Time-lapse traveltime change of singly scattered acoustic waves

Abstract

S U M M A R YWe present a technique based on the single-scattering approximation that relates time-lapse localized changes in the propagation velocity to changes in the traveltime of singly scattered waves. We describe wave propagation in a random medium with homogeneous statistical properties as a single-scattering process where the fluctuations of the velocity with respect to the background velocity are assumed to be weak. This corresponds to one of two end-member regimes of wave propagation in a random medium, the first being single scattering, and the second multiple scattering. We present a formulation that relates the change in the traveltime of the scattered waves to a localized change in the propagation velocity by means of the Born approximation for the scattered wavefield. We validate the methodology with synthetic seismograms calculated with finite differences for 2-D acoustic waves. Potential applications of this technique include non-destructive evaluation of heterogeneous materials and time-lapse monitoring of heterogeneous reservoirs.

Detecting remotely triggered temporal changes around the Parkfield section of the San Andreas fault

“…In comparison, Sleep (2009) suggested that the temporal changes observed by Brenguier et al (2008b) could also be explained by the rock damage in the near surface layers (e.g., Rubinstein and Beroza, 2005). Systematic studies of the sensitivity kernels of the obtained NCCFs (e.g., Pacheco and Snieder, 2006) and the frequency dependent effects of the temporal changes (e.g., Xu and Song, 2009) could help to provide further constraints on the depth extent of the observed temporal changes. Finally, it is possible that the temporal changes are transient, and only occur during the large-amplitude waves, followed by near-instantaneous recovery (e.g., Wu et al, 2010).…”

A feasibility study of time-lapse seismic monitoring of CO2 sequestration in a layered basalt reservoir

“…In this three-layer model with a localized velocity perturbation, the recorded signal spends a significant time traveling through unperturbed material, and equation 9 must be adjusted to account for this. For random media, Pacheco and Snieder (2006) and Pacheco and Snieder (2005) consider probabilities of time lags due to localized changes for singly and multiply scattered waves. Here, we aim for a deterministic solution:…”

Automatic identification of multiply diffracted waves and their ordered scattering paths

“…Diffractions play an important role in many fields of theoretical and applied acoustics, including medical imaging (Insana et al, 1990;Tadayyon et al, 2014), localization and destruction of kidney stones using medical ultrasound and lithotripsy (Fink et al, 2003), ocean acoustics for the detection of marine organisms (Brekhovskikh and Lysanov, 2003;Foote, 2008), but also in other fields of physics including quantum mechanics (Friedrich, 2006), non-destructive testing (Prada et al, 2002), remote sensing (Ferretti et al, 2001), ground-penetrating radar (Papziner and Nick, 1998), near-surface geophysics (Harmankaya et al, 2013;Kaslilar et al, 2014), seismic exploration and monitoring (Landa et al, 1987;Khaidukov et al, 2004;Pacheco and Snieder, 2006;Halliday and Curtis, 2009;Jixiang et al, 2014), and global seismology (Wu and Aki, 1988). In all such cases being able to predict or interpret diffracted energy is crucial.…”