the FIGURE 5 embodiment, production fluid flowing through tubing I6
causes
stress and/or vibration against the tubing wall which motion is converted by
the
piezoelectric elements into electrical charges by the electronics unit 91.
While an important feature of the present invention is that the primary
passageway in production tubing 16 remain clear for the passage of tools and
such
items as coil tubing, it will be appreciated that the flexible bladder
embodiments of
FIGURES 4A and 4B may be positioned within the primary passageway of tubing 16
and yet still not impede or block said passageway unlike prior art devices
such as the
turbine shown in Patent 3,342,267. For example, referring to FIGURE I2, the
flexible
bladder 82 is shown mounted between a pair of lower mounts 144 and upper
mounts
146 such that production fluid is allowed to easily pass upwardly through
bladder 82
towards the surface. It will be appreciated that while the mounts 144, 146 and
bladder
82 do narrow to some extent the primary passageway 22, such narrowing is
minimal
and still permits the passage of coil tubing or other tooling through the
center of


CA 02221463 2005-08-22
WO 97/01018 PGTIiJ596110546
-22-
bladder 82. Of course, as in the FIGURES 4A and 4B embodiments, magnets 84 are
positioned on the outside of bladder 82 and coils 86, 88 are positioned an
either side of
magnet 84 so as togenerate electricity through the fluxuatians of magnet 84
between
coils 86, 88. An optional turbulence enhaneer 90 is also provided. The
electronics
package 92 and rechargeable battery 94 are preferably positioned outside of
production
tubing 16 within the annulus LO preferably within an enclosure 148 as shown in
FIGURE 12.
The rechargeable battery described in each and every one of the numerous
embodiments of this invention rE,presents an important feature of the present
invention.
In an exemplary embodiment, the battery will have the ability to operate at
high
temperatures (above 175 ° C), have a long operating life (as much as
five years), be of
small size (for example sized or otherwise adapted to fit within an envelope
of 1" in
diameter), have the ability far continuous discharge for ias~umentation in
microprocessors ( 10 milliamperes), have the ability for periodic discharge
far
I 5 communications equipment (15 milliamperes per minute at 2% duty cycle),
have the
ability far a minimum of 1 t)0 recharging cycles firm external power soure$s
as a
generator, include high energy density and excellent self-discharge
characteristics.
Preferably, the rechargeable battery comprises a solid lithium-mete! polymer
electrolyte secondary battery of the type described in the paper entitled
"Large Lithium
Polymer Battery Development: 'fhe lrnmobile Solvent Concept", M. Gauthier et
al, tlxe
entire contents of which is incorporated herein by zeference. Batteries of
this type are
also disclosed in ~J.S. Patent Nos. 4,357,401; 4,578,326 and 4,758,483. It is
believed that
such lithium polymer battery cells are preferred over other battery technology
Such as
nickel cadmium or lead acid due to the higher energy density, smaller size and
better self
z5 discharge characteristics of the lithium polymer batteries. Still another
rechargeable
battery which is believed to be 4speciaIly useful in the present invention are
those
rechargeable batteries available from Duraceh Xnc. of Bethel, Connecticut
which
incorporate therein an integrated circuit chip for extending and/or optimizing
the battery
life, providing high energy density, high power and a wide temperature range


CA 02221463 1997-11-18
WO 97/01018 PCT/US96/10546
-23-
for performance. Such batteries are sold by Duracell Inc. under the tradenames
DR15,
DR17, DR30, DR35 and DR36.
Based on the foregoing, and as shown, for example, in FIGURES 1-6 and 9-12
it will be appreciated that an important feature of this invention is a long-
term power
supply to be mounted on hydrocarbon production tubing downhole in a wellbore
for
providing electrical power to equipment mounted on the production tubing
comprising
(1 ) an electrical power generating device powered by fluid flow downhole; (2)
a
rechargeable battery for storing electrical power from the generating device;
and (3) a
charging circuit receiving electrical power as generated from the generating
device and
producing a charging current for delivery of power to the battery wherein the
battery is
recharged on a periodic basis by the charging circuit and serves as a source
of power
for the downhole equipment.
Although several of the apparatus for generating power are described as being
powered by fluid flowing out of the well, it is also possible to generate
power by
1 S forcing fluid into the well. The orientation of the power generating
apparatus may be
reveresed to accomodate the reverse fluid flow. This would allow power to be
generated during applications such as water flood or gas lift. In addition,
the power
generating apparatus can be made retrievable by mounting the entire power
generating
apparatus in a side pocket of the well.
The downhole electrical energy generating apparatus of the present invention
provides many features and advantages relative to the prior art. An important
feature
and advantage is that the present invention provides no obstructions within
the
production tubing. That is, the present invention generates electricity while
simultaneously maintaining production tubing 16 obstruction free such that
devices
including coil tubing may be delivered through the production tubing without
interruption. The ability to provide electrical power generation without
obstructing the
'production tubing constitutes an important feature of this invention and an
important
advance over the prior art such as the turbo generator of U.S. Patent
3,342,267 wherein
the turbines cause an impassible obstruction within the production tubing.


CA 02221463 2005-08-22
W O 97101018 PCTNS9b110546
_7ø
Still other features and advantages of the present invention is the ability to
generate electricity using relatively economical anti environmentally friendly
components. The use of a rechargeable battery allows the present invention to
provide
electricity both during times when production fluids are flowing as well as
those times
when production fluid flow has ceased.
It will be appreciated that in those embodiments which utilize a movable
magnet and fixed coil, an acceptable (although less preferred) arrangement is
where the
magnet is fixed and the coif is movable.
It will fiirther bt appreciated that in those embodiments of this inverttian
where
1 Q fluid motion gives rise to power generation, the fluid may originate
either from one or
both of the production tubing or the annulus.
While preferred embodiments have been shown and described, various
modifications and substitutions xnay be made thereto without departing from
the spirit
and scope of the invention. Accordingly, it is to be understood that tlxe
present
invention has been described by way of illustrations and not limitation.

Representative Drawing
A single figure which represents the drawing illustrating the invention.
Administrative Status

For a clearer understanding of the status of the application/patent presented on this page, the site Disclaimer , as well as the definitions for Patent , Administrative Status , Maintenance Fee  and Payment History  should be consulted.

Administrative Status

Title Date
Forecasted Issue Date 2006-10-31
(86) PCT Filing Date 1996-06-19
(87) PCT Publication Date 1997-01-09
(85) National Entry 1997-11-18
Examination Requested 2003-05-29
(45) Issued 2006-10-31
Expired 2016-06-20

Abandonment History

There is no abandonment history.

Payment History

Fee Type Anniversary Year Due Date Amount Paid Paid Date
Registration of a document - section 124 $100.00 1997-11-18
Application Fee $300.00 1997-11-18
Maintenance Fee - Application - New Act 2 1998-06-19 $100.00 1998-06-02
Maintenance Fee - Application - New Act 3 1999-06-21 $100.00 1999-06-15
Maintenance Fee - Application - New Act 4 2000-06-19 $100.00 2000-06-09
Maintenance Fee - Application - New Act 5 2001-06-19 $150.00 2001-06-07
Maintenance Fee - Application - New Act 6 2002-06-19 $150.00 2002-06-05
Request for Examination $400.00 2003-05-29
Maintenance Fee - Application - New Act 7 2003-06-19 $150.00 2003-06-05
Maintenance Fee - Application - New Act 8 2004-06-21 $200.00 2004-06-07
Maintenance Fee - Application - New Act 9 2005-06-20 $200.00 2005-06-13
Maintenance Fee - Application - New Act 10 2006-06-19 $250.00 2006-06-13
Final Fee $300.00 2006-08-14
Maintenance Fee - Patent - New Act 11 2007-06-19 $250.00 2007-05-30
Maintenance Fee - Patent - New Act 12 2008-06-19 $250.00 2008-05-30
Maintenance Fee - Patent - New Act 13 2009-06-19 $250.00 2009-06-01
Maintenance Fee - Patent - New Act 14 2010-06-21 $250.00 2010-06-01
Maintenance Fee - Patent - New Act 15 2011-06-20 $450.00 2011-05-31
Maintenance Fee - Patent - New Act 16 2012-06-19 $450.00 2012-05-30
Maintenance Fee - Patent - New Act 17 2013-06-19 $450.00 2013-05-08
Maintenance Fee - Patent - New Act 18 2014-06-19 $450.00 2014-05-15
Maintenance Fee - Patent - New Act 19 2015-06-19 $450.00 2015-05-29
Owners on Record

Note: Records showing the ownership history in alphabetical order.

Current Owners on Record
BAKER HUGHES INCORPORATED
Past Owners on Record
BAUGH, JOHN L.
HOLCOMBE, MICHAEL WAYNE
MULLINS, ALBERT A., II
ROSS, ROBERT CHAPMAN
TUBEL, PAULO
Past Owners that do not appear in the "Owners on Record" listing will appear in other documentation within the application.
Documents

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Document
Description 
Date
(yyyy-mm-dd) 
Number of pages   Size of Image (KB) 
Representative Drawing 1998-03-02 1 17
Abstract 1997-11-18 1 65
Representative Drawing 2006-10-03 1 17
Cover Page 2006-10-03 2 57
Description 1997-11-18 24 1,222
Cover Page 1998-03-02 2 74
Claims 1997-11-18 13 391
Drawings 1997-11-18 18 525
Description 2005-08-22 27 1,307
Claims 2005-12-13 9 332
Assignment 1997-11-18 3 122
PCT 1997-11-18 20 684
Prosecution-Amendment 1997-11-18 1 21
Correspondence 1998-02-17 1 31
Assignment 1998-04-20 5 170
Prosecution-Amendment 2003-05-29 1 49
Prosecution-Amendment 2003-08-27 1 28
Prosecution-Amendment 2005-02-21 2 74
Fees 2005-06-13 1 54
Assignment 2005-04-11 2 58
Correspondence 2005-05-30 1 14
Prosecution-Amendment 2005-08-22 18 555
Prosecution-Amendment 2005-09-15 1 28
Prosecution-Amendment 2005-12-13 10 356
Correspondence 2006-08-14 1 51