U.S. patent application number 13/065702 was filed with the patent office on 2012-10-04 for sliding valve downhole pump.
Invention is credited to John E. Freeman.
Application Number | 20120251337 13/065702 |
Document ID | / |
Family ID | 46927506 |
Filed Date | 2012-10-04 |
United States Patent
Application |
20120251337 |
Kind Code |
A1 |
Freeman; John E. |
October 4, 2012 |
Sliding valve downhole pump
Abstract
Downhole pumps for producing hydrocarbons and/or other fluids
from a well bore include a barrel having a plunger or plunger valve
disposed therein and a stationary valve engaged with the barrel.
The valve(s) include(s) an outer housing and an inner piston
movable within the outer housing. Responsive to movement of the
plunger or plunger valve relative to the barrel, the inner
piston(s) is(are) movable between a first position that permits
fluid flow through the valve and a second position that prevents
fluid flow therethrough.
Inventors: |
Freeman; John E.; (Big
Spring, TX) |
Family ID: |
46927506 |
Appl. No.: |
13/065702 |
Filed: |
March 28, 2011 |
Current U.S.
Class: |
417/53 ;
417/553 |
Current CPC
Class: |
E21B 43/127 20130101;
F04B 47/02 20130101 |
Class at
Publication: |
417/53 ;
417/553 |
International
Class: |
F04B 53/12 20060101
F04B053/12; F04B 49/00 20060101 F04B049/00 |
Claims
1. A downhole pump for producing fluids from a well bore, the pump
comprising: a stationary valve comprising an outer housing with an
inlet opening and an outlet opening and an inner piston movable
within the outer housing, wherein the inner piston includes a
channel extending therethrough; a barrel engaged with the
stationary valve; and a plunger valve disposed within the barrel
and engaged with a connecting rod that extends through a bore in
the stationary valve, wherein the plunger valve comprises a plunger
housing with an intake opening and an output opening and a plunger
piston movable within the plunger housing, wherein the plunger
piston includes a plunger channel extending therethrough, wherein
the inner piston is movable between a first position in which the
channel is in communication with the inlet opening and the outlet
opening to define a fluid pathway and a second position in which
the channel is isolated from communication with at least one of the
inlet opening and the outlet opening, and wherein the plunger
piston is movable between an open position in which the plunger
channel is in communication with the intake opening and the output
opening to define a plunger fluid pathway and a closed position in
which the plunger channel is isolated from communication with at
least one of the intake opening and the output opening.
2. The downhole pump of claim 1, further comprising at least one
securing member engaging the connecting rod, the plunger valve, or
combinations thereof for retaining the plunger valve in a fixed
position relative to the connecting rod.
3. The downhole pump of claim 1, wherein the outer housing of the
stationary valve further comprises a securing member for retaining
the outer housing of the stationary valve and the barrel in a fixed
position for facilitating reciprocation of the plunger valve.
4. The downhole pump of claim 1, further comprising a securing
member for retaining the plunger valve in a fixed position for
facilitating reciprocation of the barrel.
5. The downhole pump of claim 1, wherein the lower end of the inner
piston of the stationary valve comprises a sealing surface for
isolating the outlet opening from the channel, the plunger piston
comprises a sealing surface for isolating the output opening from
the plunger channel, or combinations thereof.
6. A method for producing fluids from a well bore, the method
comprising the steps of: lowering a downhole pump into the
wellbore, wherein the downhole pump comprises a stationary valve
engaged with a conduit and a barrel, and a plunger valve within the
barrel, wherein the stationary valve comprises a standing housing
and a standing piston, and wherein the plunger valve comprises a
plunger housing and a plunger piston; causing movement of the
plunger valve in a first direction relative to the barrel, thereby
moving the plunger piston into an open position that enables flow
of fluid through the plunger valve into the barrel and moving the
standing piston into a closed position that prevents flow of fluid
from the conduit into the barrel; and causing upward movement of
the plunger valve in a second direction relative to the barrel,
thereby moving the plunger piston into a closed position that
prevents flow of fluid through the plunger valve and moving the
standing position into an open position that enables flow of fluid
from the barrel through the stationary valve and into the
conduit.
7. The method of claim 6, wherein the step of lowering the downhole
pump into the well bore comprises engaging a string of connecting
members to the downhole pump and inserting the downhole pump
through the conduit by extending successive joints of the string of
connecting members into the well bore to position the downhole pump
a selected position for production of fluid.
8. The method of claim 6, wherein the step of lowering the downhole
pump into the well bore comprises engaging a securing member within
the wellbore to retain the standing housing or the plunger housing
in a fixed position relative to the conduit.
9. The method of claim 6, wherein the step of causing movement of
the plunger valve in the first direction relative to the barrel,
the step of causing movement of the plunger valve in the second
direction relative to the barrel, or combinations thereof,
comprises reciprocating a connecting member engaged with the
downhole pump to cause movement of the plunger valve within the
barrel, thereby displacing fluid to cause movement of the plunger
piston and the standing piston.
10. The method of claim 6, wherein the step of causing movement of
the plunger valve in the first direction relative to the barrel,
the step of causing movement of the plunger valve in the second
direction relative to the barrel, or combinations thereof,
comprises reciprocating a connecting member engaged with the
downhole pump to cause movement of the barrel about the plunger
valve, thereby displacing fluid to cause movement of the plunger
piston and the standing piston.
11. A downhole pump for producing fluid from a well bore, the pump
comprising: a stationary valve; a barrel engaged with the
stationary valve; and a plunger disposed within the barrel and
engaged with a connecting rod extending through a bore in the
stationary valve, wherein the stationary valve comprises an outer
housing with an inlet opening and an outlet opening and an inner
piston movable within the outer housing, wherein the inner piston
includes a channel extending therethrough, and wherein the inner
piston is movable between a first position in which the channel is
in communication with the inlet opening and the outlet opening to
define a fluid pathway and a second position in which the channel
is isolated from communication with at least one of the inlet
opening and the outlet opening; and wherein movement of the plunger
relative to the barrel causes movement of the inner piston between
the first position and the second position.
12. The downhole pump of claim 11, wherein the plunger comprises: a
plunger valve having an outer housing and an inner piston movable
within the outer housing, wherein the outer housing comprises a
first end having an inlet opening and a second end having an outlet
opening, wherein the inner piston comprises an upper end, a lower
end, and a channel and a bore extending between the upper end and
the lower end, wherein the inner piston is movable between a first
position in which the channel is in communication with the inlet
opening and the outlet opening to define a fluid pathway and a
second position in which the channel is isolated from communication
with at least one of the inlet opening and the outlet opening,
wherein downward movement of the plunger relative to the barrel
causes movement the inner piston of the plunger valve toward the
first position and further causes movement of the inner piston of
the stationary valve toward the second position, thereby permitting
fluid flow into the barrel through the fluid pathway of the plunger
valve while preventing fluid flow through the stationary valve, and
wherein upward movement of the plunger relative to the barrel
causes movement of the inner piston of the plunger valve toward the
second position and further causes movement of the inner piston of
the stationary valve toward the first position, thereby permitting
fluid flow from the barrel through the fluid pathway of the
stationary valve while preventing fluid flow through the plunger
valve.
13. The downhole pump of claim 12, further comprising at least one
securing member engaging the connecting rod, the plunger valve, or
combinations thereof for retaining the plunger valve in a fixed
position relative to the connecting rod.
14. The downhole pump of claim 12, wherein the outer housing of the
stationary valve further comprises a securing member for retaining
the outer housing of the stationary valve and the barrel in a fixed
position for facilitating reciprocation of the plunger valve.
15. The downhole pump of claim 12, further comprising a securing
member for retaining the plunger in a fixed position for
facilitating reciprocation of the barrel.
16. The downhole pump of claim 12, wherein the lower end of the
inner piston of the stationary valve, the lower end of the inner
piston of the plunger valve, or combinations thereof, comprise a
sealing surface for isolating the outlet opening from the
channel.
17. The downhole pump of claim 11, wherein the outer housing of the
stationary valve further comprises a side surface having an intake
opening, wherein the inner piston further comprises an outer
surface having a recession formed therein and in intake channel
extending from the recession to the lower end of the inner piston,
wherein downward movement of the plunger relative to the barrel
causes movement of the inner piston within the outer housing to
align the recession with the intake opening, thereby defining an
intake passage from the intake opening through the intake channel
and the inlet opening for permitting flow of fluid into the barrel,
and wherein upward movement of the plunger relative to the barrel
causes movement of the inner piston to define an outlet passage
from the inlet opening through the channel and the outlet opening
for permitting flow of fluid from the barrel through the stationary
valve.
18. The downhole pump of claim 17, wherein the lower end of the
inner piston comprises a sealing surface for engaging a surface of
the second end of the outer housing to isolate the intake channel
from the fluid pathway.
19. The downhole pump of claim 17, wherein the upper end of the
inner piston comprises a sealing surface for engaging a surface of
the first end of the outer housing to isolate the fluid
pathway.
20. The downhole pump of claim 17, wherein the second end of the
outer housing further comprises a securing member for retaining the
outer housing and barrel in a fixed position for facilitating
reciprocation of the plunger.
21. The downhole pump of claim 17, further comprising a securing
member for retaining the plunger in a fixed position for
facilitating reciprocation of the barrel.
22. A method for producing fluid from a well bore, the method
comprising the steps of: engaging a valve with a barrel, wherein
the valve comprises an outer housing and an inner piston movable
within the outer housing, wherein the barrel comprises a plunger
disposed therein, and wherein the plunger is engaged with a
connecting member that extends through the barrel and valve;
lowering the valve and the barrel through a conduit into the well
bore; engaging the connecting member with a device adapted to
impart motion to the connecting member; imparting motion to the
connecting member to cause downward movement of the plunger
relative to the barrel, thereby moving the inner piston to a first
position that enables flow of fluid through the valve into the
barrel; and imparting motion to the connecting member to cause
upward movement of the plunger relative to the barrel, thereby
moving the inner piston to a second position that enables flow of
fluid from the barrel through the valve to the conduit.
23. The method of claim 22, wherein the step of engaging the valve
with the barrel comprises threadably connecting a lower end of the
outer housing to an upper end of the barrel.
24. The method of claim 22, wherein the step of lowering the valve
and the barrel through the conduit into the well bore comprises
extending successive joints of the connecting member into the well
bore to position the valve and the barrel at a selected position
for production of fluid.
25. The method of claim 22, wherein the step of lowering the valve
and the barrel through the conduit into the well bore further
comprises engaging a securing member within the wellbore to retain
an upper end of the outer housing or the plunger in a fixed
position relative to the conduit.
26. The method of claim 22, wherein the step of imparting motion to
the connecting member comprises reciprocating the connecting member
using the device disposed above the wellbore to cause movement of
the plunger within the barrel, thereby displacing fluid to cause
movement of the inner piston.
27. The method of claim 22, wherein the step of imparting motion to
the connecting member comprises reciprocating the connecting member
using the device disposed above the wellbore to cause movement of
the barrel about the plunger, thereby causing displacement of fluid
to impart movement to the inner piston.
Description
FIELD
[0001] Embodiments usable within the scope of the present
disclosure relate, generally, to downhole pumps and methods for
producing a well, e.g. through a secondary recovery process.
BRIEF DESCRIPTION OF THE DRAWINGS
[0002] In the detailed description of various embodiments of the
present invention presented below, reference is made to the
accompanying drawings, in which:
[0003] FIG. 1A depicts a diagrammatic cross-sectional view of an
embodiment of a downhole pump usable within the scope of the
present disclosure, during a downstroke of the plunger rod.
[0004] FIG. 1B depicts a diagrammatic cross-sectional view of the
downhole pump of FIG. 1A during an upstroke of the plunger rod.
[0005] FIG. 2A depicts a diagrammatic cross-sectional view of an
embodiment of a standing valve, usable within the downhole pump of
FIGS. 1A and 1B, in a closed position.
[0006] FIG. 2B depicts a diagrammatic cross-sectional view of the
standing valve of FIG. 2A in an open position.
[0007] FIG. 3 depicts a perspective view of an embodiment of the
outer housing of a standing valve.
[0008] FIG. 4A depicts a perspective view of an embodiment of an
inner piston of a standing valve.
[0009] FIG. 4B depicts an end view of the inner piston of FIG.
4A.
[0010] FIG. 5A depicts an end view of an alternate embodiment of an
inner piston of a standing valve.
[0011] FIG. 5B depicts a side view of the inner piston of FIG.
5A.
[0012] FIG. 5C depicts a perspective view of the inner piston of
FIGS. 5A and 5B.
[0013] FIG. 6A depicts a diagrammatic cross-sectional view of an
embodiment of a plunger valve, usable within the downhole pump of
FIGS. 1A and 1B, in a closed position.
[0014] FIG. 6B depicts a diagrammatic cross-sectional view of the
plunger valve of FIG. 6A in an open position.
[0015] FIG. 7 depicts a perspective view an embodiment of the outer
housing of a plunger valve.
[0016] FIG. 8A depicts a diagrammatic cross-sectional view of an
embodiment of a valve usable within the scope of the present
disclosure, in a first position for flowing fluid from a production
zone into a pump barrel.
[0017] FIG. 8B depicts a diagrammatic cross-sectional view of the
valve of FIG. 8A, in a second position for flowing fluid from the
pump barrel into production tubing.
[0018] FIG. 9A depicts a diagrammatic cross-sectional view of an
embodiment of a downhole pump that includes the valve of FIGS. 8A
and 8B, during a downstroke of the plunger.
[0019] FIG. 9B depicts a diagrammatic cross-sectional view of the
valve of FIG. 9A, during an upstroke of the plunger.
[0020] FIG. 10 depicts a diagrammatic view of the downhole pump of
FIGS. 1A and 1B, coupled with a reciprocating surface device.
[0021] Embodiments of the present invention are described below
with reference to the listed Figures.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0022] Before describing selected embodiments of the present
invention in detail, it is to be understood that the present
invention is not limited to the particular embodiments described
herein. The disclosure and description herein is illustrative and
explanatory of one or more presently preferred embodiments of the
invention and variations thereof, and it will be appreciated by
those skilled in the art that various changes in the design,
organization, order of operation, means of operation, equipment
structures and location, methodology, and use of mechanical
equivalents, as well as in the details of the illustrated
construction or combinations of features of the various elements,
may be made without departing from the spirit of the invention.
[0023] As well, the drawings are intended to describe the concepts
of the invention so that the presently preferred embodiments of the
invention will be plainly disclosed to one of skill in the art, but
are not intended to be manufacturing level drawings or renditions
of final products and may include simplified conceptual views as
desired for easier and quicker understanding or explanation of the
invention. As well, the relative size and arrangement of the
components may differ from that shown and still operate within the
spirit of the invention as described throughout the present
application.
[0024] Moreover, it will be understood that various directions such
as "upper," "lower," "bottom," "top," "left," "right," "uphole,"
and "downhole," and so forth are made only with respect to
explanation and clarity in conjunction with the drawings, and that
the components may be oriented differently, for instance, during
transportation and manufacturing as well as operation. Because many
varying and different embodiments may be made within the scope of
the inventive concept(s) herein taught, and because many
modifications may be made in the embodiments described herein, it
is to be understood that the details herein are to be interpreted
as illustrative and non-limiting.
[0025] Embodiments usable within the scope of the present
disclosure relate, generally, to downhole pumps, including both
insertion pumps and tubing pumps, and methods for producing
hydrocarbons and other fluids (e.g., water, drilling fluids, and/or
carbon dioxide or other gasses) from a well bore, that utilize a
smaller number of moving parts than conventional pumps, thereby
reducing wear and decreasing the potential for vapor locking of the
valves, while providing for an improved flow capacity.
[0026] A conventional downhole pump (e.g. an insertion or tubing
pump) includes at least two ball check valves, which open and close
in alternating fashion, though various existing downhole pumps can
include as many as six or more valves. Each valve, seat, and
sealing surface of these pumps are prone to wear and failure,
requiring frequent repair and/or replacement. Also, when gas is
produced from the well bore simultaneously with liquid, it is
common for the gas to become trapped in the pump, preventing the
build up of fluid pressure necessary to continue actuating the
valves (e.g. known as gas or vapor locking). Additionally, the flow
capacity of an insertion pump is limited by the diameter and
configuration of the pump, which must be sized to pass through a
production conduit as a single unit, and by the limited flow
capacity of the ball valves. As a result, insertion pumps may be
insufficient for production of wells where a significant volume of
fluid flow must be accommodated.
[0027] Referring now to FIGS. 1A and 1B, a diagrammatic view of
embodiment of a downhole pump usable within the scope of the
present disclosure is depicted, secured to a lower end of a string
of production tubing (10), or a similar conduit through which fluid
can be transported. The pump, generally, includes a first,
stationary valve, e.g., a standing valve (12), shown engaged to a
pump barrel (16) via threads (18), and a second valve, e.g., a
plunger valve (14), disposed within the pump barrel (16). A plunger
rod (20), which can be connected to and/or a part of a sucker rod
string or similar string of connecting members extending to the
surface for reciprocation by a pump jack or similar device, extends
through the standing valve (12), and is shown secured to the
plunger valve (14) via interior threads (22). The depicted plunger
valve (14) can be retained in a fixed position relative to the
plunger rod (20) using lock nuts (24), or other similar fasteners
and/or securing methods (e.g., steel roll pins, C-clips, cotter
keys, etc.)
[0028] The standing valve (12) is shown having an inner piston (26)
movable within an outer housing (28), e.g., between a first, closed
position, shown in FIG. 1A, and a second, open position, shown in
FIG. 1B. While FIGS. 1A and 1B depict the inner piston (26)
abutting the lower end of the outer housing (28) in the closed
position, and abutting the upper end of the outer housing (28) in
the open position, it should be understood that various
configurations of the standing valve (12) that enable movement of
the inner piston (26) in any direction relative to the outer
housing (28) to open and close the standing valve (12) are
possible. When the standing valve (12) is in the open position,
shown in FIG. 1B, fluid flow through the standing valve (12) is
permitted. Specifically, fluid from within the pump barrel (16)
enters a first opening in the outer housing (28), e.g., an inlet
opening (30), passes through one or more channels (34) in the inner
piston (26), then into the production tubing (10) through a second
opening in the outer housing (28), e.g., an outlet opening (32).
When the standing valve (12) is in the closed position, shown in
FIG. 1A, fluid through the channels (34) of the inner piston (26)
is prevented, e.g., through use of sealing surfaces. Operation of
the depicted embodiment of the standing valve (12) is further
described and depicted in FIGS. 2A and 2B.
[0029] The plunger valve (14) is similarly shown having an inner
piston (36) movable within an outer housing (38) between a first,
open position, shown in FIG. 1A, and a second, closed position,
shown in FIG. 1B. When the plunger valve (14) is in the open
position, shown in FIG. 1A, fluid flow through the plunger valve
(14) is permitted. Specifically, fluid flow from the exterior of
the pump barrel (16) (e.g., from within a production zone of a
wellbore) enters a first opening in the outer housing (38), e.g.,
an intake opening (40), passes through one or more plunger channels
(44) in the inner piston (36), then into the pump barrel (16)
through a second opening in the outer housing (38), e.g., an output
opening (42). When the plunger valve (14) is in the closed
position, shown in FIG. 1B, fluid through the plunger channels (44)
is prevented, e.g., through use of sealing surfaces. Operation of
the depicted embodiment of the plunger valve (14) is further
described and depicted in FIGS. 6A and 6B.
[0030] During typical operations, the standing valve (12) and the
plunger valve (14) will function in tandem, opening and closing in
alternating fashion with each stroke of the plunger rod (20). FIG.
1A depicts the downhole pump during a downstroke of the plunger rod
(20) (e.g., movement of the plunger rod (20) and plunger valve (14)
in a downhole direction via lowering of an attached sucker rod
string or similar string of connecting members). As the plunger rod
(20) is moved in a downhole direction, it slides through a bore in
the standing valve (12), which remains generally stationary, while
the plunger valve (14) is moved in the downhole direction via its
connection to the plunger rod (20). Increased fluid pressure at the
lower end of the plunger valve (14), caused by the movement
thereof, causes the inner piston (36) of the plunger valve (14) to
move upward, thereby opening the valve and permitting fluid to flow
through the plunger valve (14) into the pump barrel (16). Increased
fluid pressure at the upper end of the standing valve (12), caused
in part by the downstroke of the plunger rod (20), causes the inner
piston (26) of the standing valve (12) to move downward, thereby
closing the valve and preventing the reverse-flow of fluid from the
production tubing (10) through the standing valve (12).
[0031] FIG. 1B depicts the downhole pump during an upstroke of the
plunger rod (20) (e.g., movement of the plunger rod (20) and
plunger valve (14) in an uphole direction by raising a sucker rod
string or similar connector attached to the plunger rod (20)). As
the plunger rod (20) is moved in an uphole direction, it slides
through the bore of the standing valve (12), which remains
generally stationary, while the plunger valve (14) is moved in the
uphole direction via its connection to the plunger rod (20).
Increased fluid pressure at the lower end of the standing valve
(12), caused by the upward movement of the plunger rod (20) and the
plunger valve (14), causes the inner piston (26) of the standing
valve (12) to move upward, thereby opening the valve and permitting
the flow of fluid from the pump barrel (16) to the production
tubing (10). Increased fluid pressure at the upper end of the
plunger valve (14), caused by the upward movement of the plunger
rod (20) and the plunger valve (14), causes the inner piston (36)
of the plunger valve (14) to move in a downward direction, thereby
closing the valve and preventing the reverse-flow of fluid from the
pump barrel (16) to the exterior thereof.
[0032] It should be understood that while the standing valve (12)
and/or the plunger valve (14) can be actuated through fluid
pressure at either end thereof, in various embodiments, the valves
(12, 14) can be actuated through electrical, hydraulic, pneumatic,
and/or mechanical means, or any similar method of actuation.
[0033] Referring now to FIGS. 2A and 2B, a diagrammatic
cross-sectional view of an embodiment of a standing valve (12) is
shown, having an inner piston (26) movable within an outer housing
(28). The outer housing (28) is shown having exterior threads (18)
for securing the standing valve (12) to a pump barrel, a conduit,
or a similar object; however, it should be understood that any
manner of securing device, sealing member, fastener, and/or hold
down assembly can be used to secure the standing valve (12) within
or proximate to a production conduit and/or a pump barrel. The
outer housing (28) is also shown having an inlet opening (30) and
an outlet opening (32) for accommodating fluid flow through the
standing valve (12), and a bore (46) for accommodating passage of a
plunger rod and/or similar connecting rod. The diameter of the bore
(46) can be selected such that the plunger and/or connecting rod
can freely slide within the standing valve (12) without affecting
the position of the standing valve (12) or causing significant wear
thereto. The inlet and outlet openings (30, 32) can include any
number and any type of orifice, slot, bore, channel, or other
manner of opening. While the outer housing (28) is shown as a
generally cylindrical structure, it should be understood that the
outer housing (28) can have any shape or dimension, and can be
formed as a unitary structure or a structure having multiple parts,
e.g., a body with an end threadably secured thereto to permit
opening of the outer housing (28) to access the inner piston (26).
The outer housing (28) can be formed from any generally rigid
materials suitable for use within a wellbore environment, such as
metal, plastic, and/or one or more polymers or composites.
[0034] The inner piston (26) is shown having a central opening
coincident with the bore (46) of the outer housing (28) to permit
the passage of the outer housing (28) and slidable movement of the
inner piston (26) therein. The inner piston (26) is also shown
having one or more channels (34) for permitting fluid flow, and one
or more sealing surfaces (48, 50) for abutting against the outer
housing (28) to isolate the channels (34) from and/or place the
channels (34) into communication with the inlet and outlet openings
(30, 32), defining a fluid pathway through the standing valve (12).
While the inner piston (26) is shown as a generally cylindrical
structure, it should be understood that the inner piston (26) can
have any shape or dimension able to fit within the outer housing
(28), and can be formed as a unitary structure or a structure
having multiple parts. Additionally, while the channels (34) are
shown as flutes and/or notches, formed at the exterior of the inner
piston (26), it should be understood that any number and type of
channels, bores, slots, and/or orifices can be used to flow fluid
through any portion of the inner piston (26). The inner piston (26)
can be formed from any generally rigid materials suitable for use
within a wellbore environment, such as metal, plastic, and/or one
or more polymers or composites. In an embodiment, the material of
the inner piston (26) can be selected based on the desired weight
of the inner piston (26) and/or the desired fluid pressure
necessary to move the inner piston (26) to open and/or close the
standing valve (12). For example, the inner piston (26) can be
formed from plastic to minimize weight and enable the standing
valve (12) to be operated using a minimum of energy.
[0035] FIG. 2A depicts the standing valve (12) in a closed
position, e.g., during a downstroke of the plunger rod and plunger
valve. In this position, increased fluid pressure at the upper end
of the standing valve (12) imparts a force against the upper
surface of the inner piston (26), causing downward movement of the
inner piston (26) until the lower sealing surface (50) abuts the
lower end of the outer housing (28). In this position, the lower
sealing surface (50) prevents communication between the inlet
opening (30) and the channels (34), thereby preventing the flow of
fluid through the standing valve (12).
[0036] FIG. 2B depicts the standing valve (12) in an open position,
e.g., during an upstroke of the plunger rod and plunger valve. In
this position, increased fluid pressure at the lower end of the
standing valve (12) imparts a force against the lower surface of
the inner piston (26), causing upward movement of the inner piston
(26), thereby permitting the flow of fluid through the inlet
opening (30), the channels (34), and the outlet opening (32),
defining a fluid pathway (52) for accommodating the flow of fluid
through the standing valve (12). The upper sealing surface (48) can
isolate the fluid pathway (52) from other regions within the
standing valve (12). It should be noted that while FIGS. 2A and 2B
depict upper and lower sealing surfaces (48, 50), any number of
sealing surfaces can be positioned throughout the standing valve
(12) (e.g., along the sides thereof) to isolate the fluid pathway
(52) and/or prevent fluid flow when the inner piston (26) is in a
closed position. The sealing surfaces (48, 50) can include any
manner of sealing member, such as an O-ring or similar compressible
member, or a protruding portion of the inner piston (26) that forms
a seal through abutment with the inner surface of the outer housing
(28).
[0037] Referring now to FIG. 3, an embodiment of the outer housing
(28) of a standing valve is shown. Specifically, the outer housing
(28) is shown as a two-part, cylindrical structure having a lower
portion (54) with a central shaft (58) therein, adapted to engage
an upper portion (56) via complementary threads (60). While FIG. 3
depicts a two-part housing, it should be understood that a
single-piece housing, or an outer housing having more than two
parts is also usable within the scope of the present disclosure,
and that any means of securing, threaded or otherwise, can be used.
The lower portion (54) is shown having external threads (18) formed
thereon for securing the standing valve to a pump barrel or similar
conduit, inlet openings (30) for permitting fluid flow into the
outer housing (28), and a bore (46) for accommodating passage of a
plunger rod or similar connecting member. A series of holes,
notches, bores, and/or orifices (62) for are also shown for
enabling the outer housing (28) to be gripped and/or manipulated by
a spanner wrench or similar tool. The upper portion (56) is shown
having outlet openings (32), and a central opening (64) coincident
with the bore (46) of the lower portion (54) for permitting passage
of the plunger rod.
[0038] Referring now to FIGS. 4A and 4B, an embodiment of an inner
piston (26) usable within the outer housing of FIG. 3 is shown.
Specifically, FIG. 4A shows a perspective view of the inner piston
(26), while FIG. 4B depicts an end view thereof. The inner piston
(26) is shown having channels (34) formed therethrough for
accommodating the passage of fluid through the standing valve. A
central bore (66) is also shown for permitting passage of the shaft
(58, shown in FIG. 3) of the outer housing to pass therethrough.
The central bore (66) can be sized such that the inner piston (26)
is slidable within the outer housing responsive to fluid pressure
at either end thereof.
[0039] While FIGS. 4A and 4B depict the channels (34) as generally
elongate, curved openings extending through the length of the inner
piston (26), it should be understood that the inner piston (26) can
include any number and configuration of channels (34). For example,
FIGS. 5A, 5B, and 5C depict an alternate embodiment of an inner
piston (26), having channels (34) formed as notches and/or flutes
within the exterior surface thereof Specifically, FIG. 5A depicts
an end view of the inner piston (26), within which the central bore
(66) is visible, FIG. 5B depicts a side view of the inner piston
(26), and FIG. 5C depicts a perspective view thereof Formation of
flutes and/or notches within the exterior surface of the inner
piston (26) facilitates ease of manufacture, while also
accommodating a greater fluid flow than drilled holes or similar,
restrictive channels therethrough.
[0040] Referring now to FIGS. 6A and 6B, a diagrammatic
cross-sectional view of an embodiment of a plunger valve (14) is
shown, having an inner piston (36) movable within an outer housing
(38). The outer housing (38) is shown having interior threads (22)
for securing the plunger valve (14) to a plunger rod or similar
connecting member, such that the plunger valve (14) is movable
concurrent with reciprocation of the connecting member, e.g.,
through reciprocation of a sucker rod string from the surface.
While FIGS. 6A and 6B depict interior threads (22), it should be
understood that any manner of securing device, sealing member,
fastener, and/or hold down assembly can be used to secure the
plunger valve (14) to the plunger rod. The outer housing (38) is
shown having an intake opening (40) and an output opening (42) for
accommodating fluid flow through the plunger valve (14), and a bore
(68) for accommodating the plunger rod and/or a similar connecting
rod. The intake and outtake openings (40, 42) can include any
number and any type of orifice, slot, bore, channel, or other
manner of opening. While the outer housing (38) is shown as a
generally cylindrical structure, it should be understood that the
outer housing (38) can have any shape or dimension, and can be
formed as a unitary structure or a structure having multiple parts,
e.g., a body with an end threadably secured thereto to permit
opening of the outer housing (38) to access the inner piston (36).
The outer housing (38) can be formed from any generally rigid
materials suitable for use within a wellbore environment, such as
metal, plastic, and/or one or more polymers or composites.
[0041] The inner piston (36) is shown having a central opening
coincident with the bore (68) of the outer housing (38) to permit
the passage of the outer housing (38) and slidable movement of the
inner piston (36) therein. The inner piston (36) is also shown
having one or more channels (44) for permitting fluid flow, and one
or more sealing surfaces (70, 72) for abutting against the outer
housing (38) to isolate the channels (44) from and/or place the
channels (44) into communication with the intake and output
openings (40, 42), defining a fluid pathway through the plunger
valve (14). While the inner piston (36) is shown as a generally
cylindrical structure, it should be understood that the inner
piston (36) can have any shape or dimension able to fit within the
outer housing (38), and can be formed as a unitary structure or a
structure having multiple parts. Additionally, while the channels
(44) are shown as flutes and/or notches, formed at the exterior of
the inner piston (36), it should be understood that any number and
type of channels, bores, slots, and/or orifices can be used to flow
fluid through any portion of the inner piston (36). The inner
piston (36) can be formed from any generally rigid materials
suitable for use within a wellbore environment, such as metal,
plastic, and/or one or more polymers or composites. In an
embodiment, the material of the inner piston (36) can be selected
based on the desired weight of the inner piston (36) and/or the
desired fluid pressure necessary to move the inner piston (2636 to
open and/or close the plunger valve (14). For example, the inner
piston (36) can be formed from plastic to minimize weight and
enable the plunger valve (14) to be operated using a minimum of
energy.
[0042] FIG. 6A depicts the plunger valve (14) in a closed position,
e.g., during an upstroke of the plunger rod and plunger valve (14).
In this position, increased fluid pressure at the upper end of the
plunger valve (14), caused in part by movement thereof, imparts a
force against the upper surface of the inner piston (36), causing
downward movement of the inner piston (36) until the lower sealing
surface (72) abuts the lower end of the outer housing (38). In this
position, the lower sealing surface (72) prevents communication
between the intake opening (40) and the channels (44), thereby
preventing the flow of fluid through the plunger valve (14).
[0043] FIG. 6B depicts the plunger valve (14) in an open position,
e.g., during a downstroke of the plunger rod and plunger valve
(14). In this position, increased fluid pressure at the lower end
of the plunger valve (14), caused in part by the movement thereof,
imparts a force against the lower surface of the inner piston (36),
causing upward movement of the inner piston (36), thereby
permitting the flow of fluid through the intake opening (40), the
channels (44), and the output opening (42), defining a fluid
pathway (74) for accommodating the flow of fluid through the
plunger valve (14). The upper sealing surface (70) can isolate the
fluid pathway (74) from other regions within the plunger valve
(14). While FIGS. 6A and 6B depict upper and lower sealing surfaces
(70, 72), it should be noted that any number and type of sealing
surfaces throughout the plunger valve (14) to isolate the fluid
pathway (74) and/or prevent the flow of fluid when the inner piston
(36) is in a closed position. The sealing surfaces (70, 72) can
include any manner of sealing member, such as an 0-ring or similar
compressible member, or a protruding portion of the inner piston
(36) that forms a seal through abutment with the inner surface of
the outer housing (38).
[0044] Referring now to FIG. 7, an embodiment of the outer housing
(38) of a plunger valve is shown. The outer housing (38) is shown
as a two-part, cylindrical structure having a lower portion (76)
with a central shaft (80) therein, adapted to engage an upper
portion (78) via complementary threads (82). It should be
understood that a single-piece housing, or an outer housing having
more than two parts is also usable within the scope of the present
disclosure, and that any means of securing, threaded or otherwise,
can be used. The lower portion (76) is shown having intake openings
(40) for permitting fluid flow into the outer housing (38), and a
bore (68) within which the plunger rod or a similar connecting
member can be secured. One or more of holes, notches, bores, and/or
orifices (84) are also shown, for enabling the outer housing (38)
to be gripped and/or manipulated by a spanner wrench or similar
tool. The upper portion (78) is shown having output openings (42),
and a central opening (86) coincident with the bore (68) of the
lower portion (76) for permitting passage and/or securing the
plunger rod.
[0045] The inner piston of the plunger valve may be of similar
construction to that of the standing valve, depicted in FIGS. 4A,
4B, 5A, 5B, and 5C, for example, having channels (e.g., holes,
slots, notches, and/or flutes) extending therethrough and a central
bore or opening to accommodate passage of the central shaft (80) of
the outer housing (38) and permit slidable movement of the inner
piston therein.
[0046] Referring now to FIGS. 8A and 8B, an embodiment of a valve
(88) is shown, which is usable within downhole pumps that include a
single valve (e.g., a standing valve), for use in conjunction with
a plunger and a pump barrel. The valve (88) is depicted having an
inner piston (90) movable within an outer housing (92). The outer
housing (92) includes a central shaft (94) with a bore (96) therein
for accommodating passage of a plunger rod or similar connecting
member. The shaft (94) passes through a bore (98) of the inner
piston (90) to retain the inner piston (90) while permitting
slidable movement thereof.
[0047] The outer housing (92) is shown having an inlet opening
(102) at a first end thereof, and an outlet opening (104) at a
second end thereof The outer housing (92) is further shown having
an intake opening (100) in a side surface thereof The inner piston
(90) is shown having flow channels (110) extending between ends
thereof, a recession (106) formed in an outer surface thereof, and
intake channels (108) extending from the recession (106) to the
lower end of the inner piston (90). Upper and lower sealing
surfaces (112, 114) shown on the inner piston (90) are usable to
isolate the channels (108, 110) from the inlet and outlet openings
(102, 104), depending on the position of the inner piston (90)
within the outer housing (92).
[0048] Specifically, FIG. 8A depicts the valve (88) during a
downstroke of a plunger and/or connecting rod, enabling the flow of
fluid from the exterior of the valve (88) (e.g., within a
production zone), through the valve (88), and into a pump barrel.
As the plunger is moved in a downward direction, fluid pressure at
the upper end of the inner piston (90) can cause the inner piston
(90) to move in a downward direction until the lower sealing
surface (114) abuts the outer housing (92). The recession (106) of
the inner piston (90) is thereby aligned with the intake opening
(100) in the side surface of the outer housing (92), enabling fluid
to pass through the intake opening (100) into the recession (106),
then flow through the intake channels (108) and the inlet opening
(102) into a pump barrel disposed beneath the valve (88).
[0049] FIG. 8B depicts the valve (88) during an upstroke of a
plunger and/or connecting rod, enabling the flow of fluid from a
pump barrel beneath the valve (88) through the valve (88) and into
production tubing or a similar conduit above the vale (88). As the
plunger is moved in an upward direction, fluid pressure at the
lower end of the inner piston (90) can cause the inner piston (90)
to move in an upward direction until the upper sealing surface
(112) abuts the outer housing (92), thereby preventing reverse-flow
of fluid through the intake channels (108) and intake opening
(100), while permitting fluid to flow from the pump barrel through
inlet opening (102) and flow channels (110) of the inner piston
(90), then through the outlet opening (104) of the outer housing
(92) into an adjacent conduit (e.g., production tubing).
[0050] Referring now to FIGS. 9A and 9B, a diagrammatic
cross-sectional view of an embodiment of a downhole pump (116)
usable within the scope of the present disclosure is shown.
Generally, the downhole pump (116) includes a valve (88), such as
that depicted in FIGS. 8A and 8B, a pump barrel (118) secured to
the valve (88), e.g., through use of a threaded connection,
fasteners or securing devices, hold down assemblies, sealing
members, welding, or other similar methods of connection, and a
plunger (124) disposed with the pump barrel (118) and secured to a
string of connecting members (126) that extends through the valve
(88). The downhole pump (116) is shown secured at a lower end of a
conduit (120), such as a string of production tubing, using a
securing assembly (122), which can include various sealing members,
hold-down assemblies, packers, welding, threaded connections, or
similar devices as known in the art.
[0051] Specifically, FIG. 9A depicts the downhole pump (116) during
a downstroke of the plunger (124), such that fluid pressure within
the valve (88) causes movement of the inner piston (90) toward a
lowered position, as shown. FIG. 9B depicts the downhole pump (116)
during an upstroke of the plunger (124), such that fluid pressure
within the valve (88) causes movement of the inner piston (90)
toward a raised position, as shown.
[0052] During operation, the string of connecting members (126)
(e.g., a string of sucker rods or similar connecting members) can
be reciprocated using a pump jack or similar surface device,
causing movement of the plunger (124) within the pump barrel (118).
This movement can generate fluid pressure that causes the inner
piston (90) to move in a manner that defines an inlet passage, as
described previously, enabling the flow of fluid from the exterior
of the valve (88) to flow into the pump barrel (118) along the flow
path (128). During an upstroke of the plunger (124), the inner
piston (90) is moved to define an outlet passage, as described
previously, enabling the flow of fluid from the pump barrel (118)
through the valve (88) and into the conduit (120) along the flow
path (130).
[0053] It should be understood that while FIGS. 9A and 9B depict
the pump barrel (118) secured in a downhole direction relative to
the valve (88), with the plunger (124) disposed within the pump
barrel (118), other configurations are also usable to cause
reciprocation of the inner piston (90) within the outer housing
(92). For example, the inner piston (90) and/or the outer housing
(92) could be inverted, the plunger (124) and/or the pump barrel
(118) could be secured in an uphole direction relative to the
valve, or combinations thereof In an alternate embodiment, the
plunger (124) can be secured in a fixed position relative to the
conduit (120), e.g., through use of threaded connections and/or
other types of securing assemblies, such that reciprocation of the
string of connecting rods (126) causes movement and reciprocation
of the barrel (118) about the plunger (124), thereby causing
movement of the inner piston (90) within the outer housing
(92).
[0054] Referring now to FIG. 10, a diagrammatic view of an
embodiment of a downhole pump is shown in which the outer housing
(28) and inner piston (26) of a first valve, the outer housing (38)
and inner piston (36) of a second valve, and a pump barrel have
been lowered through a conduit string (10) (e.g., as a single unit
in the manner of an insertion pump), then secured in a desired
position relative to the conduit string (10) using a securing
assembly (122). A string of connecting rods (20), which can include
an integral or separate plunger rod at the lower end thereof,
extends through the outer housing (28) and inner piston (26) of the
first valve, connecting the outer housing (38) and/or the inner
piston (36) of the second valve to a pump jack (130) or similar
reciprocating apparatus at the surface. As known in the art, the
pump jack (130) can engage the string of connecting rods (20) via a
polished rod, stuffing box, and/or other surface equipment (not
shown). Reciprocation of the string of connecting rods (20) by the
pump jack (130) causes reciprocation of the outer housing (38) and
inner piston (36) of the second valve within the barrel (16), which
reciprocates the inner pistons (26, 36) of both valves through
changes in fluid pressure.
[0055] As described previously, each stroke of the pump jack (130)
and thereby, each stroke of the inner pistons (26, 36) can draw
fluid from the exterior of the pump barrel (16) through the second
valve and into the pump barrel (16), and from the pump barrel (16)
through the first valve and into the conduit string (120), and move
fluid upward through the conduit string (10). Also, as described
above, it should be noted that reciprocation of the second valve
can cause movement of one or both inner pistons (26, 36)
independent of its placement or its movement relative to the first
valve. As such, in alternate embodiments, the second valve could be
disposed in an uphole direction relative to the first valve, and/or
the second valve could be secured in a fixed position relative to
the conduit string (10) while the pump barrel (16) and/or the first
valve is reciprocated by the pump jack (130).
[0056] Additionally, while FIG. 10 depicts the pump jack (130)
coupled to a downhole pump similar to that shown in FIGS. 1A and
1B, for illustrative purposes, it should be readily understood that
a downhole pump similar to that shown in FIGS. 9A and 9B is also
usable in the manner described above.
[0057] Embodiments described herein thereby provide downhole pumps
and methods having a minimum of moving parts, that can provide an
improved flow capacity over that of conventional downhole
pumps.
[0058] While various embodiments of the present invention have been
described with emphasis, it should be understood that within the
scope of the appended claims, the present invention might be
practiced other than as specifically described herein.
* * * * *