U.S. patent application number 12/816901 was filed with the patent office on 2011-11-03 for subsea control module with removable section.
This patent application is currently assigned to HYDRIL USA MANUFACTURING LLC. Invention is credited to David Dietz, JR., Luis Melendez, Dat Nguyen, Hardev Singh.
Application Number | 20110266002 12/816901 |
Document ID | / |
Family ID | 44170093 |
Filed Date | 2011-11-03 |
United States Patent
Application |
20110266002 |
Kind Code |
A1 |
Singh; Hardev ; et
al. |
November 3, 2011 |
Subsea Control Module with Removable Section
Abstract
A subsea device is configured to control a subsea well. The
subsea device includes a frame, a blowout preventer connected to
the frame and configured to close a bore that fluidly communicates
with the subsea well, a pressure supply line connected to the frame
and configured to provide a fluid under high pressure, and a
control module connected to the frame and configured to receive the
fluid from the pressure supply line. The control module includes a
fixed part and a removable section. The fixed part has a valve
manifold that houses a hydraulic activated valve. The removable
section is configured to detachably attach to the fixed part and
includes an electrically activated valve. The hydraulic activated
valve of the fixed part are configured to be actuated by the
electrically activated valve when the removable section is mated to
the fixed part.
Inventors: |
Singh; Hardev; (San Antonio,
TX) ; Dietz, JR.; David; (Tomball, TX) ;
Melendez; Luis; (Humble, TX) ; Nguyen; Dat;
(Houston, TX) |
Assignee: |
HYDRIL USA MANUFACTURING
LLC
Houston
TX
|
Family ID: |
44170093 |
Appl. No.: |
12/816901 |
Filed: |
June 16, 2010 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61329883 |
Apr 30, 2010 |
|
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|
Current U.S.
Class: |
166/339 |
Current CPC
Class: |
E21B 33/06 20130101;
E21B 33/038 20130101; E21B 33/0385 20130101; E21B 33/0355 20130101;
E21B 33/037 20130101 |
Class at
Publication: |
166/339 |
International
Class: |
E21B 43/01 20060101
E21B043/01; E21B 33/064 20060101 E21B033/064; E21B 41/00 20060101
E21B041/00 |
Claims
1. A subsea device that is configured to control a subsea well, the
subsea device comprising: a frame; a blowout preventer connected to
the frame and configured to close a bore that fluidly communicates
with the subsea well; a pressure supply line connected to the frame
and configured to provide a fluid under pressure; a control module
connected to the frame and configured to receive the fluid from the
pressure supply line and to distribute the fluid to control various
functions of the subsea device, the control module including a
fixed part and a removable section; the fixed part having a valve
manifold that houses a hydraulic activated valve; and the removable
section being configured to detachably attach to the fixed part and
including an electrically activated valve, wherein the hydraulic
activated valve of the fixed part is configured to be actuated by
the electrically activated valve when the removable section is
mated to the fixed part.
2. The subsea device of claim 1, wherein the fixed part does not
include electrically activated valves.
3. The subsea device of claim 1, wherein the removable section does
not include hydraulically activated valves and the removable
section is removable by a remotely operated vehicle.
4. The subsea device of claim 1, the removable section further
comprising: an electronic section configured to control the
electrically activated valve.
5. The subsea device of claim 1, the removable section further
comprising: a connection device configured to be connected to a
remotely operated vehicle for being removed from the fixed
part.
6. The subsea device of claim 1, the removable section further
comprising: a wet-mate electrical connector configured to be
connected to a corresponding wet-mate electrical connector on the
fixed part for receiving electrical signals to actuate the
electrically actuated valve; and at least one of a fluid filter,
pressure sensing devices, or pressure regulation devices.
7. The subsea device of claim 1, wherein the fixed part receives
electrical signals from a MUX pod.
8. The subsea device of claim 1, wherein the subsea device is a
blowout preventer stack.
9. The subsea device of claim 1, wherein the subsea device is a
lower marine riser package that is configured to be removably
attached to a blowout preventer stack.
10. The subsea device of claim 1, further comprising: a MUX pod
device configured to receive electrical signals and includes plural
hydraulic activated valves fluidly connected to plural electrically
activated valves that are not removable from the MUX pod by a
remotely operated vehicle.
11. The subsea device of claim 1, wherein the pressure supply line
is fluidly connected to a MUX pod or is a regulated or unregulated
supply line that provides the fluid under pressure to the blowout
preventer.
12. A control module configured to control various elements of a
subsea device to be attached to a subsea well, the control module
comprising: a fixed part attached to a frame of the subsea device,
the fixed part having a valve manifold that includes a hydraulic
activated valve; and a removable section being configured to be
removably attached to the fixed part and including an electrically
activated valve, wherein the fixed part is configured to receive a
fluid under pressure from a pressure supply line and to distribute
the fluid under pressure to the hydraulic activated valve and the
electrically activated valve, the hydraulic activated valve of the
fixed part is configured to be actuated by the electrically
activated valve when the removable section is mated to the fixed
part, and the removable section being configured to receive
electrical signals for controlling the electrically activated
valve.
13. The control module of claim 12, wherein the fixed part does not
include electrically activated valves.
14. The control module of claim 12, wherein the removable section
does not include hydraulic activated valves and the removable
section is removable by a remotely operated vehicle.
15. The control module of claim 12, the removable section further
comprising: a cavity that includes an electronic section configured
to control the electrically actuated valve, the cavity being
configured to maintain a pressure of substantially 1 atm.
16. The control module of claim 12, the removable section further
comprising: a connection device configured to be connected to a
remotely operated vehicle for being removed from the fixed
part.
17. The control module of claim 12, the removable section further
comprising: a wet-mate electrical connector configured to be
connected to a corresponding wet-mate electrical connector on the
fixed part for receiving the electrical signals to actuate the
electrically actuated valve.
18. The control module of claim 12, wherein the fixed part receives
the electrical signals from a MUX pod.
19. The control module of claim 12, wherein the pressure supply
line is fluidly connected to a regulated or unregulated supply line
that provides the fluid under pressure to a blowout preventer.
20. A subsea blowout preventer stack that is configured to control
a subsea well, the stack comprising: a frame; plural blowout
preventers connected to the frame and configured to close a bore
that fluidly communicates with the subsea well; a pressure supply
line connected to the frame and configured to provide a fluid under
pressure; a control module connected to the frame and configured to
receive the fluid from the pressure supply line and to distribute
the fluid to control various functions of the subsea device, the
control module including a fixed part and a removable section; the
fixed part having a valve manifold that houses a hydraulic
activated valve; and the removable section being configured to
detachably attach to the fixed part and including an electrically
activated valve, wherein the hydraulic activated valve of the fixed
part is configured to be actuated by the electrically activated
valve when the removable section is mated to the fixed part.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority and benefit from
Provisional Patent Application No. 61/329,883, filed Apr. 30, 2010,
for "Subsea Control Module with Removable Section and Method", the
entire contents of which are incorporated herein by reference.
BACKGROUND
[0002] 1. Technical Field
[0003] Embodiments of the subject matter disclosed herein generally
relate to methods and systems and, more particularly, to mechanisms
and techniques for removing and/or replacing a section of a subsea
control module.
[0004] 2. Discussion of the Background
[0005] Subsea oil and gas exploration becomes more challenging as
the exploration depth increases. Complex devices are disposed on
the ocean floor for extracting the oil and for the safety of the
oil equipment and the environment. These devices have to withstand,
among other things, high pressures (from 3,000 to 60,000 psi (200
to 4000 bar) or more) and highly corrosive conditions. Although
precautions are taken when building these devices, component parts
of these devices wear out with time and need to be replaced.
[0006] As these parts are disposed on the ocean floor (sometimes
more than 2000 m below sea level) and sometimes are provided inside
larger components, access to them may be problematic. For example,
FIG. 1 illustrates a lower blowout preventer stack ("lower BOP
stack") 10 that may be rigidly attached to a wellhead 12 upon the
sea floor 14, while a Lower Marine Riser Package ("LMRP") 16 is
retrievably disposed upon a distal end of a marine riser 18,
extending from a drill ship 20 or any other type of surface
drilling platform or vessel. As such, the LMRP 16 may include a
stinger 22 at its distal end configured to engage a receptacle 24
located on a proximal end of the lower BOP stack 10.
[0007] In typical configurations, the lower BOP stack 10 may be
rigidly affixed atop the subsea wellhead 12 and may include (among
other devices) a plurality of ram-type blowout preventers 26 useful
in controlling the well as it is drilled and completed. The
flexible riser provides a conduit through which drilling tools and
fluids may be deployed to and retrieved from the subsea wellbore.
Ordinarily, the LMRP 16 may include (among other things) one or
more ram-type blowout preventers 28 at its distal end, an annular
blowout preventer 30 at its upper end, and a MUX pod (in reality
two, which are referred to in the industry as blue and yellow pods)
32.
[0008] When desired, the ram-type blowout preventers of the LMRP 16
and the lower BOP stack 10 may be closed and the LMRP 16 may be
detached from the lower BOP stack 10 and retrieved to the surface,
leaving the lower BOP stack 10 atop the wellhead. Thus, for
example, it may be necessary to retrieve the LMRP 16 from the
wellhead stack in times of inclement weather or when work on a
particular wellhead is to be temporarily stopped.
[0009] Also, when a part of the LMRP 16 fails, the entire LMRP 16
may need to be raised on the ship 20 for repairs and/or
maintenance. One such part that may require maintenance from time
to time is the MUX pod 32. A conventional MUX pod system 40, is
shown in FIG. 2 and may provide between 50 and 100 different
functions to the lower BOP stack and/or the LMRP and these
functions may be initiated and/or controlled from or via the
LMRP.
[0010] The MUX pod 40 is fixedly attached to a frame (not shown) of
the LMRP and may include hydraulically activated valves 50 (called
in the art sub plate mounted (SPM) valves) and solenoid valves 52
that are fluidly connected to the hydraulically activated valves
50. The solenoid valves 52 are provided in an electronic section 54
and are designed to be actuated by sending an electrical signal
from an electronic control board (not shown). Each solenoid valve
52 is configured to activate a corresponding hydraulically
activated valve 50. The MUX pod 40 may include pressure sensors 56
also mounted in the electronic section 54. The hydraulically
activated valves 50 are provided in a hydraulic section 58 and are
fixedly attached to the MUX pod 40 (i.e., a ROV vehicle cannot
remove them when the same is disposed on the seafloor).
[0011] In typical subsea blowout preventer installations, multiplex
("MUX") cables (electrical) and/or lines (hydraulic) transport
control signals (via the MUX pod and the pod wedge) to the LMRP 16
and lower BOP stack 10 devices so specified tasks may be controlled
from the surface. Once the control signals are received, subsea
control valves are activated and (in most cases) high-pressure
hydraulic lines are directed to perform the specified tasks. Thus,
a multiplexed electrical or hydraulic signal may operate a
plurality of "low-pressure" valves to actuate larger valves to
communicate the high-pressure hydraulic lines with the various
operating devices of the wellhead stack.
[0012] A bridge between the LMRP 16 and the lower BOP stack 10 is
formed that matches the multiple functions from the LMRP 16 to the
lower BOP stack 10, e.g., fluidly connects the SMP valves 50 from
the MUX pod provided on the LMRP to dedicated components on the BOP
stack or the LMRP. The MUX pod system is used in addition to choke
and kill line connections (not shown) or lines that ensure pressure
supply to, for example, the shearing function of the BOPs.
[0013] The bridge is shown in FIG. 3 and may include a pod wedge 42
configured to engage a receiver 44 on the BOP stack. The pod wedge
42 has plural holes (not shown), depending on the number of
functions provided, that provide various hydraulic and/or
electrical signals from the LMRP 16 to the lower BOP stack 10.
However, it is noted that the pod wedge 42 is designed with a given
number of functions (holes) and after being deployed, the MUX pod
system cannot be modified to handle more functions.
[0014] Examples of communication lines bridged between LMRPs and
lower BOP stacks through feed-thru components include, but are not
limited to, hydraulic choke lines, hydraulic kill lines, hydraulic
multiplex control lines, electrical multiplex control lines,
electrical power lines, hydraulic power lines, mechanical power
lines, mechanical control lines, electrical control lines, and
sensor lines. In certain embodiments, subsea wellhead stack
feed-thru components include at least one MUX pod connection
whereby a plurality of hydraulic control signals are grouped
together and transmitted between the LMRP 16 and the lower BOP
stack 10 in a single mono-block feed-thru component as shown, for
example, in FIG. 3.
[0015] In conventional MUX pods, when one or more of the solenoid
valves 52 or any of the various other instruments and components
require service or replacement, which happens from time to time,
the whole MUX pod 40 has to be brought to the surface. However, as
the MUX pod 40 is bolted to the LMRP, it is necessary that the
entire LMRP be brought to the surface for repair. This operation is
disrupting for the functioning of the well as the drilling or oil
extraction has to be stopped, which involves production losses. In
addition, the size and weight of the MUX pod 40 and the LMRP are
large (sometimes in the range of tens to hundreds of tons), which
makes the entire retrieval process not only time consuming but
dangerous.
[0016] An approach to limit the disruption of oil extraction has
been presented in U.S. Pat. No. 7,216,714 to G. Reynolds, the
entire disclosure of which is incorporated here by reference. U.S.
Pat. No. 7,216,714 uses a control module 60 (shown in FIG. 4, which
corresponds to FIG. 5 of U.S. Pat. No. 7,216,714) that combines a
pilot valve (solenoid valve) 62 with a hydraulically activated
valve 64, both disposed in a single casing 66. The control module
60 has a connector 68 that connects to a receiver 70 that is
fixedly attached to the BOP stack. Thus, when the pilot valve 62
fails, the entire control module 60 may be detached from receiver
70 and brought to the surface for repair by use of a Remotely
Operated Vehicle (ROV). In this way, the BOP stack remains on the
well head. This process minimizes the down time of the oil rig.
[0017] However, this process is still cumbersome as both the
hydraulically activated valve and the solenoid valve need to be
removed and brought to the surface. Once there, the control module
60 has to be disassembled and only the failed part replaced with a
new part. However, the weight and size of the control module may be
significant, thus imposing considerable power requirements on the
ROV vehicle. Another disadvantage of the existing devices is that
most of the time there is no need to bring to the surface the SPM
valves as these valves are more reliable than the electro-hydraulic
valves. Accordingly, it would be desirable to provide systems and
methods that are faster and simpler than the afore-described
approaches.
SUMMARY
[0018] According to one exemplary embodiment, there is a subsea
device that is configured to control a subsea well. The subsea
device includes a frame; a blowout preventer connected to the frame
and configured to close a bore that fluidly communicates with the
subsea well; a pressure supply line connected to the frame and
configured to provide a fluid under pressure; a control module
connected to the frame and configured to receive the fluid from the
pressure supply line and to control a distribution of the fluid to
various functions, the control module including a fixed part and a
removable section. The fixed part has a valve manifold that houses
a hydraulic activated valve and the removable section is configured
to detachably attach to the fixed part and includes an electrically
activated valve. The hydraulic activated valve of the fixed part is
configured to be actuated by the electrically activated valve when
the removable section is mated to the fixed part.
[0019] According to another exemplary embodiment, there is a
control module configured to control various elements of a subsea
device attached to a subsea well. The control module includes a
fixed part attached to a frame of the subsea device, the fixed part
having a valve manifold that includes a hydraulic activated valve;
and a removable section being configured to be removably attached
to the fixed part and including an electrically activated valve.
The fixed part is configured to receive a fluid under pressure from
a pressure supply line and to distribute the fluid under pressure
to the hydraulic activated valve and the electrically activated
valve. The hydraulic activated valve of the fixed part is
configured to be actuated by the electrically activated valve when
the removable section is mated to the fixed part. The removable
section is configured to receive electrical signals for controlling
the electrically activated valve.
[0020] According to still another exemplary embodiment, there is a
method for assembling a control module having a fixed part and a
removable section. The method includes attaching the control module
to a frame; connecting the fixed part of the control module to a
pressure supply line for receiving a fluid under pressure;
providing a valve manifold that houses a hydraulic activated valve
in the fixed part; detachably attaching the removable section of
the control module to the fixed part; fluidly connecting an
electrically activated valve of the removable section to the
hydraulic activated valve such that the electrically activated
valve controls the hydraulic activated valve; and electrically
connecting the electrically activated valve to a control
system.
[0021] According to still another exemplary embodiment, there is a
subsea blowout preventer stack that is configured to control a
subsea well. The stack includes a frame; plural blowout preventers
connected to the frame and configured to close a bore that fluidly
communicates with the subsea well; a pressure supply line connected
to the frame and configured to provide a fluid under pressure; a
control module connected to the frame and configured to receive the
fluid from the pressure supply line and to distribute the fluid to
control various functions of the subsea device, the control module
including a fixed part and a removable section; the fixed part
having a valve manifold that houses a hydraulic activated valve;
and the removable section being configured to detachably attach to
the fixed part and including an electrically activated valve. The
hydraulic activated valve of the fixed part is configured to be
actuated by the electrically activated valve when the removable
section is mated to the fixed part.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] The accompanying drawings, which are incorporated in and
constitute a part of the specification, illustrate one or more
embodiments and, together with the description, explain these
embodiments. In the drawings:
[0023] FIG. 1 is a schematic diagram of a conventional offshore
rig;
[0024] FIG. 2 is a schematic diagram of a MUX pod;
[0025] FIG. 3 is a schematic diagram of a feed-thru connection of a
MUX pod attached to a subsea structure;
[0026] FIG. 4 is a schematic diagram of a conventional control
module that includes both hydraulic and solenoid retrievable
valves;
[0027] FIG. 5 is a schematic diagram of a BOP stack having a
control module according to an exemplary embodiment;
[0028] FIG. 6 is a schematic diagram of an LMRP having a MUX
pod;
[0029] FIG. 7 is a schematic diagram of a control module having a
removable section according to an exemplary embodiment;
[0030] FIG. 8 is a schematic diagram of a removable section of a
control module according to an exemplary embodiment;
[0031] FIG. 9 is a schematic diagram of a control module according
to an exemplary embodiment;
[0032] FIG. 10 is a schematic diagram of a control module provided
on a BOP stack according to an exemplary embodiment;
[0033] FIG. 11 is an overall view of a control module according to
an exemplary embodiment;
[0034] FIG. 12 is an overall view of a fixed part of a control
module according to an exemplary embodiment;
[0035] FIG. 13 is an overall view of a removable section of a
control module according to an exemplary embodiment;
[0036] FIG. 14 is a schematic diagram of a control module according
to an exemplary embodiment;
[0037] FIG. 15 is a schematic diagram of a control module having a
detachable part according to an exemplary embodiment; and
[0038] FIG. 16 is a flow chart illustrating a method for assembling
a control module according to an exemplary embodiment.
DETAILED DESCRIPTION
[0039] The following description of the exemplary embodiments
refers to the accompanying drawings. The same reference numbers in
different drawings identify the same or similar elements. The
following detailed description does not limit the invention.
Instead, the scope of the invention is defined by the appended
claims. The following embodiments are discussed, for simplicity,
with regard to the terminology and structure of a BOP stack.
However, the embodiments to be discussed next are not limited to
BOP stacks, but may be applied to other elements, e.g., LMRP, that
are located in difficult to reach locations.
[0040] Reference throughout the specification to "one embodiment"
or "an embodiment" means that a particular feature, structure, or
characteristic described in connection with an embodiment is
included in at least one embodiment of the subject matter
disclosed. Thus, the appearance of the phrases "in one embodiment"
or "in an embodiment" in various places throughout the
specification is not necessarily referring to the same embodiment.
Further, the particular features, structures or characteristics may
be combined in any suitable manner in one or more embodiments.
[0041] According to an exemplary embodiment, a subsea structure is
operated by providing a first predetermined number of functions.
These functions are achieved by actuating hydraulically activated
valves (SPM valves). A hydraulically activated valve is controlled
by a pilot valve, which may be an electrically activated valve. A
fixed part of a control module is configured to include the
hydraulically activated valves while a removable section is
configured to include the electrically activated valves. The fixed
part is fixedly attached to the subsea structure while the
removable section is detachably attached to the fixed part. Since
the electrically activated valves are more likely to fail in
comparison to the hydraulically activated valves, given their
service history, the separation of the two types of valves may
offer the operator of the subsea structure the possibility to
remove with a ROV only the electrically activated valves (the
removable section) and not the hydraulically activated valves (the
fixed part).
[0042] In this way, the size and weight of the part that has to be
removed from the subsea structure is smaller, which consequently
simplifies the replacement process. In addition, one or more
embodiments to be discussed later have the advantage that the
control module discussed above is capable of augmenting the number
of functions already provided by a dedicated MUX pod. As was
discussed previously, a MUX pod may be a standard piece of
equipment for an LMRP. The MUX pod has a dedicated number of
functions that are customized for each user. After being deployed
on the subsea structure, the MUX pod ability to increase the
provided number of functions is limited because of the connection
between the BOP stack and the LMRP (see FIG. 3). Thus, the above
discussed control module is also capable of extending the number of
functions to be implemented at the subsea structure.
[0043] The structure of the control module is discussed now in more
details. According to an exemplary embodiment, FIG. 5 shows a BOP
stack 80. The BOP stack 80 includes a frame 82 to which one or more
BOPs (84 and 86) are attached. Besides the BOPs, a BOP stack may
include other elements, e.g., hydraulic accumulators, hydraulic
filters, electronic vessels, communication lines, power supply
lines, pressure sensors, position sensors, choke and kill valves,
shear valves, etc. The LMRP may also include the elements noted
above. An LMRP 88 is shown in FIG. 6. Part of the elements located
on the BOP stack (and/or LMRP) are actuated based on hydraulic
pressure (a fluid under pressure either pumped from the sea level
or from accumulators attached to the BOP stack) and/or electrical
signals (e.g., a solenoid valve). Thus, any subsea structure may
have a hydraulic supply and an electric supply. The LMRP 88 may
include a MUX pod 89 that is fixed to a frame 91 of the LMRP 88.
For redundancy, the LMRP 88 includes two MUX pods. The MUX pod 89
is configured to receive hydraulic pressure at an inlet 90 and
electric power/communication signals at a connection 92. Various
functions are controlled by the MUX pod 89, which acts as the brain
of the BOP 80 stack and/or LMRP 88.
[0044] According to an exemplary embodiment, when new functions
need to be added to the BOP stack 80 and the MUX pod 88 has no
available port to control the new functions, a new control module
94 (see FIG. 5) may be added to the BOP stack 80. In the following,
the BOP stack is used to describe the exemplary embodiments, but it
should be understood that the same applies to the LMRP or other
structures.
[0045] FIG. 5 shows two new control modules 94 and 96 being added
to the BOP stack 80. The number of control modules to be added
depends on the desired number of functions to be added and also on
the number of functions available at the new control module. In one
application, the control module 94 has 8 new functions. However,
this number can be smaller or larger depending on the needs of the
BOP stack operator, the space available, etc. The control modules
94 and 96 may be fixed to their own frame 98 that is attached to
the BOP stack's frame 82 as shown in FIG. 5.
[0046] FIG. 7 shows in more details the control module 94. Control
module 94 includes a fixed part 100 that is fixedly attached to the
frames 82 or 98. The fixed part 100 may include a valve manifold
102 having plural hydraulic fluid ports 104 that connect to the
various functions that are desired to be implemented and
controlled. The valve manifold 102 is configured to house a
predetermined number of hydraulically activated valves (SPM valves)
106. FIG. 7 shows 8 SPM valves 106 but a different number may be
used. The SPM valves 106 are fixedly attached to the valve manifold
102 and they are configured to control a fluid flow to the fluid
ports 104.
[0047] A SPM valve 106 is hydraulically activated, e.g., it needs a
supply of a fluid under pressure to open or close the valve. In
other words, the SPM valve controls the flow of a fluid under
pressure there through by receiving the supply of a hydraulic fluid
under pressure at a gate of the SPM valve. The supply of fluid
under pressure is provided by a corresponding pilot valve 108,
which is better seen in FIG. 8. The pilot valve 108 may be an
electrically activated valve. An electrically activated valve is a
valve that controls a fluid flow based on electrical signals. An
example of an electrically activated valve is a solenoid valve. The
pilot valves 108 are located in a removable section 110 that is
configured to be detachably attached to the fixed part 100.
[0048] In one exemplary embodiment, the removable section 110 may
include a connecting device 112 (see FIG. 7) that is configured to
be handled by the ROV vehicle when the removable section 110 needs
to be removed. The shape and size of the connecting device 112
depends on an existing tool on the ROV vehicle or other
considerations of the operator. In one application, the connecting
device is a bucket as shown in FIG. 14. Back to FIG. 7, the
removable section 110 may include guides 113 that mate with
corresponding guides 114 on the fixed part 100. The guides may be
used by the ROV vehicle when mating the removable section 110 to
the fixed part 100.
[0049] The removable section 110 may also include a fitting 116 (as
shown in FIG. 8) that connects the pilot valve 108 to the SPM valve
106, a power and communication board 118 that is configured to
receive the electric communications and/or a power supply and a
communication connection 122, e.g., a wet-mate electrical connector
that is configured to communicate to the MUX pod 60 and to
distribute the power and/or signals to corresponding pilot valves
108 and pressure sensing devices (not shown). FIG. 8 also shows a
ROV handle port 120 corresponding to the connecting device 112 and
the wet-mate electrical connector 122 that is configured to connect
to a corresponding wet-mate connector on the fixed part for
receiving the electrical signals and/or power supply from the MUX
pod 60. A cavity 124 may be present inside the removable section
110 that accommodates the power and communication board 118. The
cavity 124 may be maintained at a pressure around atmospheric
pressure so as to protect the electrical components when the high
pressures undersea are exerted on the removable section.
Alternately, cavity 124 may be filled with a non-conducting fluid
maintained at ambient subsea pressure (using, for example, a
compensator) at a given subsea depth at which the control module is
installed.
[0050] In this way, the pilot valves 108 and the associated
electronics may be separated from the SPM valves 106 and thus, in
case of failure of a pilot valve or an electronic component, only
these elements are retrieved and not the SPM valves. For this
reason, the weight and size of the removed part is considerable
less than the weight and size of the entire unit, which makes the
replacement more feasible.
[0051] According to an exemplary embodiment, a schematic diagram of
the fixed part 100 and the removable section 110 is shown in FIG.
9. FIG. 9 shows an implementation of the fixed part 100 and the
removable section 110 on the LMRP 130. That means that the MUX pod
60 and the fixed part 100 are fixed to the LMRP 130. The removable
section 110 is removably attached to the fixed part 100. The fixed
part 100 includes one or more SPM valves 106 (only one is shown for
simplicity). The high pressure fluid is received via conduit 132 to
a first input 106a of the SPM valve 106. In this exemplary
embodiment, SPM valve 106 has inputs and outputs 106a to 106f. SPM
valves 106 with other configurations may be used.
[0052] SPM valve 106 is activated by receiving the fluid under high
pressure at gate 106g. This fluid is controlled by pilot valve 108
provided in the removable section 110. Pilot valve 108 may have a
similar structure as the SPM valve 106 except that an electrical
gate 108a is used to activate the valve. The pilot valve 108 may
receive the fluid under pressure from the same conduit 132 used by
the SPM valve 106 or another hydraulic source. Thus, connections
134a and 134b are implemented on the fixed part 100 and the
removable section 110, respectively, for bringing the fluid under
pressure to the pilot valve 108. Similar or different connections
136a and 136b are used for providing the fluid under pressure from
the pilot valve 108 to the SPM valve 106 when a corresponding
electrical signal is received at gate 108a. Thus, when the pilot
valve 108 is activated, the fluid from conduit 132 flows via the
pilot valve 108 to the gate 106g to activate the SPM valve 106.
After the SPM valve gate 106g is activated, fluid from conduit 132
flows via SPM valve 106 to outlet 138 and to the desired function
to be controlled.
[0053] It is noted in this exemplary embodiment that the fluid
under pressure entering conduit 132 may be provided either directly
from MUX pod 60 along a conduit or from another source, e.g., hot
line 144. The fluid may be regulated internally at the MUX pod 60.
The hot line 144 may be connected to accumulators or to a conduit
that communicates with the ship (not shown) manning the operation
of the LMRP.
[0054] Similar to the fixed part 100, the removable section 110 may
include more than one pilot valve 108. The removable section 110
also includes an electronic part 118 that is electrically connected
to the pilot valves for transmitting various commands to them. The
electronic part 118 may be connected to power supply lines 140a and
140b that are connected to the MUX pod 60 via the fixed part 100.
In addition, the electronic part 118 may include one or more lines
142 (e.g., RS 485 cables) for transmitting various commands from
the MUX pod 60 to the corresponding solenoid valves 108 via the
fixed part 100. Corresponding wet-mateable electric connectors 145
(e.g., connectors configured to mate/de-mate subsea) may be mounted
on the fixed part 100 and the removable section 110 for
transmitting the electric power and the commands from one module to
the other. Multiple fixed parts 100 and corresponding removable
sections 110 may be used on the same subsea structure.
[0055] If more than one pilot valve 108 is provided on the
removable section 110, the same supply line 146 may be used to
supply the fluid under pressure to each of the pilot valve 108.
However, each pilot valve 148 would have its own output 150 fluidly
communicating with a corresponding SPM valve 152. In other words,
for a control module (fixed part 100 and removable section 110)
having 8 functions, there are 8+1 inlet hydraulic ports, one
corresponding to conduit 146 and the others corresponding to outlet
ports 150. In one application, the conduit 146 may be connected to
another source of fluid under pressure instead of the MUX pod 60 or
conduit 144. The removable section 110 may include other elements
than those shown in the figures. For example, the removable section
110 may include one or more filtration devices, pressure sensing
devices, etc. Similarly, the fixed part may include other devices,
e.g., pressure regulators.
[0056] If the fixed part 100 and the removable section 110 are
disposed on the BOP stack, then the power supply and the
communication supply may stay the same, e.g., from MUX pod 60, but
the hydraulic supply may provided by a hot line that provides the
fluid under high pressure for operating the BOPs of the BOP
stack.
[0057] According to an exemplary embodiment, FIG. 10 illustrates a
possible hydraulic and electrical arrangement for the fixed part
100 and the removable section 110 when the control module is
provided on the BOP stack. A 5,000 psi yellow line 160 and a 5,000
psi blue line 162 (these are existing lines for supplying the fluid
under high pressure to BOPs but other lines may also be used) are
provided from the LMRP part to the BOP stack. The received fluid
may be filtered in a filtration unit 164 prior to being provided as
the hydraulic supply for the removable section 110. Various
pressure regulators 166 (devices for changing the pressure of the
fluid from, for example, 5,000 psi to 3,000 psi or another desired
value) may be used either to change the pressure of the fluid. Both
lines are provided to the fixed part 100 at inlets 168 and 170.
From here, the pilot hydraulic pressure at inlet 170 is provided
via conduit 146 to the removable section 110 while the hydraulic
pressure at inlet 168 is provided to SPM valves 106. By
appropriately controlling the pilot valves 108, via commands
received at the electronic part 118 along a power and communication
line 172, corresponding SPM valves 106 are opened or closed as
required to provide the desired functions.
[0058] The pressure values illustrated in FIG. 10 are for exemplary
purposes and not intended to limit the applicability of the novel
features. Other pressure values may be used depending on the BOP
stack and other factors. The LMRP 88 is shown detached from the BOP
stack 80. However, after the fluid connection is achieved between
the two parts, the yellow and blue lines are active and fluid under
high pressure is available to the BOP stack from the LMRP. A stack
of accumulators 180 may be present on the BOP stack and connected
to the blue and/or yellow lines to be recharged. Pressure regulator
166 reduces the pressure to 4,000 psi for the shearing function at
conduit 182 while the same fluid is provided along conduit 184
either to the fixed part 100 or via another pressure regulator 186
to the fixed part 100.
[0059] According to an exemplary embodiment illustrated in FIG. 11,
the fixed part 100 and the removable section 110 may be connected
to a frame 98 that has multiple slots for accommodating these
elements. FIG. 11 shows an empty slot 187 for receiving another
control module 94. Frame 98 also may include a docking receptacle
188 (e.g., a hole in the frame, a stab or other elements) for
helping the ROV device to dock in order to access the removable
section 110.
[0060] FIG. 12 shows in more details the fixed part 100 associated
with the embodiment illustrated in FIG. 11. The fixed part includes
guiding elements 114 that are configured to mate with corresponding
elements on the removable section 110. The wet-mate connector 122
is provided on the fixed part 100 for providing power supply and/or
communication signals to the removable section 110. A hydraulic
fluid under pressure is provided to the removable section 110
through an outlet 143. The SPM valves 106 are attached to a base
191 of the fixed part 100. Hydraulic stabs 136a are connected to
the SPM valves 106 and are configured to connect to the pilot
valves of the removable section. A hydraulic supply 193 provides
the fluid under pressure to the fixed part 100 and part of this
supply is provided to the desired functions along ports 195 when
corresponding SPM valves 106 are actuated.
[0061] FIG. 13 shows an overall view of the control module 94 in
which the removable section 110 is coupled to the fixed part 100.
FIG. 13 shows the connecting element 112 including a low torque
handle 112a. By rotating the handle 112a in one direction the
removable section 110 is locked to the fixed part 100 and by
rotating the handle 112a in the opposite direction the two
components are unlocked. Another handle 112b may be provided for
transporting the removable section. However, handle 112 is optional
and a same handle may be used to lock/unlock and transport the
removable section. FIG. 13 also shows a wet-mate electrical
connector 123 configured to connect to wet-mate connector 122 on
the fixed part 100. The cavity 124 of the removable section 110
accommodates the electronics 118. Pilot valves 108 are also visible
in this figure. A compensator 196 (to be discussed later) is
provided in communication with a port 197 that fluidly communicates
with the ambient.
[0062] According to an exemplary embodiment illustrated in FIG. 14,
the removable section 110 has a bucket as the connecting element
112. Bucket 112 is configured to mate with a ROV vehicle for
removing or attaching the removable section 110 to the fixed part
100. The removable section 110 may include a locking device 190 for
locking the removable section 110 to the fixed part 100. The fixed
part may have a receiving part 192 for receiving the locking device
190. In one application, the locking device 190 includes a
screw.
[0063] A compensator 196 may be added to the removable section 110
for negating a differential pressure between an ambient subsea
pressure (e.g., pressure generated at the ocean floor by the water
above) and a pressure inside cavity 124 (when the cavity 124 is
filled with a non-conducting fluid, e.g., a dielectric fluid). In
this way, the removable section 110 may be located on the ocean
floor without endangering the integrity of the electronic
components provided inside cavity 124, e.g., power and
communication part 118. In this respect, it is noted that some of
the electronic components may trap inside air at atmospheric
pressure and exposing these components to the high pressure
undersea might cause damage.
[0064] While the above discussed exemplary embodiments had the
removable section 110 configured to have a mechanism such that the
ROV can connect to the mechanism and remove the removable section,
FIG. 15 illustrates an exemplary embodiment in which the removable
section 110 does not have such a mechanism. In other words,
according to this embodiment, the removable section 110 is still
removable from the fixed part 100 but not by an ROV vehicle. FIG.
15 shows a hydraulic supply 200 providing the fluid under pressure
to the fixed part 100. The fluid under pressure is provided from
the fixed part 100 to the removable section 110 when the two parts
are mated. The solenoid valves 108 are shown grouped together on
the removable section 110 while the SPM valves 106 are shown
grouped together on the fixed part 100. Conduits 202 are shown
connecting the solenoid valves 108 to corresponding stubs 204 that
fluidly communicate with the SPM valves 106. The pressure
compensator 196 is shown mounted on the removable section 110.
[0065] This exemplary embodiment differs from other embodiments
discussed above in that an electrical bulkhead connector 206 is
provided on the removable section 110 to be connected to, for
example, the MUX pod (not shown in this figure) without passing
through the fixed part 100. An advantage of this exemplary
removable section 110 is as discussed next. Assuming that at least
a solenoid valve 108 is faulty, the entire control module 208 needs
to be brought to the surface for maintenance. The control module
208 may have a weight of approximately 800 kg while the removable
section 110 may have a weight of approximately 200 kg. However,
because only the removable section 110 needs to be handled as the
solenoid valve 108 is provided in the removable section 110, a
crane for removing the removable section 110 may be smaller and/or
the effort and human involvement in manipulating the removable
section 110 may be reduced.
[0066] According to an exemplary embodiment, illustrated in FIG.
16, there is a method for assembling a control module. The method
includes a step 1600 of attaching a control module to a frame, a
step 1602 of connecting a fixed part of the control module to a
high pressure supply line for receiving a fluid under high
pressure, a step 1604 of providing a valve manifold that houses
plural hydraulic activated valves in the fixed part, a step 1606 of
detachably attaching a removable section of the control module to
the fixed part, a step 1608 of fluidly connecting plural
electrically activated valves of the removable section to the
plural hydraulic activated valves such that the plural electrically
activated valves control the plural hydraulic activated valves, and
a step 1610 of electrically connecting the plural electrically
activated valves to a control system.
[0067] The disclosed exemplary embodiments provide a system and a
method for assembling a control module. It should be understood
that this description is not intended to limit the invention. On
the contrary, the exemplary embodiments are intended to cover
alternatives, modifications and equivalents, which are included in
the spirit and scope of the invention as defined by the appended
claims. Further, in the detailed description of the exemplary
embodiments, numerous specific details are set forth in order to
provide a comprehensive understanding of the claimed invention.
However, one skilled in the art would understand that various
embodiments may be practiced without such specific details.
[0068] Although the features and elements of the present exemplary
embodiments are described in the embodiments in particular
combinations, each feature or element can be used alone without the
other features and elements of the embodiments or in various
combinations with or without other features and elements disclosed
herein.
[0069] This written description uses examples of the subject matter
disclosed to enable any person skilled in the art to practice the
same, including making and using any devices or systems and
performing any incorporated methods. The patentable scope of the
subject matter is defined by the claims, and may include other
examples that occur to those skilled in the art. Such other
examples are intended to be within the scope of the claims.
* * * * *