Low frequency passive seismic interferometry for land data

Low frequency passive seismic interferometry for land data

Sjoerd de Ridder

Abstract:

Here we report results achieved by low-frequency seismic interferometry on a passive seismic land dataset recorded at a field in Saudi Arabia. Computed spectra for different portions of the data show a time varying ambient seismic wavefield displaying a diurnal pattern. At low frequencies ($< 10$ Hz) the ambient seismic wavefield mainly consists of surface waves in two modes, the fundamental mode propagates with a velocity of about $1250$ ms. Results suggest that sufficient coherent energy is recorded between $1$ Hz and $7$ Hz for retrieval of a Rayleigh surface wave. The strength of the ambient seismic field affects the convergence rate of the correlations. The directionality in the ambient seismic field affects the radiation pattern of the virtual sources. Retrieved Rayleigh waves at low frequencies show spatial variation and dispersive behavior. Dispersion curve estimation opens opportunities for reservoir monitoring by background velocity estimation.

Low frequency passive seismic interferometry for land data