U.S. patent application number 13/202757 was filed with the patent office on 2012-04-19 for apparatus and system to actuate and pump well bore liquids from hydrocarbon wells.
Invention is credited to Robert Joseph Foster.
Application Number | 20120093663 13/202757 |
Document ID | / |
Family ID | 42634403 |
Filed Date | 2012-04-19 |
United States Patent
Application |
20120093663 |
Kind Code |
A1 |
Foster; Robert Joseph |
April 19, 2012 |
APPARATUS AND SYSTEM TO ACTUATE AND PUMP WELL BORE LIQUIDS FROM
HYDROCARBON WELLS
Abstract
Pump apparatus and pump systems for use with hydrocarbon wells
are actuated in response to a working fluid delivered at a high
pressure to pump a fluid to be pumped or production fluid. The pump
advantageously employs translation motion of a piston. Some
embodiments employ working fluids at two ports. Other embodiments
employ working fluid at one port and a spring. Working fluid may be
provided via one or more hydraulically powered piston
subassemblies, which may be controlled via one or more hydraulic
power supplies. A flush system may include flush pump, flush valve
and may be responsive to a characteristic of a fluid in a line.
Inventors: |
Foster; Robert Joseph;
(Calgary, CA) |
Family ID: |
42634403 |
Appl. No.: |
13/202757 |
Filed: |
February 12, 2010 |
PCT Filed: |
February 12, 2010 |
PCT NO: |
PCT/US2010/024151 |
371 Date: |
December 23, 2011 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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61154263 |
Feb 20, 2009 |
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Current U.S.
Class: |
417/246 |
Current CPC
Class: |
E21B 43/129 20130101;
F04F 1/08 20130101 |
Class at
Publication: |
417/246 |
International
Class: |
F04B 23/00 20060101
F04B023/00; F04B 3/00 20060101 F04B003/00; F04B 1/00 20060101
F04B001/00 |
Claims
1. A pump suitable for hydrocarbon well applications, the pump
comprising: an elongated pump body having a first end and a second
end opposite the first end, a first port at least proximate the
first end and a second port at least proximate the second end, a
central body portion between the first and the second ends and a
pair of peripheral body portions between the central body portions
and respective ones of the first and the second ends, the pump body
forming a longitudinally extending pump body chamber extending
between the first and the second ports, the first and the second
ports providing fluid communication between the longitudinally
extending pump body chamber and an exterior of the pump body, the
longitudinally extending pump body chamber including a production
chamber between the first and the second ends and a pair of
pressure chambers between the production chamber and respective
ones of the first and the second ends, the production chamber
having a circumference that is larger than a circumference of
either of the pressure chamber; and a piston having an elongated
piston body including a first end and a second end opposite the
first end, a central piston body portion between the first and the
second ends and a pair of peripheral piston body portions between
the central piston body portion and respective ones of the first
and the second ends, the central piston body portion having an
external circumference sized to be closely received by the
production chamber of the pump body and the peripheral piston body
portions each having a respective external circumference sized to
be closely received by respective ones of the pressure chamber of
the pump body, the piston body forming a passageway extending
between and through the first and the second ends, the piston body
slideably received in the longitudinally extending pump chamber of
the pump body such that the central piston body portion divides the
production chamber of the pump body into two production chamber
portions, each of the production chamber portions having a volume
that varies inversely with the volume of the other one of the
production chamber portions, and the peripheral piston body
portions received by respective ones of the pressure chambers of
the pump body such that a respective volume of each of the pressure
chambers of the pump body varies inversely with the volume of the
other one of the pressure chamber.
2. The pump of claim 1, further comprising: a first seal, the first
seal received about the circumference of the central piston body to
form a seal with the production chamber portion; a second seal, the
second seal received about the circumference of one of the
peripheral piston body portions to form a seal with a respective
one of the pressure chambers; and a third seal, the third seal
received about the circumference of the other one of the peripheral
piston body portions to form a seal with a respective one of the
pressure chambers.
3. The pump of claim 2 wherein the first, the second and the third
seals are urethane ring seals.
4. The pump of claim 2 wherein the first, the second and the third
seals are metal ring seals and the pump body chamber is
hardened.
5. The pump of claim 1 wherein the pump body includes a third and a
fourth port that provide fluid communication with respective ones
of the production chamber portions from the exterior of the pump
body to receive and expel fluid to be pumped, and wherein each of
the peripheral piston body portions includes a piston head surface
positioned in respective ones of the pressure chambers to be acted
on by a working fluid introduced under pressure into the pressure
chambers via the first and second ports to cause selective
translation of the piston in the pump body chamber in two opposed
directions.
6. The pump of claim 5 wherein the piston body forms a first
production fluid port that provides fluid communication between the
passageway of the piston body and the third port of the pump body
and a second production fluid port that provides fluid
communication between the passageway of the piston body and the
fourth port of the pump body, further comprising: a first valve
received in the passageway of the piston body between the first end
of the piston body and the third port of the pump body; and a
second valve received in the passageway of the piston body between
the second end of the piston body and the fourth port of the pump
body.
7. The pump of claim 6 wherein the piston body forms a bypass
channel, further comprising: a flush valve received in the
passageway of the piston body between the first and the second
valves, the flush valve response to a much higher pressure than the
first and the second valves.
8. The pump of claim 6 wherein the piston body forms a bypass
channel, further comprising: a first production screen coupled to
the third port of the pump body; a first production valve coupled
to control a fluid flow via the third port of the pump body; a
second production screen coupled to the fourth port of the pump
body; and a second production valve coupled to control a fluid flow
via the fourth port of the pump body.
9. The pump of claim 1 wherein each of the peripheral piston body
portions includes a piston head surface, the piston head surface of
a first one of the peripheral piston body portions positioned in a
respective first one of the pressure chambers to be acted on by a
working fluid introduced under pressure into the first one of the
pressure chambers via the first port to cause selective translation
of the piston in the pump body chamber in a first direction, and
further comprising: a spring positioned to act on the piston head
surface of the other one of the peripheral piston body portions to
cause selective translation of the piston in the pump body chamber
in a second direction opposite the first direction, wherein a fluid
to be pumped is received in the pump body via the second port and
is expelled from the pump body via the first port.
10. The pump of claim 9 wherein the spring moves the piston in the
second direction to a position at which the piston head surface of
the first one of the peripheral piston body portions is adjacent
the first outlet.
11. The pump of claim 9, further comprising: a first valve received
in the passageway of the piston body between the first and the
second ends of the piston body; and a check valve received in the
passageway of the piston body between the first valve and the
second end of the piston body, wherein the first valve and the
check valve are cooperatively operable to selectively allow a fluid
to be pumped to flow from the production chamber to the first
pressure chamber without allowing a working fluid to flow from the
first pressure chamber to the production chamber.
12. The pump of claim 9, further comprising: at least one spring
sub removably physically coupled to the pump body and to the
spring.
13. The pump of claim 1 wherein each of the peripheral piston body
portions includes a piston head surface, the piston head surface of
a first one of the peripheral piston body portions positioned in a
respective first one of the pressure chambers to be acted on by a
working fluid introduced under pressure into the first one of the
pressure chambers via the first port to cause selective translation
of the piston in the pump body chamber in a first direction, and
further comprising: a spring positioned to act on the piston head
surface of the other one of the peripheral piston body portions to
cause selective translation of the piston in the pump body chamber
in a second direction opposite the first direction, wherein a fluid
to be pumped is received in the pump body via the second port and
is expelled from the pump body via a third port spaced distally
from the second port with respect to the first port.
14. The pump of claim 13 wherein the spring moves the piston in the
second direction to a home position at which the piston head
surface of the first one of the peripheral piston body portions is
spaced from the first outlet.
15. The pump of claim 13, further comprising: a first valve that
selectively controls a flow via the third port of the pump body;
and a second valve that selectively controls a flow via the second
port of the pump body, wherein the first and the second valves are
cooperatively operable to selectively allow a fluid to be pumped to
be received via the second port and expelled via the third port
without allowing the fluid to be pumped to be expelled via the
second port or received via the third port.
16. The pump of claim 13, further comprising: at least one spring
sub removably physically coupled to the pump body and to the
spring.
17. A pump system suitable for hydrocarbon well applications, the
pump system comprising: a downhole pump apparatus selectively
operable to pump a production fluid in response to a pressurized
working fluid via translation of a piston; at least one
hydraulically powered piston subassembly configured to alternately
supply a working fluid at high pressure to actuate the downhole
pump apparatus to pump a fluid to be pumped; at least one hydraulic
power supply coupled to operate the at least one piston
subassembly.
18. The pump system of claim 17 wherein the downhole pump apparatus
is a downhole pump apparatus according to any of claims 1 through
16.
19. The pump system of claim 17, further comprising: a flushing
pump; and a flushing valve, the flushing pump and flushing valve
configured to force a very high pressure stream of liquid through
the downhole pump apparatus to flush any contaminants or any
buildups out of the downhole pump apparatus.
20. The pump system of claim 19, further comprising: a sensor line
to monitor a flow of fluid in a fluid line; and a controller
configured to shutdown the at least one hydraulic power supply and
to actuate the flushing pump to generate the very high pressure
stream of liquid in response to a characteristic of the flow of
fluid in the sensor line that is indicative of debris in the fluid
flow.
21. The pump system of claim 20 wherein the controller is
configured to cause the very high pressure stream to exist the
flush value in at least one of a steady state or in bursts.
22. The pump system of claim 17 wherein the at least one
hydraulically powered piston subassembly includes two hydraulically
powered piston subassemblies, each of the hydraulically powered
piston subassemblies coupled a respective first and second working
fluid ports of the downhole pump apparatus and configured to
alternately supply a working fluid at high pressure to the first
the second working fluid ports.
23. The pump system of claim 22 wherein the at least one hydraulic
power supply includes two hydraulic power supplies, each of the
hydraulic power supplies coupled to operate a respective one of the
hydraulically powered piston subassemblies.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a U.S. national stage application filed
under 35 U.S.C. .sctn.371 of International Patent Application
PCT/US2010/024151, accorded an international filing date of Feb.
12, 2010, which claims benefit under 35 U.S.C. 119(e) to U.S.
provisional patent application Ser. No. 61/154,263, filed Feb. 20,
2009, and entitled "Apparatus and System to Actuate and Pump Well
Bore Liquids from Hydrocarbon Wells," both of which are
incorporated herein by reference in their entirety.
BACKGROUND
[0002] 1. Technical Field
[0003] This application relates generally to down hole pumps for
hydrocarbon wells, and more particularly to an extended life design
to operate in high temperature environments and to pump abrasive
silt-laden aqueous and/or chemically harsh well-bore liquid ("WBL")
from such wells.
[0004] 2. Description of the Related Art
[0005] Hydrocarbon wells, particularly gas wells, having water and
other liquids being produced at the same level in the formation as
the desired produce need periodic de-watering because well-bore
liquids ("WBL") block free flow through the casing to the surface
and interfere with evacuation of gaseous hydrocarbons rising from
production zone. Such WBL typically take the form of a gaseous
mixture of caustic water contaminated with oil, but may take other
forms. Conventional downhole pumping systems include rotating parts
(e.g., shafts and impellers) typically separated by polymer seals
and in some cases driven by electrical motors that require
insulated wires. Disadvantageously, these devices have a very
limited life cycle when subjected to the abrasive and chemically
harsh conditions encountered when de-watering well bores. Most of
the devices are completely unsuitable for high temperature
applications, such as steam assisted gravity drainage (SAGD)
extraction of oil. Similarly, there are formations from which it is
necessary to isolate different production zones accessible from a
single well for either regulatory or contractual reasons.
BRIEF SUMMARY
[0006] According to the apparatus of the invention a dual-action
sliding reciprocating piston non-rotating pump includes a
continuous self-cleaning feature according to which each side of
the production chamber is alternately flooded and evacuated in the
reverse direction every half cycle thereby tending to resist silt
build-up at either end of the production chamber or around the
piston seals. Further, the continuous monitoring of the net flow of
the system permits a PLC to trigger the clean water flushing of the
pump body as needed by ejecting a very high (e.g. 5000 psi)
pressure stream of flush water through both pressure chambers and
the production chamber. In normal operation the low-speed
high-volume piston moves smoothly alternating between the ends of
its cycle pumping silt on every stroke in both directions so as to
transfer silt-laden water up hole at a rate exceeding the
installation's settling rate and thus keep any sediment in solution
making it more efficient to pump out. Whenever the flow monitoring
elements of the invented system detect a sufficient decrease in net
flow between the pressure and production chambers, the PLC switches
the system into flush mode and uses clean water from the surface to
wash the inside of the pump under very high pressure returning any
material, whether settled out or packed around the seals, to
solution for evacuation from the pump. Whereas conventional pumps
tend to last less than a year in service in these harsh conditions,
advantageously the system of the invention permits this pumping
apparatus to remain in service more than 2 years with minimal
maintenance and less downtime. When applied to a normal temperature
de-watering application the apparatus of the invention may be
installed with urethane seals that handle abrasive solids and
chemical attack very well. However, when applied to a very high
temperature application such as SAGD oil pumping, the apparatus of
the invention will preferably be installed with overlapping
interlocking metal seals akin to the steel piston rings of a diesel
engine.
[0007] Actuation of the pumping or output stroke of the apparatus
of the invention occurs in 2 embodiments by fluid pressure (this
fluid actuation subsystem charges each spring with potential
energy) and in a 3.sup.rd embodiment by spring pressure forcing
liquids uphole, due to which modular design the stacking of spring
subs permits the operator to amplify the lift of WBL for use in
deeper wells.
[0008] Advantageously, the system of the invention operates for a
significantly extended life cycle due to the combined effects of
having: reduced and less aggressive movement and the elimination of
rotating parts (e.g., no shafts or impellers) in the well bore, the
related elimination of rubber or other polymer seals that would
fail around rotating components, the elimination of electrical
wires (e.g., power or control) having insulation that would melt, a
nitride hardened interior pump bore, self-priming fluid actuated or
assisted, and a self-flushing circuit. These design features result
in a system that: is not affected by a high gas to oil ratio, has
the ability to pump dry or in high sand cut installations, can
operate horizontally, and can pump in high CO2 and H2S conditions
as well as Light crude with aromatics. Advantageously the system of
the present invention offers both longer life and less downtime
(i.e., lower operating cost) but may still be installed at a lower
capital cost.
[0009] Advantageously the system of the invention by pumping
through tubes overcomes the problems associated with regulatory
restrictions on co-mingling gas zones and the contractual
requirements of separate ownership on shared wells producing from
zones of different pressure, quality or value.
[0010] A pump suitable for hydrocarbon well applications may be
summarized as including an elongated pump body having a first end
and a second end opposite the first end, a first port at least
proximate the first end and a second port at least proximate the
second end, a central body portion between the first and the second
ends and a pair of peripheral body portions between the central
body portions and respective ones of the first and the second ends,
the pump body forming a longitudinally extending pump body chamber
extending between the first and the second ports, the first and the
second ports providing fluid communication between the
longitudinally extending pump body chamber and an exterior of the
pump body, the longitudinally extending pump body chamber including
a production chamber between the first and the second ends and a
pair of pressure chambers between the production chamber and
respective ones of the first and the second ends, the production
chamber having a circumference that is larger than a circumference
of either of the pressure chamber; and a piston having an elongated
piston body including a first end and a second end opposite the
first end, a central piston body portion between the first and the
second ends and a pair of peripheral piston body portions between
the central piston body portion and respective ones of the first
and the second ends, the central piston body portion having an
external circumference sized to be closely received by the
production chamber of the pump body and the peripheral piston body
portions each having a respective external circumference sized to
be closely received by respective ones of the pressure chamber of
the pump body, the piston body forming a passageway extending
between and through the first and the second ends, the piston body
slideably received in the longitudinally extending pump chamber of
the pump body such that the central piston body portion divides the
production chamber of the pump body into two production chamber
portions, each of the production chamber portions having a volume
that varies inversely with the volume of the other one of the
production chamber portions, and the peripheral piston body
portions received by respective ones of the pressure chambers of
the pump body such that a respective volume of each of the pressure
chambers of the pump body varies inversely with the volume of the
other one of the pressure chamber.
[0011] The pump may further include a first seal, the first seal
received about the circumference of the central piston body to form
a seal with the production chamber portion; a second seal, the
second seal received about the circumference of one of the
peripheral piston body portions to form a seal with a respective
one of the pressure chambers; and a third seal, the third seal
received about the circumference of the other one of the peripheral
piston body portions to form a seal with a respective one of the
pressure chambers. The first, the second and the third seals may be
urethane ring seals. The first, the second and the third seals are
metal ring seals and the pump body chamber may be hardened. The
pump body may include a third and a fourth port that provide fluid
communication with respective ones of the production chamber
portions from the exterior of the pump body to receive and expel
fluid to be pumped, and wherein each of the peripheral piston body
portions may include a piston head surface positioned in respective
ones of the pressure chambers to be acted on by a working fluid
introduced under pressure into the pressure chambers via the first
and second ports to cause selective translation of the piston in
the pump body chamber in two opposed directions.
[0012] The pump wherein the piston body forms a first production
fluid port that provides fluid communication between the passageway
of the piston body and the third port of the pump body and a second
production fluid port that provides fluid communication between the
passageway of the piston body and the fourth port of the pump body
may further include a first valve received in the passageway of the
piston body between the first end of the piston body and the third
port of the pump body; and a second valve received in the
passageway of the piston body between the second end of the piston
body and the fourth port of the pump body.
[0013] The pump wherein the piston body forms a bypass channel may
further include a flush valve received in the passageway of the
piston body between the first and the second valves, the flush
valve response to a much higher pressure than the first and the
second valves.
[0014] The pump wherein the piston body forms a bypass channel may
further include a first production screen coupled to the third port
of the pump body; a first production valve coupled to control a
fluid flow via the third port of the pump body; a second production
screen coupled to the fourth port of the pump body; and a second
production valve coupled to control a fluid flow via the fourth
port of the pump body.
[0015] Each of the peripheral piston body portions may include a
piston head surface, the piston head surface of a first one of the
peripheral piston body portions positioned in a respective first
one of the pressure chambers to be acted on by a working fluid
introduced under pressure into the first one of the pressure
chambers via the first port to cause selective translation of the
piston in the pump body chamber in a first direction, and may
further include a spring positioned to act on the piston head
surface of the other one of the peripheral piston body portions to
cause selective translation of the piston in the pump body chamber
in a second direction opposite the first direction, wherein a fluid
to be pumped is received in the pump body via the second port and
is expelled from the pump body via the first port. The spring may
move the piston in the second direction to a position at which the
piston head surface of the first one of the peripheral piston body
portions is adjacent the first outlet.
[0016] The pump may further include a first valve received in the
passageway of the piston body between the first and the second ends
of the piston body; and a check valve received in the passageway of
the piston body between the first valve and the second end of the
piston body, wherein the first valve and the check valve are
cooperatively operable to selectively allow a fluid to be pumped to
flow from the production chamber to the first pressure chamber
without allowing a working fluid to flow from the first pressure
chamber to the production chamber.
[0017] The pump may further include at least one spring sub
removably physically coupled to the pump body and to the
spring.
[0018] Each of the peripheral piston body portions may include a
piston head surface, the piston head surface of a first one of the
peripheral piston body portions positioned in a respective first
one of the pressure chambers to be acted on by a working fluid
introduced under pressure into the first one of the pressure
chambers via the first port to cause selective translation of the
piston in the pump body chamber in a first direction, and may
further include a spring positioned to act on the piston head
surface of the other one of the peripheral piston body portions to
cause selective translation of the piston in the pump body chamber
in a second direction opposite the first direction, wherein a fluid
to be pumped is received in the pump body via the second port and
is expelled from the pump body via a third port spaced distally
from the second port with respect to the first port. The spring may
move the piston in the second direction to a home position at which
the piston head surface of the first one of the peripheral piston
body portions is spaced from the first outlet.
[0019] The pump may further include a first valve that selectively
controls a flow via the third port of the pump body; and a second
valve that selectively controls a flow via the second port of the
pump body, wherein the first and the second valves are
cooperatively operable to selectively allow a fluid to be pumped to
be received via the second port and expelled via the third port
without allowing the fluid to be pumped to be expelled via the
second port or received via the third port.
[0020] The pump may further include at least one spring sub
removably physically coupled to the pump body and to the
spring.
[0021] A pump system suitable for hydrocarbon well applications may
be summarized as including a downhole pump apparatus selectively
operable to pump a production fluid in response to a pressurized
working fluid via translation of a piston; at least one
hydraulically powered piston subassembly configured to alternately
supply a working fluid at high pressure to actuate the downhole
pump apparatus to pump a fluid to be pumped; at least one hydraulic
power supply coupled to operate the at least one piston
subassembly. The downhole pump apparatus may be a downhole pump
apparatus according to any of claims 1 through 15.
[0022] The pump system may further include a flushing pump; and a
flushing valve, the flushing pump and flushing valve configured to
force a very high pressure stream of liquid through the downhole
pump apparatus to flush any contaminants or any buildups out of the
downhole pump apparatus.
[0023] The pump system may further include a sensor line to monitor
a flow of fluid in a fluid line; and a controller configured to
shutdown the at least one hydraulic power supply and to actuate the
flushing pump to generate the very high pressure stream of liquid
in response to a characteristic of the flow of fluid in the sensor
line that is indicative of debris in the fluid flow. The controller
may be configured to cause the very high pressure stream to exist
the flush value in at least one of a steady state or in bursts. The
at least one hydraulically powered piston subassembly may include
two hydraulically powered piston subassemblies, each of the
hydraulically powered piston subassemblies coupled a respective
first and second working fluid ports of the downhole pump apparatus
and configured to alternately supply a working fluid at high
pressure to the first the second working fluid ports. The at least
one hydraulic power supply may include two hydraulic power
supplies, each of the hydraulic power supplies coupled to operate a
respective one of the hydraulically powered piston
subassemblies.
[0024] The accompanying drawings, which are incorporated in and
constitute a part of this specification, illustrate preferred
embodiments of the method, system, and apparatus according to the
invention and, together with the description, serve to explain the
principles of the invention.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0025] In the drawings, identical reference numbers identify
similar elements or acts. The sizes and relative positions of
elements in the drawings are not necessarily drawn to scale. For
example, the shapes of various elements and angles are not drawn to
scale, and some of these elements are arbitrarily enlarged and
positioned to improve drawing legibility. Further, the particular
shapes of the elements as drawn, are not intended to convey any
information regarding the actual shape of the particular elements,
and have been solely selected for ease of recognition in the
drawings.
[0026] FIG. 1 is a cut away isometric view of a pump apparatus that
employs a double coil fluid actuated design, according to one
illustrated embodiment.
[0027] FIG. 2 is an isometric partially broken view of a pump
system including the pump apparatus of FIG. 1, configured for use
dewatering the production zone of a gas lease by pumping well-bore
liquids to the surface for disposal at a well site, according to
one illustrated embodiment.
[0028] FIG. 3 is a cross-sectional view of a pump apparatus that
employs a single coil spring actuated design, according to another
illustrated embodiment.
[0029] FIG. 4 is cross-sectional broken view of the pump apparatus
of FIG. 3 illustrating multiple spring subs (B and C) added to a
basic pump body with spring sub A, according to yet another
illustrated embodiment.
[0030] FIG. 5 is an schematic view of a pump system including the
pump apparatus of FIG. 3, configured for use dewatering the
production zone of a gas lease by pumping well-bore liquids to the
surface for disposal at a well site, according to one
embodiment.
[0031] FIG. 6 is a partial cross-sectional view of a pump apparatus
that employs a single coil fluid actuated design, according to
still another embodiment.
[0032] FIG. 7 is a broken cross-sectional view of the pump
apparatus of FIG. 6, illustrating multiple spring subs (B and C)
added to a basic pump body with spring sub A, according to yet
still another embodiment.
[0033] FIG. 8 is a schematic diagram of a pump system including the
pump apparatus of FIG. 6, configured for use dewatering the
production zone of a gas lease by pumping well-bore liquids further
downhole to a disposal zone at a well site, according to one
illustrated embodiment.
DETAILED DESCRIPTION
[0034] In the following description, certain specific details are
set forth in order to provide a thorough understanding of various
disclosed embodiments. However, one skilled in the relevant art
will recognize that embodiments may be practiced without one or
more of these specific details, or with other methods, components,
materials, etc. In other instances, well-known structures
associated with wells, drilling equipment and pumping equipment
have not been shown or described in detail to avoid unnecessarily
obscuring descriptions of the embodiments.
[0035] Unless the context requires otherwise, throughout the
specification and claims which follow, the word "comprise" and
variations thereof, such as, "comprises" and "comprising" are to be
construed in an open, inclusive sense, that is as "including, but
not limited to."
[0036] Reference throughout this specification to "one embodiment"
or "an embodiment" means that a particular feature, structure or
characteristic described in connection with the embodiment is
included in at least one embodiment. Thus, the appearances of the
phrases "in one embodiment" or "in an embodiment" in various places
throughout this specification are not necessarily all referring to
the same embodiment. Further more, the particular features,
structures, or characteristics may be combined in any suitable
manner in one or more embodiments.
[0037] As used in this specification and the appended claims, the
singular forms "a," "an," and "the" include plural referents unless
the content clearly dictates otherwise. It should also be noted
that the term "or" is generally employed in its sense including
"and/or" unless the content clearly dictates otherwise.
[0038] The headings and Abstract of the Disclosure provided herein
are for convenience only and do not interpret the scope or meaning
of the embodiments.
[0039] FIG. 1 shows an embodiment of a pump apparatus 100,
according to one illustrated embodiment.
[0040] The pump apparatus 100 illustrated in FIG. 1 takes the form
of a double coil-tube fluid actuated pumping device. The pumping
device 100 has a body comprised of three segments, namely first and
second peripheral pump bodies 110 and 120, respectively, and
central pump body 130 interposed therebetween. The body includes an
interior bore. The surface of the interior bore is preferably
hardened by any suitable hardening treatment--e.g., nitride to 3000
Vicors.
[0041] The first and second peripheral pump bodies 110, 120 each
form respective internal pressure chambers 118, 128, respectively.
A coil tube connection 116 to an inlet/outlet port 115 and coil
tube connection 126 to an inlet/outlet port 125 provides fluid
access to the internal pressure chambers 118, 128, respectively.
The central pump body 130 forms a production chamber 138. A
double-ended piston assembly 131 is slidingly received in the
production chamber 138. The double-ended piston assembly 131
includes a pair of peripheral ends 140, 160 and a central piston
body 150 to which the peripheral ends 140, 160 are mechanically
coupled. The central piston body has two opposed faces which form
respective small piston heads 139a, 139b. Piston assembly 131
slidingly engages interior walls forming the chambers 118, 128, 138
of the respective pump body segments 110, 120, 130. Further, piston
assembly 131 sealingly engages the interior of said chambers 118,
128, 138 with seals 147, 157 and 167. Thus, the double-ended piston
assembly 131 divides the production chamber 138 into two production
chamber portions 138a, 138b, respectively, each of production
chamber portion 138a, 138b having a volume that varies inversely
with the volume of the other production chamber portion 138a, 138b.
Likewise, respective volumes of each of pressure chambers 118, 128
vary inversely with the volume of the other pressure chamber
portion 118, 128.
[0042] Each of the peripheral ends 140, 160 of the double-ended
piston assembly 131 includes a respective annular passage 145, 165,
respectively. The annular passages 145, 165 permit well-bore liquid
("WBL") to pass through the peripheral ends 140, 160 of the
double-ended piston assembly 131 as the WBL moves between the two
pressure chambers 118, 128 and the two production chamber portions
138a, 138b, respectively.
[0043] In summary, pump apparatus 100 alternately receives and
expels WBL through each coil-tube 116 and 126. During a given
pumping cycle, high pressure (e.g., typically 3000 psi) is applied
to apparatus 100 through coil-tube 116 causing actuating liquid
pumped from the surface to flow into pump apparatus 100 through
inlet/outlet port 115 and coil-tube 116 while pressure is released
from coil-tube 126 so as to permit production liquid to be expelled
through inlet/outlet port 125 as the WBL in production chamber
portion 138b mixes with the WBL in pressure chamber 128 and a
quantity of WBL evacuates to the surface.
[0044] More particularly, at the beginning of a pumping cycle WBL
is delivered under high pressure (i.e., working fluid) through
inlet/outlet port 115 to fill pressure chamber 118 and apply high
pressure to small piston head 119 also filling passage 145 to close
valve 170 whereupon piston assembly 131 slides away from
inlet/outlet port 115 causing chambers 118 and 138a to expand. As
production chamber 138a expands WBL (i.e., fluid to be pumped or
production fluid) is drawn into pump apparatus 100 through a filter
such as a screen 133 and valve 132 then passage 134 under
relatively low pressure. The volume of such fluid is, according to
the embodiment shown, greater than the volume of high-pressure
fluid forced into pressure chamber 118. At the end of this stroke,
central piston body 150 engages the opposing end of production
chamber 138 so as to stop, with pump chamber 138a substantially
filled with WBL. Any fluid previously inside pressure chamber 128
and production chamber portion 138b will of course be flushed out
or expelled from pump apparatus 100 into coil-tube 126.
[0045] Commencing the second stroke of the two stroke pumping
cycle, surface pressure is released from coil-tube 116 and WBL is
delivered from the surface under high pressure (i.e., working
fluid) through coil-tube 126 and inlet/outlet port 125 to fill
pressure chamber 128 and apply high pressure to relatively small
piston head 129 and fill passage 165 to close valve 180 whereupon
piston assembly 131 slides away from inlet/outlet port 125 causing
chambers 128 and 138b to expand. As production chamber 138b expands
WBL (i.e., fluid to be pumped or production fluid) is drawn into
pump apparatus 100 through screen 136 and valve 135 then passage
137 under relatively low pressure, while the mix of WBL in chambers
138a and 118 is expelled from pump apparatus 100 through coil-tube
116 to the surface for processing and/or disposal.
[0046] Advantageously, the double acting design permits pump
apparatus 100 to pump relatively efficiently in almost any
conditions and installed at any angle of orientation whether
vertical or horizontal or otherwise.
[0047] Advantageously, the low speed operation of piston assembly
131 sliding back and forth within central pump body 131 and the use
of high-endurance (e.g., urethane) seals 147, 157, 167 permit pump
apparatus 100 to survive the abrasive and chemically harsh downhole
conditions typical of hydrocarbon wells for which de-watering of
the production zone is required. However, to further enhance the
operational lifespan, the pump apparatus 100 advantageously
incorporates bypass channel 146 and very high pressure flush valve
190 (any suitable valve that does not open at all until a desired
high operating pressure is applied (e.g., 5000 psi in certain
applications) to piston assembly 131. At any point in the
de-watering operation of a given well when the net production of
WBL to the surface drops below a definable rate (as measured by
surface borne flow rate meters not shown) for the formation in
question, a system 200 (seen in FIG. 2) switches into a "flush
mode." In flush mode, piston assembly 131 is preferably moved to a
home position and then a very high pressure (e.g., typically 5000
psi) stream of clean liquid (e.g., typically filtered surface
water) is temporarily caused to flow down coil-tube 116 to wash
(e.g., silt, compressed clay and other contaminants) out pressure
chamber 118. The clean liquid then fills passage 145 and bypass
channel 146 to force open very high pressure valve 190 as well as
high pressure valve 180 and wash all contaminants in passage 165
out of pump apparatus 100 through coil-tube 126. The containments
may be expelled to the surface where the system 200 (FIG. 2)
monitors the condition (e.g., characteristic indicative of debris
in the fluid flow) of the flushing stream until the flushing stream
runs "clean" or otherwise meets definable criteria. A flushing
subsystem provides for the resetting of the position of piston
assembly 131 so as to repeat or pulse the flushing cycle and permit
the flushing water (entrained with any suitable solvents if
required) to clean the interior of at least one portion of the
production chamber 138 so as to reach a major portion of the three
pumping chambers 118, 128, 138 in the course of a given flushing
cycle. According to an alternate embodiment, a very high pressure
flush valve could also be installed (not shown) below valve 135 so
as to permit back flushing to the formation through passage 137 in
extremely silt-laden conditions.
[0048] According to an alternate embodiment of pump apparatus 100,
the high-endurance seals 147, 157, 167 typically of urethane
suitable for de-watering applications are replaced with overlapping
steel or other suitable metal rings (similar to engine piston
rings) that permit pump apparatus 100 to survive the very
high-temperatures of SAGD operating near 340.degree. C. while
pumping heated oil.
[0049] FIG. 2 shows a pump system 200, according to one illustrated
embodiment.
[0050] The pump system 200 is illustrated as installed in and
around a well casing 210 perforated so as to harvest production
flow 220 from which liquids drain into well sump 215 later to be
pumped up-hole via double coil-tube assembly 230 and gaseous
hydrocarbons rise up inside well casing 210 to supply a well head
Christmas Tree 240 for collection in any suitable manner.
[0051] Double coil-tube assembly 230 comprises two coil-tubes 116,
126. According to a preferred embodiment, at least a portion of the
coil-tubes 116, 126 are installed concentric one to another. The
surface coil-tube 126 delivers WBL to line 238 whereas coil-tube
116 delivers WBL to line 235. Hydraulically powered piston
subassemblies 250/257 and 260/267 alternately supply high pressure
(e.g., 3000 psi) to coil-tubes 116, 126 respectively to actuate
pump apparatus 100. Any suitable hydraulic power supplies 255 and
265 are used to operate piston subassemblies 250/257 and 260/267
together with any suitable hydraulic switching control and line
assembly 280.
[0052] Advantageously, after relieving the pressure on piston
subassembly 260/267, flushing valve 275 may be used in conjunction
any suitable supply of clean liquid (not shown) and flushing pump
270 (any suitable pump such as a CAT.RTM. pump) to force a very
high pressure stream liquid through pump apparatus 100 so as to
flush contaminants and any build-up of compressed clay or abrasives
out of the pump apparatus 100 and up coil-tube 126 for surface
disposal. The sensor line 272 is used to monitor the flow in lines
235 and 238 so as to determine when silt constriction of pump
apparatus 100 has reached a level that requires flushing. Any
suitable programmable logic controller (PLC) or other controller
(e.g., microprocessor, programmable gate array, digital signal
processor,) and flow metering circuitry may be used to set the
flushing sub-system parameters so as to trigger the shutdown of
hydraulic power supplies 255 and 265, together with switching
control and line assembly 280, while engaging flushing pump 270 to
generate very high pressure either at steady state or in bursts
through flush valve 275.
[0053] FIG. 3 shows a pump apparatus denoted generally as 300,
according to another illustrated embodiment.
[0054] The pump apparatus 300 takes the form of a single-coil
spring actuated pump apparatus. Pump body 310 is fluidly coupled to
single coil-tube 316 via inlet/outlet port 315 to supply a fluid
(i.e., working fluid), typically a WBL, under high pressure into
pressure chamber 318. The WBL pumped downhole into pressure chamber
318 acts on the head 319 of piston assembly 320. Piston assembly
320 is comprised of a small piston top 321, larger piston head 325,
and piston shaft 340 within which piston annulus 322 is in fluid
communication with pressure chamber 318. On each intake stroke, WBL
inside piston annulus 322 applies a relatively high pressure to
keep valve 330 closed while WBL (i.e., fluid to be pumped or
production fluid) from the production zone (not shown) enters pump
apparatus 300 through inlet port 385A at the downhole end of spring
sub 360A which the WBL enters under the relatively low pressure of
the surrounding formation flooding through piston intake passages
347 and thereafter rising through piston lower annulus 345 and
check valve 335 to fill production chamber 328 through piston fluid
exchange passages 327. The downhole end of spring sub 360A may be
removeably coupled to pump bottom 350 by any suitable coupling
structure, for example threads. As piston assembly 320 moves to the
bottom of its intake stroke, spring 370A compresses and production
chamber 328 expands and fills with WBL. At the end of this intake
stroke the surface pressure source (not shown but similar to
hydraulic power supply 255) switches to release the pressure
previously applied on piston head 319 through coil tube 316,
whereupon the output or pumping stroke commences with spring 370A
releasing its charge of potential energy to force piston assembly
320 towards its home position, simultaneously expelling the WBL
contents of production chamber 328 through piston fluid exchange
passages 327 then valve 330 and up piston annulus 322 to combine
with the WBL already then in pressure chamber 318. The blend of
which WBL is expelled up-hole through coil-tube 316 for surface
disposal.
[0055] FIG. 4 shows a pump apparatus denoted generally as 400,
according to another illustrated embodiment.
[0056] The pump apparatus 400 is similar to the pump apparatus 300
shown in FIG. 3, but includes a number of extending spring subs
added thereto. The basic pump body 310 has been physically coupled
(e.g., threaded) to a first actuating spring sub 360A in order to
permit apparatus 300 to function as a pump returning WBL to the
surface from shallow wells. Apparatus 400 is formed by adding
spring sub 360B and spring sub 360C so as to permit pumping from
slightly deeper wells. A person of skill in the art of spring
actuated pumping would understand that multiplying the potential
energy stored when the springs are compressed during the down or
intake stroke--by increasing the number of springs so
compressed--enables apparatus 400 to overcome the greater head
pressure associated with deeper well applications. Further, each
spring sub 360B and 360C mechanically and fluidly connects to the
spring sub positioned relatively above it. According to the
embodiment illustrated in FIG. 4, spring sub 360B threads into base
375A, and spring sub 360C threads into base 375B, but it is to be
understood that subs may be added in series by any suitable
connection.
[0057] Similar elements are numbered similarly, and will not be
specifically called out in the description in the interest of
clarity and brevity.
[0058] FIG. 5 shows a pump system denoted generally as 500,
according to another illustrated embodiment.
[0059] The pump system 500 may include apparatus 300 of FIG. 3,
configured for use de-watering production zone 410 of a gas lease
by pumping well-bore liquids to the surface for disposal. It is to
be understood that gas well de-watering is but one of the down hole
applications for which system 500 is suitable. Pump apparatus 300
may be configured for high temperature operation and for the
pumping of liquids (e.g., oil or mixtures having a high "sand cut")
other than water and hence suitable for applications other than
those WBL pumping applications previously described. However, as
illustrated, pump apparatus 300 is lowered through well casing 505
into production zone 510 where WBL stream 515 enters apparatus 300
through spring sub 360A and is pumped to the surface through
coil-tube 316 in the manner described above in reference to FIG. 3.
Upon reaching the surface, WBL stream 515 enters fluid exchange
lines 530 where the WBL stream passes to reservoir 540 from which
excess WBL may be either processed or disposed of via system
outflow line 545. Power source 540 is any suitable engine, pump and
valve combination for controlling flow and pressure between
coil-tube 316 and outflow line 545. A preferred embodiment of a
power source 540 is the hydraulic pumping system 200 (FIG. 2). With
the WBL stream 515 evacuated from well casing 505, gaseous flow 520
rises through well casing 505 past pump apparatus 300 to be
harvested at well-head Christmas Tree 240 (called out in FIG. 2,
not called out in FIG. 5) as production flow 525.
[0060] FIG. 6 shows a pump apparatus denoted generally as 600,
according to yet another illustrated embodiment.
[0061] The pump apparatus 600 takes the form of a single-coil fluid
actuated pump apparatus. Pump body 610 is fluidly coupled to single
coil-tube 316 via inlet/outlet port 315 to supply a suitable fluid
under high pressure (i.e., working fluid) into pressure chamber
618. Since the fluids in pressure chamber 618 and production
chamber 638 never mix, according to this embodiment any clean fluid
(e.g., hydraulic oil) may be used as stream 617 to actuate pump
apparatus 600. Further, while the embodiment of FIG. 3 uses spring
370A to pump fluid up-hole, spring 670A of apparatus 600 is only
used to return piston assembly 620 to a home position during which
upstroke pump body 660 draws WBL (i.e., fluid to be pumped or
production fluid) inside production chamber 638 from production
zone 810 (see FIG. 8). It is the subsequent delivery of surface
fluid--as pressure stream 617 to pressure chamber 618 that applies
pressure to piston head 619 forcing piston assembly 620
downward--that actuates the pumping or output stroke during which
WBL is expelled downward to disposal zone 830 (FIG. 8), rather than
to the surface, at a location lower in the formation below
production zone 810.
[0062] As upper piston assembly 620 slides inside of pump body 610,
piston extension shaft 630 passes through pump bottom 350 and into
spring sub 360A to engage sub shaft 645A and compress spring 670A
thereby charging it with potential energy. Sub shaft 645A in turn
engages lower piston shaft 650 causing lower piston 655 to slide
inside lower pump body 660. As lower piston 655 moves downward
under the pressure of fluid stream 617 the WBL contents of
production chamber 638 are expelled through passage 672 and valve
675 and then passage 671 passing through packer 690 and outgoing
fluid stream 695 injected into the formation below packer 690.
Packer 690 is fluidly and mechanically coupled to lower pump body
670 by any suitable tube and fluid coupling sub-assembly 697. With
sub spring 670A fully charged at the bottom of the previously
described pumping or output stroke, the pressure at the surface is
released and fluid stream 617 flows back up-hole through coil-tube
316 causing pressure chamber 618 to empty as spring 670A returns
upper piston assembly 620 to its home position--simultaneously
causing lower piston 655 to move upward and draw new WBL into
production chamber 638 as low pressure stream 685 through inlet
passage 682 opening valve 680 so as to flood through passage 672
into production chamber 638. Once spring 670A is fully extended and
relaxed lower piston 655 is at the top of its intake stroke, the
cycle repeats.
[0063] FIG. 7 shows a pump apparatus denoted generally as 700,
according to still another illustrated embodiment.
[0064] The pump apparatus 700 is similar to the pump apparatus 600
(FIG. 6) but includes a number of extending spring subs added
thereto. Basic pump body 610 has been physically coupled (e.g.,
threaded) to a first spring sub 360A. The first spring sub 360A has
in turn been physically coupled (e.g., threaded) to a second spring
sub 360B. The second spring sub 360B has in turn been physically
coupled (e.g., threaded) to lower pump body 660. Lower pump body
660 has in turn been coupled to packer 690--all in order to permit
pump apparatus 700 to function as a pump. It is to be understood
that dummy subs (i.e., subs having no springs) may also be added in
series via any suitable connection structure so as to increase a
length of pump apparatus 700, if needed or desired. Further, in the
event that a distance between the production zone inlet stream 685
and the bottom of packer 690 needs to be increased for a given
formation, the length of tube and fluid coupling sub-assembly 697
may be increased.
[0065] FIG. 8 shows a pump system denoted generally as 800,
according to yet still another illustrated embodiment.
[0066] The pump system 600 includes pump apparatus 600 (FIG. 6),
and is shown configured for use de-watering production zone 810 of
a gas lease by pumping well-bore liquids downward to disposal zone
830. It is to be understood that gas well de-watering is but one of
the down hole applications for which system 800 is suitable. Since
pump apparatus 600 may be configured for high temperature operation
and/or for the pumping of liquids (e.g., hot oil or mixtures having
a high "sand cut") other than water, the system 800 may be used for
applications other than the WBL pumping applications previously
described. No WBL from production zone 810 is delivered to the
surface, but the WBL is instead expelled downward into the disposal
zone 830. Pump apparatus 600 operates within casing 805 that has
been perforated at the level of production zone 810, but then
extends deeper through the formation into disposal zone 830 where
WBLs may be disposed of without the need to bring the WBLs to the
surface. Pump apparatus 600 is lowered inside casing 805 to a
formation level where screen (not shown) is exposed to the WBL in
production zone 810 and packer 690 is placed below the level of
production zone 810 so as to seal casing 805 and prevent fluid
exchange between production zone 810 and disposal zone 830.
[0067] Assisted by one or more springs 370 (not shown in FIG. 8),
pump apparatus 600 is filled with WBL from production zone 810 in
the manner described above with reference to FIG. 6. Thereafter WBL
streams 685 and 695 are respectively drained and expelled from well
casing 805, such that gaseous flow 820 rises through well casing
805 past pump apparatus 600 to be harvested at well-head Christmas
Tree 240 (not called out in FIG. 8) as production flow 825. Fluid
stream 617 simply flows back and forth through coil-tube 316
between reservoir 840 and pressure chamber 618 (not called out in
FIG. 8) periodically actuating the pumping stroke of pump apparatus
600. Power source 850 and reservoir 840 are any suitable engine,
pump and valve combination a preferred embodiment of which is based
on hydraulic pumping system 200 (FIG. 2).
[0068] Although the disclosure describes and illustrates various
embodiments of the invention, it is to be understood that the
invention is not limited to these particular embodiments. Many
variations and modifications will now occur to those skilled in the
art of hydrocarbon well de-watering and high temperature pumping.
For example, the various embodiments described may be combined to
provider further embodiments. These and other changes can be made
to the embodiments in light of the above-detailed description. In
general, in the following claims, the terms used should not be
construed to limit the claims to the specific embodiments disclosed
in the specification and the claims, but should be construed to
include all possible embodiments along with the full scope of
equivalents to which such claims are entitled. Accordingly, the
claims are not limited by the disclosure.
* * * * *