• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
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    • 专利摘要:
    APPLIANCE FOR MONITORING A SUBMARINE RESERVOIR. The present invention relates to an arrangement for monitoring an underwater reservoir comprising a number of sensor units located in a set (1) on the seabed and an interrogation unit for obtaining data in the reservoir from units of sensor. The interrogating unit comprises a transmitting unit (20) for sending optical signals to the sensor assembly and a receiving unit for receiving modulated optical signals from the assembly. The optical radiation from an optical source (22) is transmitted over an optical uplink fiber which is divided into a number of positions (36, 38) to form the array. The receiver unit comprises optical to electrical converters (54) for converting optical signals to electrical signals, a phase demodulator (58), a multiplexer (60) for multiplexing signals from the phase demodulator, a signal processor (68) and a recording unit (70). The interrogating unit is divided into a concentrator that includes one or more of the splitters and converters from optical to electrical, a phase demodulator, etc. and an interrogation cube that includes the optical source.
    公开号:BR112013023145B1
    申请号:R112013023145-9
    申请日:2012-03-12
    公开日:2021-02-02
    发明作者:Philip John Nash；Edward Austin；Frank Eisenhower；Richard Luff
    申请人:Stingray Geophysical Hong Kong Limited；
    IPC主号:
    专利说明:

    [0001] The present invention relates to sets of sensors, and especially to sets of passive optical sensors that are located in environments where the sensor set is difficult to access. The invention is particularly suitable for subsea seismic sensor assemblies, although it is appreciated that the invention can be used with sensors of other types. For example, the set can be used with electric field sensors to determine the presence of oil by changes in the electric field as the conductivity of the stone containing the oil changes. In other systems, the set may be part of a safety warning system that contains several hydrophones for detecting unauthorized vessels.
    [0002] Submarine seismic sensor sets are widely used in the exploration and monitoring of oil and gas reservoirs under the seabed. In these seismic monitoring techniques, a set of accelerometers and / or hydrophones is developed as sensor packages on the seabed and are used to detect the reflected seismic waves, and the results are analyzed to provide information regarding the nature and state of the geological structures. under the sea bed.
    [0003] Typically, a large number of sensors, for example, 16,000 or more, are arranged over a number of optical cables that are spaced from one another to form a two-dimensional array that extends across a large area, for example , an area of 100 square kilometers or more. In a form of the arrangement that can be referred to as a "4C" sensor unit, three seismic vibration sensors are arranged in orthogonal directions together with a hydrophone to form an optical sensor unit (OSU), and a number of sensor units optical is located along an optical line at spaced intervals, for example, in the range of about 20 to 100 meters. A number of lines, for example, 30, although more or less can be used, can extend from a cube located on the seabed in a direction generally parallel to each other and spaced from each other, for example, by 100 to 500 meters, to form a set. The hub can be connected by an optical cable to an interrogator located on an exploration or production platform or on a floating production and storage discharge vessel (FPSO) that monitors the sensors by reflectometry or other interferometric devices. The optical cable will contain at least one optical fiber for each of the lines extending from the hub (typically a pair of fibers). In operation, the interrogator sends an optical pulse along the cable where it is divided into the cube before being sent along individual lines to the optical sensor units. Vibration sensors may comprise a length of optical fiber that is wrapped around a flexible former to form a coil, and the optical threads may contain reflectors, for example, formed by a mirror ending a fiber attached to the line, preferably upstream and downstream of the sensors. As the external pressure varies, the fiber coil is compressed or released, thereby changing the length of the fiber in the coil. If a signal is sent along the optical fiber, it is partially reflected back along the line in each of the mirrors so that the signal, for example, a phase shift in the signal that depends on the distance between the reflectors, is affected by a seismic activity. In this way, any mechanical impulse caused by an air gun or other explosion in the vicinity of the set will cause a phase change in the signals reflected by the sensors in the set, which can be observed by the interrogator.
    [0004] The signals that are sent along the optical lines will normally be multiplexed in view of the large number of sensor units, normally multiplexed by time division and multiplexed by wavelength division.
    [0005] The interrogator of the system thus typically comprises a transmitter having a number of light sources such as lasers, for example 16, for the formation of optical signals, and optical switches, and a receiver for receiving and processing the reflected optical signals. The receiver will need to demultiplex a number of sequences multiplexed by division of time and wavelength that reach the various optical lines in electrical signals, digitize them and transmit them forward or store them. The interrogator is usually the only part of the system that contains electronic parts or requires electrical power.
    [0006] Such sensor assemblies can include a large number of optical fiber pairs, for example, from 100 to 200 pairs or more de-pendent of the assembly size, and up to 700 fibers in some cases, and they will extend to from the hub to the platform or FPSO in the form of an elevator cable that generally extends vertically from the seabed, although there may be a significant horizontal component, where the cable extends to an interrogator receiving unit located in the platform or FPSO.
    [0007] While such systems generally work well in practice, they can have a number of problems. For example, in some forms of design where the sensor set is a long distance from the interrogator, this would require an elevator cable with 100 to 200 pairs of fiber extending in the region of 100 km or more between the interrogator and the assembly, which it can be impractical and extremely expensive. In other circumstances, the platform or FPSO may use existing optical cables to receive data from the set, in which case it may not have enough optical fibers in the elevator. For example, many installations may employ existing optical cables having only six fibers or more. In other cases, it may be difficult to route the fibers in the elevator cable to the interrogator and, in many cases, such elevator cable termination is not possible. For example, in the case of an FPSO, the elevator cable can emerge on a stationary table while the rest of the interrogator will be located on the vessel which can rotate around the table at least to a limited point due to currents, tides, etc. . This often requires some means to allow the optical fibers to rotate around the geometric axis of the elevator cable at least to a certain point, for example, a slip ring otherwise called an optical fiber rotary joint, to allow the optical fibers extend between the elevator cable and the interrogator at the FPSO. However, such slip rings typically accept only a few optical fibers and even the largest number of optical fibers that can be accepted by a slip ring (31 at that time) is only a fraction of the number of optical fibers in a typical elevator cable, so that seven slip rings are needed. Additionally, the specification of such a slip ring is insufficient for the purpose of a seismic fiber optic assembly in many cases since the two-way insertion loss can be 9 dB bringing the set insertion loss above 60 dB in some cases. Additionally, the minimum return loss of the slip ring can be 18 dB, which means that the posterior reflexes can be sent to the set degrading its performance, or alternatively, insulators would be necessary in order to prevent such posterior reflexes. Finally, the interrogator's physical size can be quite large, on the order of two or three cubic meters, and there may not be enough space on the platform or FPSO for the interrogator.
    [0008] According to one aspect, the present invention provides a sensor arrangement for monitoring a sub-marine reservoir, which comprises:
    [0009] a sensor assembly comprising a plurality of sensor units located or to be located across an area of the seabed in the region of the reservoir to be monitored; and
    [00010] an interrogator unit for obtaining data in the reservoir from the sensor units, which comprises a transmitting unit for sending optical signals to the sensor assembly, and a receiving unit for receiving modulated optical signals from the response assembly the transmitted optical signals;
    [00011] the transmitting unit comprising an optical switch, for example, an acoustic-optical modulator (AOM) for receiving optical radiation from an optical source and transmitting optical signals generated over an uplink optical fiber, and at least a splitter for splitting the uplink optical fiber into a plurality of optical fibers that extend to the sensors across the area to be monitored; and
    [00012] the receiving unit comprising an optical to electrical converter to convert optical signals from each fiber in the set to electrical signals, a phase demodulator, a multiplexer to multiply the electrical signals from the phase demodulator, and a unit of signal processing and recording for recording multiplexed signals.
    [00013] The interrogator unit can be divided into a concentrator and an interrogator cube, the concentrator including the splitter and the optical to electrical converter, the phase demodulator and multiplexer of the receiving unit and the interrogator cube including the optical source and co - optical switch of the transmitting unit, the signal processing and recording unit, so that the optical source, the optical switch, the signal processing and recording unit can be located on a platform or on the shore, and the converter electrical to optical, the phase demodulator and multiplexer can be located on the seabed.
    [00014] The interrogating unit may include means for transmitting signals from or each concentrator to the interrogating cube along a connected or wireless line.
    [00015] The sensor arrangement according to the invention has the advantage that, by dividing the receiver, and preferably the transmitter and receiver, within two parts, one submarine (the concentrator) and the other above the water (the water hub). interrogator) and by multiplexing the signals from the sensor set in the receiver's submarine part, only a small number of optical fibers are needed in the elevator extending between the submerged part of the interrogator and the surface part. The particular number of optical fibers in the elevator between the submerged and the surface part of the interrogator will depend on the particular design of the arrangement, but it is possible to employ only a single optical fiber for uplink (that is, from the transmitter to the set and an additional single downlink optical fiber unless signals are transmitted from the hub to the wireless interrogator hub) so that the elevator contains only a single pair of fibers. Other optical fibers may be necessary or desirable depending on the circumstances as explained below.
    [00016] The optical fibers extending from the interrogator cube to the assembly are preferably spatially arranged in proximity to the return fibers extending from the assembly to the interrogator cube, and especially together so that the sensors are connected to the cube by means of optical cables formed from a pair of fibers. In addition, the interrogator unit can have a number of configurations. For example, in a drawing it may have only a single concentrator from which a number of fibers extend to the sensor assembly, each line of the assembly being formed from a pair of fibers. In another design, an optical cable formed from a relatively small number of optical fibers can extend from the interrogation hub to a passive hub where it branches into a number of additional optical cables, each extending from the passive hub to a concentrator and typically having two fibers (an uplink carrying transmission pulses and a downlink containing digitized sensor data). From each concentrator, the fibers extend into the bundle as described above. Such an overall design will contain more than two optical fibers in the elevator cable, for example, up to six or eight fibers or even more, but nothing like the number of fibers used in prior art systems. Other set configurations are also possible.
    [00017] In some circumstances other fibers may be present, for example, for sending timing signals to synchronize the transmitter and receiver. For example, an additional optical fiber for synchronization may be present extending directly from the transmission in the interrogator's cube to the submerged part of the receiver, that is, bypassing the sensor set, although such an arrangement is not preferred since it increases the number of fibers in the elevator. Alternatively, timing signals can be sent from a synchronization unit in the interrogation hub to both the acoustic-optical modulator on the transmitter and to the phase and / or multiplexer demodulator of the receiving unit along the uplink or downlink optical fiber. extending along the elevator cable. In another arrangement, timing signals can be sent along the optical fiber extending on the transmitting side of one or more of the sensors in the assembly to the phase demodulator, for example, in proximity to the downlink optical fibers extending from of the set. Only a single optical fiber is required for a complete set. In addition, it is possible for different fibers in the elevator to send signals to and from different parts of the sensor set depending on the presentation of the set, but in such cases it is unlikely that more than six or eight optical fibers are present in the elevator.
    [00018] It is possible for interrogator hubs to be permanently attached to the seabed, especially if the electron parts of the heater are relatively simple, but the heater can be supplied in an impermeable module that is submersible and can be raised to the platform or FPSO for maintenance or repair purposes, but which otherwise remains on the seabed. Such a module can be provided with a storage and unfolding arrangement for storing the lifeline when the module is raised and for unfolding the cable when the module is lowered to the seabed.
    [00019] Where the concentrator requires electricity, this can be supplied through connection to the interrogation hub, through a separate electrical cable from the platform or other seabed location, or through a local battery.
    [00020] Although the interrogator and concentrator cube is often located close to each other (with one on the surface and one under the water) it is possible that the concentrator and interrogator cube are separated from each other, even over a long distance , for example, up to 100 km or more.
    [00021] Although the concentrator is normally located underwater, and the interrogation cube on the surface, in certain circumstances, both can be located on the surface, for example, when the concentrator is located in a fixed tower and the cube interrogator on the rotating part of a floating production platform (FPSO). In such cases, the concentrator is usually located in a location where space and energy requirements may be limited, and it is desirable to minimize the number of optical fibers in the connection between the concentrator and the interrogation cube.
    [00022] An arrangement according to the present invention will now be described by way of example with reference to the accompanying drawings in which:
    [00023] Figure 1 is a schematic view of a conventional seismic sensor arrangement;
    [00024] Figure 2 is a schematic view of a topography form of sensor assembly according to the invention;
    [00025] Figure 3 is a schematic view of another form of the topography of sensor assembly according to the invention;
    [00026] Figure 4 is a schematic view of an FPSO in which an arrangement according to the invention can be used;
    [00027] Figure 5 is a schematic diagram illustrating the main parts of the arrangement according to the invention;
    [00028] Figure 6 is a schematic view illustrating part of the arrangement of Figure 5 that uses a derived sensor technique (DST); and
    [00029] Figure 7 is a schematic view of an arrangement that employs a submersible module.
    [00030] With reference to Figure 1, a marine oil platform 7 is observed, supported in extensions from the seabed. A seismic sensor assembly 1 as described in GB 2 449 941 is deployed on the seabed in order to detect changes in the underlying reservoir. The seismic sensor assembly comprises a plurality of seismic cables 2 each of which can be chiseled from a number of modules 3 that are joined by the assembly elements 4 and contain a number of sensor units 45 that are spaced along the cables. Connection seismic cables 2 lead to a passive hub 8, where all seismic cables 2 are joined to form a lifeline that extends from hub 8 to an operating system 6 on platform 7. Signals are generated by a transmitter in the operating system or interrogator 6 and sent to the sensor units 5, and returns are received from the sensor units 5 in the operating system 6, where the signal returns are analyzed in order to determine the nature of the structures under the seabed. As indicated above, this form of assembly has the disadvantage that the elevator cable needs to employ a large number of optical fibers, for example, from 50 to 200 fibers or more.
    [00031] As illustrated in Figure 2, a shape of a sensor assembly similar to that illustrated in Figure 1 is illustrated in which a lift cable 10 comprising only a pair of optical fibers extends from an interrogation hub 11 which is located on platform and includes a transmitting and receiving unit. The cable extends to a concentrator 12 located on the seabed in the region of the platform where the optical fibers in the cable are divided to form a number of separate seismic cables 14 corresponding to the cables 2 in Figure 1 that extend from the concentrator through the region of interest. In addition, a slip ring 15 can be located on the interrogation hub in order to accommodate the relative rotational movement between the elevator cable and the interrogation hub.
    [00032] An alternative topography for the sensor is illustrated in Figure 3 where an elevator cable 10 comprising in this case six optical fibers extends from the interrogation hub 11 to a passive hub 16 where the optical fibers are divided into three separate optical cables 17 , each having a pair of fibers. Each of the optical cables 17 extends to a concentrator 12 where the fibers in the cable are split as before to form a number of seismic cables 14.
    [00033] A sensor unit 5 that can be used in the sensor typically comprises three seismic sensors arranged in orthogonal directions and a hydrophone. Each seismic sensor is in the form of a spiral or optical fiber wrapped around an anterior one whose diameter will vary slightly when subjected to seismic vibrations so that the length of the fiber optic coil will also vary. Mirrors or other reflex devices such as Bragg classifications are arranged between the spirals of the optical fiber, so that a signal sent along the optical fiber is reflected by each mirror to form a pair of pulses whose separation will depend on the length of the fiber winding. optics. Such sensor units comprising three orthogonal seismic sensors and a hydrophone can be referred to as an optical sensor unit (OSU). The sensors can also be connected in other ways well known in the field, for example, in a transmission coupler configuration.
    [00034] The seismic sensors and hydrophone are fiber optic devices, and the connecting cable will comprise a number of optical fibers for connecting the sensors of each sensor unit to its neighbors in the current. In one embodiment, a continuous length of cable 2 can connect all sensor units in an deployment device. The cable can have a number of fiber optic pairs running along its length, and in each sensor unit a single fiber can be removed from the cable and connected to sensors in that sensor unit.
    [00035] Each optical sensor unit (OSU) will require four channels (one for each seismic sensor and one for the hydrophone) and can be unfolded in groups of four, which requires 16 optical channels per group. This can be conveniently achieved by time division multiplexing, where the optical input signal is pulsed and optical return pulses from different sensors are distinguished by the time of flight. The additional multiplexing that is necessary in order to interrogate all optical sensor units is achieved through wavelength division multiplexing, where pulses from a number of different wavelengths, typically 16, are sent to the system and each wavelength is directed to a separate set of time multiplexed sensors using commonly known selective wavelength components. The received signals are therefore sent from optical sensor units to the receiver as a number of currents multiplexed by time division and multiplexed by wavelength division. The optical signal of each sensor contains data from that sensor encoded as a phase modulation. Typically, the receiver can receive on the order of 30 different TDM / WDM streams corresponding to 480 channels. An implementation of this architecture is described in European patent N °. EP 1 169 619 B1.
    [00036] In addition to being deployed on a fixed oil production platform as illustrated in Figure 1, the arrangement can be enclosed in a floating production and storage discharge vessel (FPSO) schematically illustrated in Figure 4. This is essentially a vessel 10 having a fixed tower 11 through which the lifeline extends. The vessel is moored by means of cables 14, but the vessel can yaw to a certain point due to the waves, currents and tides, so that vessel 10 can rotate around the fixed tower 11. Questioner 16 is located on the vessel.
    [00037] Figure 5 is a schematic diagram illustrating the main representation of the arrangement according to the invention. The arrangement comprises an interrogator forming the main part of the diagram comprising an interrogator cube 20 and a concentrator connected to each other by an elevator cable. The interrogator sends signals to a set of sensors as shown in Figures 2 and 3, a line 1 from which it is illustrated and receives, processes and stores the return signals from the set. The interrogator comprises a transmitter for sending an optical drive signal to the assembly comprising a high specification laser source 22 for the generation of a constant optical signal and an optical acoustic modulator (AOM) 24 (or another optical switch) suitable as an electro-optical switch) to pulse and change the frequency of the optical signal. Typically, AOM will produce a pair of pulses, one of which is delayed in time and changed in frequency by typically 50 kHz with respect to the first pulse, from the transmitter to the array so that a sequence of pulses is reflected by mirrors located between the sensor coils of the OSUs within the assembly. If the time delay of the second pulse corresponds to the time it takes for a pulse to travel through a coil between two mirrors and its return after the mirror reflection on the far side of the coil, the pulses will be generated and are an overlap of the initial pulses and time delay 26 reflected by the different mirrors in the set, and that superimposed pulse, which is at a frequency other than typically 50 kHz, carries the phase information from the sensor between these mirrors as a phase modulation of the carrier frequency. The repetition rate for this pair of pulses 26 is typically 200 kHz and this can be amplified via amplifier 28. The interrogator may also need to generate a timing or synchronization signal 30 which is sent to the transmitter's AOM and also for the concentrator. The laser source AOM 24 and any amplifier 28 that may be present will normally be located on the platform or FPSO inside the interrogation cube 20. The arrangement includes an optical fiber 32, preferably a single optical fiber, which forms part of the elevator cable and extends from the platform or FPSO down to a concentrator located on the seabed in the region of the platform. In the concentrator there are typically several di-displays, for example, a 1: 2 divider 36, dividers 1:16 38 for each of the fibers from divider 36 and an additional 1: 2 divider 40 to divide the optical fiber 32 into 64 fibers. The fiber can be divided into any suitable number of fibers, but it will normally be divided into 128 fibers more or less. In addition, additional amplifiers 42, 44 may be present. The optical signal can be amplified directly by means of an optical amplifier, for example, an erbium-coated fiber amplifier (EDFA). Any amplifier employed can also be a distributed optical amplifier that amplifies the optical signals continuously over part or all of the connection between the interrogator and the set 1.
    [00038] The set comprises a two-dimensional set of optical sensor units (OSUs) formed on each set line, and each sensor unit comprising three orthogonal oriented seismic vibration sensors and a hydrophone, the vibration sensors being typically separated by mirrors so that the delay and, thus, the phase change of the signals reflected by the mirrors depend on the parameter being detected by the OSUs. The sensors can also be connected in other configurations allowing the measurement of the optical phase change of the individual sensor.
    [00039] After leaving the set, the fibers return to the concentrator. Only a single fiber 50 is illustrated leaving the assembly line 1 for the sake of clarity since in fact only one fiber 46 is illustrated entering the assembly, but as indicated above, typically 64 to 128 fibers will be employed. After leaving the set, the signals can be amplified by an additional amplifier 52 (one for each optical fiber 50 leaving the set) that will typically be located inside the concentrator or can be located outside if a distributed amplifier is employed. After amplification, the signal is passed to an optical to electrical converter typically comprising a detector formed from an avalanche photodiode or pins. Electric signals produced in this way are sent to an A / D converter 56 to sample the signals, for example, at 200 kHz, and to digitize them, and the digital signals are passed to a phase 58 demodulator. In an implementation, the signals will have a carrier frequency of 50 kHz, which is modulated in phase by the seismic signal that will typically be over a frequency range of 5 to 500 Hz.
    [00040] After the phase demodulation, the signals from the optical fiber 50 together with the signals on all other optical fibers 52 of the set are multiplexed by means of multiplexer 60 which also receives timing signals sent from the interrogation cube. As an alternative to sending timing signals directly to the receiver, timing signals sent to the assembly line by the transmitter can be detected before being sent to the assembly and then sent to the phase 58 demodulator over fiber 57. The multiplexed signal is then converted to an optical signal by diode 62 or laser. Multiplexing can be performed electrically or optically or by a mixture of both and the signal in the fiber exiting the submersible module will preferably be multiplexed by wavelength division (WDM) especially multiplexed by dense wavelength division (DWDM) where up to 128 signals can, for example, be carried by a single fiber in the 1550 nm band.
    [00041] The DWDM signal is then carried by a single optical fiber 64 on the elevator cable to the platform or FPSO where it is converted into an electrical signal by means of photodetector 66 and sent to the signal processing module 68 where the data is recorded and stored on disk 70 if necessary. Frequently, signal processing module 68 and the disk or other recorder will be physically located close to each other in the same interrogator or housing module, but, as indicated above, the interrogator's transmitter and receiver can be physically separated by a significant distance. Similarly, it is possible for different parts of the receiver to be separated between the concentrator and the interrogation cube. For example, it is possible for the receiver to include a communications module for packaging multiplexed signals and sending them along a transmission channel to a recorder 70 as a single data stream, using well-known communications techniques. digital data. The communications module can operate to send data from demodulator 58 and multiplexer 60 by any suitable means, for example, via a satellite or microwave link, despite operating normally to send data from the demodulator using a cable, especially an optical cable. This can be the same cable as the elevator cable or a different cable.
    [00042] For a typical set, the receiver will receive 16 data streams multiplexed by time division, each of which is converted into an electrical signal using a separate photodiode 54. These are multiplexed WDM at 16 wavelengths, taking to 256 TDM data streams. The electrical data streams are digitized to generate 256 multiplexed phase-modulated outputs per time domain to generate the phase 58 modulator. In a typical heterodyne modulated system, each channel will have a 50 kHz heterodyne carrier frequency and will be sampled at a sampling frequency of 200 kHz, although many other phase-modulated data configurations are possible. It will be necessary to multiplex the data at a rate high enough to ensure that the entire bandwidth of the modulated data has been captured, thus allowing for accurate demodulation of the data. For example, in a typical system a data sample rate of 50 kHz with 32 bits per sample, 16 channels per wavelength and 16 different wavelengths will generate a signal with 0.4 Gbits per second for each sensor line. If 64 sensor lines are employed as described above, this provides a total data transmission rate of 26 Gbits per second transmitted over fiber 64. Clearly, other data sample rates, or even data compression techniques, can chosen resulting in a different total data transmission rate.
    [00043] The arrangement, according to the invention, in this way, allows the set 1 to be connected to the main part of the interrogator (the interrogator cube), that is, those parts of significant size or that involve the processing of significant electronic signal , for only a small number of optical fibers so that conventional slip rings can be used, or even, depending on the way in which the optical fibers are packaged, so that the slip rings can be distributed with and so that any change in direction of the fiber in the system can be accommodated by folding the fiber. As described above with reference to Figure 5, the concentrator can be located on the seabed within a watertight module requiring only a small number of fiber energy connections for the interrogator. The hub includes a stored multi-way lifter cable connecting the multiplexing optical and electronic parts to the set cables.
    [00044] Such a form of concentrator is illustrated schematically in Figure 7. Here the interrogator is formed as a permanent installation 80 (which is the interrogator cube) on a platform 82 and includes a submersible module 84 (concentrator housing) which is connected to the permanent installation 80 by the elevator cable 9 comprising optical fibers 32 and 64 optionally in conjunction with any electrical cable. The submersible module will house those parts of the interrogate that are located underwater, typically the demodulator of the receiver and the multiplexer, and also preferably parts of the transmitter as described above. The total volume of these parts of the interrogator within the submersible module will be of the order 0.2 cubic meters, significantly less than the total interrogator that will have a volume of at least 3 cubic meters. The submersible module may include a reel or other means of storing the lifeline which is capable of collecting the lifeline as the module is lifted into platform 82 and to loosen any other cables if necessary connected to the assembly to accommodate the change in the position of the module. Similarly, the module can be arranged to release the elevator cable 9 as it is lowered from the platform to the seabed and to collect any other cables attached to the assembly. The submersible module would normally be located on the seabed, although it can be used in any position in the water column.
    [00045] It is possible in other cases to employ a multi-fiber elevator cable with one fiber for each sensor unit in the set, and to locate the closure (including the phase demodulator and multiplexer) in a stationary tower of an FPSO with single fibers directed to the interrogator unit in the main part of the FPSO by means of conventional slip rings. The closure that employs the submersible module can be used with an FPSO if desired.
    [00046] It is possible that more than one concentrator is used, as illustrated in Figure 3. In this case, the individual concentrators 12 are each connected by a transmission optical fiber and a return datalink to the interrogator cube 11 via a passive hub 16 that combines the individual transmission fibers and the return fibers (if used) in a single elevator 6. Alternatively, the hubs 12 can be connected via a single cable arranged in a loop that connects all hubs to the hub passive. The loop can be arranged so that signals can be transmitted in any direction around the loop.
    [00047] As described in relation to Figure 5, the sensor set sends the phase-modulated optical pulses whose amplitude of phase modulation depends on the output of the sensors along the fiber 50 to the receiver. However, it is possible that the pulses returned have a very high phase modulation amplitude and cause the perceived information based on the phase to become distorted resulting in failure of the demodulation process. According to a preferred aspect of the invention, the sensors of the sensor array can be operated to generate derived signals (i.e., signals depending on the rate of phase change) instead of, or in addition to, the amplitude-dependent signals. For example, this can be achieved as described in WO2008 / 110780, the description of which is incorporated herein by reference. In this case, since two derived signals are sent in addition to the phase amplitude signals, there will be approximately three data streams instead of one, and the system will require three times the bandwidth. Derived feedback pulses (which are dependent on the rate of phase change) will have a much smaller phase modulation amplitude than pulses that are dependent on phase amplitude, and thus can be used instead of amplitude feedback pulses. . In this case, it is possible that the arrangement has a much larger dynamic beech based on high sensitivity amplitude feedback pulses where required and, on the contrary, based on lower sensitivity derived feedback pulses.
    [00048] It is possible to vary the sensitivity of the return signals by varying the time separation of the initial signal and to increase the dynamic range of the system. In addition, as described in WO2010 / 023434, the description of which is also incorporated here by reference, the optical fiber that returns the signals from the sensors can be divided so that the light can be sent to two different interferometers that reflect the light along of the 50 return optical fibers. One interferometer may have a relatively large path imbalance (say 20 m or 200 ns) while the other interferometer may have a much smaller path imbalance (say, 1 m) that will be less than the pulse duration and will change the dynamic value of the signal accordingly. As a result, it is possible that the derived sensor technique for generating feedback pulses over a range of sensitivities, from high sensitivity feedback signals based on the amplitude of the reflected signals to medium and low sensitivity feedback signals with based on the phase derivation of the reflected signals.
    [00049] Although the derived sensor technique can be used to generate feedback signals of three different sensitivities, different sensitivity signals for each of the different wavelengths in the WDM feedback signals can be carried over the same optical fiber. For example, one fiber can be used to carry medium sensitivity feedback signals (referred to as "long DST" signals), while another fiber can be used to carry normal low and full sensitivity feedback signals (referred to as normal "STD signals"). "and" shorts ", respectively).
    [00050] The two fibers can extend in parallel to each other as illustrated in Figure 6. A single optical fiber 46 transmits the pulses of the transmitter 20 to a number of interferometers 5 on the concentrator that generates three signals, an output derived from DST sensitivity medium (referred to as long output) on optical fiber 50 (1) and a full sensitivity amplitude output (referred to as normal sensitivity) and a low sensitivity derived output (referred to as short output) that are multiplexed on optical fiber 50 (2 ). In that case, each of the separate lines is converted to electrical signals, amplified where necessary, digitized with a sampling rate of 200 kHz, demodulated in phase by phase 58 demodulators, and sampled downward to a sample rate of 1 kHz separately before to be multiplexed with each other and with signals from the other OSUs as a whole by multiplexer 60. Timing signals that were sent from the interrogator hub under the elevator cable and received by multiplexer 60 are sent to the phase demodulators 58 along lines 72. In this arrangement, the phase delay between a 50 kHz sync signal and the input data will be computed at a 50 kHz data rate. The data in approximately 1.5 Gbit s-1 of four set lines received by fibers 50 and 52 of Figure 5 will be multiplexed by multiplexer 60 to generate the payload of 5.84 Gbits s-1 for each wavelength which can be carried over a 10 Gbit Ethernet line or other transmission protocol. The data from the 16 lines is then multiplexed by multiplexer 61 by dense wavelength division multiplexing (DWDM) to allow data from 64 fiber pairs to be multiplexed into a single return fiber.
    权利要求:
    Claims (21)
    [0001]
    1. Device for monitoring an underwater reservoir comprising: a set of sensors comprising a plurality of sensor units (5) adapted to be positioned over an area of the seabed in the region of the reservoir to be monitored; and an interrogator (11, 80) to obtain data on the reservoir from the sensor units (5) comprising: a transmitting unit for sending optical signals to the sensor array, the transmitter including an optical switch (24) for receiving optical radiation from an optical source (22) and transmit optical signals generated in this way over an optical uplink fiber (32) and at least one splitter (36, 38, 40) to divide the optical uplink fiber into a plurality of optical fibers extending to the sensor units (5) over the area to be monitored; and a receiver unit for receiving optical modulated signals from the matrix in response to the optical signals transmitted to the receiver unit comprising an optical-electrical converter (54) for converting optical signals from each fiber of the matrix into electrical signals, a phase demodulator (58), a multiplexer (60) for multiplexing the electrical signals from the phase demodulator and a signal processing and recording unit (68, 70) for recording the multiplexed signals; characterized by the fact that the interrogator is divided into at least one concentrator (12) and an interrogator cube (11, 20), the concentrator or concentrators including one or more of the separators (36, 38, 40) and the optical-to-converter electrical (54), phase demodulator (58) and multiplexer (60) of the receiving unit and interrogator hub (11, 20) including the optical source (22) and optical switch (24) of the transmitting unit, and the unit processing and recording signal (68, 70) of the receiving unit, so that the interrogator cube (11, 20) can be located on a platform or on land and the or each concentrator (12) can be located at the bottom of the sea, in any underwater position or on the platform in a separate location from the interrogator's cube (11, 20); the device further including means (9, 10) for transmitting signals from or from each concentrator (12) to the interrogator cube (11, 20) over a single line or wirelessly.
    [0002]
    2. Sensor assembly according to claim 1, characterized by the fact that the means (9, 10) for transmitting signals from the or each concentrator (12) are operable to transmit the signals along a single line .
    [0003]
    3. Sensor set according to claim 1, characterized by the fact that one or more uplink optical fibers extend from the interrogator cube (11, 20) to the sensor set, the one or more optical fibers being positioned together with one or more downlink optical fibers that extend from the set of sensors to the interrogator hub (11, 20) in the form of a lifting cable (9, 10).
    [0004]
    4. Sensor set according to claim 1, characterized by the fact that the concentrator (12) includes one or more optical amplifiers (42, 44).
    [0005]
    5. Sensor set according to claim 1, characterized by the fact that the interrogator hub (11, 20) includes a synchronization unit to generate timing signals (30) to synchronize the transmitting and receiving units.
    [0006]
    6. Sensor set according to claim 5, characterized by the fact that it includes an additional optical fiber to send timing signals that extend directly from the transmitter in the interrogator's hub (11, 20) to the concentrator (12 ), Ignoring the sensor array.
    [0007]
    7. Sensor set according to claim 5, characterized by the fact that it is operable to send timing signals from the synchronization unit on the interrogator hub (11, 20) to the optical switch (24) in the transmitting unit and for the phase demodulator and / or multiplexer of the receiving unit along one or more optical fibers of uplink or downlink that extend along the elevator cable (9, 10).
    [0008]
    8. Sensor set according to claim 5, characterized by the fact that it is operable to send timing signals along an optical fiber that extends over the transmitter side of one or more of the sensors in the array to the phase demodulator.
    [0009]
    9. Sensor set according to claim 1, characterized by the fact that the one or more uplink optical fibers extend for at least 30 km.
    [0010]
    10. Sensor set according to claim 1, characterized by the fact that the transmitter and the receiving unit in the interrogator's cube (11, 20) are located together.
    [0011]
    11. Sensor set according to claim 1, characterized by the fact that the concentrator (12) is capable of being raised to the sea surface.
    [0012]
    12. Sensor set, according to claim 1, characterized by the fact that one or more uplink and downlink optical fibers that extend between the concentrator (12) and the in-terrestrator hub (11, 20) extend through an optical slip ring.
    [0013]
    13. Sensor set according to claim 1, characterized by the fact that the interrogator's hub (11, 20) is located on a floating extraction, production and storage vessel.
    [0014]
    14. Sensor set according to claim 1, characterized by the fact that the sensor units (5) of the matrix are positioned to cause a deformation to be exerted on the fibers in response to a parameter to be monitored.
    [0015]
    15. Sensor assembly according to claim 14, characterized by the fact that the sensor units (5) of the matrix comprise coils in which the optical fiber is wound and which are operable to exert a deformation on the optical fiber through seismic activity.
    [0016]
    16. Sensor set according to claim 14, characterized by the fact that the sensor units (5) of the matrix are operable to generate signals derived from time, in addition to amplitude signals.
    [0017]
    17. Sensor set according to claim 16, characterized in that it includes a downlink optical fiber to transmit time-derived signals and an optical fiber to transmit amplitude signals.
    [0018]
    18. Sensor set according to claim 1, characterized by the fact that electrical power is supplied to at least one concentrator (12) via a platform cable or another location on the seabed.
    [0019]
    19. Sensor set, according to claim 1, characterized by the fact that the electrical energy is supplied to at least one concentrator (12) through a local battery inside or adjacent to the concentrator (12).
    [0020]
    20. Method for monitoring an underwater reservoir in which a set of sensors comprising a plurality of sensor units (5) is located over an area of the seabed in the region of the reservoir to be monitored; the method characterized by understanding to obtain data on the reservoir from the sensing units (5) by: i. sending optical signals to the sensor array, the optical signals being generated by an optical source (22) and sent over an optical uplink fiber; ii. dividing the optical signal and sending it to a plurality of optical fibers that extend up to the sensor units (5) over the area to be monitored; iii. receiving modulated optical signals from the sensor array in response to transmitted optical signals; iv. converting the modulated optical signals received from each fiber in the sensor array into electrical signals; v. demodulate phases and multiplex electrical signals, and vi. process and record multiplexed signals; in which the steps of sending the optical signals and processing and recording the signal of the received signals are performed in an interrogator's cube located on a platform or on land; and in which the steps of dividing the optical signal, receiving modulated optical signals, converting the modulated optical signals into electrical signals and demodulating and multiplexing the phases of the electrical signals are carried out in one or more concentrators (12) located under the sea, in any underwater position, or on the platform, in a separate location from the interrogator's cube (11, 20); and the method includes transmitting signals from or from each concentrator (12) to the interrogator cube (11, 20) over a single line or wirelessly.
    [0021]
    21. Sensor set according to claim 15, characterized by the fact that the sensor units (5) of the sensor set are operable to generate signals derived from time, in addition to amplitude signals.
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    同族专利:
    公开号 | 公开日
    EP2684077B1|2015-06-17|
    GB2488841B|2014-09-10|
    GB201104196D0|2011-04-27|
    US20140063493A1|2014-03-06|
    US9086325B2|2015-07-21|
    WO2012123698A1|2012-09-20|
    GB2488841A|2012-09-12|
    CN103597375A|2014-02-19|
    BR112013023145A2|2017-02-07|
    CN103597375B|2017-05-24|
    EP2684077A1|2014-01-15|
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    法律状态:
    2018-05-22| B25A| Requested transfer of rights approved|Owner name: 9328394 CANADA INC. (CA) |
    2018-06-05| B25D| Requested change of name of applicant approved|Owner name: STINGRAY GEOPHYSICAL INC. (CA) |
    2018-06-19| B25A| Requested transfer of rights approved|Owner name: STINGRAY GEOPHYSICAL HONG KONG LIMITED (HK) |
    2018-12-18| B06F| Objections, documents and/or translations needed after an examination request according art. 34 industrial property law|
    2019-11-19| B06U| Preliminary requirement: requests with searches performed by other patent offices: suspension of the patent application procedure|
    2020-11-17| B09A| Decision: intention to grant|
    2021-02-02| B16A| Patent or certificate of addition of invention granted|Free format text: PRAZO DE VALIDADE: 20 (VINTE) ANOS CONTADOS A PARTIR DE 12/03/2012, OBSERVADAS AS CONDICOES LEGAIS. |
    优先权:
    申请号 | 申请日 | 专利标题
    GB1104196.9|2011-03-11|
    GB1104196.9A|GB2488841B|2011-03-11|2011-03-11|Sensor array|
    PCT/GB2012/000239|WO2012123698A1|2011-03-11|2012-03-12|Sensor array|
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