U.S. patent application number 14/854593 was filed with the patent office on 2016-03-17 for modular, retrievable valve packs for blowout preventer multiplexer controls.
This patent application is currently assigned to HYDRIL USA DISTRIBUTION, LLC. The applicant listed for this patent is HYDRIL USA DISTRIBUTION, LLC. Invention is credited to Christopher Lance Kalinec, Chad Eric Yates.
Application Number | 20160076331 14/854593 |
Document ID | / |
Family ID | 54197127 |
Filed Date | 2016-03-17 |
United States Patent
Application |
20160076331 |
Kind Code |
A1 |
Kalinec; Christopher Lance ;
et al. |
March 17, 2016 |
MODULAR, RETRIEVABLE VALVE PACKS FOR BLOWOUT PREVENTER MULTIPLEXER
CONTROLS
Abstract
Retrievable sub-pods for use in a blowout preventer (BOP) stack,
including systems of sub-pods and methods for use, are disclosed.
The sub-pod includes a valve assembly, wherein the valve assembly
includes a solenoid, an electronics interface, and a directional
control valve. The sub-pod further includes a modular valve pack
and a controller, wherein the modular valve pack comprises a
manifold, and wherein the manifold is operable to support the valve
assembly within the manifold.
Inventors: |
Kalinec; Christopher Lance;
(Houston, TX) ; Yates; Chad Eric; (Houston,
TX) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
HYDRIL USA DISTRIBUTION, LLC |
Houston |
TX |
US |
|
|
Assignee: |
HYDRIL USA DISTRIBUTION,
LLC
Houston
TX
|
Family ID: |
54197127 |
Appl. No.: |
14/854593 |
Filed: |
September 15, 2015 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
62050617 |
Sep 15, 2014 |
|
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|
Current U.S.
Class: |
166/363 |
Current CPC
Class: |
E21B 33/064 20130101;
E21B 33/06 20130101 |
International
Class: |
E21B 33/064 20060101
E21B033/064 |
Claims
1. A retrievable sub-pod for use in a blowout preventer (BOP)
stack, the retrievable sub-pod comprising: a valve assembly,
wherein the valve assembly comprises a solenoid, an electronics
interface, and a directional control valve; a modular valve pack,
wherein the modular valve pack comprises a manifold, and wherein
the manifold is operable to support the valve assembly within the
manifold; and a controller, wherein the controller is operable to
control a state of the valve assembly for carrying out functions in
the BOP stack, wherein the sub-pod can be docked subsea within the
BOP stack, and wherein the sub-pod can be removed from the BOP
stack subsea and replaced in the BOP stack subsea by an alternative
sub-pod.
2. The retrievable sub-pod of claim 1, wherein the valve assembly
comprises a pilot stage.
3. The retrievable sub-pod of claim 1, wherein the sub-pod
comprises more than one modular valve pack, the modular valve packs
being stacked and separable subsea.
4. The retrievable sub-pod of claim 1, further comprising a
connection interface for connecting the retrievable sub-pod with
hydraulic fluid, electronic communications, and power provided from
the BOP stack.
5. The retrievable sub-pod of claim 4, the connection interface
comprising an electronic communications connection selected from
the group consisting of: a controller area network vehicle bus
(CANbus) and a Modbus.
6. The retrievable sub-pod of claim 1, further comprising an
electro-hydraulic (EH) closed-loop controlled regulator.
7. The retrievable sub-pod of claim 1, further comprising a
hydraulic connection wedge and plumbing operable to dock the
sub-pod to the BOP stack and to distribute hydraulic fluid to
components in the BOP stack.
8. The retrievable sub-pod of claim 1, wherein pressure surrounding
the solenoid is controlled by a pressure control device selected
from the group consisting of: a pressure compensated dielectric
fluid and a pressure-controlled enclosure.
9. A decentralized BOP stack system, the system comprising: a lower
marine riser package (LMRP) portion; a lower stack portion, wherein
the LMRP portion is disposed above the lower stack portion; at
least two retrievable sub-pods, wherein each retrievable sub-pod
independently comprises: a valve assembly; a modular valve pack,
wherein the modular valve pack comprises a manifold, and wherein
the manifold is operable to support the valve assembly within the
manifold; and a controller, wherein the controller is operable to
control a state of the valve assembly for carrying out functions in
the BOP stack system, wherein each sub-pod can be docked subsea
within the BOP stack system, and wherein each sub-pod can be
removed from the BOP stack system subsea and replaced in the BOP
stack system subsea by an alternative sub-pod.
10. The decentralized BOP stack system of claim 9, wherein the at
least two retrievable sub-pods are disposed within the LMRP portion
of the BOP stack system.
11. The decentralized BOP stack system of claim 9, wherein at least
one sub-pod is disposed within the lower stack portion of the BOP
stack system.
12. The decentralized BOP stack system of claim 9, wherein the at
least two retrievable sub-pods are stacked together.
13. The decentralized BOP stack system of claim 9, wherein an
introduction of the at least two retrievable sub-pods to the system
reduces a required amount of plumbing to operate the decentralized
BOP stack system relative to the system without the at least two
retrievable sub-pods.
14. The decentralized BOP stack system of claim 9, wherein the
valve assembly comprises a solenoid, an electronics interface, and
a directional control valve.
15. A method for decentralizing a BOP control pod in a BOP stack,
the method comprising the steps of: integrating at least one
sub-pod into the BOP stack, the at least one sub-pod connected to
BOP stack hydraulics, communications, and a power supply;
modularizing the functions of the BOP control pod by assigning
functions of the BOP control pod to the sub-pod; and reducing an
amount of tubing disposed in the BOP stack.
16. The method of claim 15, wherein the step of integrating at
least one sub-pod into the BOP stack occurs subsea.
17. The method of claim 15, further comprising the steps of:
retrieving the at least one sub-pod subsea from the BOP stack; and
replacing the at least one sub-pod subsea with an alternative
sub-pod.
18. The method of claim 15, further comprising the step of reducing
a height of the BOP control pod.
19. The method of claim 15, wherein the at least one sub-pod
comprises: a valve assembly, wherein the valve assembly comprises a
solenoid, an electronics interface, and a directional control
valve; a modular valve pack, wherein the modular valve pack
comprises a manifold, and wherein the manifold is operable to
support the valve assembly within the manifold; and a controller,
wherein the controller is operable to control a state of the valve
assembly for carrying out functions in the BOP stack, wherein the
sub-pod can be docked subsea within the BOP stack, and wherein the
sub-pod can be removed from the BOP stack subsea and replaced in
the BOP stack subsea by an alternative sub-pod.
20. The method of claim 19, further comprising the step of
operating the controller to translate CANbus data from a central
computer to solenoid functions.
21. The method according to claim 15, further comprising the step
of stacking multiple sub-pods disposed within the BOP stack.
Description
RELATED PATENT APPLICATIONS
[0001] This application is a non-provisional application and claims
priority to and the benefit of U.S. Provisional Patent Application
No. 62/050,617, filed on Sep. 15, 2014, incorporated herein by
reference in its entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field
[0003] The field of invention relates generally to blowout
preventer (BOP) equipment for use in oil and gas production, and
specifically to BOP multiplexer (MUX) control systems.
[0004] 2. Description of the Related Art
[0005] BOP systems are hydraulic systems, used to prevent blowouts
from subsea oil and gas wells. BOP equipment typically includes a
set of two or more redundant control systems with separate
hydraulic pathways to operate a specified BOP function. The
redundant control systems are commonly referred to as blue and
yellow control pods. In known systems, a communications and power
cable sends information and electrical power to an actuator with a
specific address. The actuator in turn moves a hydraulic valve,
thereby opening fluid to a series of other valves/piping to control
a portion of the BOP.
[0006] At times, the hydraulic elements in each of these redundant
systems may fail to operate as intended, and necessitate that the
control system switch master controls from one pod to the other. At
this point, the drilling operator loses redundancy in the system,
because there is no functioning back-up pod. As a result, the
operator may be required to suspend operations and pull the BOP
stack from the sea floor for costly downtime and repairs.
[0007] One problem with creating redundancy in hydraulic systems is
that hydraulic systems are typically hard-plumbed, and are not
capable of being readily re-configured or repaired. Due to size and
weight constraints, functionality of the control system has been
limited in the industry to only the necessary functions, and
internal hydraulic redundancy has not been built in to existing
systems.
[0008] Previous methods for addressing system redundancy include
having multiple back-up systems. Remotely operated vehicles (ROV's)
and acoustic control systems have been used as back-ups; they,
however, require a different controls interface and often lead to a
degradation in system performance. Thus, they are often a method of
last resort.
SUMMARY
[0009] As disclosed, the present invention includes systems of and
methods for using modular "sub-pods" to decentralize one or more
BOP stack control pods. The present technology consists of a
modular, retrievable valve pack array that comprises one or more
sub-pods. As used herein, a sub-pod is a unit consisting of any
number of desired control functions. The sub-pod(s) can be located
anywhere on a BOP stack or lower marine riser package (LMRP), and
can include a hydraulic supply, communications, and an electrical
power supply to function. Any number of sub-pods can be used,
individually or together, to provide redundancy to a control
system.
[0010] In one example embodiment, the technology works by
configuring an array of valves into discrete manifold modules.
These discrete modules can then be combined and arranged to control
any number of valves.
[0011] The technology described herein provides solutions to
problems faced by known systems having one or more centralized
control pods. For example, some known systems require excessive
tubing running from one central hub throughout the BOP to various
valves and other components. The present technology solves this
problem by integrating the valve assembly (e.g., solenoids, pilot
stage, and directional control valves) into valve manifolds, and
allowing the modules to be split into sub-pods that have a
sufficient level of on board components to function with just
power, communications and hydraulic fluid being supplied. The
present technology also reduces or eliminates problems associated
with water hammer. Water hammer is associated with pilot stage
plumbing issues, regulator chatter, and instability. Elimination of
these problems can be accomplished by replacing current regulators
with closed-loop, controlled, electro-hydraulic mechanisms located
at each sub-pod.
[0012] The present technology provides additional advantages,
including: (1) modularity and scalability--for example, any number
of sub-pods may be used, and functions can be added as required;
(2) reduction in valve quantity--for example, the sub-pod valves
can be configured to operate more than one function by utilizing a
master spool valve to toggle circuits, or using 4-way 2-position
control valves; and (3) redundancy--for example, any number of
sub-pods may be added without affecting the central control, power
and communication hardware.
[0013] Therefore, disclosed herein is a retrievable sub-pod for use
in a blowout preventer (BOP) stack. The retrievable sub-pod
includes a valve assembly, wherein the valve assembly comprises a
solenoid, an electronics interface, and a directional control
valve; a modular valve pack, wherein the modular valve pack
comprises a manifold, and wherein the manifold is operable to
support the valve assembly within the manifold; and a controller,
wherein the controller is operable to control a state of the valve
assembly for carrying out functions in the BOP stack, wherein the
sub-pod can be docked subsea within the BOP stack, and wherein the
sub-pod can be removed from the BOP stack subsea and replaced in
the BOP stack subsea by an alternative sub-pod.
[0014] In some embodiments, the valve assembly comprises a pilot
stage. In other embodiments, the sub-pod comprises more than one
modular valve pack, the modular valve packs being stacked and
separable subsea. Still other embodiments include a connection
interface for connecting the retrievable sub-pod with hydraulic
fluid, electronic communications, and power provided from the BOP
stack. In certain embodiments, the connection interface includes an
electronic communications connection selected from the group
consisting of: a controller area network vehicle bus (CANbus) and a
Modbus. Still in yet other embodiments, the sub-pod further
includes an electro-hydraulic (EH) closed-loop controlled
regulator.
[0015] Certain embodiments further include a hydraulic connection
wedge and plumbing operable to dock the sub-pod to the BOP stack
and to distribute hydraulic fluid to components in the BOP stack.
Still in other embodiments, pressure surrounding the solenoid is
controlled by a pressure control device selected from the group
consisting of: a pressure compensated dielectric fluid and a
pressure-controlled enclosure.
[0016] Further disclosed herein is a decentralized BOP stack
system. The system includes a lower marine riser package (LMRP)
portion; a lower stack portion, wherein the LMRP portion is
disposed above the lower stack portion; at least two retrievable
sub-pods, wherein each retrievable sub-pod independently comprises:
a valve assembly; a modular valve pack, wherein the modular valve
pack comprises a manifold, and wherein the manifold is operable to
support the valve assembly within the manifold; and a controller,
wherein the controller is operable to control a state of the valve
assembly for carrying out functions in the BOP stack system,
wherein each sub-pod can be docked subsea within the BOP stack
system, and wherein each sub-pod can be removed from the BOP stack
system subsea and replaced in the BOP stack system subsea by an
alternative sub-pod.
[0017] In certain embodiments of the system, the at least two
retrievable sub-pods are disposed within the LMRP portion of the
BOP stack system. In some embodiments, at least one sub-pod is
disposed within the lower stack portion of the BOP stack system.
Still in other embodiments, the at least two retrievable sub-pods
are stacked together. In some embodiments, an introduction of the
at least two retrievable sub-pods to the system reduces a required
amount of plumbing to operate the decentralized BOP stack system
relative to the system without the at least two retrievable
sub-pods. In certain embodiments, the valve assembly comprises a
solenoid, an electronics interface, and a directional control
valve.
[0018] Further disclosed herein is a method for decentralizing a
BOP control pod in a BOP stack, the method comprising the steps of:
integrating at least one sub-pod into the BOP stack, the at least
one sub-pod connected to BOP stack hydraulics, communications, and
a power supply; modularizing the functions of the BOP control pod
by assigning functions of the BOP control pod to the sub-pod; and
reducing an amount of tubing disposed in the BOP stack.
[0019] In some embodiments of the method, the step of integrating
at least one sub-pod into the BOP stack occurs subsea. In other
embodiments of the method, the steps include retrieving the at
least one sub-pod subsea from the BOP stack; and replacing the at
least one sub-pod subsea with an alternative sub-pod. Still in
other embodiments of the method, the steps further include the step
of reducing a height of the BOP control pod.
[0020] In some embodiments of the method, the at least one sub-pod
comprises: a valve assembly, wherein the valve assembly comprises a
solenoid, an electronics interface, and a directional control
valve; a modular valve pack, wherein the modular valve pack
comprises a manifold, and wherein the manifold is operable to
support the valve assembly within the manifold; and a controller,
wherein the controller is operable to control a state of the valve
assembly for carrying out functions in the BOP stack, wherein the
sub-pod can be docked subsea within the BOP stack, and wherein the
sub-pod can be removed from the BOP stack subsea and replaced in
the BOP stack subsea by an alternative sub-pod.
[0021] Still in other embodiments of the method, the steps include
operating the controller to translate CANbus data from a central
computer to solenoid functions. In certain embodiments, the method
includes the step of stacking multiple sub-pods disposed within the
BOP stack.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] These and other features, aspects, and advantages of the
present disclosure are better understood with regard to the
following Detailed Description of the Preferred Embodiments,
appended Claims, and accompanying Figures.
[0023] FIG. 1 is a representative system overview of a BOP
stack.
[0024] FIG. 2 is a representative diagram of a decentralized
sub-pod system in one embodiment of the present disclosure.
[0025] FIGS. 3A and 3B are side view and front view schematics,
respectively, showing valve assemblies in one embodiment of the
present disclosure.
[0026] FIG. 4 is a schematic showing modular valve packs, which
make up an exemplary sub-pod of the present disclosure.
[0027] FIG. 5 is a front-view schematic showing a pilot valve pack
used with a sub-plate mounted (SPM) valve pack.
[0028] FIG. 6 is a schematic circuit diagram for the embodiment of
FIG. 5.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0029] The Specification, which includes the Summary, Brief
Description of the Drawings and the Detailed Description of the
Preferred Embodiments, and the appended Claims refer to particular
features (including process or method steps) of the disclosure.
Those of skill in the art understand that the invention includes
all possible combinations and uses of particular features described
in the Specification. Those of skill in the art understand that the
disclosure is not limited to or by the description of embodiments
given in the Specification. The inventive subject matter is not
restricted except only in the spirit of the Specification and
appended Claims.
[0030] Those of skill in the art also understand that the
terminology used for describing particular embodiments does not
limit the scope or breadth of the disclosure. In interpreting the
Specification and appended Claims, all terms should be interpreted
in the broadest possible manner consistent with the context of each
term. All technical and scientific terms used in the Specification
and appended Claims have the same meaning as commonly understood by
one of ordinary skill in the art to which this invention belongs
unless defined otherwise.
[0031] As used in the Specification and appended Claims, the
singular forms "a," "an," and "the" include plural references
unless the context clearly indicates otherwise. The verb
"comprises" and its conjugated forms should be interpreted as
referring to elements, components or steps in a non-exclusive
manner. The referenced elements, components or steps may be
present, utilized or combined with other elements, components or
steps not expressly referenced. The verb "couple" and its
conjugated forms means to complete any type of required junction,
including electrical, mechanical or fluid, to form a singular
object from two or more previously non-joined objects. If a first
device couples to a second device, the connection can occur either
directly or through a common connector. "Optionally" and its
various forms means that the subsequently described event or
circumstance may or may not occur. The description includes
instances where the event or circumstance occurs and instances
where it does not occur.
[0032] The present invention relates to control systems and related
methods for components of a subsea blow-out preventer (BOP).
Typically, such control systems are hydraulic systems, and include
a set of two or more redundant control systems with separate
hydraulic pathways to operate a specified BOP function. The
redundant control systems are commonly referred to as blue and
yellow control pods. In known systems, a communications and power
cable sends information and electrical power to an actuator with a
specific address. The actuator in turn moves a hydraulic valve,
thereby opening fluid to a series of other valves/piping to control
a portion of the BOP and/or the BOP supporting equipment.
[0033] Referring first to FIG. 1, a representative system overview
of a BOP stack is shown. In FIG. 1, a BOP stack 100 is pictured,
which includes a lower marine riser package (LMRP) 102 and a lower
stack 104. LMRP 102 includes an annular 106, a blue control pod
108, and a yellow control pod 110. A hotline 112, a blue conduit
114, and a yellow conduit 120 proceed downwardly from a riser 122
into LMRP 102 and through a conduit manifold 124 to control pods
108, 110. A blue power and communications line 116 and a yellow
power and communications line 118 proceed to control pods 108, 110,
respectively. An LMRP connector 126 connects LMRP 102 to lower
stack 104. Hydraulically activated wedges 128 and 130 are disposed
to suspend connectable hoses or pipes 132, which can be connected
to shuttle panels, such as shuttle panel 134.
[0034] Lower stack 104 includes shuttle panel 134, and further
includes a casing shear ram BOP 136, a blind shear ram BOP 138, a
first pipe ram 140, and a second pipe ram 142. BOP stack 100 is
disposed above a wellhead connection 144. Lower stack 104 further
includes optional stack-mounted accumulators 146 containing a
necessary amount of hydraulic fluid to operate certain functions
within BOP stack 100.
[0035] Referring now to FIG. 2, a representative diagram of a
decentralized sub-pod system is shown. Sub-pod system 200 has an
LMRP portion 202 and a lower stack portion 204. A coupling 206
proceeds between LMRP portion 202 and lower stack portion 204.
Coupling 206 can include any one of or any combination of electric
communication connections, power connections, and hydraulic
connections. LMRP portion 202 includes a first sub-pod 208 and a
second sub-pod 210. More or fewer sub-pods can be disposed within
LMRP portion 202. Sup-pods 208, 210 can replace components of a
single pod, such as, for example, blue control pod 108 or yellow
control pod 110 of FIG. 1. Sup-pod 208 is operably coupled to
annular BOP 209, and sub-pod 210 is operably coupled to annular BOP
211. Sup-pod 208 controls operation of annular BOP 209, and sup-pod
210 is used to control annular BOP 211.
[0036] Lower stack portion 204 includes a sub-pod 212. Sub-pod 212
is in fluid communication with a casing shear ram BOP 236, a blind
shear ram BOP 238, a first pipe ram 240, and a second pipe ram 242.
More or fewer sub-pods and/or rams can be disposed within lower
stack portion 204. Sub-pods 208, 210, and 212 can be controlled by
centrally-located remote controls, such as, for example, a personal
computer. Sub-pods 208, 210, and 212 advantageously decentralize a
single control pod, such that the failure of any one component does
not require the replacement of all components. For instance,
Sub-pods 208, 210, and 212 are independently retrievable by a
remotely operated vehicle (ROV), or similar means, and are
independently replaceable and repairable, without replacing all of
the sub-pods.
[0037] In the embodiment of FIG. 2, sub-pods 208, 210, 212
individually communicate with a central subsea electronics module,
or SEM (not pictured), which in turn communicates with a user on
the surface. Electrical connections can be wireless, wet-mate, or
hard-wired to the surface. The power/communications (P/C) module in
FIG. 2 receives instructions from the user on the surface, or other
auxiliary inputs (e.g. an ROV), and via a chosen communications
protocol (such as described below with regard to FIG. 4) instructs
the appropriate sub-pod's controller, such as controller 410 shown
in FIG. 4, to execute a commanded function. A controller, such as
controller 410 shown in FIG. 4, translates the instructions into
discrete output signals that will power a solenoid or other energy
transducer required for the requested function. A sub-pod
controller will also determine the required pressure for the
requested function (e.g. blind-shear ram (BSR) close, annular BOP
close, etc.), and send the appropriate output signal to a
closed-loop controlled regulator, such as EH closed-loop controlled
regulator 412.
[0038] Sub-pods 208, 210, and 212 include modular valve packs that
can be scaled as required. They are located as required to minimize
plumbing and/or achieve other layout goals within LMRP portion 202
and lower stack portion 204. Any number of sub-pods can be used in
either LMRP portion 202 or lower stack portion 204 as is required
for a number of customer functions and/or required redundancy.
Sub-pods 208, 210, and 212 include common connection interfaces for
hydraulics, electrical power, and communications.
[0039] For a new BOP stack, plumbing can be customized to suit the
layout of the BOP stack with one or more sub-pods. In other words,
a sub-pod would be placed where it optimally suits the individual
BOP stack layout. For a retrofit of an existing BOP stack, the
plumbing might be new from the sub-pods up to the shuttle valves,
such as shuttle panel 134 in FIG. 1, but from there the existing
plumbing in the BOP stack would be used.
[0040] Referring now to FIGS. 3A and 3B, side view and front view
schematics are shown, respectively, providing valve assemblies in
one embodiment of the present disclosure. In some embodiments of
the present disclosure, three valve components are integrated into
a single assembly. FIG. 3A provides a side view of a valve assembly
300, which includes a solenoid 302, an electronics interface 304,
an optional pilot stage 306, and a 3-way, 2-position directional
control valve (DCV) 308. In existing systems, a 3-way, 2-position
DCV is a sub-plate mounted (SPM) valve. Solenoid 302 is in a
pressure compensated dielectric fluid or a pressure controlled
enclosure at about 1 atmosphere (atm). FIG. 3B provides a front
view of modular valve pack 310. Manifold 312 can include any number
of valves, such as valve assembly 300, in any configuration. For
example, there can be two rows and five columns of valves, or there
can be ten rows and nine columns of valves.
[0041] Solenoid 302, electronics interface 304, optional pilot
stage 306, and 3-way, 2-position directional control valve (DCV)
308 are new components in the sub-pods relative to existing control
pods. In some embodiments, the solenoids and pilots would be
selected based on the requirements of a BOP system. Electronics
interface 304, like in existing pods, houses certain electronics
(such as wiring, solenoids, etc.) and can be an oil-filled pressure
compensated enclosure, or an air or nitrogen filled enclosure that
is structurally suitable for deep subsea environments and the
external pressure loads.
[0042] The valves in modular valve pack 310 can be similar to valve
assembly 300 shown in FIG. 3A, or can be of a different
configuration. Modular valve packs, such as modular valve pack 310,
can be stacked together to form any desired size "sub-pod," such
as, for example, sub-pods 208, 210, and 212 shown in FIG. 2. As
noted previously, any sub-pods are independently retrievable by an
ROV or similar device. Similarly, in some embodiments the modular
valve packs are independently retrievable by an ROV or similar
device. Independently retrievable refers to detaching a single
sub-pod from a BOP stack and raising it to the surface, optionally
for repairs, while not removing other sub-pods on the BOP
stack.
[0043] Referring now to FIG. 4, a schematic is provided showing the
modular valve packs that make up an exemplary sub-pod of the
present disclosure. A sub-pod 400 includes modular valve packs 402,
404, 406, and 408. Additionally, sub-pod 408 has controller 410 and
electro-hydraulic (EH) closed-loop controlled regulator 412. In
such a system, valve repair can be done by individual modular valve
packs 402, 404, 406, and 408. In other words, modular valve packs
402, 404, 406, and 408 are stackable, unstackable, and retrievable
subsea.
[0044] In this way, one defective modular valve pack can be removed
from service and/or removed from sub-pod 400. While the defective
modular valve pack is being serviced, either by an ROV with the
modular valve pack remaining in the sub-pod or at the surface,
spare modular valve packs, either already in the sub-pod or placed
in the sub-pod, can be used to replace the functions of the
defective modular valve pack. Ultimately the sub-pods can be
designed to be retrievable subsea by a unit such as an ROV, as
could individual modular valve packs 402, 404, 406, 406, controller
410 and EH closed-loop controlled regulator 412.
[0045] The present technology reduces or eliminates problems
associated with water hammer. Water hammer is associated with pilot
stage plumbing issues, regulator chatter, and instability.
Elimination of these problems can be accomplished by replacing
current regulators with closed-loop, controlled, electro-hydraulic
mechanisms, such as EH closed-loop controlled regulator 412,
located at each sub-pod.
[0046] In the embodiment of FIG. 4, sub-pod 400 has each of the
following connections: at least one 1.5 inch hydraulic pipe
connection, at least one electronic communications connection, and
at least one power connection. The communications connection can be
any one of or any combination of a controller area network vehicle
bus (CANbus) and a Modbus. Controller 410 is used to translate
CANbus data from a central computer to the solenoid functions, such
as, for example, solenoid 302 in FIG. 3A. Controller 410 is also
used control regulators to any desired output pressures.
[0047] Sub-pod 400 also includes a wedge 414 and plumbing 416,
similar to hydraulically activated wedges 128, 130 and connectable
hoses or pipes 132 shown in FIG. 1. Wedge 414 is a hydraulic
connection interface used to dock sub-pod 400 and distribute
hydraulic fluid to components in a BOP stack. Any other suitable
hydraulic connection can also be used. Plumbing 416 distributes
hydraulic fluid to various functions on the BOP stack, such as the
rams, for example casing shear ram BOP 136, blind shear ram BOP
138, first pipe ram 140, and second pipe ram 142 shown in FIG.
1.
[0048] Referring now to FIG. 5, a front-view schematic is provided
showing a pilot valve pack used with a sub-plate mounted (SPM)
valve pack. A system 500 includes a pilot valve pack 502 and an SPM
valve pack 504. As noted previously, FIG. 3A provides a side view
of valve assembly 300, which includes solenoid 302, electronics
interface 304, an optional pilot stage 306, and 3-way, 2-position
directional control valve (DCV) 308. In some embodiments of the
present disclosure, a system such as system 500 is replaced by,
integrated with, or repackaged according to the embodiments of
FIGS. 3A and 3B.
[0049] Such replacement, integration, or repackaging can be used to
reduce the height of the system 500 (shown as distance "D" in FIG.
5), and can be used to modularize a BOP control pod stack. In some
embodiments, the distance D can be about 92 inches, and
modularization of the system 500 including pilot valve pack 502 and
SPM valve pack 504 reduces the distance D to less than about 92
inches. Modularization allows for removal and replacement of one
module, rather than pulling the entire stack for repair or
replacement. Additionally, replacement, integration, or repackaging
can be used to eliminate tubing which runs from pilot valve pack
502 to SPM valve pack 504 (shown and described in FIG. 6).
[0050] In certain embodiments, the height of one or more control
pods is reduced as valve assemblies of the present disclosure, such
as valve assembly 300 in FIG. 3A, are much smaller compared to the
existing equivalent, such as that shown in FIG. 5.
[0051] As discussed above, FIG. 3B provides a front view of modular
valve pack 310. Manifold 312 can include any number of valves in
any configuration. For example, there can be two rows and five
columns of valves, or there can be ten rows and nine columns of
valves.
[0052] Referring now to FIG. 6, a schematic circuit diagram is
shown for the embodiment of FIG. 5. A circuit 600 includes a
solenoid operated pilot valve 602 (also known as a shear seal
valve) and an SPM valve 604. Referring also to FIG. 5, solenoid
operated pilot valves, such as solenoid operated pilot valve 602,
are present in pilot valve pack 502, and SPM valves, such as SPM
valve 604, are present in SPM valve pack 504. Solenoid operated
pilot valve 602 and SPM valve 604 are fluidly coupled by tubing
606. About four feet of tubing 606 runs between pilot valve pack
502 and SPM valve pack 504 for each function or SPM valve (about 96
functions in some embodiments of BOP control pods). The various
functions are mostly actuators of various sizes.
[0053] In embodiments of the present disclosure, tubing between
pilot valve packs and SPM valve packs, such as for example tubing
606 of FIG. 6 which is used to connect pilot valve pack 502 to SPM
valve pack 504, is not required.
[0054] At an inlet 608, hydraulic fluid is supplied to solenoid
operated pilot valve 602 at a pressure of about 3,000 psi. Solenoid
operated pilot valve 602 has a vent 610 that can vent excess
pressure to the surrounding ocean environment. After passing
through solenoid operated pilot valve 602, the hydraulic fluid
passes through tubing 606. In some embodiments, the max flow rate
of tubing 606 can be at least about 250 gallons per minute (gpm),
but in other embodiments the max flow rate of tubing 606 can be at
least about 500 gpm.
[0055] At an inlet 612, hydraulic fluid is supplied to SPM valve
604 at a pressure of between about 1,500 psi to about 5,000 psi.
SPM valve 604 has a vent 614 that can vent excess pressure to the
surrounding ocean environment. SPM valve 604 can include valve
sizes of about 0.5, 1.0, and 1.5 inches in various embodiments of
circuit 600. In some embodiments of the present disclosure,
solenoid operated pilot valve 602, tubing 606, and SPM valve 604
are combined into one integral package. For example, FIG. 3A
provides a side view of valve assembly 300, which includes solenoid
302, electronics interface 304, optional pilot stage 306, and
3-way, 2-position directional control valve (DCV) 308. FIG. 3B
provides a front view of modular valve pack 310.
[0056] In some embodiments, cartridge-style valves, such as that
shown in FIG. 3A, are placed in modular, manifold arrays, such as
that shown in FIGS. 3B and 4. Solenoid stages can be enclosed in
oil-filled, pressure-balanced enclosures.
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