U.S. patent application number 12/488387 was filed with the patent office on 2009-12-24 for hydraulic intensifiers.
This patent application is currently assigned to Vetoo Gray Controls Limited. Invention is credited to Simon David Gill, Timothy James Roberts.
Application Number | 20090317267 12/488387 |
Document ID | / |
Family ID | 39672519 |
Filed Date | 2009-12-24 |
United States Patent
Application |
20090317267 |
Kind Code |
A1 |
Gill; Simon David ; et
al. |
December 24, 2009 |
HYDRAULIC INTENSIFIERS
Abstract
A hydraulic intensifier with a piston and cylinder assembly (1)
having a first piston (3) in a chamber (4) of low pressure cylinder
and a second piston (7) in a chamber (8) of a high pressure
cylinder. The first and second pistons are coupled together and the
first piston has a larger cross-sectional area than the second
piston. A high pressure output (19) is coupled to the chamber of
the high pressure cylinder, there being; means (13) for supplying
low pressure hydraulic fluid to the chamber of the low pressure
cylinder; an electrically operated directional control valve (11)
for controlling the supply of low pressure hydraulic fluid to the
chamber of the low pressure cylinder; and electronic means (14) for
controlling operation of the directional control valve.
Inventors: |
Gill; Simon David; (Bristol,
GB) ; Roberts; Timothy James; (South Gloucestershire,
GB) |
Correspondence
Address: |
BRACEWELL & GIULIANI LLP
P.O. BOX 61389
HOUSTON
TX
77208-1389
US
|
Assignee: |
Vetoo Gray Controls Limited
Bristol
GB
|
Family ID: |
39672519 |
Appl. No.: |
12/488387 |
Filed: |
June 19, 2009 |
Current U.S.
Class: |
417/53 ;
417/505 |
Current CPC
Class: |
F15B 3/00 20130101 |
Class at
Publication: |
417/53 ;
417/505 |
International
Class: |
F04B 49/06 20060101
F04B049/06; F04B 7/00 20060101 F04B007/00 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 19, 2008 |
GB |
0811205.4 |
Claims
1. A hydraulic intensifier comprising: a piston and cylinder
assembly having a first piston in a chamber of a low pressure
cylinder and a second piston in a chamber of a high pressure
cylinder, the first and second pistons being coupled together and
the first piston having a larger cross-sectional area than the
second piston; a high pressure output coupled to the chamber of the
high pressure cylinder; a low pressure hydraulic fluid supply in
fluid communication with the chamber of the low pressure cylinder;
and an energizable directional control valve in selective fluid
communication with the low pressure hydraulic fluid supply, in
selective fluid communication with the chamber of the low pressure
cylinder, and in selective fluid communication with the, so that
when the directional control valve is energized the low pressure
fluid supply and low pressure cylinder chamber are in fluid
communication.
2. A hydraulic intensifier according to claim 1, comprising: a
second piston and cylinder assembly, the high pressure output being
coupled to the chamber of the high pressure cylinder of the second
piston and cylinder assembly; and a second directional control
valve having a side in fluid communication with the low pressure
hydraulic fluid supply and a side in fluid communication with the
chamber of die second low pressure cylinder, so that when the
directional control valve is energized the low pressure fluid
supply and the second low pressure cylinder chamber are in fluid
communication.
3. A hydraulic intensifier comprising: a first piston and cylinder
assembly having a first piston in a chamber of a low pressure
cylinder and a second piston in a chamber of a high pressure
cylinder, the first and second pistons being coupled together and
the first piston having a larger cross-sectional area than the
second piston; a second piston and cylinder assembly; a high
pressure output coupled to the chambers of the high pressure
cylinders of the first and second piston and cylinder assemblies;
means for supplying low pressure hydraulic fluid to the chambers of
the low pressure cylinders of the first and second piston and
cylinder assemblies; first and second electrically operated
directional control valves for controlling the supply of low
pressure hydraulic fluid to the chambers of the low pressure
cylinders of the first and second piston and cylinder assemblies
respectively; and electronic means for controlling operation of the
directional control valves to supply low pressure hydraulic fluid
alternately to the chambers of said low pressure cylinders.
4. A hydraulic intensifier according to claim 3, wherein low
pressure hydraulic fluid is supplied to the chambers of the high
pressure cylinders via respective ones of first and second check
valves, said chambers of the high pressure cylinders being coupled
with said high pressure output via respective ones of third and
fourth check valves.
5. A hydraulic intensifier according to claim 1, comprising means
coupled to said electronic means for sensing pressure of hydraulic
fluid at said high pressure output and causing the or each
directional control valve not to supply hydraulic fluid to the
chamber or chambers of the low-pressure cylinder or cylinders in
response to the sensed pressure being at a required value.
6. A hydraulic intensifier according to claim 3, comprising means
coupled to said electronic means for sensing pressure of hydraulic
fluid at said high, pressure output and causing the or each
directional control valve not to supply hydraulic fluid to the
chamber or chambers of the low pressure cylinder or cylinders in
response to the sensed pressure being at a required value.
7. A hydraulic intensifier according to claim 1, wherein said
electronic means comprises a bistable device.
8. A hydraulic intensifier according to claim 3, wherein said
electronic means comprises a bistable device.
9. A hydraulic intensifier according to claim 1, comprising a
hydraulic accumulator coupled with said high pressure output.
10. A hydraulic intensifier according to claim 3, comprising a
hydraulic accumulator coupled with said high pressure output.
11. A hydraulic intensifier according to claim 1, adapted for use
in a subsea well.
12. A hydraulic intensifier according to claim 3, adapted for use
in a subsea well.
13. A hydraulic intensifier according to claim 1, wherein said
electronic means is provided via a subsea electronics module for a
subsea well.
14. A hydraulic intensifier according to claim 3, wherein said
electronic means is provided via a subsea electronics module for a
subsea well.
15. A hydraulic intensifier according to claim 11, wherein the or
each directional control value is provided by a directional control
valve of a subsea control module for a subsea well.
16. A hydraulic intensifier according to claim 12, wherein the or
each directional control value is provided by a directional control
valve of a subsea control module for a subsea well.
17. A method of producing high pressure hydraulic fluid comprising:
providing a piston and cylinder assembly having a first piston in a
chamber of low pressure cylinder and a second piston in a chamber
of a high pressure cylinder, the first and second pistons being
coupled together, the first piston having a larger cross-sectional
area than the second piston and there being a high pressure output
coupled to the chamber of the high pressure cylinder; supplying low
pressure hydraulic fluid to the chamber of the low pressure
cylinder; providing an electrically operated directional control
valve for controlling the supply of low pressure hydraulic fluid to
the chamber of the low pressure cylinder; and electronically
controlling operation of the directional control valve.
18. A method according to claim 17, comprising: providing a second
piston and cylinder assembly, the high pressure output being
coupled to the chamber of the high pressure cylinder of the second
piston and cylinder assembly; providing a second such directional
control valve for controlling supply of low pressure fluid to the
chamber of the low pressure cylinder of the second piston and
cylinder assembly; and electronically controlling the directional
control valves to supply low pressure fluid alternately to the
chambers of the low pressure cylinders of the first and second
piston and cylinder assemblies.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This Application relates claims priority to and the benefit
of co-pending United Kingdom Patent Application No. 0811205.4 filed
on 19 Jun. 2008, the full disclosure of which is hereby
incorporated fay reference.
BACKGROUND
[0002] 1. Field of Invention
[0003] The present invention relates to hydraulic intensifiers.
[0004] 2. Description of Related Art
[0005] Hydraulic intensifiers are devices that generate high
hydraulic pressure from a low pressure source. When employed in
subsea wells such as hydrocarbon production or injection wells,
they provide a source of high pressure hydraulic fluid for the
operation of hydraulically actuated devices, such as valves and
flow control chokes. Such wells are, typically, supplied with low
pressure hydraulic fluid via an umbilical, which can be in excess
of 100 Km in length. The supply of high pressure fluid via the
umbilical is not favoured by well operators, as a high pressure
feed within the umbilical, needing a much greater wall thickness
than usual, results in much greater umbilical and handling costs.
Intensifiers use relatively large cross-sectional area pistons,
operating at low pressure, to actuate small cross-sectional area
pistons, to generate high pressures, thus utilising the mechanical
advantage of the ratios of the piston cross-sectional areas to
`intensify` the pressure.
[0006] Typically, two sets of pistons are utilised which operate
alternately to sustain a continuous flow of fluid. The alternate
operation of the piston sets is controlled by a complicated
arrangement of valves and springs and since these and the piston
sets are integrated into one assembly, current hydraulic
intensifiers are complicated devices, which are difficult to
manufacture and thus of high cost. Furthermore, they are heavy
devices, typically 37 Kg, and are prone to a multiplicity of
problems which include failure of `slipper` seals and changeover
valves, sensitivity to contamination and a tendency to `lock-up`
due to pressure in their return lines. Repair requires the complete
removal and strip down of the assembly which is also expensive, and
new designs require full approval testing before they can be
employed.
[0007] GB-A-2 275 969 discloses a hydraulic intensifier comprising
two sets of high and low pressure pistons for the compression of
low pressure liquid, the piston sets being coupled together by the
slider of a pilot valve so as to act in mutual opposition, the low
pressure pistons of the piston sets being driven by low pressure
liquid supplied by way of a changeover valve and the changeover
valve being changed over at the end of each stroke of the pilot
valve to reverse the motion of the piston sets, the changeover
valve being effective to maintain a supply of low pressure liquid
to drive the piston sets throughout the stroke of the pilot
valve.
SUMMARY
[0008] Disclosed herein is a hydraulic intensifier having a piston
and cylinder assembly with a first piston in a chamber of a low
pressure cylinder and a second piston in a chamber of a high
pressure cylinder, the first and second pistons being coupled
together and the first piston having a larger cross-sectional area
than the second piston, a high pressure output coupled to the
chamber of the high pressure cylinder, means for supplying low
pressure hydraulic fluid to the chamber of the low pressure
cylinder, an electrically operated directional control valve for
controlling the supply of low pressure hydraulic fluid to the
chamber of the low pressure cylinder, and an electronic device
operatively connected to the directional control valve.
[0009] The hydraulic intensifier may further include a second
piston and cylinder assembly, rite high pressure output being
coupled to the chamber of the high pressure cylinder of the second
piston and cylinder assembly; and a second directional control
valve for controlling the supply of low pressure fluid from the
supplying means to the chamber of the low pressure cylinder of the
second piston and cylinder assembly, the electronic device
connected to the directional control valves to supply low pressure
fluid alternately to the chambers of the low pressure cylinders of
the first and second piston and cylinder assemblies.
[0010] Another embodiment of a hydraulic intensifier includes a
first piston and cylinder assembly having a first piston in a
chamber of a low pressure cylinder and a second piston in a chamber
of a high pressure cylinder, the first and second pistons being
coupled together and the first piston having a larger
cross-sectional area than the second piston, a second piston and
cylinder assembly, a high pressure output coupled to the chambers
of the high pressure cylinders of the first and second piston and
cylinder assemblies, a low pressure hydraulic fluid supply to the
chambers of the low pressure cylinders of the first and second
piston and cylinder assemblies, first and second electrically
operated directional control valves in fluid communication with the
supply of low pressure hydraulic fluid and the chambers of the low
pressure cylinders of the first and second piston and cylinder
assemblies respectively, and an electronic device operatively
coupled to the directional control valves to selectively energize
the control valves to thereby supply low pressure hydraulic fluid
alternately to the chambers of said low pressure cylinders.
[0011] Low pressure hydraulic fluid could he supplied to the
chambers of the high pressure cylinders via respective ones of
first and/or second check valves, said chambers of the high,
pressure cylinders being coupled with said high pressure output via
respective ones of third and fourth check valves.
[0012] The hydraulic intensifier could include a pressure sensing
device coupled to said electronic means for sensing pressure of
hydraulic fluid at said high pressure output and causing the or
each directional control valve not to supply hydraulic fluid to the
chamber or chambers of the low pressure cylinder or cylinders in
response to the sensed pressure being at a required value. The
electronic device could comprise a bistable device. A hydraulic
accumulator can be optionally included that is coupled with the
high pressure output.
[0013] A hydraulic intensifier could be one for use in a subsea
well. In a subsea application electrical control could be provided
via a subsea electronics module for a subsea well and/or the
directional flow control could be provided by a directional control
valve of a subsea control module for a subsea well.
[0014] Also disclosed herein is a method of producing high pressure
hydraulic fluid. In one example the method includes providing a
piston and cylinder assembly having a first piston in a chamber of
low pressure cylinder and a second piston in a chamber of a high
pressure cylinder, the first and second pistons being coupled
together, the first piston having a larger cross-sectional area
than the second piston and there being a high pressure output
coupled to the chamber of the high pressure cylinder, supplying low
pressure hydraulic fluid to the chamber of the low pressure
cylinder, and controlling the supply of low pressure hydraulic
fluid to the chamber of the low pressure cylinder by selectively
energizing the directional control valve.
[0015] The method can also include providing a second piston and
cylinder assembly, the high pressure output being coupled to the
chamber of the high pressure cylinder of the second piston and
cylinder assembly, providing a second directional control valve for
controlling supply of low pressure fluid to the chamber of the low
pressure cylinder of the second piston and cylinder assembly, and
using an electronic device to selectively energize the directional
control valves to supply low pressure fluid alternately to the
chambers of the low pressure cylinders of the first and second
piston and cylinder assemblies.
[0016] The present disclosure, in one example, enables a modular
hydraulic intensifier which utilises standard approved directional
control valves (DCVs) which are controlled electronically, in
conjunction with piston sets sealed with proven standard approved
seals. By being modular, such an intensifier can be serviced by the
replacement of individual components, most of which are standard
devices which will already be held as spares for the rest of the
well control system.
DESCRIPTION OF FIGURES
[0017] FIG. 1 schematically illustrates an example of a hydraulic
intensifier in accordance with the present disclosure.
DETAILED DESCRIPTION OF THE INVENTION
[0018] The method and system of the present disclosure will now be
described more fully hereinafter with reference to the accompanying
drawings in which embodiments are shown. The method and system of
the present disclosure may be in many different forms and should
not be construed as limited to the illustrated embodiments set
forth herein; rather, these embodiments are provided so that this
disclosure will be through and complete, and will fully convey its
scope to those skilled in the art. Like numbers refer to like
elements throughout.
[0019] An example of a hydraulic intensifier for a subsea
hydrocarbon extraction or injection well is provided in FIG. 1. Two
piston and cylinder assemblies 1 and 2, which may be identical, are
shown in sectioned view. An associated hydraulic circuit is shown
schematically. Each piston assembly has a large cross-sectional
area piston 3, 3' depending from one side and a smaller
cross-sectional area piston 7, 7' depending from its opposite end.
The larger cross-sectional area piston 3, 3' is shown disposed in
the chamber 4, 4' of a low pressure cylinder. Seals 5, 5' and 6, 6'
are shown between the piston 3, 3' and chamber 4, 4' of low
pressure cylinder. The smaller cross-sectional area piston 7, 7' is
shown in high pressure cylinder chamber 8, 8' with seal 9, 9'
therebetween. The chamber 4, 4' of each low pressure cylinder
includes a buffer 10, 10'; that can be manufactured from a
resilient, hydraulic fluid resistant material, to minimise the
impact of a fast-returning piston.
[0020] The operation of each of the piston assemblies 1 and 2, may
be controlled, alternately, by respective ones of standard
solenoid-operated directional control valves (DCVs) 11 and 12. A
low pressure (LP) supply 13, typically via the well umbilical, is
shown providing hydraulic fluid to the DCVs 11 and 12. The
solenoids of the DCVs 11 and 12 are electrically energised
alternately from a dc power source switched by an electronic device
14 such as a multivibrator, that can be bistable. Each DCV 11 and
12 is coupled to the chamber 4, or 4' of the respective low
pressure cylinder via a respective restrictor 15 or 16. Source 13
is shown connected to the chambers 8, 8' of the high pressure
cylinders via check valves 17 and 18 respectively. Also, each of
the chambers 8, 8' is shown connected to a high pressure (BP)
intensifier output line 19 via check valves 20 and 21 respectively,
reference numeral 22 designating a hydraulic accumulator connected
with line 19 and reference numeral 23 designating a pressure switch
connected to device 14. Reference numeral 24 designates a return
line for excess fluid.
[0021] An example of a mode of operation of the intensifier is as
follows. After installation, low pressure hydraulic fluid from the
source 13 primes the system and additionally provides, via check
valves 17 and 18 respectively, a continuous supply of hydraulic
fluid to the chambers 8, 8' of the high pressure cylinders. In the
condition of the assemblies 1 and 2 and DCVs 11 and 12 as shown,
the solenoid of DCV 11 has been de-energised and that of DCV 12 has
been energised so that piston 3' has been driven by low pressure
fluid that entered chamber 4'. Then, the solenoid of DCV 11 is
energised by dc power, switched by the device 14, which allows low
pressure hydraulic fluid to operate the piston 3 in the chamber 4
of the low pressure cylinder of the piston/cylinder assembly 1, the
solenoid of DCV 12 being de-energised. The rate of movement of the
piston 3 may be controlled by an optional hydraulic restrictor 15.
The resultant operation of piston 7 forces hydraulic fluid from the
chamber 8 of the high pressure cylinder of assembly 1 at high
pressure (HP), via check valve 20, to the intensifier output line
19 and into hydraulic accumulator 22. The check valve 17 will close
to isolate the generated high pressure from the low pressure
source.
[0022] The piston 7' in the piston/cylinder assembly 2 will be
forced downwards, with the hydraulic fluid transferring from below
the piston 3' in the chamber 4' to above the piston 3' in the
chamber 4' via the DCV 12. When de-energized, the DCV 12 directs
flow received from the hydraulic restrictor 16 and along a path
through the circuit as indicated by arrow 25. At the same time, the
chamber 8' of the high pressure cylinder of assembly 2 is filled by
the low pressure source 13 via the check valve 18. The transfer of
fluid from beneath to above the piston 3' within the chamber 4', in
the flow direction 25, minimises the consumption of hydraulic
fluid. Optionally, as the piston 3' downstrokes, fluid in the
chamber 4' beneath the piston 3' can be routed to chamber 8'. Yet
further optionally, as either of pistons 3, 3' is being urged
upwards. fluid in die respective chamber 4, 4' above the piston 3,
3' being raised can be routed to the other chamber 4, 4' of the low
pressure cylinder above the respective piston 3, 3'.
[0023] At a pre-set time, the electronic device 14, will change
state, thus removing dc power from the solenoid of DCV 11 and
applying dc power to the solenoid of DCV 12. When energized, the
DCV 12 directs low pressure fluid from the source 13 through the
restrictor 16 and into the chamber 4' below the piston 3'. Although
pressure in chambers 4' and 8' is initially substantially the same,
the larger surface area of piston 3' creates an upward resultant
force pushing the piston 7' into the chamber 8' to thereby form
high pressure fluid in the piston/cylinder assembly 2. The high
pressure fluid is pumped via check valve 21 to the intensifier
output line 19 and to the accumulator 22. Thus, the DCVs 11 and 12
operate alternately, providing alternate pumping by the
piston/cylinder assemblies 1 and 2 of high pressure fluid to the
accumulator 22. Excess fluid from the process is exhausted via
return line 24 as for existing intensifiers. The pumping process
continues until the required high pressure is achieved at the
accumulator 22 as sensed by pressure switch 23, which then switches
off the dc power to the DCV solenoids via device 14.
[0024] In practice, the device 14 may be dispensed with in atypical
well installation, since control of the solenoids of the DCVs can
be effected by the subsea control module (SCM) of the well. This
module already houses DCVs and a subsea electronics module (SEM) to
electronically control them, typically by an electronic processor
driving power amplifiers to operate the DCV solenoids. It would
therefore be a relatively simple addition to the SEM to incorporate
the functions of the device 14 within the software of the SCM
processor, and the necessary solenoid power drivers to the SCM
Also, the intensifier DCVs could be housed in the SCM. Furthermore,
the hydraulic accumulator 22 may not be necessary for some
installations.
[0025] Although the above example of the invention uses a dual
piston/cylinder arrangement, the intensifier could use a single
piston/cylinder arrangement. However the twin arrangement described
provides redundancy in the event of a failure and is therefore
generally the preferred option.
[0026] Preferably, the DCVs are standard-approved devices, a main
advantage of using the same to control the intensifier being that
they would not require an expensive test for type approval in a
subsea well environment.
[0027] Other advantages which are enabled by the invention are:
modularity, which, permits cost-effective repair; only two basic
moving parts compared to existing designs that use a multiplicity
of moving parts to mechanically provide the fluid switching
sequences to operate the hydraulic pistons; cheaper manufacture as
only two `special` parts (piston/cylinder assemblies) are required;
and the potential of using existing facilities (e.g. spare DCVs
and/or processing power) within a SCM to operate the pistons.
[0028] The improvements described herein, therefore, are well
adapted to carry out the objects and attain the ends and advantages
mentioned, as well as others inherent therein. While presently
preferred embodiments have been given for purposes of disclosure,
numerous changes exist in the details of procedures for
accomplishing the desired results. These and other similar
modifications will readily suggest themselves to those skilled in
the art, and are intended to be encompassed within the spirit of
the present disclosure and the scope of the appended claims.
* * * * *