U.S. patent application number 14/106489 was filed with the patent office on 2014-04-17 for multiple receiver line deployment and recovery.
This patent application is currently assigned to FAIRFIELD INDUSTRIES INCORPORATED. The applicant listed for this patent is FAIRFIELD INDUSTRIES INCORPORATED. Invention is credited to James N. THOMPSON, Reagan Neil WOODWARD.
Application Number | 20140102353 14/106489 |
Document ID | / |
Family ID | 42265851 |
Filed Date | 2014-04-17 |
United States Patent
Application |
20140102353 |
Kind Code |
A1 |
WOODWARD; Reagan Neil ; et
al. |
April 17, 2014 |
MULTIPLE RECEIVER LINE DEPLOYMENT AND RECOVERY
Abstract
Embodiments described herein relate to an apparatus and method
of transferring seismic equipment to and from a marine vessel and
subsurface location. In one embodiment, a marine vessel is
provided. The marine vessel includes a deck having a plurality of
seismic sensor devices stored thereon, two remotely operated
vehicles, each comprising a seismic sensor storage compartment, and
a seismic sensor transfer device comprising a container for
transfer of one or more of the seismic sensor devices from the
vessel to the sensor storage compartment of at least one of the two
remotely operated vehicles.
Inventors: |
WOODWARD; Reagan Neil;
(Sugar Land, TX) ; THOMPSON; James N.; (Sugar
Land, TX) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
FAIRFIELD INDUSTRIES INCORPORATED |
Sugar Land |
TX |
US |
|
|
Assignee: |
FAIRFIELD INDUSTRIES
INCORPORATED
Sugar Land
TX
|
Family ID: |
42265851 |
Appl. No.: |
14/106489 |
Filed: |
December 13, 2013 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
13671645 |
Nov 8, 2012 |
8611181 |
|
|
14106489 |
|
|
|
|
12343136 |
Dec 23, 2008 |
8310899 |
|
|
13671645 |
|
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Current U.S.
Class: |
114/364 |
Current CPC
Class: |
B63B 27/10 20130101;
G05D 1/0206 20130101; G01V 1/3852 20130101; B63B 25/28 20130101;
G01V 1/3843 20130101; G01V 1/3808 20130101; B63C 11/52 20130101;
G01V 2210/1427 20130101 |
Class at
Publication: |
114/364 |
International
Class: |
B63B 25/28 20060101
B63B025/28 |
Claims
1. A marine vessel, comprising: a deck configured to store a
plurality of seismic sensor devices; two remotely operated
vehicles, each comprising a seismic sensor storage compartment; and
a seismic sensor transfer device comprising a container for
transfer of one or more of the seismic sensor devices from the
vessel to the sensor storage compartment of at least one of the two
remotely operated vehicles.
2. The marine vessel of claim 1, further comprising: a first crane
and a second crane coupled to the vessel.
3. The marine vessel of claim 2, wherein one of the remotely
operated vehicles is coupled to the first crane and the seismic
sensor transfer device is coupled to the second crane.
4. The marine vessel of claim 3, wherein the seismic sensor
transfer device is configured to be positioned at a subsurface
location.
5. The marine vessel of claim 4, wherein the remotely operated
vehicle and the seismic sensor transfer device are configured to
mate at the subsurface location to transfer seismic sensor devices
therebetween.
6. The marine vessel of claim 1, wherein the seismic sensor
transfer device is configured to be towed behind the vessel.
7. A marine vessel, comprising: at least two cranes disposed on the
vessel; a deck configured to store a plurality of seismic sensor
devices; a remotely operated vehicle coupled to the vessel, the
remotely operated vehicle comprising a seismic sensor storage
compartment; and a seismic sensor transfer device configured to
transfer one or more seismic sensor devices from the vessel to the
remotely operated vehicle.
8. The marine vessel of claim 7, wherein the remotely operated
vehicle is coupled to a first crane of the at least two cranes and
the seismic sensor transfer device is coupled to a second crane of
the at least two cranes.
9. The marine vessel of claim 8, wherein the seismic sensor
transfer device is positioned at a subsurface location.
10. The marine vessel of claim 9, wherein the remotely operated
vehicle and the seismic sensor transfer device are configured to
mate at the subsurface location to transfer seismic sensor devices
therebetween.
11. The marine vessel of claim 10, wherein the seismic sensor
transfer device comprises a conveyor configured to facilitate
transfer of the seismic sensor devices.
12. The marine vessel of claim 10, wherein the seismic sensor
transfer device comprises a rack configured to facilitate transfer
of the seismic sensor devices.
13. The marine vessel of claim 10, wherein the seismic sensor
transfer device comprises a movable platform configured to
facilitate transfer of the seismic sensor devices.
14. The marine vessel of claim 10, wherein the seismic sensor
transfer device comprises a tray configured to facilitate transfer
of the seismic sensor devices.
15. The marine vessel of claim 7, wherein the seismic sensor
transfer device is configured to be towed behind the vessel.
16-57. (canceled)
58. The marine vessel of claim 1, wherein the seismic sensor
transfer device and the remotely operated vehicle are configured to
transfer a seismic sensor device therebetween at a subsurface
location above a seabed.
59. The marine vessel of claim 1, wherein the seismic sensor
transfer device and the remotely operated vehicle are configured to
transfer a seismic sensor device therebetween at a subsurface
location at a seabed.
60. The marine vessel of claim 3, wherein the seismic sensor
transfer device is configured to be positioned at a subsurface
location based on an intermittent time interval.
61. The marine vessel of claim 7, wherein the seismic sensor
transfer device is positioned at a subsurface location above a
seabed.
62. The marine vessel of claim 7, wherein at least one of the
seismic sensor transfer device and the seismic sensor storage
compartment comprises at least one of a container, a drone, a skid
structure, a transfer skid, a basket, a rack, and a magazine.
Description
CROSS-REFERENCES TO RELATED APPLICATIONS
[0001] This application claims the benefit of priority under 35
U.S.C. .sctn.120 as a divisional of U.S. patent application Ser.
No. 13/671,645 filed Nov. 8, 2012, which claims the benefit of
priority under 35 U.S.C. .sctn.120 as a continuation of U.S. patent
application Ser. No. 12/343,136 filed Dec. 23, 2008, each of which
are incorporated by reference herein in their entirety.
FIELD OF THE INVENTION
[0002] Embodiments described herein relate to the field of seismic
exploration in a marine environment. More particularly, to an
apparatus and method of transferring seismic equipment to and from
an operations platform and an underwater location.
DESCRIPTION OF THE RELATED ART
[0003] Seismic exploration in deep water typically utilizes seismic
sensor devices stored on a first marine vessel that are transferred
from the first vessel and placed on or near the seafloor or seabed.
These devices are typically referred to as Ocean Bottom Cabling
(OBC) or Ocean Bottom Seismometer (OBS) systems, such as Seafloor
Seismic Recorders (SSR's). These SSR devices contain seismic
sensors and electronics in sealed packages, and record seismic data
on-board the devices while deployed on the seabed as opposed to
digitizing and transmitting the data to an external recorder while
deployed. The recorded data is obtained by retrieving the devices
from the seabed to a location on the first vessel and downloading
the recorded data from the devices to a recorder while onboard the
first vessel.
[0004] In typical operation, hundreds or thousands of OBS units are
deployed from the first vessel to the seabed from the first vessel.
In one conventional method, the OBS units are deployed using a
remotely operated vehicle (ROV) tethered to the first vessel. The
ROV is lowered below the surface of the water and positioned
subsurface. One or more OBS units are placed by the ROV on the
seabed at predetermined locations in a linear row, which may be
known as a receiver line. When at least one receiver line
consisting of a suitable number of the OBS units is formed, a
seismic survey may be performed by providing a source signal, such
as an acoustic or vibrational signal. Reflected signals from the
seabed and underlying structures are recorded on the one or more
OBS units. The source signal or "shot" is typically provided by a
second marine vessel, which may be known as a gun boat.
[0005] In the deployment of the OBS units, the speed at which the
OBS units can be deployed is primarily limited to the speed at
which the equipment can be towed through the water. Specifically,
support equipment for the ROV, such as an umbilical cable and a
tether management system (TMS) have large drag coefficients. The
drag of these components typically limit the speed of the first
vessel. Thus, the number of OBS units that can be deployed or
retrieved in a given time period is limited. The deployment time
also affects the efficiency of the seismic survey as the second
vessel must wait until the at least one receiver line is laid prior
to shooting. The first vessel continues laying other receiver lines
while the second vessel is shooting, but as shooting is often
completed prior to completion of the next receiver line, the second
vessel must again wait until the second receiver line is
formed.
[0006] Therefore, what is needed is a method and apparatus for
transferring seismic sensor devices to and from the first vessel
and/or the ROV in a manner that maximizes the number of seismic
sensor devices deployed and retrieved, and provides a buffer for a
second vessel.
SUMMARY OF THE INVENTION
[0007] Embodiments described herein relate to an apparatus and
method of transferring seismic sensor devices to and from a marine
vessel and subsurface location.
[0008] In one embodiment, a marine vessel is provided. The marine
vessel includes a deck having a plurality of seismic sensor devices
stored thereon, two remotely operated vehicles, each comprising a
seismic sensor storage compartment, and a seismic sensor transfer
device comprising a container for transfer of one or more of the
seismic sensor devices from the vessel to the sensor storage
compartment of at least one of the two remotely operated
vehicles.
[0009] In another embodiment, a marine vessel is provided. The
marine vessel includes at least three cranes disposed thereon, a
plurality of seismic sensor devices stored on the deck, a remotely
operated vehicle coupled to the vessel, the remotely operated
vehicle comprising a seismic sensor storage compartment, and a
seismic sensor transfer device comprising a container for transfer
of one or more seismic sensor devices from the vessel to the
remotely operated vehicle.
[0010] In another embodiment, a method for performing a seismic
survey in a marine environment is provided. The method includes
deploying a first remotely operated vehicle from a first vessel
moving in a direction, deploying a seismic sensor transfer device
from the first vessel having a plurality of sensor devices disposed
therein, transferring the plurality of sensor devices from the
seismic sensor transfer device to a sensor storage compartment of
the first remotely operated vehicle at a subsurface location, and
placing each of the first plurality of sensor devices in selected
locations in the marine environment using the first remotely
operated vehicle.
[0011] In another embodiment, a method for performing a seismic
survey in a marine environment is provided. The method includes
deploying a first remotely operated vehicle from a first vessel,
the first vessel powered to operate in a direction at a speed
greater than zero knots, placing a first plurality of sensor
devices in selected locations in the marine environment using the
first remotely operated vehicle, deploying a seismic sensor storage
container from the first vessel having a second plurality of sensor
devices disposed thereon, and transferring the second plurality of
sensor devices to the first remotely operated vehicle at a
subsurface location.
[0012] In another embodiment, a method for deploying seismic sensor
devices in a marine environment is provided. The method includes
deploying a remotely operated vehicle from a vessel, powering the
vessel to operate at a first speed in a first direction, the first
speed being greater than zero knots, operating the remotely
operated vehicle at a second speed to deploy a first plurality of
sensor devices, the second speed being greater than the first speed
at intermittent intervals, wherein the remotely operated vehicle
deploys the first plurality of sensor devices in a pattern relative
to the first direction of the vessel, deploying a seismic sensor
container from the vessel, the seismic sensor container having a
second plurality of sensor devices disposed thereon, and
transferring the second plurality of sensor devices onto the
remotely operated vehicle.
[0013] In another embodiment, a method for deploying a plurality of
sensor devices in a marine environment is provided. The method
includes deploying at least a first remotely operated vehicle from
a vessel, the first remotely operated vehicle comprising an onboard
sensor storage compartment, loading the onboard sensor storage
compartment with a plurality of sensor devices, operating the
vessel in a first direction, and placing the sensor devices in a
pattern in the marine environment, wherein the pattern comprises at
least three linear rows of sensor devices relative to the first
direction.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] So that the manner in which the above recited features of
the present invention can be understood in detail, a more
particular description of the invention, briefly summarized above,
may be had by reference to embodiments, some of which are
illustrated in the appended drawings. It is to be noted, however,
that the appended drawings illustrate only typical embodiments of
this invention and are therefore not to be considered limiting of
its scope, for the invention may admit to other equally effective
embodiments.
[0015] FIG. 1 is an isometric schematic view of one embodiment of a
seismic operation in deep water.
[0016] FIG. 2 is an isometric schematic view of another embodiment
of a seismic operation in deep water.
[0017] FIG. 3 is a schematic plan view of one embodiment of a
seismic sensor device layout.
[0018] FIG. 4 is a schematic plan view of another embodiment of a
seismic sensor device layout.
[0019] FIG. 5 is a schematic plan view of another embodiment of a
seismic sensor device layout.
[0020] FIG. 6 is a schematic plan view showing a continuation of
the seismic sensor device layout of FIG. 5.
[0021] FIG. 7 is a schematic plan view showing a continuation of
the seismic sensor device layout of FIG. 6.
[0022] FIG. 8 is a flow chart showing one embodiment of a
deployment method.
[0023] FIG. 9 is a flow chart showing another embodiment of a
deployment method.
[0024] To facilitate understanding, identical reference numerals
have been used, where possible, to designate identical elements
that are common to the figures. It is also contemplated that
elements disclosed in one embodiment may be beneficially utilized
on other embodiments without specific recitation.
DETAILED DESCRIPTION
[0025] Embodiments described herein relate to an apparatus and
method for transferring one or more seismic sensor devices to or
from a marine vessel on a surface of a body of water and a
subsurface marine location using a remotely operated vehicle (ROV).
The ROV may be an autonomous underwater vehicle (AUV) or any
apparatus capable of operating autonomously or semi-autonomously in
a marine environment. The marine vessel may be a boat, a ship, a
barge or a floating platform adapted to store and transfer a
plurality of seismic sensor devices. Each of the seismic sensor
devices as described herein may be a discrete subsurface sensor,
for example, sensors and/or recorders, such as ocean bottom
seismometers (OBS), seafloor seismic recorders (SSR), and similar
devices. SSR's are typically re-usable and may be recharged and
serviced before re-deployment. The seismic sensor devices may be
configured to communicate by wireless connections or configured to
communicate through cables. The seismic sensor devices contain
seismic sensors and electronics in sealed packages, and record
seismic data within an on-board recorder while deployed on the
seabed as opposed to digitizing and transmitting the data to an
external recorder. The recorded data is obtained by retrieving the
seismic sensor devices from the seabed using the ROV or AUV.
[0026] FIG. 1 is an isometric schematic view of one embodiment of a
seismic operation in deep water facilitated by a first marine
vessel 5. The first vessel 5 is positioned on a surface 10 of a
water column 15 and includes a deck 20 which supports operational
equipment. At least a portion of the deck 20 includes space for a
plurality of sensor device racks 90 where seismic sensor devices
are stored. The sensor device racks 90 may also include data
retrieval devices and/or sensor recharging devices.
[0027] The deck 20 also includes one or more cranes 25A, 25B
attached thereto to facilitate transfer of at least a portion of
the operational equipment, such as an ROV and/or seismic sensor
devices, from the deck 20 to the water column 15. For example, a
crane 25A coupled to the deck 20 is configured to lower and raise
an ROV 35A, which transfers and positions one or more sensor
devices 30 on a seabed 55. The ROV 35A is coupled to the first
vessel 5 by a tether 46A and an umbilical cable 44A that provides
power, communications, and control to the ROV 35A. A tether
management system (TMS) 50A is also coupled between the umbilical
cable 44A and the tether 46A. Generally, the TMS 50A may be
utilized as an intermediary, subsurface platform from which to
operate the ROV 35A. For most ROV 35A operations at or near the
seabed 55, the TMS 50A can be positioned approximately 50 feet
above seabed 55 and can pay out tether 46A as needed for ROV 35A to
move freely above seabed 55 in order to position and transfer
seismic sensor devices 30 thereon.
[0028] A crane 25B is coupled to a stern of the first vessel 5, or
other locations on the first vessel 5. Each of the cranes 25A, 25B
may be any lifting device and/or launch and recovery system (LARS)
adapted to operate in a marine environment. In this embodiment, the
crane 25B is coupled to a seismic sensor transfer device 100 by a
cable 70. The transfer device 100 may be a drone, a skid structure,
a basket, or any device capable of housing one or more sensor
devices 30 therein. The transfer device 100 may be a structure
configured as a magazine adapted to house and transport one or more
sensor devices 30. In one embodiment, the transfer device 100 is
configured as a sensor device storage rack for transfer of sensor
devices 30 from the first vessel 5 to the ROV 35A, and from the ROV
35A to the first vessel 5. The transfer device 100 may include an
on-board power supply, a motor or gearbox, and/or a propulsion
system (all not shown). Alternatively, the transfer device 100 may
not include any integral power devices and/or not require any
external or internal power source. If needed, the cable 70 may
provide power and/or control to the transfer device 100.
Alternatively, the cable 70 may be an umbilical, a tether, a cord,
a wire, a rope, and the like, that is configured solely for support
of the transfer device 100.
[0029] The ROV 35A includes a seismic sensor device storage
compartment 40 that is configured to store one or more seismic
sensor devices 30 therein for a deployment and/or retrieval
operation. The storage compartment 40 may be a magazine, a rack, or
a container configured to store the seismic sensor devices. The
storage compartment 40 may also include a movable platform having
the seismic sensor devices thereon, such as a carousel or linear
platform configured to support and move the seismic sensor devices
30 therein. In one embodiment, the seismic sensor devices 30 may be
deployed on the seabed 55 and retrieved therefrom by operation of
the movable platform. In this embodiment, the ROV 35A may be
positioned at a predetermined location above or on the seabed 55
and seismic sensor devices 30 are rolled, conveyed, or otherwise
moved out of the storage compartment 40 at the predetermined
location. In another embodiment, the seismic sensor devices 30 may
be deployed and retrieved from the storage compartment 40 by a
robotic device 60, such as a robotic arm, an end effector or a
manipulator, disposed on the ROV 35A.
[0030] For example, in a deployment operation, a first plurality of
seismic sensor devices, comprising one or more sensor devices 30,
may be loaded into the storage compartment 40 while on the first
vessel 5 in a pre-loading operation. The ROV 35A, having the
storage compartment coupled thereto, is then lowered to a
subsurface position in the water column 15. The ROV 35A utilizes
commands from personnel on the first vessel 5 to operate along a
course to transfer the first plurality of seismic sensor devices 30
from the storage compartment 40 and deploy the individual sensor
devices 30 at selected locations on the seabed 55. Once the storage
compartment 40 is depleted of the first plurality of seismic sensor
devices 30, the transfer device 100 is used to ferry a second
plurality of seismic sensor devices 30 as a payload from first
vessel 5 to the ROV 35A.
[0031] The transfer device 100 is preloaded with a second plurality
of seismic sensor devices 30 while on or adjacent the first vessel
5. When a suitable number of seismic sensor devices 30 are loaded
onto the transfer device 100, the transfer device 100 may be
lowered by crane 25B to a selected depth in the water column 15.
The ROV 35A and transfer device 100 are mated at a subsurface
location to allow transfer of the second plurality of seismic
sensor devices 30 from the transfer device 100 to the storage
compartment 40. When the transfer device 100 and ROV 35A are mated,
the second plurality of seismic sensor devices 30 contained in the
transfer device 100 are transferred to the storage compartment 40
of the ROV 35A. Once the storage compartment 40 is reloaded, the
ROV 35A and transfer device 100 are detached or unmated and seismic
sensor device placement by ROV 35A may resume. In one embodiment,
reloading of the storage compartment 40 is provided while the first
vessel 5 is in motion. If the transfer device 100 is empty after
transfer of the second plurality of seismic sensor devices 30, the
transfer device 100 may be raised by the crane 25B to the vessel 5
where a reloading operation replenishes the transfer device 100
with a third plurality of seismic sensor devices 30. The transfer
device 100 may then be lowered to a selected depth when the storage
compartment 40 needs to be reloaded. This process may repeat as
needed until a desired number of seismic sensor devices 30 have
been deployed.
[0032] Using the transfer device 100 to reload the ROV 35A at a
subsurface location reduces the time required to place the seismic
sensor devices 30 on the seabed 55, or "planting" time, as the ROV
35A is not raised and lowered to the surface 10 for seismic sensor
device reloading. Further, mechanical stresses placed on equipment
utilized to lift and lower the ROV 35A are minimized as the ROV 35A
may be operated below the surface 10 for longer periods. The
reduced lifting and lowering of the ROV 35A may be particularly
advantageous in foul weather and/or rough sea conditions. Thus,
safety of personnel and lifetime of equipment may be enhanced as
the ROV 35A and related equipment are not raised above surface 10,
which may cause the ROV 35A and related equipment to be damaged, or
pose a risk of injury to the vessel personnel.
[0033] Likewise, in a retrieval operation, the ROV 35A utilizes
commands from personnel on the first vessel 5 to retrieve each
seismic sensor device 30 that was previously placed on seabed 55.
The retrieved seismic sensor devices 30 are placed into the storage
compartment 40 of the ROV 35A. In one embodiment, the ROV 35A may
be sequentially positioned adjacent each seismic sensor device 30
on the seabed 55 and the seismic sensor devices 30 are rolled,
conveyed, or otherwise moved from the seabed 55 to the storage
compartment 40. In another embodiment, the seismic sensor devices
30 may be retrieved from the seabed 55 by a robotic device 60
disposed on the ROV 35A.
[0034] Once the storage compartment 40 is full or contains a
pre-determined number of seismic sensor devices 30, the transfer
device 100 is lowered to a position below the surface 10 and mated
with the ROV 35A. The transfer device 100 may be lowered by crane
25B to a selected depth in the water column 15, and the ROV 35A and
transfer device 100 are mated at a subsurface location. Once mated,
the retrieved seismic sensor devices 30 contained in the storage
compartment 40 are transferred to the transfer device 100. Once the
storage compartment 40 is depleted of retrieved sensor devices, the
ROV 35A and transfer device 100 are detached and sensor device
retrieval by ROV 35A may resume. Thus, the transfer device 100 is
used to ferry the retrieved seismic sensor devices 30 as a payload
to the first vessel 5, allowing the ROV 35A to continue collection
of the seismic sensor devices 30 from the seabed 55. In this
manner, sensor device retrieval time is significantly reduced as
the ROV 35A is not raised and lowered for sensor device unloading.
Further, safety issues and mechanical stresses placed on equipment
related to the ROV 35A are minimized as the ROV 35A may be
subsurface for longer periods.
[0035] In this embodiment, the first vessel 5 may travel in a first
direction 75, such as in the +X direction, which may be a compass
heading or other linear or predetermined direction. The first
direction 75 may also account for and/or include drift caused by
wave action, current(s) and/or wind speed and direction. In one
embodiment, the plurality of seismic sensor devices 30 are placed
on the seabed 55 in selected locations, such as a plurality of rows
R.sub.n in the X direction (R.sub.1 and R.sub.2 are shown) and/or
columns C.sub.n in the Y direction (C.sub.1-C.sub.3 are shown),
wherein n equals an integer. In one embodiment, the rows R.sub.n
and columns C.sub.n define a grid or array, wherein each row
R.sub.n comprises a receiver line in the width of a sensor array (X
direction) and/or each column C.sub.n comprises a receiver line in
a length of the sensor array (Y direction). The distance between
adjacent sensor devices 30 in the rows is shown as distance L.sub.R
and the distance between adjacent sensor devices 30 in the columns
is shown as distance L.sub.C. While a substantially square pattern
is shown, other patterns may be formed on the seabed 55. Other
patterns include non-linear receiver lines and/or non-square
patterns. The pattern(s) may be pre-determined or result from other
factors, such as topography of the seabed 55. In one embodiment,
the distances L.sub.R and L.sub.C may be substantially equal and
may include dimensions between about 60 meters to about 400 meters,
or greater. The distance between adjacent seismic sensor devices 30
may be predetermined and/or result from topography of the seabed 55
as described above.
[0036] The first vessel 5 is operated at a speed, such as an
allowable or safe speed for operation of the first vessel 5 and any
equipment being towed by the first vessel 5. The speed may take
into account any weather conditions, such as wind speed and wave
action, as well as currents in the water column 15. The speed of
the vessel may also be determined by any operations equipment that
is suspended by, attached to, or otherwise being towed by the first
vessel 5. For example, the speed is typically limited by the drag
coefficients of components of the ROV 35A, such as the TMS 50A and
umbilical cable 44A, as well as any weather conditions and/or
currents in the water column 15. As the components of the ROV 35A
are subject to drag that is dependent on the depth of the
components in the water column 15, the first vessel speed may
operate in a range of less than about 1 knot. In this embodiment,
wherein two receiver lines (rows R.sub.1 and R.sub.2) are being
laid, the first vessel includes a first speed of between about 0.2
knots and about 0.6 knots. In other embodiments, the first speed
includes an average speed of between about 0.25 knots, which
includes intermittent speeds of less than 0.25 knots and speeds
greater than about 1 knot, depending on weather conditions, such as
wave action, wind speeds, and/or currents in the water column
15.
[0037] During a seismic survey, one receiver line, such as row
R.sub.1 may be deployed. When the single receiver line is completed
a second vessel 80 is used to provide a source signal. The second
vessel 80 is provided with a source device 85, which may be a
device capable of producing acoustical signals or vibrational
signals suitable for obtaining the survey data. The source signal
propagates to the seabed 55 and a portion of the signal is
reflected back to the seismic sensor devices 30. The second vessel
80 may be required to make multiple passes, for example at least
four passes, per a single receiver line (row R.sub.1 in this
example). During the time the second vessel 80 is making the
passes, the first vessel 5 continues deployment of a second
receiver line. However, the time involved in making the passes by
the second vessel 80 is much shorter than the deployment time of
the second receiver line. This causes a lag time in the seismic
survey as the second vessel 80 sits idle while the first vessel 5
is completing the second receiver line.
[0038] In this embodiment, the first vessel 5 utilizes one ROV 35A
to lay sensor devices to form a first set of two receiver lines
(rows R.sub.1 and R.sub.2) in any number of columns, which may
produce a length of each receiver line of up to and including
several miles. In one embodiment, the two receiver lines (rows
R.sub.1 and R.sub.2) are substantially parallel. When a single
directional pass of the first vessel 5 is completed and the first
set (rows R.sub.1, R.sub.2) of seismic sensor devices 30 are laid
to a predetermined length, the second vessel 80, provided with the
source device 85, is utilized to provide the source signal. The
second vessel 80 is typically required to make eight or more passes
along the two receiver lines to complete the seismic survey of the
two rows R.sub.1 and R.sub.2.
[0039] While the second vessel 80 is shooting along the two rows
R.sub.1 and R.sub.2, the first vessel 5 may turn 180 degrees and
travel in the -X direction in order to lay seismic sensor devices
30 in another two rows adjacent the rows R.sub.1 and R.sub.2,
thereby forming a second set of two receiver lines. The second
vessel 80 may then make another series of passes along the second
set of receiver lines while the first vessel 5 turns 180 degrees to
travel in the +X direction to lay another set of receiver lines.
The process may repeat until a specified area of the seabed 55 has
been surveyed. Thus, the idle time of the second vessel 80 is
minimized as the deployment time for laying receiver lines is cut
approximately in half by deploying two rows in one pass of the
vessel 5.
[0040] Although only two rows R.sub.1 and R.sub.2 are shown, the
sensor device 30 layout is not limited to this configuration as the
ROV 35A may be adapted to layout more than two rows of sensor
devices in a single directional tow. For example, the ROV 35A may
be controlled to lay out between three and six rows of sensor
devices 30, or an even greater number of rows in a single
directional tow. The width of a "one pass" run of the first vessel
5 to layout the width of the sensor array is typically limited by
the length of the tether 46A and/or the spacing (distance L.sub.R)
between sensor devices 30.
[0041] FIG. 2 is an isometric schematic view of another embodiment
of a seismic operation in deep water facilitated by the first
vessel 5. In this embodiment, the first vessel 5 has multiple ROV's
operating therefrom. In FIG. 2, by way of example and not
limitation, two ROV 35A and ROV 35B are shown. Each of the ROV's
35A, 35B include a respective TMS 50A, 50B, tether 46A, 46B, and
umbilical cable 44A, 44B. The first ROV 35A is coupled to the first
crane 25A on the port side 6A of the first vessel 5 and the second
ROV 35B is coupled to a third crane 25C on the starboard side 6B of
the first vessel 5.
[0042] The first ROV 35A and the second ROV 35B are configured to
provide a layout pattern for the plurality of sensor devices 30 on
the seabed 55 on both sides of the first vessel 5. Each of the
ROV's 35A and 35B may be controlled independently or synchronously
to travel in a direction or course relative to the vessel 5 to
deploy the sensor devices 30 on the seabed in a pre-determined
pattern. In one aspect, each of the ROV's 35A and 35B deploy a
plurality of rows and columns as described above. In the embodiment
depicted in FIG. 2, rows R.sub.1-R.sub.4 and columns
C.sub.1-C.sub.4 define, respectively, the width and the length of a
seismic array.
[0043] In this embodiment, ROV 35A moves in a first pattern
relative to the vessel direction 75 to deploy a plurality of rows
of sensor devices 30 (rows R.sub.1 and R.sub.2 are shown) while ROV
35B moves in a second pattern relative to the vessel direction 75
to deploy a plurality of rows of sensor devices 30 (rows R.sub.3
and R.sub.4 are shown). The pattern of the first ROV 35A may be the
same or different than the pattern of the second ROV 35B. The
distance between adjacent sensor devices 30 in the rows
R.sub.1-R.sub.4 is shown as distance L.sub.R and the distance
between adjacent sensor devices 30 in the columns C.sub.1-C.sub.4
is shown as distance L.sub.C. While a substantially square pattern
is shown, other patterns may be formed on the seabed 55. Other
patterns include non-linear receiver lines and/or non-square
patterns. The pattern(s) may be pre-determined or result from other
factors, such as topography of the seabed 55. In one embodiment,
the distances L.sub.R and L.sub.C may be substantially equal and
may include dimensions between about 60 meters to about 400 meters,
or greater. The distance between adjacent seismic sensor devices 30
may be predetermined and/or result from topography of the seabed 55
as described above.
[0044] In the embodiment shown, the rows R.sub.1-R.sub.4 form a
first set of four receiver lines and the rows are complete when a
sufficient number of columns are provided. Once the first set is
completed, the second vessel may provide the source signal. In this
embodiment, the second vessel must make at least 16 passes to shoot
the four rows R.sub.1-R.sub.4. During this time, the first vessel 5
is laying a second set of receiver lines, which may include four
rows. Thus, the deployment time of the four receiver lines (rows
R.sub.1-R.sub.4) by the vessel 5 is effectively reduced by about 25
percent as compared to deployment of a single receiver line. The
minimized deployment time results in less idle time of the second
vessel, which results in greater efficiency and reduced costs of
the seismic survey.
[0045] As in the embodiment shown in FIG. 1, the rows R.sub.1,
R.sub.2 formed by ROV 35A and rows R.sub.3, R.sub.4 formed by the
ROV 35B are not limited as described and may consist of three,
four, five, six, or greater number of rows. In one example, each of
the ROV's 35A, 35B may lay four sensor devices 30 to form four rows
such that eight sensor devices 30 comprise each column. In this
example, when a sufficient number of columns are provided to form
the rows, eight receiver lines define the present width of the
array. The lateral pattern (Y direction) used to deploy each row is
typically chosen to maintain forward motion of the vessel 5 and
minimize stopping forward motion of the vessel 5. Thus the lateral
pattern to deploy additional rows may be limited by the speed of
the ROV's 35A, 35B, specifically the speed of the ROV's 35A, 35B in
the Y direction. The lateral (Y direction) distance from the first
vessel 5 is limited by a length of the tethers 46A, 46B. Thus, in
one embodiment, the maximal distance for placement of seismic
sensor devices 30 in rows R.sub.1 and R.sub.4 from the first vessel
5 is substantially equal to the length of the tethers 46A, 46B. In
this embodiment, the maximal distance from the first vessel 5 where
the seismic sensor devices 30 in rows R.sub.1 and R.sub.4 are
positioned are between about 600 meters to about 1200 meters, or
greater from the first vessel 5. In other embodiments, the maximal
distance is between about 1000 meters to about 1600 meters from the
first vessel 5.
[0046] FIG. 3 is a schematic plan view of one embodiment of a
seismic sensor device layout 300 which, in one embodiment,
comprises a plurality of receiver lines (rows R.sub.1-R.sub.6).
Points 301A-309A represent locations for placement of seismic
sensor devices on a seabed along the port side 6A of the first
vessel 5 and points 301B-309B represent locations for placement of
seismic sensor devices on the seabed along the starboard side 6B of
the first vessel 5. While not shown, an ROV operating on the port
side 6A and an ROV operating on the starboard side 6B facilitate
placement of the seismic sensor devices at the points 301A-309A and
301B-309B.
[0047] In this embodiment, seismic sensor device placement by the
ROV 35A starts at point 301A on the port side 6A and placement of
the seismic sensor devices by the ROV 35B on the starboard side 6B
starts at point 301 B. The port side 6A and starboard side 6B
placement then proceeds in the +Y direction to points 302A and
302B, respectively. The port side 6A pattern (and starboard side
pattern) then proceeds in a +Y direction to point 303A (and point
303B), then in the X direction to point 304A (and point 304B), then
in the -Y direction to point 305A and point 306A (points 305B and
306B). In this embodiment, identical X-Y patterns P.sub.A and
P.sub.B are defined by points 301A-307A on the port side 6A and
points 301B-307B on the starboard side 6B. A repeating X-Y pattern
is then executed at 307A and 307B until a sufficient number of
columns C.sub.n are formed.
[0048] FIG. 4 is a schematic plan view of another embodiment of a
seismic sensor device layout 400 which, in one embodiment,
comprises a plurality of receiver lines (rows R.sub.1-R.sub.6).
Points 401A-409A represent locations for placement of seismic
sensor devices on a seabed along the port side 6A of the first
vessel 5 and points 401B-409B represent locations for placement of
seismic sensor devices on the seabed along the starboard side 6B of
the first vessel 5. While not shown, an ROV operating on the port
side 6A and an ROV operating on the starboard side 6B facilitate
placement of the seismic sensor devices at the points 401A-409A and
401B-409B.
[0049] In this embodiment, the port side 6A placement by the ROV
35A starts at point 401A and the starboard side 6B placement by the
ROV 35B starts at point 401B. The port side placement then proceeds
in the +Y direction to point 402A and 403A, then in the X direction
to point 404A, then in the -Y direction to point 405A and point
406A. The starboard side 6B placement proceeds in the -Y direction
to point 402B and 403B, then in the X direction to point 404B, then
in the +Y direction to 405B and 406B. In this embodiment, a
mirror-image of X-Y patterns P.sub.A and P.sub.B are defined by
points 401A-407A on the port side 6A and points 401B-407B on the
starboard side 6B. A repeating mirrored X-Y pattern is then
executed at 407A and 407B until a sufficient number of columns
C.sub.n are formed.
[0050] FIG. 5 is a schematic plan view of another embodiment of a
seismic sensor device layout 500. The array layout is similar to
the array layout 300 and pattern of FIG. 3 with the exception of
sensor devices being laid over a portion of the points 301A-312A on
the port side 6A of the first vessel 5 and a portion of the points
301B-312B on the starboard side 6B of the first vessel 5. The
sensor devices that have been positioned on the respective points
301A-306A and 301B-306B are referenced as sensor devices 501A-506A
on the port side 6A of the first vessel 5 and sensor devices
501B-506B on the starboard side 6B of the first vessel 5.
Additionally, the port side 6A ROV 35A is shown as well as the
starboard side 6B ROV 35B.
[0051] As described in FIGS. 1 and 2, each of the ROV's 35A, 35B
include an integral storage compartment 40 which are not shown in
the plan view of FIG. 5. In one embodiment, each of the storage
compartments 40 contains a first plurality of seismic sensor
devices 30. For example, the storage compartment 40 may have a
capacity of about 14 seismic sensor devices. The sensor devices may
be pre-loaded into each storage compartment 40 on the first vessel
5 for subsequent transfer to each point. Once the sensor devices
have been laid on the points in the array layout 500, the storage
compartments 40 are replenished without surfacing the ROV's 35A,
35B. In this embodiment, a transfer device 100 is towed behind the
first vessel 5 to facilitate reloading of sensor devices in the
storage compartment of ROV 35A. In one embodiment, the pre-loading
and reloading of the storage compartments 40 of each ROV 35A, 35B
with seismic sensor devices 30 are unequal to facilitate a
staggered or alternating reloading operation between each ROV 35A,
35B.
[0052] In this embodiment, after sensor device 506A is deployed at
point 306A, the ROV 35A is reloaded. The transfer device 100 is
towed behind the first vessel 5 below the vessel 5. The ROV 35A may
travel to the towed transfer device 100 in a course 550 to a
position adjacent the transfer device 100. The ROV 35A and transfer
device 100 are mated in a manner to transfer the seismic sensor
devices to the storage compartment 40. While the ROV 35A is
reloaded, the storage compartment 40 of the ROV 35B may not be
depleted and continues deployment on the starboard side 6B. In this
embodiment, the ROV 35A is reloaded with additional sensor devices
by the transfer device 100 while the ROV 35B continues deployment
of sensor devices. After the storage compartment of ROV 35A is
reloaded, the ROV 35A and transfer device 100 are detached and the
ROV 35A travels in a course 555 toward the next deployment point
307A. Each of the courses 550, 555 may be a lateral direction, a
diagonal direction, or a linear or serpentine path. The reloading
operation is staggered between the ROV's 35A and 35B to enhance
efficiency of the deployment of the array. During reloading, the
first vessel 5 may be stopped, slowed or maintained at a speed that
was used during deployment of seismic sensor devices along the
array.
[0053] FIG. 6 is a schematic plan view showing a continuation of
the seismic sensor device layout 500 of FIG. 5. In this embodiment,
after sensor device 509B is deployed at point 309B, the ROV 35B is
reloaded. ROV 35A, which has been reloaded with a second plurality
of sensor devices as shown in FIG. 5, continues deployment on the
port side 6A (shown as sensor devices 601A-603A). In this
embodiment, the ROV 35B is reloaded with a second plurality of
sensor devices by the transfer device 100 while the ROV 35A
continues deployment of sensor devices.
[0054] FIG. 7 is a schematic plan view showing a continuation of
the seismic sensor device layout 500 of FIG. 6. In this embodiment,
after sensor device 612A is deployed at point 318A, the ROV 35A is
reloaded. ROV 35B, which has been reloaded with a second plurality
of sensor devices, continues deployment on the starboard side 6B
(shown as sensor devices 701B-709B). In this embodiment, the ROV
35A is reloaded with a third plurality of sensor devices by the
transfer device 100 while the ROV 35B continues deployment of
sensor devices.
[0055] As shown in the embodiments of FIGS. 5-7, eighteen sensor
devices have been deployed at points 301A-318A by ROV 35A and
eighteen sensor devices have been deployed at points 301B-318B by
ROV 35B for a total of thirty six sensor devices in one-pass of the
vessel. The reloading operation to replenish the ROV storage
compartment is alternated between the ROV's 35A, 35B to enhance
efficiency of the layout of the array. During the deployment of the
rows, the speed of the first vessel 5 may be maintained at a
substantially constant speed.
[0056] In one operational embodiment, an example of deploying
sensor devices using the embodiments described in FIGS. 5-7 will be
described. The first vessel 5 speed may be maintained or averaged
at about 0.25 knots along direction 75 while a port side 6A ROV 35A
and a starboard side ROV 35B may be operated at speeds of less than
about 10 knots. The distances L.sub.R and L.sub.C between points
may be about 400 meters. A first plurality of sensor devices 30,
consisting of six sensor devices, may be preloaded into ROV 35A and
a first plurality of sensor devices 30, consisting of nine sensor
devices, may be preloaded into ROV 35B. Seismic sensor devices
501A-506A may be deployed and ROV 35A should be reloaded with a
second plurality of seismic sensor devices as shown in FIG. 5. The
second plurality of seismic sensor devices may comprise twelve
sensor devices. In this embodiment, the first vessel 5 may be
maintained at about 0.25 knots during the reloading operation.
[0057] The first vessel 5 proceeds in the direction 75 and ROV 35A
continues deployment of seismic sensor devices beginning at point
307A while ROV 35B places a seismic sensor device 507B at point
307B as shown in FIG. 6. Both ROV's 35A and 35B may continue
deployment along the patterns until deployment of seismic sensor
device 509B by ROV 35B.
[0058] After deployment of seismic sensor device 509B by ROV 35B,
ROV 35B may be reloaded with a second plurality of seismic sensor
devices, as shown in FIG. 6. The second plurality of sensor devices
may comprise another twelve seismic sensor devices. The first
vessel 5 may be maintained at about 0.25 knots during the reloading
operation. The first vessel 5 proceeds in the direction 75 and ROV
35B may continue deployment of seismic sensor devices beginning at
point 310B while ROV 35A places a seismic sensor device 604A at
point 310A as shown in FIG. 7. Both ROV's 35A, 35B may continue
deployment along the pattern as shown. After ROV 35A deploys a
sensor device 612A at point 318A, the ROV 35A may be reloaded with
a third plurality of seismic sensor devices, for example, another
twelve seismic sensor devices. The pattern may continue until a
sufficient number of columns are completed. After completion, the
second vessel (not shown) may begin shooting, which may involve at
least 24 passes of the second vessel. During the shooting, the
first vessel may begin another one pass lay of another six receiver
lines.
[0059] FIG. 8 is a flow chart showing one embodiment of a
deployment method 800. The method 800 may be used to deploy a
plurality of seismic sensor receiver lines in one pass of a first
vessel as described in the above embodiments. At 810, at least one
ROV is deployed from a vessel. At 815, the vessel is operated in a
first direction relative to a seabed. The first direction may be a
compass heading or other linear or substantially linear direction.
At 820, a plurality of seismic sensor devices are deployed from the
at least one ROV to form at least two receiver lines on the seabed
along the first direction. In one embodiment, the at least two
receiver lines are substantially parallel to the first direction.
In another embodiment, the at least two receiver lines are
substantially parallel to each other.
[0060] FIG. 9 is a flow chart showing another embodiment of a
deployment method 900. The method 900 may be used to deploy a
plurality of seismic sensor receiver lines in one pass of a first
vessel as described in the above embodiments. The method begins at
910 using at least two ROV's coupled to the first vessel in a body
of water. At 915, the vessel operates in a first direction in the
body of water. The first direction may be a compass heading or
other linear and/or directional path. At 920, a plurality of sensor
devices are deployed from the at least two ROV's while the vessel
travels in the first direction. The plurality of sensor devices may
be deployed in a plurality of receiver lines comprising a pattern.
The pattern may be an X/Y pattern in a mirror-image, an identical
X/Y pattern, or other pattern using the at least two ROV's. In one
embodiment, the plurality of receiver lines are substantially
parallel to the first direction. In another embodiment, the
plurality of receiver lines are substantially parallel to each
other.
[0061] The deployment of multiple receiver lines has been
determined empirically as described in FIG. 1. While setting the
vessel speed to safe operating speed, the number of seismic sensor
devices deployed in a specific time period was greater than the
conventional deployment method in the same time period. In one
example according to the embodiment described in FIG. 1, two
receiver lines were deployed at a rate of about ten seismic sensor
units per hour, while the conventional one pass method of deploying
ten seismic sensor units in a single receiver line took
approximately five hours. In one specific example using the
embodiment described in FIG. 1, two receiver lines were deployed
having 5 seismic sensor devices each (ten seismic sensor units
total) at 400 meter spacings (distances L.sub.R and L.sub.C). The
vessel 5 was slowed to about one-half of the conventional speed. In
this example, the one pass deployment of the two receiver lines
resulted in a time savings of about thirty minutes as compared to
conventional deployment of a single receiver line (ten seismic
sensor units) in one pass at twice the travel speed. This time
saving may be extrapolated to multiple columns up to and including
several miles and when the receiver lines are completed, the second
vessel will be utilized for many hours or days, dependent upon the
number of columns or length of the receiver lines. While the second
vessel is shooting, the first vessel continues to deploy other
receiver lines in one pass. Thus, a buffer time for the first
vessel may be created using the one pass multiple receiver line
deployment method.
[0062] Using the embodiments described herein, the deployment time
of seismic sensor devices is significantly minimized, which allows
the second vessel to operate with minimal or no idle time waiting
for receiver line placement. The decreased deployment time also
minimizes the time the first vessel is operating on the water. The
decreased time on the water also minimizes labor costs and fuel
usage. The decreased time on the water also allows seismic array
layouts to be completed in a time frame that coincides with fair
weather windows. Thus, deployment (and/or retrieval) of the sensor
devices is less likely to be suspended due to periods of foul
weather. As the seismic sensor devices include batteries with a
limited operational time, the shortened deployment time also
increases the probability that the survey can be complete before
exhaustion of the batteries of the seismic sensor devices. For
example, a seismic survey utilizing one thousand sensor devices may
be completed in one week, including deployment and shooting, as
opposed to conventional deployment methods which may take many
weeks to cover the same area. Retrieval of the sensor devices may
be completed in another week using the methods described
herein.
[0063] While the foregoing is directed to embodiments of the
present invention, other and further embodiments of the invention
may be devised without departing from the basic scope thereof, and
the scope thereof is determined by the claims that follow.
* * * * *