BACKGROUND
TECHNICAL FIELD
[0001] Embodiments of the subject matter disclosed herein generally relate to
methods and systems and, more particularly, to mechanisms and techniques for
coating and/or cleaning seismic equipment that is deployed in water or underwater
DISCUSSION OF THE BACKGROUND
[0002] During the past years, Interest in developing new oil and gas
^ P production fields has dramatically increased. However, the availability of land-based
production fields is limited. Thus, the industry has now extended drilling to offshore
locations, which appear to hold a vast amount of fossil fuel. Offshore drilling is an
expensive process. Thus, those engaged in such a costly undertaking invest
substantially in geophysical surveys to more accurately decide where to drill in order
to avoid a dry well.
[0003] Marine seismic data acquisition and processing generate a profile
(image) of the geophysical structure (subsurface) under the seafloor. This profile is
used by those trained in the field to evaluate the presence or absence of oil and/or
^ ^ gas traps. Thus, providing a high-resolution image of the subsurface is an ongoing
process for the exploration of natural resources, including, among others, oil and/or
gas.
[0004] During a seismic gathering process, as shown in Figure 1, a vessel 10
tows an array of seismic detectors provided on streamers 12. The streamers may be
disposed horizontally, i.e., lying at a constant depth relative to a surface 14 of the
2
r
ocean. The vessel 10 also tows a sound source assembly 16 that is configured to
generate an acoustic wave 18. The acoustic wave 18 propagates downward, toward
the seafloor 20, and penetrates the seafloor until eventually a reflecting structure 22
(reflector) reflects the acoustic wave. The reflected acoustic wave 24 propagates
upward until it is detected by a detector on streamer 12.
[0005] The above-noted arrangement is towed underwater for days, if not
weeks, for a given survey. Thus, it was noted that various marine creatures or
animals, e.g., barnacles, attach to vahous components of the streamer, e.g., external
skin, electronic components, birds, etc. The barnacles may increase the drag on the
^ ^ streamer, which increase fuel consumption and may damage the equipment, or they
may change the desired weight of the streamer, may make the streamer deviate
from its desired towed position, may affect the recorded signal, may introduce noise
or simply may make it difficult to manipulate the streamer for maintenance or when
deployed underwater.
[0006] Traditional methods employ a cleaning device configured to move
along the streamer and clean the streamer of marine animals. However, there are
problems with these devices because they are bulky and they need to travel along
various elements (e.g., birds, electronic boxes, etc.) connected to the streamer
^ p [0007] An improved method is disclosed in U.S. Provisional Patent
Application Serial No. 61/657,511 ('511 herein), assigned to the same assignee as
the present patent application. Figure 2, which corresponds to Figure of '511, shows
a cleaning device 200 that is deployed over (around) a streamer 202 for providing
one or more functions (e.g., cleaning, repairing, etc.) to the streamer. The streamer
202 extends into the water and is towed by a vessel (not shown) along direction X.
3
The cleaning device 200 has a body 204 made of a flexible material, e.g., composite,
plastic, metal or a combination thereof. The body 204 has a spiral-type shape and
may be wrapped around the streamer 202. The body 204 preferably is able to twist
one portion relative to another portion, i.e., it is flexible for reasons to be discussed
later. Thus, the body 204 may have a spring shape as shown in Figure 2 and is
capable of compressing or extending depending on the applied forces.
[0008] For making the cleaning device 200 advance along the streamer 202
(along direction 210), a movement-generating device 206 is provided at one end 208
of the body 204. The movement-generating device 206 may be an anchor or a
^ ^ surface configured to be acted upon by the water while the streamer is towed with a
given velocity so that the cleaning device 200 is drag-propelled while the streamer is
towed.
[0009] For providing rotational motion to the body 204, or for supplementing
j the rotational motion, wings 220 may be provided along the body 204, The wings
220 are oriented relative to the body 204 so that due to the motion of the streamer
along direction X, the water acts on the wings 220 to rotate them and implicitly the
body 204 along the rotational direction 212. The cleaning device 200 may have
various elements to provide desired functions, e.g., cleaning, repairing, etc.
[0010] However, one or more components of the above described system j
may become blocked, e.g., when passing a bird, and thus, may fail to achieve the
intended use.
[0011] Accordingly, it would be desirable to provide systems and methods that
avoid the afore-described problems and drawbacks.
4
SUMMARY
[0012] According to one exemplary embodiment, there is a coating and/or
cleaning device for cleaning a marine seismic streamer. The device includes a body
having an opening configured to receive the marine seismic streamer; an actuator
configured to be removably attached to the marine seismic streamer; a rope
connecting the body to the actuator; and a control device configured to activate the
actuator to retract or release the body. The body is configured to coat the marine
seismic streamer with a biocide material.
^ ^ [0013] According to another exemplary embodiment, there is a coating and/or
cleaning system for cleaning a mahne seismic streamer. The system includes a first
coating and/or cleaning device configured to be attached to the marine seismic
streamer, between first and second birds; a second coating and/or cleaning device
j configured to be attached to the marine seismic streamer, between second and third
birds; a rope connecting the first coating and/or cleaning device to the second
coating and/or cleaning device; and a pulley-type device attached to the marine
seismic streamer and configured to handle the rope such that a movement of the first
coating and/or cleaning device along a direction of the marine seismic streamer
^ P makes the second coating and/or cleaning device to move in an opposite direction of
the marine seismic streamer. The system is configured to apply a biocide material
on the streamer.
[0014] According to still another exemplary embodiment, there is a coating
and/or cleaning device for cleaning a marine seismic streamer. The device includes
a body having an opening configured to receive the marine seismic streamer; an
5
actuator attached to the body; and a control device configured to activate the
actuator to move the along the marine seismic streamer between two consecutive
birds. The body is configured to coat the marine seismic streamer with a biocide
material.
[0015] According to yet another exemplary embodiment, there is a method for
coating with a biocide materia! a streamer. The method includes a step of attaching
a coating and/or cleaning device to the streamer; a step of controlling a movement of
the coating and/or cleaning device along the streamer; and a step of applying a coat
of the biocide material on the streamer when the coating and/or cleaning device
^^ moves along the streamer.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] The accompanying drawings, which are incorporated in and constitute
I a part of the specification, illustrate one or more embodiments and, together with the
description, explain these embodiments. It is noted that no dimensions should be
inferred from the drawings unless specifically indicated in the specification. In the
drawings:
[0017] Figure 1 is a schematic diagram of a conventional seismic data
acquisition configuration; I
[0018] Figure 2 is a schematic diagram of a conventional cleaning device;
[0019] Figure 3 is a schematic diagram of a coating and/or cleaning device
according to an exemplary embodiment;
[0020] Figure 4 is a schematic view of a body of a coating and/or cleaning
device according to an exemplary embodiment;
6
[0021] Figure 5 illustrates how a coating and/or cleaning device moves along
a streamer according to an exemplary embodiment;
[0022] Figures 6 and 7 illustrate another coating and/or cleaning device
according to an exemplary embodiment;
[0023] Figure 8 shows a body of a coating and/or cleaning device according to
an exemplary embodiment;
[0024] Figure 9 illustrate yet another coating and/or cleaning device
according to an exemplary embodiment;
[0025] Figure 10 is a schematic view of a control device according to an
^ ^ exemplary embodiment;
[0026] Figure 11 is a flowchart of a method for applying a coating to a
streamer while underwater; and
[0027] Figure 12 is a schematic view of a seismic survey acquisition system
I that uses a cleaning and/or coating device according to an embodiment.
DETAILED DESCRIPTION
[0028] The following description of the exemplary embodiments refers to the
accompanying drawings. The same reference numbers in different drawings identify
the same or similar elements. The following detailed description does not limit the j
invention. Instead, the scope of the invention is defined by the appended claims. The
following embodiments are discussed, for simplicity, with regard to the terminology and
structure of a streamer having one or more obstacles, e.g., birds, and a cleaning and/or
coating device that can travel along the streamer between the birds. However, the
7
embodiments to be discussed next are not limited to a streamer, but may be applied to
other structures that are exposed to a marine environment.
[0029] Reference throughout the specification to "one embodiment" or "an
embodiment" means that a particular feature, structure or characteristic described in y
connection with an embodiment is included in at least one embodiment of the subject
matter disclosed. Thus, the appearance of the phrases "in one embodiment" or "in an
embodiment" in various places throughout the specification is not necessarily referring
to the same embodiment. Further, the particular features, structures or characteristics
may be combined in any suitable manner in one or more embodiments.
^ ^ [0030] According to an exemplary embodiment, a streamer and a cleaning
and/or coating system 300 is shown in Figure 3. The system 300 includes the
streamer 302 and the cleaning and/or coating device 304. The streamer 302 may be
any known streamer in the industry. The streamer 302 may have or not birds. A bird
j is known in the industry to be a positioning device that has wings or other means
(e.g., water pumps) for controlling a position (horizontal and/or vertical) of the
streamer while deployed in water. The birds may be clamped to the streamer or
have their bodies attached in between sections of the streamer.
[0031] Figure 3 shows a streamer 302 having first and second birds 306A and
^ p 306B attached to the streamer. For example, the streamer may be a Sentinel
streamer (manufactured by Sercel, located in Nantes, France) and the birds may be
Nautilus birds (also manufactured by Sercel).
[0032] The cleaning and/or coating device 304 is configured, as discussed
next, to travel both ways between consecutive birds 306A and 306B. The cleaning
and/or coating device 304 may have various functions. For example, the cleaning
8
and/or coating device 304 may liave a cleaning function, i.e., it may have a
component 308 (e.g., a scraper for removing material deposited on the streamer, a
brush for coating a material on the streamer, a sweeper, or equivalent part) attached
to a body 310 of the cleaning and/or coating device 304, as shown in Figure 4, for
removing and/or cleaning an exterior surface of the streamer. The body 310 may
have a ring shape with an opening 305 for receiving the streamer 302. In one
application, the body 310 is made of two parts that are attached over the streamer
(e.g., using screws, hinges, etc.) The component 308 may be continuous or not
around the streamer. The cleaning and/or coating device 304 may also provide a
^ ^ coating function to the streamer. For example, the component 308 may be a brush
loaded with a biocide material (e.g., a pesticide, an antimicrobial, etc.) in the form of
a gel or a wax. The biocide material 311, after being deposited on the streamer 302
as shown in Figure 3, removes, kills and/or prevents the marine life (e.g., barnacles)
j to attach to the streamer. Supplementary biocide material may be stored in the body
310 and supplied to the brush as necessary, for example, while the streamer is
towed underwater. Rollers 312 may be provided on the body 310 for improving a
motion of the body along the streamer. Other systems may be used instead of the
brush for supplying and applying the biocide material to the streamer.
[0033] Returning to Figure 3, the mechanism for making the cleaning and/or I
coating device 304 travels along the streamer is now discussed. Figure 3 shows an
actuator 320 (e.g., an electric motor that is supplied with electric power from the
streamer 302) that is attached to the streamer, behind the first bird 306A. The
actuator 320 may be removably fixed to the streamer. Thus, when the streamer is
retracted on the vessel, the actuator may be removed before wounding the streamer
9
on a spool on the vessel's deck. Alternatively, the actuator 320 may be directly
attached to the bird as shown by reference number 320A.
[0034] A rope 322 extends from the actuator 320 to the cleaning and/or
coating device 304. The rope 322 may be made of a synthetic material, a natural
material, may include cables to transmit data and/or electric power or may be just a
cable. In one application, rope 322 may be guided through an enclosure 323.
Enclosure 323 may be closed to prevent damage from ocean on the rope. In one
application, more than one rope may be connected between the actuator and the
cleaning and/or coating device for preventing applying an unbalanced force on one
^^ side of the body 310. Alternatively, rollers 312 prevent the application of an
unsymmetrical force on the body 310. One or more wings (or other equivalent
devices) 330 may be attached to the body 310 for propulsion purposes, as will be
discussed later. A switch 340 is also provided on the body 310 and disposed to face
the second bird 306B. The switch 340 is used to detect a contact between the
device 304 and the second bird 306B and to switch a traveling direction of the
cleaning and/or coating device 304. A control device 350 is responsible for receiving
the data from the switch 340, switching the travelling direction, coordinating the
movement of the wings 330, coordinating the actuator 320, etc. In another
^ p embodiment, the control device 350 in coordination with a vessel's central control
device (not shown) coordinate the cleaning and/or coating device's movement as
discussed later. In still another embodiment, a mechanical system may be
implemented for automatizing the switching of the travelling direction. The body 310
may also include a battery 360 for supplying electric power to the control device 350.
Alternatively, if electric power is received either from the streamer (e.g., inductive
10
electric power transfer) or from the actuator 320, an interface 362 is provided in the
body 310 for managing the power transfer. If the last version is implemented, then
the actuator 320 may inductively receive electric power from the streamer and in this
case, the rope 322 serves not only to retrieve the cleaning and/or coating device 304
but also to supply the electric power. In still another exemplary embodiment, the
rope 322 provides a path (e.g., a cable) for exchanging data between the streamer
and/or the actuator and the cleaning and/or coating device. In yet another
exemplary embodiment, the cleaning and/or coating device may exchange data
directly with the streamer.
^ ^ [0035] The functionality of the cleaning and/or coating device 304 is now
discussed. Suppose that the streamer travels along the positive direction of the X
axis as shown in Figure 3, and that the cleaning and/or coating device 304 is located
next to the first wing 306A. Under these conditions, the control device 350 may
instruct the actuator 320 to release the rope 322 so that the cleaning and/or coating
device 304 moves in the negative direction of the X axis as shown in Figure 5. To
facilitate this movement, the control device 350 may instruct the wings 330 to deploy
as also shown in Figure 5. This movement of the cleaning and/or coating device 304
continues until the switch 340 contacts the second bird 306B in Figure 5. At that
^ p time, the switch sends a signal to the control device 350 indicative of the proximity of
the cleaning and/or coating device 304 to the second bird 306B. Based on this
information, the control device 350 may instruct the actuator 320 to retract the rope
322 to bring the cleaning and/or coating device 304 back to the original position, i.e.,
next to the first bird 306A. The control device 350 also instructs the wings to retract
to a folded position when the cleaning and/or coating device is next to the second
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bird 306B, to reduce the drag. In another application, the control device 350 waits a
predetermined time before instructing the actuator 320 to retrieve the rope 322. In
still another embodiment, the vessel's control system transmits data to the control
device 350 about a timing when to retract or release the rope 322 and/or when to
deploy or retract the wings.
[0036] Note that when the cleaning and/or coating device 304 travels from the
first bird 306A to the second bird 306B, the biocide matehal may be coated to the
streamer. In one application, the biocide material is applied when the cleaning
and/or coating device 304 travels from the second bird to the first bird. In still
^^ another exemplary embodiment, the biocide material is applied both ways. In yet
another exemplary embodiment, the control device 350 or the vessel's control device
may instruct the cleaning and/or coating device 304 when to apply the coating. The
cleaning function may be implemented in a similar way.
I [0037] According to another exemplary embodiment illustrated in Figure 6, a
cleaning and/or coating device may be used without an actuator 320 as shown in
Figures 3 and 5. In this embodiment, two cleaning and/or coating devices 602 and
604 are mechanically connected to each other through a rope 606. The rope 606,
similar to the rope 322 in Figure 3, may transmit data and/or electric power. The
^ P rope 606 may pass through a pulley 608 or equivalent device, which may reduce a
friction of the rope 606 with the streamer 610. A length of the rope 606 may be
substantially twice a distance between two adjacent birds. The pulley 608 may be
removably attached to the streamer 610 or to a bird. Three birds 612A, 612B and
612C are shown in the figure and each of the cleaning and/or coating device is
provided between two adjacent birds.
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[0038] When the streamer is towed along the positive direction of the OX axis,
the cleaning and/or coating device 602, which has a variable drag system 620,
instructs the wings 622 of the variable drag system 620 to take a position that
increases the drag in water. In this way, the cleaning and/or coating device 602
moves in the negative direction of the OX axis (as illustrated by arrow A) while the
cleaning and/or coating device 604 moves in the positive direction of the OX axis (as
illustrated by arrow B). The pulley 608 may include a brake device 609 for slowing
down a rotation of the pulley, to control a speed of the cleaning and/or coating device
along the streamer. The brake device 609 may be controlled by the control device to
^ ^ be discussed later.
[0039] When the cleaning and/or coating device 602 reaches the bird 61 OB,
the switch (not shown but similar to switch 340) informs the control device (not
shown but similar to control device 350) that a change in the travelling direction is
necessary and thus, the variable drag system 620 of the cleaning and/or coating
device 602 reduces its drag, as shown in Figure 7. The current drag of the cleaning
and/or coating device 602 needs to be smaller than the drag of the cleaning and/or
coating device 604 so that this last device moves along the negative direction of the
OX axis and pulls the device 602 along the positive direction of the OX axis as
% indicated by arrows C and D in Figure 7.
[0040] Note that in this arrangement the cleaning and/or coating devices work
in pairs and at least one of the devices needs to have the variable drag system 620.
In one application, both devices 602 and 604 have the variable drag system 620.
The variable drag system 620, as shown in Figure 8, may be distributed inside the
body 630 of the cleaning and/or coating device 602. The variable drag system 620
13
includes one or more wings 622 and one or more corresponding actuators 624 for
moving the wings in a desired direction E or F. The actuator 624 can be entirely
mechanical (e.g., springs and levers as known in the art), or electrical (as discussed
above) or a combination of both.
[0041] The variable drag system 620 may be coordinated by the control
device 650. Electric power may be fed to the variable drag system 620 from a
battery 660 or through an interface 662 (e.g., from the rope 606, from the streamer
602 or through an inductive process), both of which can be installed on the body
630.
^ ^ [0042] According to another exemplary embodiment illustrated in Figure 9, a
system 900 includes a streamer 902 and a cleaning and/or coating device 904 that is
configured to move back and forth between first and second birds 906A and 906B.
In this embodiment, the cleaning and/or coating device 904 has a body 905 on which
an actuator 910 (e.g., an electrical motor) for providing autonomous propulsion is
distributed. As in the previous embodiments, the electric power may be provided by
a battery or through an inductive interface and the control is managed by a control
device (not shown but similar to control device 350 in Figure 3). The control device
may be localized on the cleaning and/or coating device, or distributed on the device
^ P and the streamer and/or vessel.
[0043] Wheels 920 may be attached to the cleaning and/or coating device 904
to contact the streamer and to advance along the streamer when the actuator 910
actuates them. The wheels 920 may be mounted with a spring force to maintain
contact with the streamer. A switch 930A informs the control device when the
cleaning and/or coating device 904 has reached the second bird 906B and another
14
I
switch 930B informs the control device when the device 904 has reached the first
bird 906A. As in the previous embodiments, the cleaning and/or coating device does
not have to continuously move from one bird to the other bird to coat or clean the
streamer. The control device may be programmed with predetermined time delays
between consecutive displacements of the cleaning and/or coating device between
the birds.
[0044] An exemplary control device is illustrated in Figure 10. The control
device 350 includes an input/output interface 360 that is connected through a bus
370 to processor 380 and a memory 390. The processor 380 may read from the
^ ^ memory 390 or from data received through the interface 360 data from the vessel,
the various switches and/or the wings. Based on this data, the processor 380 is
programmed to change a movement direction of the device, or to modify the position
of the wings, or to determine when to activate the device. Optionally, the processor
j 380 may be programmed to determine how much biocide material to apply to the
streamer.
[0045] A method for coating with biocide matehal a streamer is now described
with regard to Figure 11. The method includes a step 1100 of attaching a coating
and/or cleaning device to the streamer, a step 1102 of controlling a movement of the
^ P coating and/or cleaning device along the streamer, and a step 1104 of applying a
coat of the biocide material on the streamer when the coating and/or cleaning device
moves along the streamer. Any of the devices described in the previous
embodiments may be used for this method.
[0046] For improving the cleaning and/or coating functions, the cleaning
and/or coating device may be configured to rotate (partially or totally) relative to the
15
I
streamer. The rotation of the cleaning device is achieved with additional wings. For
the embodiments illustrated in Figures 3, 5, 6, and 7, the cleaning and/or coating
device does not need to fully rotate around the streamer. It may be enough for these
devices to rotate by a couple of degrees, e.g., less than 90°, while traveling along the
streamer. Thus, the cleaning and/or coating device may simultaneously rotate
relative to the streamer and advance along the X axis relative to the streamer. The
combined rotation and translation of the device relative to the streamer is useful for
cleaning and/or coating. In one application, the cleaning and/or coating device may
be used to regularly clean the streamer when barnacles are microscopic and
^ ^ combine the cleaning with an antifouling application, e.g., like toothpaste, to have a
preventive action with a fresh coating. The cleaning and/or coating device may be
used not only with a streamer but with any seismic equipment that is towed in water.
[0047] The disclosed exemplary embodiments provide a device and a method
for coating and/or cleaning a streamer. It should be understood that this description
is not intended to limit the invention. On the contrary, the exemplary embodiments
are intended to cover alternatives, modifications and equivalents, which are included
in the spirit and scope of the invention as defined by the appended claims. For
example, a claim including a streamer and a cleaning and/or coating device is
^ P envisioned to be supported by this document. Also, a claim including a vessel
towing a streamer and a cleaning and/or coating device is envisioned to be
supported by this document. Further, a claim disclosing a vessel towing a source
that emits acoustic waves and also towing a streamer that has a cleaning and/or
coating device is believed to be disclosed by this document.
16
[0048] For example, Figure 12 shows an acquisition system 1200 that
includes a vessel 1202 towing plural streamers 1204 and one or more seismic
source arrays 1206. Streamer 1204 includes plural seismic sensors 1208 for
recording the seismic data originated by source array 1206. Streamer 1204 also
may include a positioning device 1210 (e.g., bird) and a cleaning and/or coating
device 1212 as discussed above. The cleaning device 1212 may move between
consecutive positioning devices 1210 while the seismic sensors 1204 record seismic
data. In one application, seismic sources 1206 are shoot while the cleaning and/or
coating device 1212 cleans the streamer.
^^ [0049] Furthermore, in the detailed description of the exemplary
embodiments, numerous specific details are set forth in order to provide a
comprehensive understanding of the claimed invention. However, one skilled in the
art would understand that various embodiments may be practiced without such
I specific details.
[0050] Although the features and elements of the present exemplary
embodiments are described in the embodiments in particular combinations, each
feature or element can be used alone without the other features and elements of the
embodiments or in various combinations with or without other features and elements
^m disclosed herein.
[0051] This written description uses examples of the subject matter disclosed to
enable any person skilled in the art to practice the same, including making and using
any devices or systems and performing any incorporated methods. The patentable
scope of the subject matter is defined by the claims, and may include other examples
17
that occur to those skilled in the art. Such other examples are intended to be within the
scope of the claims.
18

lAVe Claim:
1. A cleaning device (304) for cleaning a marine seismic equipment (302), the
device (304) comprising:
a body (310) having an opening (305) configured to receive the marine
seismic equipment (302);
an actuator (320) configured to be removably attached to the marine seismic
equipment (302);
a rope (322) connecting the body (310) to the actuator (320); and
a control device (350) configured to activate the actuator (320) to retract or
^ release the body (310),
wherein the body (310) is configured to clean the marine seismic equipment.
2. The device of Claim 1, further comprising:
a switch (340) provided on the body (310) and configured to generate a signal
when the body (310) is close to an obstacle (306B),
wherein the control device is configured to receive a signal from the switch
(340) and to reverse a movement direction of the body.
3. The device of Claim 1, further comprising:
at least one wing (330) controllable by the control device (330) and configured
to produce drag underwater so that the body moves along the marine seismic
equipment.
4. The device of Claim 3, further comprising:
19
an electrical motor (624) provided in the body (310) and configured to change
a position of the wing (330, 622).
5. The device of Claim 1, further comprising;
a coating device (308) attached to the body (310) for coating a biocide
material on the marine seismic equipment.
6. The device of Claim 1, further comprising:
# a cleaning component (308) attached to the body (310) for removing material
deposited on the marine seismic equipment.
7. A cleaning system (602, 604) for cleaning a marine seismic equipment
(610), the system (602, 604) comprising:
a first cleaning device (602) configured to be attached to the marine seismic
equipment (610), between first and second birds (612A, 612B);
a second cleaning device (604) configured to be attached to the mahne
seismic equipment (610), between second and third birds (612B, 612A);
a rope (606) connecting the first cleaning device (602) to the second cleaning
^ ^ device (604); and
a device (608) attached to the marine seismic equipment and configured to
handle the rope (606) such that a movement of the first cleaning device (602) along
a direction of the marine seismic equipment (610) makes the second cleaning device
(604) to move in an opposite direction of the marine seismic equipment (610),
wherein the system is configured to clean the equipment.
20
•
I
8. The system of Claim 7, wherein a length of the rope is substantially twice a
distance between two adjacent birds distributed along the equipment.
9. The system of Claim 7, further comprising:
a breaking mechanism (609) for controlling a speed of the rope,
wherein one of the first or second cleaning devices comprises:
a body;
# a wing attached to the body;
an actuator provided in the body and connected to the wing to change a
position of the wing;
a switch configured to contact one of the first, second and third birds; and
a control device configured to control the actuator based on a signal received
j from the switch.
10. A cleaning device (904) for cleaning a marine seismic equipment (902),
the device (904) comprising:
a body (905) having an opening configured to receive the marine seismic
^ equipment (902);
an actuator (910) attached to the body (905); and
21
a control device (350) configured to activate the actuator (910) to move the
body (905) along the marine seismic equipment (902) between two consecutive birds
(906A, 906B),
wherein the body (905) is configured to clean the marine seismic equipment.