396 results about "Distributed acoustic sensing" patented technology

The invention discloses a planning method and system of a power distribution communication access network, particularly relates to the technical field of power distribution communication network dynamic topology management, and is used for solving the problems of fault misjudgment and inaccurate positioning caused by topology update delay in the prior art. A dynamic topological data set is generated by dynamically monitoring the operation state of each optical fiber node and a link transmission signal, a real-time topological view with a dynamic version identifier is generated based on a preset topological planning strategy, and a network change area is quickly locked by combining a topological difference identification technology of an alarm moment and a historical view. Candidate fault links are screened through the conflict relation between link switching frequency and service priority, and the vibration characteristics of the construction machinery are further analyzed by using distributed acoustic sensing data and external force damage interference is eliminated; and finally, optical cable breakage faults are confirmed through optical power interruption verification, heartbeat signal loss detection and redundant optical fiber phase mirror symmetry verification. And multi-dimensional accurate positioning of the topological data fault root cause is realized.

In some embodiments, a system for producing fluid from a well can include an electrical submersible pump (ESP) disposed in a wellbore of the well and configured to pump the fluid. The system may further include a distributed acoustic sensing (DAS) system, for example having an interrogator unit and a fiber optic cable extending downhole in the wellbore. An end of the fiber optic cable can be disposed downhole relative to the ESP. In embodiments, the system may further include a controller configured to receive data from the DAS system, process the data to detect a slug, determine a parameter of the detected slug, and alter operation of the ESP in response to determining that the parameter exceeds a threshold.

A computer-implemented method useful for performing seismic tomography, including obtaining seismic data comprising distributed acoustic sensing (DAS) data, comprising at least one of P-wave or S-wave travel times from a plurality of seismic events to a plurality of recording stations coupled to a network of optical fibers in a geological structure; and generating tomography data from the DAS data, wherein tomography data is useful for characterizing the geological structure. We employ distributed acoustic sensing data recorded along a 100-km fiber-optic cable traversing the caldera to image its subsurface structure. Our images highlight a definite separation between the shallow hydrothermal system and the large magma chamber located at ˜12 km depth. The combination of the geological evidence with our results shows how fluids exsolved through second boiling provide the source of the observed uplift and seismicity. Thus Fiber-seismic tomography reveals that the unrest in the Long Valley Caldera is likely driven by fluid from second boiling, not new magma intrusion.

The invention discloses a signal-to-noise ratio improvement method based on a multi-core optical fiber dual-channel distributed acoustic sensing system, and the method comprises the steps: carrying out the light splitting of light emitted by a narrow linewidth laser through a first coupler C1, enabling one path of light to generate a pulse signal through an acoustic optical modulator (AOM), enabling the other path of light to pass through a second coupler C2, and enabling the other path of light to pass through a second coupler C1; the pulse light is divided into two beams of transmission light, the two beams of transmission light are injected into a connected sensing optical fiber through two groups of erbium-doped optical fiber amplifiers (EDFA), two groups of filters, two groups of circulators and a fan-in coupler Fan-in Coupler, and the pulse light is subjected to backward Rayleigh scattering in the sensing optical fiber; based on a dual-channel DAS system, a multi-core optical fiber is used as a sensing optical fiber, three cores and four cores of the multi-core optical fiber are connected in series to form two sensing channels, seven-core space division signals are multiplexed, the equivalent self-noise pressure suppression effect of the seven-core space division signals is analyzed, after noise correlation is removed through a time domain dislocation-frequency domain phase shift method, the signal-to-noise ratio gain can be increased to 8.65 dB, and the signal-to-noise ratio gain can be increased to 8.65 dB. And the detection capability of the system on low-frequency weak signals can be improved.

A method for monitoring pipeline integrity is provided. The method includes obtaining, using at least one hardware processor, acoustic signal captured by at least one optical fiber arranged along a pipeline. The method includes inputting, using the at least one hardware processor, the acoustic signal to a machine learning model. The machine learning model is trained to execute a first analysis on a first representation of the acoustic signal and a second analysis on a second representation of the acoustic signal, the first analysis being independent to the second analysis. An output of the trained machine learning model is at least one of a first result based on the first analysis or a second result based on the second analysis. The method includes determining, using the at least one hardware processor, an indication of pipeline integrity based on the at least one of the first result or the second result.

Disclosed are a device and method for detecting and identifying shallow-stratum foreign objects based on distributed acoustic sensing. The device includes a vibrating sensitivity-enhanced fiber optic cable, a distributed acoustic sensing demodulator, a vibrator system, a vibration data processing unit, a velocity structure inversion unit and an AI-aided locating and identification unit. The distributed acoustic sensing demodulator transmits vibration signals to the vibration data processing unit for preprocessing to obtain waveform signals; the velocity structure inversion unit performs inversion to obtain the shallow-stratum underground velocity structure; positions of shallow-stratum foreign objects are identified through the underground velocity structure and abnormal waveforms; and the types of shallow-stratum foreign objects are identified. A distributed acoustic sensing method for fiber optic cables is used to obtain vibration signals, velocity imaging is performed on a shallow-stratum velocity structure, and AI is utilized to achieve locating and type identification of shallow-stratum underground foreign objects.

A fiber optic distributed sensing system and method. The fiber optic distributed sensing system includes: an optical fiber extending through an underwater gas field; an interrogator connected to the optical fiber so that light transmitted through the optical fiber is capable of being sensed by the interrogator; and a computer system configured to obtain sensor data captured by the interrogator and determine an amount or a characteristic of gas within the underwater gas field based on the sensor data. The method includes: capturing sensor data using a fiber optic distributed sensor extending through an acoustic field; performing a wavelet transform on the sensor data in order to obtain spatiotemporal data; and matching the spatiotemporal data to an event template of a predetermined set of event templates in order to identify a spatiotemporal event.

A system may include a first DAS station, comprising a first plurality of interrogator units to launch a first plurality of DAS signals in a first direction, wherein a first interrogator unit is configured to launch a first DAS signal at a first interrogation rate and first wavelength, wherein a second interrogator unit is configured to launch a second DAS signal at a second wavelength and second interrogation rate, less than the first interrogation rate. The system may include a loopback array, comprising a plurality of loopbacks, arranged over a plurality of spans, wherein a first set of proximate loopbacks nearest to the first DAS station are configured to route back the first DAS signal to the first DAS station, and wherein a first set of intermediate loopbacks, located further from the first DAS station, are configured to route back the second DAS signal to the first DAS station.

A method and a system for monitoring an optical transmission path in an optical transmission system. A signal is transmitted on a portion of the optical transmission path. The optical transmission path includes a plurality of portions. A clock synchronization signal in a plurality of clock synchronization signals is assigned to the transmitted signal. A backscattered signal is received. The backscattered signal is generated by the portion of the optical transmission path in response to the signal being transmitted on the portion of the optical transmission path. Based on the assigned clock synchronization signal, the portion of the optical transmission path is monitored by analyzing the backscattered signal to determine a presence of an interference on the portion of the optical transmission path.

A distributed acoustic system (DAS) that may include two or more lasers that each transmit a continuous wave (CW) light, a pulser disposed after the two the two or more lasers and optically connected to each of the two or more lasers to receive the CW light from each of the two or more lasers and form a light pulse, and an optical amplifier, wherein the pulser is optically connected to the optical amplifier to receive the light pulse from the pulser as an input. The DAS may further include a splitter optically connected to the optical amplifier to optically split the light pulse into two or more light pulses for each output of the splitter a circulator optically connected to each output of the splitter, and a sensor fiber attached to each of the circulators as an output for each circulator.

The disclosed method includes: determining a subsurface space of interest; arranging a source sensor array relative to a receiver sensor array of a Surface Distributed Acoustic Sensing (S-DAS); transmitting, from the source sensor array, a first set of seismic signals indicating baseline measurements; receiving, using the receiver sensor array, the baseline measurements and thereby generate baseline data; injecting fluid into the subsurface space of interest; transmitting, using the source sensor array, a second set of seismic signals indicating fluid plume measurements; receiving, using the receiver sensor array, the fluid plume measurements and thereby generate fluid plume data; determining, based on the baseline data and the fluid plume data, time-shift data and thereby generate fluid plume extent data; formatting the fluid plume extent data into data values that characterize an extent or rate of spread of the fluid plume; and visualizing the extent or rate of spread of the fluid plume.

The invention discloses an equivalent self-noise pressure suppression method based on a dual-channel distributed acoustic sensing system, and the method comprises the steps: carrying out the light splitting of light emitted by a narrow-linewidth laser through a first coupler C1, enabling one path of light to generate a pulse signal through an acoustic optical modulator (AOM), enabling the other path of light to pass through a second coupler C2, and enabling the other path of light to pass through a second coupler C1; the pulse light is divided into two beams of transmission light, the two beams of transmission light are injected into a connected sensing optical fiber through two groups of erbium-doped optical fiber amplifiers (EDFA), two groups of filters, two groups of circulators and a fan-in coupler Fan-in Coupler, and the pulse light is subjected to backward Rayleigh scattering in the sensing optical fiber; according to the invention, based on a dual-channel DAS system, two fiber cores of the multi-core optical fiber are used as sensing optical fibers, and the space division signals of the two cores are multiplexed, so that the performance that the equivalent self-noise pressure drop is 2.54 dB in the frequency band of 100-1000Hz is realized under the condition that the noise correlation coefficient of the dual-core signals is 0.11, and the detection capability of the system on low-frequency weak signals can be improved.

Systems and methods are presented for determining a calibrated vertical seismic profile (VSP) with a distributed acoustic sensing (DAS) system in a borehole. The methods include obtaining a density log and an acoustic slowness log for the borehole; determining a first impedance, a DAS impedance from well log (DIL) curve, from the density log and the acoustic slowness log; obtaining a VSP dataset in the borehole; for each of the plurality of gauge lengths: determining a second impedance, a DAS from vibrations (DIV) curve, from the VSP dataset for the plurality of gauge lengths, and determining a fit between the DIV curves and the DIL curve by using a misfit functional for each of a plurality of depth adjustments. The method further includes determining the calibrated VSP by applying a preferred depth adjustment to the VSP dataset.

A method is provided for detecting an operating condition of a vessel including two fluid phases moving past one another, which may include providing a fiber optic cable about an exterior surface of the vessel, receiving time domain data including distributed acoustic sensing measurements from the fiber optic cable at a plurality of locations along the exterior surface of the vessel, determining frequency domain data at each of the plurality of locations based on the time domain data, performing an analysis of the frequency domain data and / or the time domain data using a pre-trained model, and determining an operating condition of the vessel based on the analysis.

The invention relates to the technical field of audio processing, and discloses an intelligent control system and method for a wireless microphone, and the method comprises the steps: collecting multi-point acoustic data through a distributed microphone network, and constructing a spatial acoustic topology model; based on a topological analysis result, constructing an adaptive notch filter bank to realize howling suppression; environment changes are monitored in real time through a distributed acoustic sensor network, and suppression parameters are dynamically optimized; integrating a lightweight convolutional neural network on microphone equipment to identify acoustic events; low-delay acoustic event processing and howling prevention are realized by adopting a layered edge computing architecture; according to the invention, the technical problems of unstable howling suppression, weak environmental adaptability and lack of spatial perception in a complex environment are effectively solved.

Disclosed are systems and methods that employ distributed fiber optic sensing (DFOS) / distributed acoustic sensing (DAS) to monitor and provide real-time estimation of ice thickness on fiber optic communications facilities, and which integrate DSA data with a hybrid processing technique that combines frequency domain decomposition (FDD) and stochastic subspace identification (SSI). Aspects of our innovative systems and methods include: i) Hybrid Signal Processing Techniques; ii) Real-time, Continuous Ice Monitoring; iii) Enhanced Noise Robustness and Non-linear Dynamics Handling; and iv) Adaptability and Scalability.

The embodiment of the invention provides a fault positioning method and device for a communication optical cable, equipment and a medium, and the method comprises the steps: carrying out the preprocessing of distributed acoustic sensing data, and obtaining the processed distributed acoustic sensing data; detecting abnormal data in the processed distributed acoustic sensing data by using a dual-threshold threshold algorithm; performing analysis of different domains on the abnormal data to obtain multi-dimensional features; and identifying the multi-dimensional features by using a trained support vector machine model, and determining the fault position of the distributed acoustic sensing data, so as to solve the problem that the real-time dangerous case positioning of the communication optical cable line cannot be realized at present.

A method for performing one or more capture utilization and sequestration (CCUS) operations. The method includes obtaining, from a vibration sensor, ambient noise data associated with a subsurface of a resource site. The method also includes generating, from the ambient noise data, passive virtual shot data indicating temporal properties or interactions present in the ambient noise data. The method also includes determining, using the passive virtual shot data, shot analysis data. The method also includes generating, using the shot analysis data, a model representing changes in past CCUS operations for the resource site. The method also includes initiating, based on the model, one or more additional CCUS operations for the resource site.

Earthquake detection via fiber sensing is provided using using a supervisory path of submarine cables wherein the supervisory system / path of a submarine optical cable conveys portion(s) of an optical signal back to an origin location periodically—i.e., at every repeater location. Advantageously, since it is known where a returning signal is coming from, a resolution equivalent to an undersea span length may be determined—which is sufficient for wide area disturbances such as earthquakes. The returned signal is sufficiently strong such that the signal-to-noise ratio of a returned / received signal is not limited by the ASE noise of the amplifiers. The returned signal is much larger as compared to a normal distributed acoustic sensing (DAS) return signal since the return signal according to aspects of the present disclosure is directed backward via an optical coupler / reflector / circulator having a much larger coupling ratio as compared to normal Rayleigh back scattering utilized in DAS.

Methods and systems for managing operation of a well are disclosed. The method may include obtaining distributed acoustic sensing (DAS) data based on a measurement made using a DAS sensing element positioned in the well. A qualification process for the DAS data may be performed to identify whether any portion of the DAS sensing element was acoustically coupled to a structure of the well during the measurement in a manner that introduced at least one artifact to the DAS data. If at least one portion of the DAS sensing element was coupled in such a manner, a remediation process may be performed to manage impacts of the at least one artifact on downstream use of the DAS data.

A long range optical fiber sensor such as a distributed acoustic sensor has a sensing fiber located remotely from the interrogator, with a length of transport fiber path connecting the two. Because no sensing is performed on the transport fiber then the pulse repetition rate from the interrogator can be high enough such that the pulse repetition rate and pulse power are optimised according to the sensing fiber length and hence sensing frequency response and sensitivity are also optimised according to the sensing fiber length. In further embodiments fiber amplifiers such as erbium doped fiber amplifiers may be included in line in the transport fiber path, typically located just before the sensing fiber in the direction of pulse travel from the interrogator, to help restore the pulse signal power before it enters the sensing fiber. In yet further embodiments at least one Raman pump source can be provided to inject light pulses on to the transport fiber at a Raman pump wavelength to stimulate the generation of signal photons at the interrogator pulse wavelength via the stimulated Raman scattering (SRS) phenomenon. This helps to maintain the forward pulses and backscatter / reflection signals as they traverse the transport fiber path to and from the sensing fiber.

The invention discloses a sea surface wind speed inversion method based on submarine optical fiber distributed acoustic sensing. The method comprises the following steps: recording wind-generated marine environment noise through a submarine optical fiber based on distributed sound wave sensing; actual sea surface wind speed data are obtained through the buoy; obtaining a time-frequency power spectrum and an effective frequency band of the noise; an effective sensing unit group is obtained after quality control is carried out on the wind-generated marine environment noise; establishing an inversion parameter model, and fitting according to the time-frequency power spectrum of the effective sensing unit group, the effective frequency band and the sea surface actual wind speed data to obtain an inversion parameter; and establishing a sea surface wind speed inversion model, and obtaining the inverted sea surface wind speed according to the inversion parameters, the noise time-frequency power spectrum to be inverted and the effective frequency band. Based on the high-density acoustic sensing technology, the widely distributed submarine optical fibers are fully utilized, the current situation that ocean site wind speed observation data are scarce is effectively improved, the wind speed observation cost is greatly reduced, and a new way is provided for sea surface wind speed observation under the extreme sea condition.

Disclosed are systems and methods employing distributed fiber optic sensing (DFOS) / distributed acoustic sensing (DAS) that continuously monitor the buried / exposed status of undersea power cables for offshore wind farms. Our DAS systems and methods continuously monitor dynamic conditions characterizing undersea power cables and advantageously detect dynamic strain of an optical fiber that may be part of a composite cable with the power cable. By measuring and monitoring these dynamic conditions, a change in status from buried to exposed is determined and service personnel deployed before damage occurs to the power cable.

The invention relates to the technical field of industrial safety monitoring, in particular to a fallen object accurate identification FOD calculation method based on a fixed tower and application of the fallen object accurate identification FOD calculation method. Comprising the following steps: synchronously acquiring multi-source heterogeneous sensing data; carrying out multi-modal data preprocessing and feature extraction; performing cross-modal feature fusion and representation construction; modeling and reasoning a time-space diagram neural network; and performing multi-dimensional threat quantification and decision output. According to the design of the invention, multi-modal sensor groups are deployed at the tower bottom, the tower middle and the tower top of a fixed tower in a layered manner, and a high-definition multispectral camera, a high-density laser radar and a distributed acoustic sensor are integrated, so that 7 * 24-hour full-automatic data acquisition is realized; according to the design, the time and environment limitation of manual inspection is eliminated, and the complex weather detection capability is improved by 80%; meanwhile, the sensor synchronously triggers the mechanism and the grading detection process, the single-frame data processing delay is less than or equal to 50ms, and the real-time monitoring requirement of an aircraft take-off and landing high-frequency scene is met.

Distributed fiber optic sensing (DFOS) / distributed acoustic sensing (DAS) that illustrate inventive techniques—applicable to all embedded systems—that deliver high-bandwidth traffic from a DFOS system to a cloud or other processing resources in real-time, employ firmware that operates at a register-transfer level and writes data repeatedly into the embedded host memory directly—without software intervention after initial configuration. This technique advantageously enables the use of the relatively large host memory to compensate for any software jitter. Preferably configured, the firmware employs only a small buffer to compensate for a transaction and host-memory arbitration latency. A second dedicated thread sends out data from the user space buffer to a cloud, or a connected server. Remote procedures that are executed on a remote system (a computer, network of computers, or cloud), receive data transmitted from the embedded system, and perform further processing as necessary.

A system and method for using a Distributed Acoustic Sensor (DAS) system to receive signals transmitted from remote autonomous sensors and to locate the autonomous sensors are disclosed. The method includes installing a DAS system in a borehole consisting of at least one fiber-optic cable connected to at least one corresponding interrogator, deploying at least one autonomous sensor and conducting at least one measurement. The methods also include encoding the at least one measurement in at least one encoded acoustic signal, transmitting the at least one encoded acoustic signal to the at least one fiber-optic cable, and detecting the at least one encoded acoustic signal with the DAS system. Furthermore, the methods include recording the at least one encoded acoustic signal received by the DAS system at a surface location and processing the at least one encoded acoustic signal with a processing unit to decode and obtain the at least one measurement.

The invention discloses a city toughness real-time determination method and system based on distributed sound wave sensing, and the method comprises the steps: carrying out the optical cable distribution of a target region, carrying out the connection with a data channel, and carrying out the channel number mapping; acquiring a strain rate signal of each channel of the optical cable; caching the acquired DAS data; detecting, screening and judging the signal quality of each channel; if the SNR value and the DR value of one channel are lower than 80% of the whole channel, the coupling is abnormal; performing multi-domain feature extraction on the data; rendering the evolution trend of the activity intensity, the disturbance duration and the regional synchronization index along with time and space; constructing a multi-index fusion matrix; different indexes are mapped to color depth and saturation, an abnormal region track is identified, and high-intensity cooperative event prompting and recording are triggered; and obtaining a regional risk evolution situation. The system comprises a sensing optical fiber unit, a DAS demodulation unit, a data storage unit, a data processing and analysis unit, a toughness collaborative analysis unit and a toughness evolution visualization unit. The method is low in cost, wide in space coverage, high in timeliness and friendly in privacy.

A method for monitoring pipeline integrity is provided. The method includes obtaining, using at least one hardware processor, acoustic signal captured by at least one optical fiber arranged along a pipeline. The method includes inputting, using the at least one hardware processor, the acoustic signal to a machine learning model. The machine learning model is trained to execute a first analysis on a first representation of the acoustic signal and a second analysis on a second representation of the acoustic signal, the first analysis being independent to the second analysis. An output of the trained machine learning model is at least one of a first result based on the first analysis or a second result based on the second analysis. The method includes determining, using the at least one hardware processor, an indication of pipeline integrity based on the at least one of the first result or the second result.

A hydraulic fracturing system and method uses a model trained with external pressure gauge data and LFDAS sensor data to identify pressure communication events based on LFDAS sensor data. One or more monitoring wells are established in proximity to a well undergoing well stimulation, each monitoring well including one or more LFDAS sensors. LFDAS sensor data is received from the LFDAS sensors of the one or more monitoring wells, the received LFDAS sensor data including data received after start of a well stimulation operation. Occurrences of pressure communication events at each monitoring well may then be identified based on the model and on the received LFDAS sensor data.

A distributed acoustic system (DAS) that may include two or more lasers that each transmit a continuous wave (CW) light, a pulser disposed after the two the two or more lasers and optically connected to each of the two or more lasers to receive the CW light from each of the two or more lasers and form a light pulse, and an optical amplifier, wherein the pulser is optically connected to the optical amplifier to receive the light pulse from the pulser as an input. The DAS may further include a splitter optically connected to the optical amplifier to optically split the light pulse into two or more light pulses for each output of the splitter a circulator optically connected to each output of the splitter, and a sensor fiber attached to each of the circulators as an output for each circulator.