Journal ArticleDOI
Automatic algorithm for triaxial hodogram source location in downhole acoustic emission measurement
TLDR
In this paper, an automatic acoustic emission (AE) source location algorithm has been developed for downhole AE measurement of subsurface cracks by using the triaxial hodogram method.Abstract:
An automatic acoustic emission (AE) source location algorithm has been developed for downhole AE measurement of subsurface cracks by using the triaxial hodogram method. The P-wave arrival time is detected by analyzing crosscorrelation coefficients among three components of AE signal energy; the P-wave direction is determined by the method of least squares. For detection of S-wave arrival time, a maximum‐likelihood method analyzes a distribution of instantaneous values of the SH-wave component amplitude. This algorithm can locate an AE source as accurately as human analysis. For field measurements, it takes less than 4 s to locate an AE source using a 16-bit personal computer with a program in C language. Automatic AE source location by the triaxial hodogram method has been realized with this algorithm.read more
Citations
More filters
Journal ArticleDOI
The removal of free surface interactions from three-component seismograms
TL;DR: In this article, the effect of the free surface can be removed from three-component seismic recordings to recover the incident upgoing wavefield, if the slowness and azimuth of the current wavefront are known as a function of time.
Book
The seismic wavefield
TL;DR: The Seismic Wavefield as mentioned in this paper provides a comprehensive guide to the understanding of seismograms in terms of physical propagation processes within the Earth, focusing on the observation of earthquakes and man-made sources on all scales, for both body waves and surface waves.
Journal ArticleDOI
Three-component analysis of regional seismograms
D. C. Jepsen,Brian Kennett +1 more
TL;DR: In this article, the authors proposed a wave-type decomposition method to estimate the propagation characteristics of different seismic phases at regional distances by testing a range of characteristics of the three-component records, and then classifying much of the seismogram in terms of wave type and direction.
Patent
Tracking objects in conduits
TL;DR: In this article, the authors described a method for tracking a pig in a pipeline using distributed acoustic sensing, which is used to obtain signal returns from a plurality of discrete longitudinal sensing portions of a fiber optic cable which is laid along the length of the conduit.
Journal ArticleDOI
Current status of seismic and borehole measurements for HDR/HWR development
Hiroaki Niitsuma,Michael Fehler,R. Jones,Stephen Wilson,James N. Albright,Andrew Green,Roy Baria,Kazuo Hayashi,Hideshi Kaieda,Kazuhiko Tezuka,Andy Jupe,Thomas Wallroth,F.H. Cornet,Hiroshi Asanuma,Hirokazu Moriya,Koji Nagano,W. Scott Phillips,James Rutledge,Leigh House,Alain Beauce,Doug Alde,Richard C. Aster +21 more
TL;DR: Seismic and borehole measurements provide significant information about HDR/HWR reservoirs that is useful for reservoir development, reservoir characterization, and performance evaluation as discussed by the authors, which is the only means to obtain direct information about reservoir characteristics away from boreholes.
References
More filters
Journal ArticleDOI
Automatic earthquake recognition and timing from single traces
TL;DR: In this article, a computer program was developed for the automatic detection and timing of earthquakes on a single seismic trace, which operates on line and is sufficiently simple that it is expected to work in inexpensive low-power microprocessors in field applications.
Journal ArticleDOI
Acoustic Emissions as a Tool for Hydraulic Fracture Location: Experience at the Fenton Hill Hot Dry Rock Site
James N. Albright,Chris Pearson +1 more
TL;DR: In this article, microearthquakes with magnitudes between -6 and -2 have been observed in three successive massive injections of water at the hot dry rock geothermal energy development project's demonstration site at Fenton Hill, NM.
Journal ArticleDOI
Seismic anisotropy in the upper oceanic crust
TL;DR: In this paper, a set of patterns indicative of hexagonally isotropic structure with a horizontal symmetry axis were observed in borehole data obtained at DSDP site 504B on DSDP leg 92.
Journal ArticleDOI
Autoregressive Representation of Seismic P-wave Signals with an Application to the Problem of Short-Period Discriminants
TL;DR: In this article, it was shown that seismic P-wave signals can be represented by parametric models of autoregressive type, which are models having the form X(t)-a1X(t-p)-1)- apX( t-p) =Z(t) where X(p) is the digitized short-period data time series defined by the P-Wave signal, and Z(t), is a white noise series.
Related Papers (5)
Precise source location of AE doublets by spectral matrix analysis of triaxial hodogram
Precise detection of a P-wave in low S/N signal by using time-frequency representations of a triaxial hodogram
Hirokazu Moriya,Hiroaki Niitsuma +1 more