U.S. patent application number 14/986004 was filed with the patent office on 2017-07-06 for systems and methods for engaging subsea equipment.
This patent application is currently assigned to CAMERON INTERNATIONAL CORPORATION. The applicant listed for this patent is CAMERON INTERNATIONAL CORPORATION. Invention is credited to Andrew JAFFREY.
Application Number | 20170191334 14/986004 |
Document ID | / |
Family ID | 59226121 |
Filed Date | 2017-07-06 |
United States Patent
Application |
20170191334 |
Kind Code |
A1 |
JAFFREY; Andrew |
July 6, 2017 |
SYSTEMS AND METHODS FOR ENGAGING SUBSEA EQUIPMENT
Abstract
A system for landing a subsea component includes a retention
assembly configured to be coupled to the subsea component, the
retention assembly including a first connector, a cable extending
between the connector and a tensioning assembly, and a releasable
lock configured to selectably actuate the tensioning assembly
between a locked position and an unlocked position, wherein, when
the tensioning assembly is in the unlocked position, a tensioning
force is applied to the cable, and an anchoring assembly configured
to anchor to a sea floor, the anchoring assembly including a second
connector configured to be coupled to the first connector of the
retention assembly.
Inventors: |
JAFFREY; Andrew;
(Oldmeldrum, GB) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
CAMERON INTERNATIONAL CORPORATION |
Houston |
TX |
US |
|
|
Assignee: |
CAMERON INTERNATIONAL
CORPORATION
Houston
TX
|
Family ID: |
59226121 |
Appl. No.: |
14/986004 |
Filed: |
December 31, 2015 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
E21B 33/064 20130101;
E21B 43/013 20130101; E21B 33/038 20130101; E21B 41/10 20130101;
E21B 43/0135 20130101 |
International
Class: |
E21B 33/038 20060101
E21B033/038; E21B 43/013 20060101 E21B043/013 |
Claims
1. A system for landing a subsea component, comprising: a retention
assembly configured to be coupled to the subsea component, the
retention assembly comprising: a first connector; a cable extending
between the connector and a tensioning assembly; and a releasable
lock configured to selectably actuate the tensioning assembly
between a locked position and an unlocked position; wherein, when
the retention assembly is disposed subsea and the tensioning
assembly is in the unlocked position, a tensioning force is applied
to the cable in response to a hydraulic pressure force applied
against the tensioning assembly by sea water from the surrounding
environment; and an anchoring assembly configured to anchor to a
sea floor, the anchoring assembly comprising a second connector
configured to be coupled to the first connector of the retention
assembly.
2. The system of claim 1, wherein the retention assembly further
comprises a locking assembly configured to allow the passage of the
cable through the locking assembly in a first direction towards the
retention assembly, and restrict passage of the cable through the
locking assembly in a second direction away from the retention
assembly.
3. The system of claim 2, wherein the tensioning assembly
comprises: a cylinder configured to couple to the subsea component;
and a piston slidably disposed in the cylinder and coupled to an
end of the cable; wherein the cylinder includes an open end for
providing fluid communication between a first end of the piston and
the subsea environment.
4. The system of claim 3, wherein: when the tensioning assembly is
in the locked position, the releasable lock physically engages the
piston to restrict the piston from being displaced through the
cylinder; and when the tensioning assembly is in the unlocked
position, the piston is displaced through the cylinder in response
to fluid pressure acting against the first end of the piston.
5. The system of claim 4, wherein, in response to the piston being
displaced through the cylinder, the cable is passed through the
locking assembly to reduce slack in the cable.
6. The system of claim 1, wherein the anchoring assembly comprises:
a first ring concentrically disposed in a second ring, and a third
ring, wherein the first and second rings are each concentrically
disposed in the third ring; wherein the first ring is pivotally
coupled to the second ring such that the first ring is configured
to pivot about a first axis relative to the second ring; and
wherein the second ring is pivotally coupled to the third ring such
that the second ring is configured to pivot about a second axis
relative to the third ring.
7. The system of claim 1, wherein the anchoring assembly comprises
a damper configured to damp forces applied to the subsea component
when the first connector is coupled to the second connector.
8. A system for landing a subsea component, comprising: a first
subsea component; a retention assembly coupled to the first subsea
component, the retention assembly comprising: a first connector; a
cable extending between the connector and a tensioning assembly,
wherein the tensioning assembly is configured to apply a tensioning
force to the cable; a locking assembly configured to allow the
passage of the cable through the locking assembly in a first
direction towards the retention assembly, and restrict passage of
the cable through the locking assembly in a second direction away
from the retention assembly; and an anchoring assembly configured
to anchor to a sea floor, the anchoring assembly comprising a
second connector for coupling with the first connector of the
retention assembly.
9. The system of claim 8, wherein the retention assembly further
comprises: a releasable lock configured to selectably actuate the
tensioning assembly between a locked position and an unlocked
position; wherein, when the tensioning assembly is in the unlocked
position, a tensioning force is applied to the cable.
10. The system of claim 9, wherein the tensioning assembly
comprises: a cylinder coupled to the subsea component; and a piston
slidably disposed in the cylinder and coupled to an end of the
cable; wherein the cylinder has an open end for providing fluid
communication between a first end of the piston and the subsea
environment.
11. The system of claim 10, wherein: when the tensioning assembly
is in the locked position, the releasable lock physically engages
the piston to restrict the piston from being displaced through the
cylinder; and when the tensioning assembly is in the unlocked
position, the piston is displaced through the cylinder in response
to fluid pressure acting against the first end of the piston.
12. The system of claim 11, wherein, in response to the piston
being displaced through the cylinder, the cable is passed through
the locking assembly to reduce slack in the cable.
13. The system of claim 8, wherein the anchoring assembly
comprises: a first ring concentrically disposed in a second ring,
and a third ring, wherein the first ring and the second ring are
each concentrically disposed in the third ring; wherein the first
ring is pivotally coupled to the second ring such that the first
ring is configured to pivot about a first axis relative to the
second ring; and wherein the second ring is pivotally coupled to
the third ring such that the second ring is configured to pivot
about a second axis relative to the third ring.
14. The system of 8, further comprising a detector configured to
detect a distance between the first subsea component and a second
subsea component, and a controller in signal communication with the
detector, wherein the controller is configured to adjust a
tensioning force applied to the cable in response to a signal
transmitted to the controller from the detector.
15. A method of landing a subsea component, comprising: deploying a
subsea component in a subsea environment; lowering the subsea
component to a target location near a sea floor; coupling a cable
extending from a retention assembly coupled to the subsea component
to an anchoring assembly; actuating a tensioning assembly of the
retention assembly to apply a tensioning force to the cable to
guide the subsea component towards the anchoring assembly; and
passing the cable through a locking assembly to reduce slack in the
cable.
16. (canceled)
17. The method of claim 15, further comprising restricting passing
the cable through the locking assembly in the second direction in
response to a force applied against the subsea component.
18. The method of claim 15, further comprising damping a force
applied against the subsea component after coupling the cable.
19. The method of claim 15, further comprising rotating a connector
of the anchoring assembly in a gimbal assembly.
20. The method of claim 15, further comprising utilizing a
controller to automatically adjust a tensioning force to the cable
in response to a threshold level of lateral gap between the subsea
component and the target location.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] Not applicable.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not applicable.
BACKGROUND
[0003] Hydrocarbon drilling systems utilize drilling fluid or mud
for drilling a wellbore in a subterranean earthen formation. In
some offshore applications, a conductor housing is installed
through a temporary guidebase disposed on the sea floor, where the
conductor housing is coupled to casing conductor that extends into
the sea floor. A permanent guidebase follows the installation of
the conductor housing in the sea floor, and a wellhead housing is
then installed within the conductor housing disposed on the sea
floor. Once the conductor and wellhead housings are secured on the
sea floor, a blowout preventer (BOP) stack is secured to the
wellhead housing for controlling the flow of fluid into and out of
the wellbore. Following the installation of the BOP stack, a lower
marine riser package (LMRP) is secured to the BOP stack for
providing a conduit for drilling fluids between a drilling vessel
at the surface and the wellhead disposed on the sea floor. Each of
the components described above, including the BOP stack and LMRP,
may be installed at the sea floor by lowering the components from a
drilling vessel or semi-submersible drilling rig disposed at the
surface. Specifically, the components may be suspended from a
marine riser, cable, or other component and lowered towards the sea
floor. In some applications, the drilling vessel includes a heave
compensation system for maintaining the vertical position (e.g.,
the vertical distance to the sea floor) of the suspended component
as the drilling vessel is displaced vertically at the surface due
to waves or other turbulence.
SUMMARY
[0004] An embodiment of a system for landing a subsea component
comprises a retention assembly configured to be coupled to the
subsea component, the retention assembly comprising a first
connector, a cable extending between the connector and a tensioning
assembly, and a releasable lock configured to selectably actuate
the tensioning assembly between a locked position and an unlocked
position, wherein, when the tensioning assembly is in the unlocked
position, a tensioning force is applied to the cable, and an
anchoring assembly configured to anchor to a sea floor, the
anchoring assembly comprising a second connector configured to be
coupled to the first connector of the retention assembly. In some
embodiments, the retention assembly further comprises a locking
assembly configured to allow the passage of the cable through the
locking assembly in a first direction towards the retention
assembly, and restrict passage of the cable through the locking
assembly in a second direction away from the retention assembly. In
some embodiments, the tensioning assembly comprises a cylinder
configured to couple to the subsea component, and a piston slidably
disposed in the cylinder and coupled to an end of the cable,
wherein the cylinder includes an open end for providing fluid
communication between a first end of the piston and the subsea
environment. In certain embodiments, when the tensioning assembly
is in the locked position, the releasable lock physically engages
the piston to restrict the piston from being displaced through the
cylinder, and when the tensioning assembly is in the unlocked
position, the piston is displaced through the cylinder in response
to fluid pressure acting against the first end of the piston. In
some embodiments, in response to the piston being displaced through
the cylinder, the cable is passed through the locking assembly to
reduce slack in the cable. In some embodiments, the anchoring
assembly comprises a first ring concentrically disposed in a second
ring, and a third ring, wherein the first and second rings are each
concentrically disposed in the third ring, wherein the first ring
is pivotally coupled to the second ring such that the first ring is
configured to pivot about a first axis relative to the second ring,
and wherein the second ring is pivotally coupled to the third ring
such that the second ring is configured to pivot about a second
axis relative to the third ring. In certain embodiments, the
anchoring assembly comprises a damper configured to damp forces
applied to the subsea component when the first connector is coupled
to the second connector.
[0005] An embodiment of a system for landing a subsea component
comprises a first subsea component, a retention assembly coupled to
the first subsea component, the retention assembly comprising a
first connector, a cable extending between the connector and a
tensioning assembly, wherein the tensioning assembly is configured
to apply a tensioning force to the cable, a locking assembly
configured to allow the passage of the cable through the locking
assembly in a first direction towards the retention assembly, and
restrict passage of the cable through the locking assembly in a
second direction away from the retention assembly, and an anchoring
assembly configured to anchor to a sea floor, the anchoring
assembly comprising a second connector for coupling with the first
connector of the retention assembly. In some embodiments, the
retention assembly further comprises a releasable lock configured
to selectably actuate the tensioning assembly between a locked
position and an unlocked position, wherein, when the tensioning
assembly is in the unlocked position, a tensioning force is applied
to the cable in response to a pressure force applied against the
tensioning assembly from the surrounding environment. In some
embodiments, the tensioning assembly comprises a cylinder coupled
to the subsea component, and a piston slidably disposed in the
cylinder and coupled to an end of the cable, wherein the cylinder
has an open end for providing fluid communication between a first
end of the piston and the subsea environment. In certain
embodiments, when the tensioning assembly is in the locked
position, the releasable lock physically engages the piston to
restrict the piston from being displaced through the cylinder, and
when the tensioning assembly is in the unlocked position, the
piston is displaced through the cylinder in response to fluid
pressure acting against the first end of the piston. In certain
embodiments, in response to the piston being displaced through the
cylinder, the cable is passed through the locking assembly to
reduce slack in the cable. In some embodiments, the anchoring
assembly comprises a first ring concentrically disposed in a second
ring, and a third ring, wherein the first ring and the second ring
are each concentrically disposed in the third ring, wherein the
first ring is pivotally coupled to the second ring such that the
first ring is configured to pivot about a first axis relative to
the second ring, and wherein the second ring is pivotally coupled
to the third ring such that the second ring is configured to pivot
about a second axis relative to the third ring. In some
embodiments, the system further comprises a detector configured to
detect a distance between the first subsea component and a second
subsea component, and a controller in signal communication with the
detector, wherein the controller is configured to adjust a
tensioning force applied to the cable in response to a signal
transmitted to the controller from the detector.
[0006] An embodiment of a method of landing a subsea component
comprises deploying a subsea component in a subsea environment,
lowering the subsea component to a target location near a sea
floor, coupling a cable extending from a retention assembly coupled
to the subsea component to an anchoring assembly, and actuating a
tensioning assembly of the retention assembly to apply a tensioning
force to the cable to guide the subsea component towards the
anchoring assembly. In some embodiments, the method further
comprises passing the cable through a locking assembly to reduce
slack in the cable. In some embodiments, the method further
comprises restricting passing the cable through the locking
assembly in the second direction in response to a force applied
against the subsea component. In certain embodiments, the method
further comprises damping a force applied against the subsea
component after coupling the cable. In certain embodiments, the
method further comprises rotating a connector of the anchoring
assembly in a gimbal assembly. In some embodiments, the method
further comprises utilizing a controller to automatically adjust a
tensioning force to the cable in response to a threshold level of
lateral gap between the subsea component and the target
location.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] For a detailed description of exemplary embodiments,
reference will now be made to the accompanying drawings in
which:
[0008] FIG. 1 is a schematic view of an embodiment of a drilling
system showing a BOP stack in a first position in accordance with
principles disclosed herein;
[0009] FIG. 2 is a cross-sectional view of a retention assembly of
the drilling system of FIG. 1 in accordance with principles
disclosed herein;
[0010] FIG. 3A is a schematic view of a locking assembly of the
drilling system of FIG. 1 in a first position in accordance with
principles disclosed herein;
[0011] FIG. 3B is a schematic view of the locking assembly of FIG.
3A in a second position;
[0012] FIG. 4A is a schematic view of an anchoring assembly in
accordance with principles disclosed herein;
[0013] FIG. 4B is a top view of the anchoring assembly of FIG.
4A;
[0014] FIG. 5 is a schematic view of the drilling system of FIG. 1
in a second position;
[0015] FIG. 6 is a schematic view of the drilling system of FIG. 1
in a third position;
[0016] FIG. 7 is a schematic view of the drilling system of FIG. 1
in a fourth position;
[0017] FIG. 8 is an embodiment of a method for landing a subsea
component in accordance with principles disclosed herein; and
[0018] FIG. 9 is a schematic view of another embodiment of a
drilling system including a BOP stack in accordance with principles
disclosed herein.
DETAILED DESCRIPTION
[0019] In the drawings and description that follow, like parts are
typically marked throughout the specification and drawings with the
same reference numerals. The drawing figures are not necessarily to
scale. Certain features of the disclosed embodiments may be shown
exaggerated in scale or in somewhat schematic form and some details
of conventional elements may not be shown in the interest of
clarity and conciseness. The present disclosure is susceptible to
embodiments of different forms. Specific embodiments are described
in detail and are shown in the drawings, with the understanding
that the present disclosure is to be considered an exemplification
of the principles of the disclosure, and is not intended to limit
the disclosure to that illustrated and described herein. It is to
be fully recognized that the different teachings of the embodiments
discussed below may be employed separately or in any suitable
combination to produce desired results.
[0020] Unless otherwise specified, in the following discussion and
in the claims, the terms "including" and "comprising" are used in
an open-ended fashion, and thus should be interpreted to mean
"including, but not limited to . . . ". Any use of any form of the
terms "connect", "engage", "couple", "attach", or any other term
describing an interaction between elements is not meant to limit
the interaction to direct interaction between the elements and may
also include indirect interaction between the elements described.
The various characteristics mentioned above, as well as other
features and characteristics described in more detail below, will
be readily apparent to those skilled in the art upon reading the
following detailed description of the embodiments, and by referring
to the accompanying drawings.
[0021] FIG. 1 is a schematic diagram illustrating an embodiment of
a drilling system 10. In an embodiment, drilling system 10
comprises a system for landing a subsea component. The drilling
system 10 can be configured to extract various minerals and natural
resources, including hydrocarbons (e.g., oil and/or natural gas),
or configured to inject substances into a sea floor 3 and a
subterranean earthen formation 5 via a well or wellbore 7. In this
embodiment, drilling system 10 generally includes a
semi-submersible drilling rig 12 disposed at a surface or waterline
9, a wellhead 18 secured to the sea floor 3 via a casing conductor
20 that extends into the formation 5, a remotely operated
underwater vehicle (ROV) 22 disposed below the waterline 9 and
including an actuatable arm or gripper 24 and a camera or image
sensor 28, a subsea component or blowout preventer (BOP) assembly
100 disposed beneath the waterline 9, and a plurality of anchoring
assemblies 160 anchored to the sea floor 3 and disposed about the
wellhead 18. In FIG. 1 BOP assembly 100 is disposed near the
waterline 9 after being lowered through the waterline 9 as BOP
assembly 100 descends towards the sea floor 3. In this embodiment,
ROV 22 is connected to the drilling rig 12 via a cable 25 that
supplies power and real-time signal communication between ROV 22
and drilling rig 12. However, in other embodiments, ROV 22 may be
untethered from drilling rig 12 and comprising an internal power
supply and an antenna for wirelessly transmitting signals to the
drilling rig 12. In still further embodiments, ROV 22 may comprise
an autonomous or semi-autonomous vehicle.
[0022] In this embodiment, drilling rig 12 includes a rig floor 14
and a derrick 17 extending from floor 14 that supports a marine
riser 16 coupled to the BOP assembly 100 as the riser 16 and BOP
assembly 100 are lowered from the waterline 9 to the wellhead 18
disposed at the sea floor 3. In this embodiment, BOP assembly 100
has a central or longitudinal axis 105 and generally includes a BOP
frame 102 coupled to a lower end of riser 16, a BOP 104 disposed
within BOP frame 102, and a plurality of retention assemblies 110
coupled to the BOP frame 110. As BOP assembly 100 is lowered
towards sea floor 3, transient forces 13 are applied to BOP
assembly 100 from subsea currents, jerks or transient forces from
riser 16, and other forces, which cause BOP assembly 100 to sway or
move laterally and angularly as BOP assembly 100 is lowered
vertically towards sea floor 3. Although in this embodiment
drilling system 10 includes drilling rig 12 and marine riser 16, in
other embodiments, drilling system 10 may include a mono-hull
drilling vessel including a crane supporting a cable from which BOP
assembly 100 is suspended, or other drilling vessels or rig
systems.
[0023] In an embodiment, drilling vessel 12 includes a heave
compensating system for controlling the vertical position
respective sea floor 3 of BOP assembly 100. Specifically, the heave
compensating system of drilling rig 12 maintains the vertical
position of BOP assembly 100 as the vertical position of drilling
rig 12 rises and falls in response to wave action at the waterline
9. Although the heave compensating system of drilling rig 12 is
configured to maintain the vertical position of BOP assembly 100
relative sea floor 3, the heave compensating system is not
configured to maintain the lateral and angular position of BOP
assembly 100 as transient forces act against BOP assembly 100.
Thus, transient forces applied to BOP assembly 100 cause
longitudinal axis 105 of BOP assembly 100 to become laterally
misaligned with a longitudinal axis 15 of wellhead 18, resulting in
a lateral gap 107 between longitudinal axis 105 and longitudinal
axis 15.
[0024] Retention assemblies 110 are configured to releasably couple
with anchoring assemblies 160 and thereby guide BOP assembly 100
into engagement with wellhead 18 such that BOP 104 may couple with
wellhead 18 to provide a sealed flowpath between an internal
throughbore of BOP 104 and a throughbore of casing conductor 20.
Particularly, retention assemblies 110 are configured to releasably
couple with anchoring assemblies 160 to align longitudinal axis 105
of BOP assembly 100 with longitudinal axis 15 of wellhead 18 such
that longitudinal axis 105 is disposed substantially coaxial with
longitudinal axis 15. In this embodiment, each retention assembly
110 generally includes a tensioning or cylinder assembly 112, a
locking assembly 130, and a first or male connector 158. In this
embodiment, four retention assemblies 110 are included in BOP
assembly 100 with a retention assembly 110 coupled to each corner
of BOP frame 102. However, in other embodiments varying numbers of
retention assemblies 110 may be coupled to BOP frame 102 or other
components of BOP assembly 100 in various configurations.
[0025] Referring to FIGS. 1 and 2, cylinder assembly 112 includes
an elongate cylinder 114 having a first or upper end 114a and a
second or lower end 114b, where lower end 114b is disposed
vertically (relative sea floor 3) below upper end 114a. Lower end
114b of cylinder 114 includes a port 116 providing for fluid
communication between an internal volume 113 of cylinder 114 and
the surrounding subsea environment. Cylinder assembly 112 also
includes a piston 118 slidably disposed within cylinder 114 and
includes an annular seal 120 that is disposed in an outer surface
thereof for sealably engaging an inner surface of cylinder 114.
Sealing engagement between annular seal 120 and the inner surface
of cylinder 114 divides volume 113 into an upper volume or chamber
113a extending between the upper end 114a of cylinder 114 and
piston 118, and a lower volume or chamber 113b extending between
piston 118 and the lower end 114b.
[0026] In this embodiment, upper chamber 113a is filled with a
compressible fluid or gas (e.g., air), while lower chamber 113b is
in fluid communication with the surrounding subsea environment. A
releasable lock 118a extends through cylinder 114 and into upper
chamber 113a to physically engage an upper end of piston 118 to
releasably lock piston 118 in a lower or first position proximal
lower end 114b of cylinder 114. In this embodiment, releasable lock
118a comprises a release pin; however, in other embodiments,
releasable lock may comprise other types of releasable locks known
in the art. In this configuration, hydrostatic pressure of the sea
water acts against a lower end of piston 118 while lock 118a holds
piston 118 into the first position and prevents piston 118 from
being displaced upwards through cylinder 114, compressing the fluid
disposed in upper chamber 113a. Also, the lower end of piston 118
includes a connector 122 coupled to an upper end of a cable or
hawser 124 that extends through port 116.
[0027] Disposed directly beneath the lower end 114b of each
cylinder 114 is a locking assembly 130. Each locking assembly 130
is configured to allow for the passage of hawser 124 therethrough
in a first direction, while selectably restricting the passage of
hawser 124 through locking assembly 130 in a second or opposing
direction. Particularly, each locking assembly 130 is configured to
allow for the passage of hawser 124 in an upwards direction towards
cylinder 114 while restricting the passage of hawser 124 in a
downwards direction away from cylinder 114.
[0028] Referring to FIGS. 1-3B, in this embodiment each locking
assembly 130 generally includes a mounting member 132, a clamping
block 134 affixed to the mounting member 132, a pivot arm 140
pivotally coupled to mounting member 132, and a guide member 156.
Mounting member 132 is mounted or coupled to BOP frame 102 of BOP
assembly 100 such that locking assembly 130 is disposed directly
beneath the lower end 114b of cylinder 114. Clamping block 134 is
affixed to mounting member 132 and includes a curved or convex
engagement surface 136 for frictionally engaging hawser 124. Pivot
arm 140 is pivotally coupled to mounting member 132 at pivot joint
142 and includes an engagement surface 144 configured to
frictionally engage hawser 124 and a handle 146 distal engagement
surface 144 and configured to be actuatable by the gripper 24 of
ROV 22. In this arrangement, a passage or pathway 148 is formed
between the engagement surface 136 of clamping block 134 and the
engagement surface 144 of pivot arm 140.
[0029] Pivot arm 140 includes a first or locked position shown in
FIG. 3A that allows the passage of hawser 124 in a first or upward
direction 150 (i.e., towards cylinder 114) through passage 148 and
restricts the passage of hawser 124 in a second or downward
direction 152 (i.e., away from cylinder 114) through passage 148.
Passage of hawser 124 is allowed in the upward direction 150 while
restricted in the downward direction 152 due to the offset position
of pivot joint 142 relative engagement surface 144. Particularly,
when hawser 124 passes in the upward direction 150, frictional
engagement between hawser 124 and engagement surface 144 causes
pivot arm 140 to pivot in a first or clockwise direction, expanding
the width of passage 148. However, when hawser 124 passes in the
downward direction 152, frictional engagement between hawser 124
and engagement surface 144 causes pivot arm 140 to pivot in a
second or counterclockwise direction, reducing the width of passage
148 and thereby causing engagement surfaces 136 and 144 to grapple
or grab hawser 124, restricting further passage of hawser 124 in
the downward direction 152. While in this embodiment pivot arm 140
is actuated via gripper 24 of ROV 22, in other embodiments, pivot
arm 140 may be actuated between the locked and unlocked positions
via the transmission of a remote signal transmitted from the
surface to an antenna in signal communication with an
electronically, hydraulically, pneumatically or otherwise
actuatable pivot arm of locking device 130.
[0030] Pivot arm 140 also includes a second or unlocked position
shown in FIG. 3B where engagement surface 144 is disposed distal
hawser 124, thereby allowing the passage of hawser 124 in both the
upward direction 150 and the downward direction 152. In this
embodiment, pivot arm 140 is biased into the first position via a
biasing member (not shown). In this arrangement, pivot arm 140 may
be actuated from the locked position shown in FIG. 3A to the
unlocked position shown in FIG. 3B via the grabber 24 of ROV 22. In
this embodiment, each locking assembly 130 also includes a guide
member 156 affixed to BOP housing 102 and disposed directly beneath
mounting member 132, where guide member 156 includes an aperture
extending therethrough to guide hawser 124 towards passage 148. In
this configuration, guide member 156 restricts hawser 124 from
becoming tangled within or slipping free from passage 148. Although
in the embodiment of FIGS. 3A and 3B, locking devices 130 comprise
base plate 132 and pivot arm 140, in other embodiments, locking
devices 130 may comprise other mechanisms configured for allowing
the passage of hawser 124 in the upwards direction 150 while
restricting the passage of hawser 150 in the downwards direction
152.
[0031] As shown particularly in FIG. 1, the lower end of hawser 124
is coupled to male connector 158. As will be discussed further
herein, male connector 158 is configured to releasably connect to a
female connector of a corresponding anchoring assembly 160, forming
a releasable connection between each retention assembly 110 and
corresponding anchoring assembly 160. In this embodiment, male
connector 158 comprises the male connector of a subsea mooring or
ball and taper connector, such as the Ballgrab.RTM. Subsea mooring
Connector (SMC) provided by First Subsea Ltd located at Lune
Industrial Estate, New Quay Road, Lancaster, Lancashire, LA1 5QP,
United Kingdom. However, in other embodiments, male connector 158
may comprise other types of male connectors known in the art
configured for usage in subsea environments, such as the quick
release lifting pins offered by Automotion Components Ltd., Alexia
House, Little Mead Industrial Estate, Cranleigh, Surrey, GU6 8NE,
UK, or other components known in the art such as shackles that may
be secured to eyes in the hawsers 124. Also, as BOP assembly 100 is
lowered towards sea floor 3, the length of hawser 124 may be coiled
to prevent hawser 124 from becoming tangled with other components
of BOP assembly 100. Prior to connecting male connector 158 with a
corresponding female connector of anchoring assembly 160, as will
be discussed further herein, grabber 24 of ROV 22 may release or
uncoil the length of hawser 124 from BOP assembly 100.
[0032] Referring to FIGS. 1, 4A, and 4B, each anchoring assembly
160 is configured to releasably couple with a corresponding
retention assembly 110 to couple BOP assembly 100 to the sea floor
3 and guide BOP assembly 100 into engagement with wellhead 18.
Particularly, in this embodiment, four anchoring assemblies 160 are
disposed about wellhead 18 corresponding with the four retention
assemblies 110 coupled to BOP frame 102. However, in other
embodiments, BOP assembly 100 may only include a single retention
assembly 110. In this arrangement, when longitudinal axis 105 of
BOP assembly 100 aligns with longitudinal axis 15 of wellhead 18,
each anchoring assembly 160 longitudinally or vertically aligns
with a corresponding retention assembly 110, as will be discussed
further herein. In this embodiment, each anchoring assembly 160
generally includes a support frame 162, a gimbal assembly 164
physically supported by support frame 162, and a female connector
assembly 180 coupled to gimbal assembly 164. Support frame 162 is
anchored or coupled to the sea floor 3 and is configured to
physically support gimbal assembly 164 and female connector
assembly 180. In this embodiment, support frame 162 comprises a
plurality of legs 162a extending from gimbal assembly 180 to the
sea floor 3.
[0033] Gimbal assembly 164 of anchoring assembly 160 is configured
to provide for the rotation of female connector assembly 180 about
multiple independent axes relative support frame 162. In this
arrangement, female connector assembly 180 may axially align with
tension forces applied to hawser 124 once male connector 158 has
been inserted into and coupled with female connector assembly 180.
In this embodiment, the gimbal assembly 164 of each anchoring
assembly 160 generally includes a first or inner ring 166, a pair
of first or inner coupling pins 168, a second or intermediate ring
170, a pair of second or outer coupling pins 172, and a third or
outer ring 174 coupled to an upper end of support frame 162. Inner
coupling pins 168 pivotally couple inner ring 166 with intermediate
ring 170, providing for rotation of inner ring 166 about a first
axis 169 relative intermediate ring 170. Also, outer coupling pins
172 pivotally couple intermediate ring 170 with outer ring 174,
providing for rotation of intermediate ring 170 about a second axis
171 relative outer ring 174. In this arrangement, inner ring 166 is
pivotal about both first axis 169 and second axis 171 relative
outer ring 174 and support frame 162. Further, first axis 169 is
disposed orthogonal to second axis 171.
[0034] Female connector assembly 180 is coupled to inner ring 166,
thus allowing female connector assembly 180 to pivot about first
axis 169 and second axis 171 relative support frame 162. The female
connector assembly 180 of each anchoring assembly 160 is configured
to releasably couple with a male connector 158 of a corresponding
retention assembly 110. Female connector assembly 180 is also
configured to dampen forces transmitted to BOP support assembly 100
from anchoring assemblies 160 once BOP assembly 100 has been
coupled to anchoring assemblies 160.
[0035] In this embodiment, each female connector assembly 180
generally includes a cylinder 182, a piston 190 disposed in
cylinder 182, and a female connector 194 coupled to an upper end of
piston 190. Cylinder 182 has a first or upper end 182a, a second or
lower end 182b, and an internal volume 184 disposed therein. The
upper end 182a of cylinder 182 includes a centrally disposed
aperture 186 and the lower end 182b includes a plurality of tuned
ports 188. Piston 190 includes an annular seal 192 disposed in an
outer surface thereof for sealingly engaging an inner surface of
cylinder 182. The sealing engagement provided by annular seal 192
divides internal volume 184 into a first or upper chamber 184a
extending between upper end 182a and the upper end of piston 190,
and a second or lower chamber 184b extending between a lower end of
piston 190 and the lower end 182b of cylinder 182. Female connector
194 couples to the upper end of piston 190 and extends through
aperture 186 at the upper end 182a of cylinder 182. An inner
surface of aperture 186 for sealingly engaging an outer surface of
female connector 194, thereby restricting fluid communication
between upper chamber 184a and the surrounding subsea environment.
In this embodiment, upper chamber 184a is filled with a
compressible fluid, such as air. Lower chamber 184b of cylinder 182
is in fluid communication with the surrounding subsea environment
via ports 188, and is thus filled with sea water.
[0036] In this embodiment, female connector 194 comprises the
corresponding female connector of a subsea mooring or ball and
taper connector, such as the Ballgrab.RTM. Subsea mooring Connector
(SMC) provided by First Subsea Ltd located at Lune Industrial
Estate, New Quay Road, Lancaster, Lancashire, LA1 5QP, United
Kingdom. However, in other embodiments, female connector 194 may
comprise other types of male connectors known in the art configured
for usage in subsea environments, such as the quick release lifting
pins and/or shackles described above with respect to male connector
158. Also, female connector 194 includes a radially flanged guided
member 194a at an upper end thereof for guiding the male connector
158 of a corresponding retention assembly 110 into engagement with
female connector 194. In this embodiment, male connector 158 may be
releasably coupled or secured to female connector 194 by axially
inserting male connector 158 into female connector 194 regardless
of the angular orientation between male connector 158 and female
connector 194. Once male connector 158 is inserted into female
connector 194, male connector 158 is restricted from being released
from female connector 194 when an upwards tension force is applied
against male connector 158.
[0037] In the configuration described above, female connector
assembly 180 is configured to act as a dampener when a force is
applied in either a first or upper (relative sea floor 3) direction
193 or a second or downwards (relative sea floor 3) direction 195.
Specifically, when a force is applied against female connector 194
in a first or upwards (relative sea floor 3) direction 193, the
fluid disposed in upper chamber 184a of cylinder 182 is compressed,
thereby absorbing shock and dissipating energy from the upwards
force 193. Also, when a force is applied against female connector
194 in a second or downwards (relative sea floor 3) direction 195,
sea water disposed in lower chamber 184b is ejected from volume 184
via ports 188 at the lower end 182b of cylinder 182. Ports 188 are
tuned to optimize the flow of the ejected sea water so as to absorb
shock and dissipate energy from the downwards force 195. In this
manner, female connector assembly 180 is configured to reduce
shocks and dissipate energy in response to forces applied to BOP
assembly 100 once BOP assembly 100 couples with anchoring
assemblies 160 via hawsers 124.
[0038] Referring to FIG. 5, as BOP assembly 100 is lowered towards
sea floor 3, BOP assembly 100 will enter a target location disposed
proximal sea floor 3. Once BOP assembly 100 is disposed in the
target location, the gripper 24 of ROV 22 releases or uncoils
hawsers 124 from BOP frame 102, thereby allowing male connectors
158 to descend further towards the sea floor 3. Once male
connectors 158 have been released and are disposed at or near the
sea floor 3, ROV 22 inserts each male connector 158 into the female
connector 194 of a corresponding anchoring assembly 160 using
gripper 24, thereby coupling BOP assembly 100 to anchoring
assemblies 160, and in turn, the sea floor 3.
[0039] During this process, BOP assembly 100 is continuously
displaced laterally, vertically, and angularly in response to
transient forces 13, causing the longitudinal axis 105 to be
disposed at an angular misalignment or angle 109 relative a
vertical axis (i.e., extending parallel longitudinal axis 15 of
wellhead 18) extending from the sea floor 3. Due to the lateral gap
107 and angular misalignment 109, the female connector assembly 180
of each anchoring assembly 160 rotates within its respective gimbal
assembly 164 such that each female connector assembly 180 is
axially aligned with the tension force applied by the coupled
hawser 124, which is placed in tension by the moving BOP assembly
100. In this arrangement, the only substantial forces applied to
female connector assemblies 180 are axial, thus limiting or
eliminating the shear forces applied against female connector
assemblies 180 and anchoring assemblies 160 by hawsers 124.
[0040] Further, in this arrangement female connector assemblies 180
act to damp the shock to BOP assembly 100 and anchoring assemblies
160 produced by the moving BOP assembly 100. For instance, a lull
in transient forces 13 on BOP assembly 100 may allow hawsers 124 to
slacken, followed by a resumption of transient forces 13 thereby
causing BOP assembly 100 to be displaced away from anchoring
assemblies 160 until hawsers 124 are rapidly drawn taut in response
to locking devices 130 gripping hawsers 124, imparting a shock or
force to both BOP assembly 100 and the anchoring assemblies 160
coupled thereto by taut hawsers 124. In this instance, the
cylinders 182 and corresponding pistons 190 described above and
shown in FIG. 4A damp the shock imparted to BOP assembly 100 and
anchoring assemblies 160 via compressing the gas disposed in upper
chamber 184a of cylinder 182.
[0041] Referring to FIG. 6, once the male connector 158 of each
retention assembly 110 is connected with the female connector 194
of a corresponding anchoring assembly 160, gripper 24 of ROV 22 is
used to release the lock 118a of each retention assembly 110,
allowing each piston 118 to displace upwards towards the upper end
112a (shown in FIG. 2) of the corresponding cylinder 112 in
response to the relatively high pressure sea water acting on the
lower end of each piston 118, as shown schematically in FIG. 6.
Although in this embodiment releasable locks 118a are used to
release pistons 118 via gripper 24 of ROV 22, in other embodiments,
pistons 118 may be released through other mechanisms, such as by
transmitting a remote signal transmitted from the surface to an
antenna coupled to an electronically actuated mechanism configured
to release pistons 118. Further, while in this embodiment the
displacement of pistons 118 through cylinders 112 tensions hawsers
124, in other embodiments, another tensioning mechanism may be used
to tension hawsers 124 following the connection of male connectors
158 with female connectors 194. For instance, in an embodiment,
lift bags are coupled to hawsers 124 including energetic materials
for generating gas within the lift bags to provide buoyancy for
tensioning hawsers 124 following the connection of male connectors
158 with female connectors 194. Alternatively, buoys may be coupled
to hawsers 124 and BOP frame 102, and following the connection of
male connectors 158 with female connectors 194, the buoys are
released from BOP frame 102 to tension hawsers 124.
[0042] In response to the upwards displacement of pistons 118,
hawsers 124 coupled to pistons 118 are also displaced upwards
through cylinders 112 and locking devices 130. The displacement of
hawsers 124 through cylinders 112 guides BOP assembly 100 towards
anchoring assemblies 160, reducing the extent of lateral gap 107
between the longitudinal axis 105 of BOP assembly 100 and the
longitudinal axis 15 of wellhead 18. In this embodiment, hawsers
124 do not necessarily pull BOP assembly 100 towards wellhead 18,
and instead, guide BOP assembly 100 towards wellhead 18 while
locking devices 130 restrict BOP assembly 100 from being displaced
away from wellhead 18 in response to the application of transient
forces 13. Particularly, locking devices 130 grip hawsers 124,
restricting hawsers 124 from passing in the downwards direction 152
(shown in FIGS. 3A and 3B), in response to transient forces 13
applied against BOP assembly 100 in a direction away from anchoring
assemblies 160, thereby restricting BOP assembly 100 from being
displaced away from anchoring assemblies 160. However, in other
embodiments, retention assemblies 110 and/or anchoring assemblies
160 include powered winches for actively pulling BOP assembly 100
towards wellhead 18 by actively retracting hawsers 124.
[0043] Referring to FIG. 7, following the release of locks 118a of
retention assemblies 110, pistons 118 continue to travel upwards
through cylinders 112, thereby guiding or directing BOP assembly
100 towards well head 18 until BOP assembly 100 engages wellhead 18
and the longitudinal axis 105 of BOP assembly 100 is substantially
aligned with the longitudinal axis 15 of wellhead 18. In this
position, the pistons 118 of each retention assembly 110 are
disposed proximal the upper end 112a (shown in FIG. 2) of a
corresponding cylinder 112. Once BOP assembly 100 has successfully
landed against wellhead 18, BOP 104 is coupled or secured to
wellhead 18. Following the coupling of BOP 104 to wellhead 18, the
gripper 24 of ROV 22 is used to disconnect the male connector 158
of each retention assembly 110 from the female connector 194 of
each corresponding anchoring assembly 160. Additional anchoring
assemblies 160 mounted to BOP frame 102 (not shown) can be
subsequently used to anchor and guide other components of drilling
system 10 into engagement with BOP 104 in a manner similar to the
guiding of BOP assembly 100 described above. For instance, in an
embodiment an LMRP assembly (not shown) is guided and landed
against BOP 104 in a manner similar to the guiding of BOP assembly
100 described above. In this embodiment, the LMRP assembly includes
one or more retention assemblies 110 each having a male connector
158 for releasably coupling with the female connector 194 of the
anchoring assemblies 160 mounted to BOP frame 102.
[0044] Referring to FIGS. 1 and 8, an embodiment of a method 200 of
guiding and engaging a subsea component is shown. Starting at block
202, a subsea component is deployed below the waterline 9 in an
offshore, subsea environment. In certain embodiments, prior to the
subsea component being deployed below the waterline 9, anchoring
assemblies are installed or coupled to the sea floor 3. In some
embodiments, the process of installing anchoring assemblies at the
sea floor 3 comprises coupling the frame 162 (shown in FIGS. 4A and
4B) to the sea floor 3 about wellhead 18, which is coupled to
casing conductor 20 that extends through the sea floor 3. In an
embodiment, block 202 comprises deploying BOP assembly 100 from
drilling rig 12, where BOP assembly 100 is suspended from riser 16
that extends from drilling rig 12. At block 204, the subsea
component is lowered to a target location proximal the sea floor 3.
In an embodiment, block 204 comprises lowering BOP assembly 100
towards the target location proximal sea floor 3 by extending riser
16 from drilling rig 12.
[0045] At block 206, retention assemblies coupled to the subsea
component are coupled to the anchoring assemblies installed at the
sea floor 3. In an embodiment, block 206 comprises coupling
retention assemblies 110 to anchoring assemblies 160 anchored to
the sea floor 3 using the gripper 24 of ROV 22, as described above
and illustrated in FIG. 5. At block 208, one or more pistons of
each retention assembly is released to guide the subsea component
towards the sea floor 3, and into engagement with another subsea
component disposed at or near the sea floor 3. In an embodiment,
block 208 comprises using the gripper 24 of ROV 22 to release the
lock 118a of each retention assembly 110, thereby releasing the
piston 118 of each retention assembly 110, as described above and
illustrated in FIGS. 6 and 7. In this embodiment, once BOP assembly
100 has landed against wellhead 18, BOP 104 of BOP assembly 100 is
coupled to wellhead 18.
[0046] Referring to FIGS. 1, 8, and 9, block 208 of method 200 may
include releasing or unlocking the locking assembly 130 of each
retention assembly 110 when the lateral gap 107 between
longitudinal axis 105 of BOP assembly 100 and the longitudinal axis
15 of wellhead 18 extends beyond a threshold level to allow BOP
assembly 100 to become aligned with wellhead 18. Particularly, if
the lateral gap 107 increases past a threshold level, the piston
118 of the retention assembly 110 in closest alignment with its
corresponding anchoring assembly 160 may be displaced an unequal
distance through its corresponding cylinder 114 with respect to the
pistons 118 of the retention assemblies 110 further out of
alignment of their corresponding anchoring assemblies 160, thereby
inhibiting the alignment of the BOP assembly 100 with the wellhead
18. For instance, such a relative misalignment between retention
assemblies 110 may result in an increased angular misalignment 109.
In an embodiment, the lateral gap 107 may be monitored by personnel
of drilling rig 12 utilizing the camera 28 of ROV 22, and in the
event of an undesirable lateral offset 107, may utilize the gripper
24 of the ROV 22 to actuate the handle 146 of the locking device of
the locking device 130 of the retention assembly 110 in greatest
relative alignment with its corresponding anchoring assembly 160,
thereby allowing the passage of hawser 124 therethrough in the
upward direction 150.
[0047] Alternatively, a control system may be utilized to
automatically unlock one or more of the locking devices 130 of the
retention assemblies 110 in the event of a threshold level of
lateral gap 107. Particularly, FIG. 9 illustrates an embodiment of
a drilling system 300 including a control system for automatically
releasing one or more retention assemblies 110 in response to a
threshold level of lateral gap 107 between the longitudinal axis
105 of BOP assembly 100 and the longitudinal axis 15 of wellhead
18. Drilling system 300 includes features similar to those of
drilling system 10, and shared features are numbered similarly. In
this embodiment, the BOP assembly 100 a detector 302 in signal
communication with a controller 304, where the detector is
configured to actively detect or measure the extent of the lateral
gap 107 between the BOP assembly 100 and the wellhead 18. In
certain embodiments, detector 302 may also be configured to detect
the angular misalignment 109 between the BOP assembly 100 and the
wellhead 18. In this embodiment, the detector 302 comprises an
optical detector; however, in other embodiments, detector 302 may
comprise an acoustic, radio-frequency, or other types of detectors
known in the art. In this embodiment, the detector 302 communicates
with the controller 304 in real-time the extent of lateral gap 107,
and in response to the lateral gap 107 exceeding a predetermined
threshold level, the controller 304 is configured to adjust the
tension in one or more of the hawsers 124 to optimize the placement
of the BOP assembly 100 and the wellhead 18. Particularly, in this
embodiment the controller 304 is configured to selectably release
and/or lock one or more locking assemblies 130 in response to the
lateral gap 107 exceeding a predetermined threshold level to allow
the BOP assembly 100 to become re-centered with the wellhead 18. In
certain embodiments, the controller 304 is further configured to
displace the piston 118 of one or more retention assemblies 110 in
response to the lateral gap 107 exceeding a threshold level in
order to optimize placement of the BOP assembly 100 with respect to
the wellhead 18.
[0048] The above discussion is meant to be illustrative of the
principles and various embodiments of the present disclosure. While
certain embodiments have been shown and described, modifications
thereof can be made by one skilled in the art without departing
from the spirit and teachings of the disclosure. The embodiments
described herein are exemplary only, and are not limiting.
Accordingly, the scope of protection is not limited by the
description set out above, but is only limited by the claims which
follow, that scope including all equivalents of the subject matter
of the claims.
* * * * *