U.S. patent application number 14/983022 was filed with the patent office on 2017-06-29 for rotary hydraulic pump with esp motor.
This patent application is currently assigned to GE Oil & Gas ESP, Inc.. The applicant listed for this patent is GE Oil & Gas ESP, Inc.. Invention is credited to Charles Collins, Aaron Noakes, Brian Paul Reeves, Eric Rohlman.
Application Number | 20170184089 14/983022 |
Document ID | / |
Family ID | 57799896 |
Filed Date | 2017-06-29 |
United States Patent
Application |
20170184089 |
Kind Code |
A1 |
Reeves; Brian Paul ; et
al. |
June 29, 2017 |
Rotary Hydraulic Pump with ESP Motor
Abstract
A submersible pumping system includes an electric motor and a
pump driven by the electric motor. The pump includes a rotatable
shaft driven by the motor, one or more piston assemblies configured
for linear reciprocating motion and a mechanism for converting the
rotational movement of the shaft to linear reciprocating movement
in the piston assemblies. In one aspect, the mechanism for
converting the rotational movement of the shaft includes a tilt
disc assembly. In another aspect, the mechanism for converting the
rotational movement of the shaft includes a camshaft assembly.
Inventors: |
Reeves; Brian Paul; (Edmond,
OK) ; Collins; Charles; (Oklahoma City, OK) ;
Noakes; Aaron; (Oklahoma City, OK) ; Rohlman;
Eric; (Oklahoma City, OK) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
GE Oil & Gas ESP, Inc. |
Oklahoma City |
OK |
US |
|
|
Assignee: |
GE Oil & Gas ESP, Inc.
Oklahoma City
OK
|
Family ID: |
57799896 |
Appl. No.: |
14/983022 |
Filed: |
December 29, 2015 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F04B 1/143 20130101;
F04B 1/14 20130101; F04B 1/148 20130101; F04B 17/03 20130101; F04B
1/053 20130101; F04B 53/10 20130101; F04B 53/144 20130101; F04B
1/16 20130101; E21B 43/128 20130101; F04B 1/128 20130101; F04B
15/02 20130101; F04B 47/06 20130101 |
International
Class: |
F04B 47/06 20060101
F04B047/06; F04B 53/10 20060101 F04B053/10; F04B 1/12 20060101
F04B001/12; F04B 53/14 20060101 F04B053/14; F04B 1/14 20060101
F04B001/14; F04B 1/16 20060101 F04B001/16 |
Claims
1. A submersible pumping system comprising: an electric motor; and
a pump driven by the electric motor, wherein the pump comprises: a
shaft driven by the motor configured for rotational movement; one
or more piston assemblies configured for linear reciprocating
movement; and wherein the reciprocating pistons are configured to
linearly reciprocate in response to the rotational movement of the
shaft.
2. The submersible pumping system of claim 1, wherein the pump
further comprises a tilt disc connected to the reciprocating
pistons and to the shaft, wherein the tilt disc assembly converts
the rotational movement of the shaft into the linearly
reciprocating motion of the reciprocating pistons.
3. The submersible pumping system of claim 2, wherein the tilt disc
assembly further comprises: a drive plate; and a rocker plate.
4. The submersible pumping system of claim 3, wherein the drive
plate is connected to the rotating shaft at a non-perpendicular
angle.
5. The submersible pumping system of claim 4, wherein the rocker
plate is adjacent to the drive plate.
6. The submersible pumping system of claim 5, wherein the rocker
plate does not rotate with the shaft.
7. The submersible pumping system of claim 6, wherein the rocker
plate further comprises: a central bearing; and one or more piston
rod recesses.
8. The submersible pumping system of claim 2, wherein the pump
further comprises a cylinder block and wherein the cylinder block
comprises: one or more intake ports; an intake valve in each of the
one or more intake ports; and a discharge valve in each of the one
or more cylinders.
9. The submersible pumping system of claim 1, wherein the pump
further comprises a camshaft assembly, wherein the camshaft
assembly converts the rotational movement of the shaft into the
linearly reciprocating motion of the reciprocating pistons.
10. The submersible pumping system of claim 9, wherein the camshaft
assembly comprises: a camshaft; a plurality of lobes on the
camshaft; and a plurality of connecting rods connected between the
lobes on the camshaft and the piston assemblies.
11. The submersible pumping system of claim 10, wherein the pump
comprises a plurality of cylinders, wherein each of the piston
assemblies reciprocates within a within a separate one of the
plurality of cylinders.
12. The submersible pumping system of claim 11, wherein the pump
further comprises a plurality of manifolds, wherein each of the
plurality of cylinders intersects a manifold
13. The submersible pumping system of claim 12, wherein the pump
further comprises a plurality of check valves within each of the
plurality of manifolds.
14. The submersible pumping system of claim 12, wherein the lobes
on the camshaft have a stepped profile that causes the piston
assemblies to sequentially reciprocate in a manner that produces a
progressive cavity within each of the plurality of manifolds.
15. The submersible pumping system of claim 1, further comprising a
seal section positioned between the pump and the motor.
16. A pump useable within a submersible pumping system, the pump
comprising: a cylinder block, wherein the cylinder block includes a
plurality of cylinders; a rotatable shaft; a tilt disc assembly,
wherein the tilt disc assembly comprises: a drive plate connected
to the rotatable shaft and configured for rotation with the shaft;
and a rocker plate that is not configured for rotation with the
shaft; and a plurality of piston assemblies, wherein each of the
plurality of piston assemblies comprises: a plunger that is
configured for reciprocating linear motion in a corresponding one
of the plurality of cylinders; and a piston rod connected to the
plunger and to the rocker plate.
17. The pump of claim 16, wherein the cylinder block further
comprises: a plurality of intake ports; an intake valve in each of
the plurality of intake ports; and a discharge valve in each of the
plurality of cylinders.
18. A pump useable within a submersible pumping system, the pump
comprising: a plurality of manifolds; a plurality of banks of
cylinders, wherein each of the plurality of banks of cylinders
corresponds to a separate one of the plurality of manifolds; a
plurality of cylinders within each of the plurality of banks of
cylinders, wherein each of the plurality of cylinders is in fluid
communication with the corresponding one of the plurality of
manifolds; a rotatable camshaft; and a plurality of pistons
assemblies, wherein each of the piston assemblies comprises: a
piston, wherein each piston is located within a separate one of the
plurality of cylinders; and a connecting rod, wherein the
connecting rod connects the piston to the camshaft.
19. The pump of claim 18, wherein the pump further comprises a
plurality of check valves within each of the plurality of
manifolds.
20. The pump of claim 18, wherein the camshaft has a stepped
profile that causes the piston assemblies to sequentially
reciprocate in a manner that produces a progressive cavity within
each of the plurality of manifolds.
Description
FIELD OF THE INVENTION
[0001] This invention relates generally to the field of submersible
pumping systems, and more particularly, but not by way of
limitation, to a rotary hydraulic pump driven by a submersible
electric motor.
BACKGROUND
[0002] Submersible pumping systems are often deployed into wells to
recover petroleum fluids from subterranean reservoirs. Typically, a
submersible pumping system includes a number of components,
including an electric motor coupled to one or more centrifugal pump
assemblies. Production tubing is connected to the pump assemblies
to deliver the petroleum fluids from the subterranean reservoir to
a storage facility on the surface. The pump assemblies often employ
axially and centrifugally oriented multistage turbomachines.
[0003] In certain applications, however, the volume of fluid
available to be produced from the well is insufficient to support
the costs associated with conventional electric submersible pumping
systems. In the past, alternative lift systems have been used to
encourage production from "marginal" wells. Surface-based sucker
rod pumps and gas-driven plunger lift systems have been used in low
volume wells. Although widely adopted, these solutions may be
unacceptable or undesirable for a number of reasons. There is,
therefore, a need for an improved submersible pumping system that
is well-suited for use in marginal wells.
SUMMARY OF THE INVENTION
[0004] In some embodiments, the present invention includes a
submersible pumping system that has an electric motor and a pump
driven by the electric motor. The pump includes a rotatable shaft
driven by the motor, one or more piston assemblies configured for
linear reciprocating motion and means for converting the rotational
movement of the shaft to linear reciprocating movement in the
piston assemblies.
[0005] In another aspect, embodiments of the invention include a
pump useable within submersible pumping system. The pump includes a
cylinder block that includes a plurality of cylinders, a rotatable
shaft, a tilt disc assembly and a plurality of piston assemblies.
The tilt disc assembly includes a drive plate connected to the
rotatable shaft and configured for rotation with the shaft and a
rocker plate that is not configured for rotation with the shaft.
Each of the plurality of piston assemblies includes a plunger that
is configured for reciprocating linear motion in a corresponding
one of the plurality of cylinders and a piston rod connected to the
plunger and to the rocker plate.
[0006] In yet another aspect, embodiments of the invention include
a pump useable within a submersible pumping system. The pump
includes a plurality of manifolds and one or more banks of
cylinders. Each of the banks of cylinders corresponds to a separate
one of the plurality of manifolds. The pump further includes a
plurality of cylinders within each of the banks of cylinders and
each cylinder is in fluid communication with the corresponding
manifold. The pump also includes a rotatable camshaft and a
plurality of pistons assemblies. Each piston assembly includes a
piston and a connecting rod that connects the piston to the
camshaft.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1 depicts a submersible pumping system constructed in
accordance with an embodiment of the present invention.
[0008] FIG. 2 provides a cross-sectional view of a rotary hydraulic
pump of the pumping system of FIG. 1 constructed in accordance with
an embodiment.
[0009] FIG. 3 is a view of the downstream side of the cylinder
block of the rotary hydraulic pump of FIG. 2.
[0010] FIG. 4 is a view of the upstream side of the cylinder block
of the rotary hydraulic pump of FIG. 2.
[0011] FIG. 5 is a view of the downstream side of the tilt plate of
the rotary hydraulic pump of FIG. 2.
[0012] FIG. 6 is a view of the downstream side of the drive of the
rotary hydraulic pump of FIG. 2.
[0013] FIG. 7 provides a cross-sectional view of a rotary hydraulic
pump constructed in accordance with an alternate embodiment.
[0014] FIG. 8 provides a side cross-sectional view of a rotary
hydraulic pump of the pumping system of FIG. 1 constructed in
accordance with an alternate embodiment.
[0015] FIG. 9 provides a top cross-sectional depiction of the
rotary hydraulic pump of FIG. 8.
DETAILED DESCRIPTION
[0016] In accordance with exemplary embodiments of the present
invention, FIG. 1 shows an elevational view of a pumping system 100
attached to production tubing 102. The pumping system 100 and
production tubing 102 are disposed in a wellbore 104, which is
drilled for the production of a fluid such as water or petroleum.
As used herein, the term "petroleum" refers broadly to all mineral
hydrocarbons, such as crude oil, gas and combinations of oil and
gas. The production tubing 102 connects the pumping system 100 to a
wellhead 106 located on the surface.
[0017] The pumping system 100 includes a pump 108, a motor 110, and
a seal section 112. Although the pumping system 100 is primarily
designed to pump petroleum products, it will be understood that the
present invention can also be used to move other fluids. It will
also be understood that, although each of the components of the
pumping system are primarily disclosed in a submersible
application, some or all of these components can also be used in
surface pumping operations.
[0018] As used in this disclosure, the terms "upstream" and
"downstream" will be understood to refer to the relative positions
within the pumping system 100 as defined by the movement of fluid
through the pumping system 100 from the wellbore 104 to the
wellhead 106. The term "longitudinal" will be understood to mean
along the central axis running through the pumping system 100; the
term "radial" will be understood to mean in directions
perpendicular to the longitudinal axis; and the term "rotational"
will refer to the position or movement of components rotating about
the longitudinal axis.
[0019] The motor 110 is an electric submersible motor that receives
power from a surface-based facility through power cable 114. When
electric power is supplied to the motor 110, the motor converts the
electric power into rotational motion that is transferred along a
shaft (not shown in FIG. 1) to the pump 108. In some embodiments,
the motor 110 is a three-phase motor that is controlled by a
variable speed drive 116 located on the surface. The variable speed
drive 116 can selectively control the speed, torque and other
operating characteristics of the motor 110.
[0020] The seal section 112 is positioned above the motor 110 and
below the pump 108. The seal section 112 shields the motor 110 from
mechanical thrust produced by the pump 108 and isolates the motor
110 from the wellbore fluids in the pump 108. The seal section 112
may also be used to accommodate the expansion and contraction of
lubricants within the motor 110 during installation and operation
of the pumping system 100. In some embodiments, the seal section
112 is incorporated within the motor 110 or within the pump
108.
[0021] Unlike prior art electric submersible pumping systems, the
pump 108 is a rotary hydraulic pump that is driven by the motor
110. The pump 108 translates rotational motion produced by the
motor 110 into linearly motion that drives reciprocating pistons
within the pump 108. Although a single pump 108 is depicted in FIG.
1, it will be appreciated that the pump 108 can be used in
combination with additional pumps and motors. For example, the pump
108 can be used with other hydraulic rotary pumps, to feed a
surface-based sucker rod pump or to feed a centrifugal pump.
[0022] In the embodiment depicted in FIG. 2, the pump 108 utilizes
a tilt-plate to translate the rotational movement of motor 110 into
reciprocating linear motion. In the cross-sectional depiction of
the pump 108 in FIG. 2, the pump 108 includes an upstream chamber
118, a downstream chamber 120 and a pump shaft 122. It will be
appreciated, however, that the scope of exemplary embodiments is
not limited to two-chamber designs. The pump 108 could
alternatively include a single chamber or more than two
chambers.
[0023] The pump 108 further includes an intake 124, a discharge 126
and a housing 128. Each of the internal components within the pump
108 is contained within the housing 128. Fluid from the wellbore
104 enters the pump 108 through the intake 124 and is carried by
the upstream and downstream chambers 118, 120 to the production
tubing 102 through the discharge 126. The pump shaft 122 is
connected to the output shaft from the motor 110 (not shown) either
directly or through a series of interconnected shafts. The pump 108
may include one or more shaft seals that seal the shaft 122 as it
passes through the upstream and downstream chambers 118, 120.
[0024] Each of the upstream and downstream chambers 118, 120
includes a cylinder block 130, one or more piston assemblies 132
and a tilt disc assembly 134. The tilt disc assembly 134 includes a
drive plate 136 and a rocker plate 138. FIGS. 5 and 6 illustrate
the upstream face of the rocker plate 138 and the upstream face of
the drive plate 136. The rocker plate 138 and the drive plate 136
may both be formed as substantially cylindrical members.
[0025] Referring back to FIG. 2, the drive plate 136 is connected
to the pump shaft 122 in a non-perpendicular orientation. In this
way, rotation of the pump shaft 122 causes an upstream and a
downstream edge of the drive plate 136 to rotate around the shaft
122 within the upstream and downstream chambers 118, 120 at
opposite times. In some embodiments, the drive plate 136 is
connected to the pump shaft 122 at a fixed angle. In other
embodiments, the angular disposition of the connection between the
drive plate 136 and the pump shaft 122 can be adjusted during
use.
[0026] The rocker plate 138 is not configured for rotation with the
pump shaft 122 and remains rotationally fixed with respect to the
cylinder block 130 and housing 128. In some embodiments, the
upstream face of the rocker plate 138 is in sliding contact with
the downstream face of the drive plate 136. In other embodiments,
the pump 108 includes a bearing between the rocker plate 138 and
the drive plate 136 to reduce friction between the two
components.
[0027] The rocker plate 138 includes a central bearing 140 and
piston rod recesses 142. The central bearing 140 permits the rocker
plate 138 to tilt in response to the rotation of the adjacent drive
plate 136. Thus, as the drive plate 136 rotates with the pump shaft
122, the varying rotational position of the downstream edge of the
drive plate 136 cause the rocker plate 138 to tilt in a rolling
fashion while remaining radially aligned with the cylinder block
130 and housing 128. The central bearing 140 may include ball
bearings, lip seals or other bearings that allow the rocker plate
138 to tilt in a longitudinal manner while remaining rotationally
fixed.
[0028] Referring now to FIGS. 2, 3 and 4, the cylinder block 130 is
fixed within the housing 128. The cylinder block 130 includes a
plurality of cylinders 144, intake ports 146 and one-way valves
148. In the exemplary embodiment depicted in FIGS. 3 and 4, the
cylinder block 130 includes six cylinders 144, six intake ports
146, six intake way valves 148 and six discharge valves 150. It
will be understood, however, that the cylinder block 130 may
include different numbers of cylinders 144, intake ports 146 and
one-way valves 148.
[0029] The piston assemblies 132 include a piston rod 152 and a
plunger 154. In the embodiment depicted in FIG. 3, the pump 108
includes six piston assemblies 132. It will be understood, however,
that fewer or greater numbers of piston assemblies 132 may also be
used. A proximal end of each the piston rods 152 is secured within
a corresponding one of the piston rod recesses 142 in the rocker
plate 138. A distal end of each of the piston rods 152 is attached
to the plunger 154. Each plunger 154 resides within a corresponding
one of the cylinders 144.
[0030] In the embodiment depicted in FIG. 3, the intake ports 146
extend to the upstream side of the cylinder blocks 130. An intake
valve 148 within the intake ports 146 allows fluid to enter the
intake port 146 from the upstream side of the cylinder block 130,
but prohibits fluid from passing back out of the upstream side of
the cylinder block 130. A corresponding discharge valve 150 allows
fluid to exit the cylinder 144, but prohibits fluid from entering
the cylinder 144.
[0031] In an alternate embodiment depicted in FIG. 7, the intake
ports 146 extend through the downstream side of a single cylinder
block 130. An intake valve 148 within the intake ports 146 allows
fluid to enter the intake port 146 from the downstream side of the
cylinder block 130, but prohibits fluid from passing back out of
the intake port 146. A corresponding discharge valve 150 allows
fluid to exit the cylinder 144, but prohibits fluid from entering
the cylinder 144. In the embodiment depicted in FIG. 7, it may be
desirable to attach discharge tubes 156 to each of the cylinders
144 to prevent fluid from recirculating through the cylinder block
130.
[0032] During operation, the motor 110 turns the pump shaft 122,
which in turn rotates the drive plate 136. As the drive plate 136
rotates, it imparts reciprocating longitudinal motion to the rocker
plate 136. With each complete rotation of the drive plate 136, the
rocker plate 138 undergoes a full cycle of reciprocating, linear
motion. The linear, reciprocating motion of the rocker plate 138 is
transferred to the plungers 154 through the piston rods 152. The
piston rods 152 force the plungers 154 to move back and forth
within the cylinders 144.
[0033] As the plungers 154 move in the upstream direction, fluid is
drawn into the cylinders through the intake ports 146 and intake
valves 148. As the plungers 154 continue to reciprocate and move in
the downstream direction, the intake valves 148 close and fluid is
forced out of the cylinders 144 through the discharge valves 150.
In this way, the stroke of the piston assemblies 132 is controlled
by the longitudinal distance between the upstream and downstream
edges of the rocker plate 138. The rate at which the piston
assemblies 132 reciprocate within the cylinder block 130 is
controlled by the rotational speed of the motor 110 and pump shaft
122.
[0034] Turning to FIG. 8, shown therein is a cross-sectional
depiction of the pump 108 constructed in accordance with another
embodiment. In the embodiment depicted in FIG. 8, the pump 108 uses
a central camshaft 158 to drive one or more series of pistons 160
within banks of cylinders 162. The cylinders 162 are connected to
manifolds 164 that extend the length of the pump 108. In exemplary
embodiments, the pump 108 includes 2, 4, 6 or 8 banks of cylinders
162, manifolds 164 and series of pistons 160 that are equally
distributed around the pump 108, as depicted in the top
cross-sectional view of FIG. 9.
[0035] The camshaft 158 includes a number of radially offset lobes
166 to which connecting rods 168 are secured for rotation. The
camshaft 158 is connected directly or indirectly to the output
shaft from the motor 110 such that operation of the motor 110
causes the camshaft 158 to rotate at the desired speed. It will be
appreciated that the pistons 160, camshaft 158 and connecting rods
168 may include additional features not shown or described that are
known in the art, including for example, wrist pins, piston seal
rings and piston skirts. Each set of pistons 160 and connecting
rods 168 can be collectively referred to as a "piston assembly"
within the description of this embodiment.
[0036] Each of the manifolds 164 includes an inlet 170 and outlet
172 and one or more check valves 174. The inlets 170 are connected
to the pump intake 124 and the outlets 172 are connected to the
discharge 126. In the embodiment depicted in FIG. 8, each manifold
164 includes a separate check valve between adjacent pistons 160.
The check valves 174 prevent fluid from moving upstream in a
direction from the outlet 172 to the inlet 170. In this way, the
check valves 174 separate the manifolds 164 into separate stages
176 that correlate to each of the pistons 160 and cylinders
162.
[0037] During operation, the camshaft 158 rotates and causes the
pistons 160 to move in reciprocating linear motion in accordance
with well-known mechanics. As a piston 160 retracts from the
manifold 164, a temporary reduction in pressure occurs within the
portion of the manifold 164 adjacent to the cylinder 162 of the
retracting piston 160. The reduction in pressure creates a suction
that draws fluid into the stage 176 from the adjacent upstream
stage 176 through the intervening check valve 174.
[0038] During a compression stroke, the piston 160 moves through
the cylinder 162 toward the manifold 164, thereby reducing the
volume of the open portion of the cylinder 162 and stage 176. As
the pressure increases within the stage 176 adjacent the piston 160
in a compression stroke, fluid is discharged to the adjacent
downstream stage through the check valve 174. The configuration and
timing of the camshaft 158 can be optimized to produce
suction-compression cycles within each stage 176 that are partially
or totally offset between adjacent stages 176 that provide for the
sequential stepped movement of fluid through the manifolds 164.
[0039] In an alternate embodiment, the pistons 160 are configured
to extend into the manifold 164. In another embodiment, the check
valves 174 are omitted and the progression of fluid through the
manifold 164 is made possible by holding the pistons 160 in a
closed position within the manifold 164 to act as a stop against
the reverse movement of fluid toward the inlet 170. The timing of
the pistons 160 can be controlled using lobed cams and rocker arms
as an alternative to the camshaft 158 and connecting rods 168. In
this way, the pistons 160 produce rolling progressive cavities
within the manifolds 164 that push fluid downstream through the
pump 108.
[0040] Thus, in each of the embodiments disclosed herein, the pump
108 provides a positive displacement, linearly reciprocating pump
that is powered by the rotating shaft of a conventional electric
submersible motor 110. The pump 108 will find particular utility in
lower volume pumping operations and in wellbores 104 that present
fluids with a large gas fraction. Because the pump 108 can be
configured to be shorter than conventional multistage centrifugal
pumps, the pump 108 is also well-suited for deployment in deviated
(non-vertical) wellbores 104.
[0041] It is to be understood that even though numerous
characteristics and advantages of various embodiments of the
present invention have been set forth in the foregoing description,
together with details of the structure and functions of various
embodiments of the invention, this disclosure is illustrative only,
and changes may be made in detail, especially in matters of
structure and arrangement of parts within the principles of the
present invention to the full extent indicated by the broad general
meaning of the terms in which the appended claims are expressed. It
will be appreciated by those skilled in the art that the teachings
of the present invention can be applied to other systems without
departing from the scope and spirit of the present invention.
* * * * *