Technical field
[0001] The present invention relates to offshore subsea communication systems, in particular
to a system for providing communication to an offshore system via a shore communication
cable.
Background
[0002] Offshore subsea systems are provided with a cable from shore to the offshore subsea
system. The cable usually provides power to the subsea system and a communication
link, such as a fiber optical cable, between a shore facility and the subsea system.
The communication link is used to control the subsea system from the shore facility.
During offshore operations an offshore vessel needs to communicate with and/or control
the subsea system. The offshore vessel is not within range of WLAN networks or cellular
networks but have to rely on satellite communication between the offshore vessel and
the shore facility. An exemplary system of prior art is illustrated in Fig. 1. Fig.
1 show an offshore subsea system 1 on the seabed 2. The subsea system 1 may be a subsea
production system or any other subsea system. The subsea system 1 is in communication
with a shore facility 3 by a cable 4. An offshore vessel 5 is in communication with
the shore facility 3 via a communication satellite 6 on satellite communication links
7 and 8.
[0003] A problem often occurring when the offshore vessel 5 needs to communicate with an
offshore subsea system 1 at high latitude is that the communication link 7 between
the offshore vessel 5 and the communication satellite 6 is disrupted by rain, atmospheric
pressure and other meteorological conditions. These disruptions may last for weeks,
hindering the offshore vessel 5 from communicating with the offshore subsea system
1 below.
[0004] WO2018160982 describes a communication buoy for wireless communication to shore connected to a
subsea system via a fiber optical cable to the seabed as a backup communication system
for control of the subsea system in case of broken communication link between the
subsea system and a platform. The system does not disclose wired connection to shore
and have the same shortcoming as the prior art system illustrated in Fig. 1 when satellite
communication on high latitude is disrupted.
[0005] In view of the above, the aim of the present invention is to provide a system to
be used in case of missing/broken communication via satellite between a subsea production
system and platform/onshore facility.
Summary of the invention
[0006] In one aspect of the present invention it is provided a system for communicating
with an offshore subsea system connected to a shore facility by a first communication
cable. The system comprising a buoyant device adapted for wireless communication with
an offshore control facility and a second communication cable adapted for connecting
the buoyant device to a subsea connector on the first communication cable, such that
the buoyant device is in communication with the shore facility; and the offshore control
facility is in communication with the offshore subsea system via the shore facility.
[0007] In one embodiment, the wireless communication may comprise at least one of a cellular
network communication and a wireless local area network communication.
[0008] In one embodiment, the at least one of the first communication cable and the second
communication cable may comprise a fiber optical cable.
[0009] In one embodiment, the buoyant device may be a buoy.
[0010] In one embodiment, the buoyant device may be adapted for anchoring to a seabed.
[0011] In one embodiment, the offshore control facility may be at least one of a ship, a
boat, a drilling rig, an airplane, a helicopter, an unmanned aerial vehicle and an
unmanned underwater vehicle.
[0012] In one embodiment, the buoyant device may be adapted to be powered by the first communication
cable via the subsea connector and the second communication cable.
Brief Description of the drawings
[0013] Following drawings are appended to facilitate the understanding of the invention.
The drawings show embodiments of the invention, which will now be described by way
of example only, where:
Fig. 1 is a schematic illustration of a prior art communication system.
Fig. 2 is a schematic illustration of a system according to the present invention.
Detailed description of the invention
[0014] In the following, different alternatives will be discussed in more detail with reference
to the appended drawings. It should be understood, however, that the drawings are
not intended to limit the scope of the invention to the subject-matter depicted in
the drawings. The scope of the invention is defined in the appended claims.
[0015] In the exemplary embodiments, various features and details are shown in combination.
The fact that several features are described with reference to a particular example
should not be construed as implying that those features be necessity have to be included
together in all the embodiments of the invention.
[0016] Conversely, features that are described with reference to different embodiments should
not be construed as mutually exclusive. As those skilled in the art will readily understand,
embodiments that incorporate any subset of features described herein and that are
not expressly interdependent have been contemplated by the inventor and are part of
the intended disclosure. However, explicit descriptions of all such embodiments would
not contribute to the understanding of the principles of the invention, and consequently
some permutations have been omitted for the sake of simplicity.
[0017] Fig. 2 is a schematic illustration of a system according to the present invention
communicating with an offshore subsea system 1 connected to a shore facility 3 by
a first communication cable 4. The first communication cable 4 may be a fiber optical
cable for high speed data communication. The first communication cable 4 may in some
embodiments additionally provide power to the offshore subsea system 1. The offshore
subsea system 1 may be a subsea production system or any other subsea system communicating
with a shore facility. The shore facility 3 may be a control site for controlling
the offshore subsea system 1. Alternatively, the shore facility 3 may be a communication
hub or communication system for relaying communication to and from the offshore subsea
system 1 to other computer systems or control sites. The illustrated system comprises
a buoyant device 9 adapted for wireless communication 12 with an offshore control
facility 5. Depending on the requirements of the system, such as the distance between
the buoyant device 9 and the offshore control facility 5, different wireless communication
protocols may be used. The buoyant device 9 may also be adapted to use several different
wireless communication protocols and switch between them based on measured Quality
of service (QoS). In one exemplary embodiment, the wireless communication 12 comprises
a cellular network communication protocol, such as 3G, 4G and 5G. In another exemplary
embodiment, the wireless communication 12 comprises a wireless local area network
(WLAN) communication protocol. A second communication cable 11 is connecting the buoyant
device 9 to a subsea connector 10 on the first communication cable 4, such that the
buoyant device 9 is in communication with the shore facility 3. The second communication
cable 11 may be a fiber optical cable for high speed data communication. The second
communication cable 11 may in some embodiments additionally provide power to the buoyant
device 9 via the subsea connector 10 and the first communication cable 4. By use of
this system, the offshore control facility 5 can communicate with the offshore subsea
system 1 via the shore facility 3. This is particularity useful when the offshore
control facility 5 is unable to communicate wirelessly with the shore facility, such
as when satellite communication between the offshore control facility 5 and the shore
facility 3 is missing or disrupted.
[0018] If the first communication cable 4 is damaged or otherwise unavailable for communication
to the shore facility 3, the subsea connector 10 is adapted to reconfigure the connection
between the second communication cable 11 and the first communication cable 4 such
that the buoyant device 9 is communicating directly with the offshore subsea system
1.
[0019] The offshore control facility 5 may be any vessel in wireless communication range
of the buoyant device 9, such as at least one of a ship, a boat, a drilling rig, an
airplane, a helicopter, an unmanned aerial vehicle and an unmanned underwater vehicle.
[0020] In one embodiment, the buoyant device 9 may be a buoy. The buoyant device 9 may be
adapted for anchoring to the seabed 2. Alternatively, the buoyant device 9 may be
provided with a dynamic positioning (DP) system adapted to automatically maintain
a position of the buoyant device 9 relative to the offshore subsea system 1.
1. A system for communicating with an offshore subsea system (1) connected to a shore
facility (3) by a first communication cable (4), the system
characterized by comprising:
a buoyant device (9) adapted for wireless communication (12) with an offshore control
facility (5),
a second communication cable (11) adapted for connecting the buoyant device (9) to
a subsea connector (10) on the first communication cable (4), such that the buoyant
device (9) is in communication with the shore facility (3); and the offshore control
facility (5) is in communication with the offshore subsea system (1) via the shore
facility (3).
2. The system of claim 1, wherein the wireless communication (12) comprises at least
one of a cellular network communication and a wireless local area network (WLAN) communication.
3. The system of any of the preceding claims, wherein at least one of the first communication
cable (4) and the second communication cable (11) comprises a fiber optical cable.
4. The system of any of the preceding claims, wherein the buoyant device (9) is a buoy.
5. The system of any of the preceding claims, wherein the buoyant device (9) is adapted
for anchoring to a seabed (2).
6. The system of any of the preceding claims, wherein the offshore control facility (5)
is at least one of a ship, a boat, a drilling rig, an airplane, a helicopter, an unmanned
aerial vehicle and an unmanned underwater vehicle.
7. The system of any of the preceding claims, wherein the buoyant device (9) is adapted
to be powered by the first communication cable (4) via the subsea connector (10) and
the second communication cable (11).