Fast and automatic microseismic phase-arrival detection and denoising by pattern recognition and reduced-rank filtering

 

Autores
Velis, Danilo Ruben; Sabbione, Juan Ignacio; Sacchi, Mauricio D.
Tipo de recurso
artículo
Estado
Versión publicada
Año de publicación
2015
País
Argentina
Institución
Consejo Nacional de Investigaciones Científicas y Técnicas
Repositorio
CONICET Digital (CONICET)
Descripción
We have developed a fast method that allowed us to automatically detect and denoise microseismic phase arrivals from 3C multichannel data. The method is a two-step process. First, the detection is carried out by means of a pattern recognition strategy that seeks plausible hyperbolic phase arrivals immersed in noisy 3C multichannel data. Then, the microseismic phase arrivals are denoised and reconstructed using a reduced-rank approximation of the singular value decomposition of the data along the detected phase arrivals in the context of a deflation procedure that took into account multiple arrivals and/or phases. For the detection, we have defined an objective function that measured the energy and coherence of a potential microseismic phase arrival along an apex-shifted hyperbolic search window. The objective function, which was maximized using very fast simulated annealing, was based on the energy of the average signal and depended on the source position, receivers geometry, and velocity. In practice, the detection process did not require any a priori velocity model, leading to a fast algorithm that can be used in real time, even when the underlying velocity model was not constant. The reduced-rank filtering coupled with a crosscorrelation-based synchronization strategy allowed us to extract the most representative waveform for all the individual traces. Tests using synthetic and field data have determined the reliability and effectiveness of the proposed method for the accurate detection and denoising of 3C multichannel microseismic events under noisy conditions. Two confidence indicators to assess the presence of an actual phase arrival and the reliability of the denoised individual wave arrivals were also developed.
Idioma
inglés
OAI Identifier
oai:ri.conicet.gov.ar:11336/53691
Enlace del recurso
http://hdl.handle.net/11336/53691
Nivel de acceso
Acceso abierto
Materia
Microseismic
Automatic event detection
Denoising
Meteorología y Ciencias Atmosféricas
Ciencias de la Tierra y relacionadas con el Medio Ambiente
CIENCIAS NATURALES Y EXACTAS