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Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 18 of 18 for “"distributed acoustic sensing"”.
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Distributed acoustic sensing: modelling, full waveform inversion, and its use in seismic monitoring
Distributed acoustic sensing (DAS) is a rapidly evolving seismic acquisition technology. Employing rugged and small optical fibers, DAS offers an opportunity for access to acquisition geometries often not accessible to more conventional geophone sensors. This is a highly attractive property of DAS …
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Non-Invasive Flow Measurement Via Distributed Acoustic Sensing Utilizing Frequency Spectra Analysis of Wall Pressure Fluctuations
This research describes a method of using distributed acoustic sensing to noninvasively measure volumetric flow rate via multiple unique sensor styles. This work modifies previously used methods of flow detection via fiber optic acoustic sensors affixed onto the exterior body of a flow apparatus. …
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Exploiting Artificial Intelligence in Volcanic Monitoring for Distributed Acoustic Sensing Analysis and GNSS-Based Source Inversion [L’Intelligenza Artificiale per il monitoraggio vulcanico: analisi di segnali DAS e modellazione della sorgente tramite inversione di dati GNSS]
… acquisiti attraverso la nuova tecnologia Distributed Acoustic Sensing (DAS) durante la crisi di Vulcano (Italia) nel 2021. Il periodo di unrest, iniziato a settembre 2021, è stato caratterizzato da un incremento di sismicità, con l’occorrenza di numerosi eventi sismici a bassa frequenza. …
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Efficient Algorithms for Data Analytics in Geophysical Imaging
Modern sensing systems such as distributed acoustic sensing (DAS) can produce massive quantities of geophysical data, often in remote locations. This presents significant challenges with regards to data storage and performing efficient analysis. To address this, we have designed and implemented …
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URBAN SEISMIC AMBIENT NOISE ANALYSIS: INNOVATIONS AND APPLICATIONS
… physical properties and needs to be analyzed. Distributed acoustic sensing (DAS) is a recently developed seismic sensor that allows for long-term, high-spatial resolution, and real-time monitoring at lower costs. However, traditional processing methods may not be reliable when applied to DAS …
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Enhanced completion evaluations in unconventional reservoirs: new applications of fiber optic sensing and machine learning
… Chalk Bluff field and equipped with fiber optic sensing technology to evaluate the completion effectiveness at each stage. The primary goal of these wells was to determine the optimal completion strategies in the field and the impact of nearby legacy wells. In recent years, fiber optic sensing …
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Seismic site characterization using broadband and DAS ambient vibration measurements on Mt Etna, Italy
… velocity data from the broadband stations and distributed acoustic sensing data from a co-located 1.5 km long fibre optic cable. High maximum amplitude values of the resulting ratios along the trajectory of the cable coincide with known faults. The outcome also indicates previously unmapped …
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Magnetic Field Sensing via Multi-Material Acoustic Sensing Optical Fibers with Magnetostrictive Cladding Inclusions
… are tested and investigated to demonstrate sensing capabilities at different field magnitudes and frequencies. Distributed acoustic sensing fibers (DAS) have been largely studied and documented across a variety of applications and sensing systems. This research uses the DAS technology in …
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Statistical approaches for spatial prediction and anomaly detection
… motion data from a fiber-optic cable using distributed acoustic sensing (DAS). First, with a simulation study the validity of the proposed method is established. We present an application of the proposed method to detect the location of subsurface anomalies near the cable as well as temporal …
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Efficient analysis of data streams
… well as textured images and hand-written digits. Distributed acoustic sensing is used to monitor oil flow at various depths throughout an oil well. Vibrations are recorded at very high resolutions, up to 10000 observations a second at each depth. Unfortunately, corruption can occur in the signal …
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Applications of Distributed Temperature Sensing in Subsurface Hydrology
… fluxes efficiently in both time and space. Distributed Temperature Sensing has recently become more accessible to researchers in Earth Sciences, and allows temperatures to be measured simultaneously, at small intervals, and over large distances along fibre optic cables. The capability of DTS …
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Full waveform inversion combining rock physics for seismic reservoir characterization and monitoring
… acquired with accelerometers and a collocated distributed acoustic sensing (DAS) fiber at the Carbon Management Canada’s Newell County Facility. The inverted porosity and lithology models are reasonably accurate at the well location and are geologically meaningful in spatial distribution. This …
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Enhanced imaging of deep lithospheric and shallow near surface structures through innovations in seismic interferometry and array processing.
… urban traffic noise recorded by nodal arrays and distributed acoustic sensing (DAS) fiber-optic cables. Application to the Tierra Grande nodal deployment and a dark fiber cable at the University of Louisiana at Lafayette demonstrates that these anthropogenic sources can serve as reliable, passive …
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Fracture characterization from seismic measurements in a borehole
… on a reservoir scale. We next study Distributed Acoustic Sensing (DAS), a novel Fiber Optic (FO) cable based seismic acquisition technology. We relate DAS measurements to traditional geophone measurements and make a comprehensive study of factors that influence DAS measurements. Using …
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Characterizing microearthquakes and shallow structure with dense array and optical fibers
… cables in several seismic applications. Distributed Acoustic Sensing (DAS) turns optical fibers into dense receiver arrays. These fiber-optic cables have the advantage of being resilient and easier to maintain compared to mechanical sensors. The cable provides a dense array that helps us …
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Elastic time-reverse imaging and transmission tomography for microseismic and DAS VSP data
… and gas industry are well-developed under the acoustic assumption. One of the main shortcomings of this assumption is that conventional acoustic imaging algorithms generally use single-component P-wave data and thus do not account for multicomponent elastic (P- and S-mode) data that can provide …
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Fully Distributed Multi-Material Magnetic Sensing Structures for Multiparameter DAS Applications
… dissertation demonstrates the first of its kind distributed magnetic field sensor based on a fiber optic distributed acoustic sensing (DAS) scheme. Ferromagnetic nickel and Metglas® were dispersed internally within a fiber optic preform and then drawn on an in-house fiber optic draw tower to …
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Microseismic guided wave eigenfunction theory with application to event depth classification in the Eagle Ford shale
The properties of guided waves that propagate in deep low-velocity zones are investigated using eigenfunction theory, and a novel application for microseismic event depth constraint to an unconventional reservoir is developed. Eigenfunctions, historically used in the analysis of Rayleigh and Love …