Use of polarization properties of seismic waves to improve Fresnel Volume Migration of three-component subsurface seismic data

Abstract

Long-range exploration in mines contributes significantly to work safety, raw material extraction and storage of materials in the subsurface. The distribution and number of source and receiver points for seismic surveys depend on the available gallery passages in the mine or underground buildings. Due to the resulting limited aperture, migration artifacts, spatial ambiguities, and geometrically induced amplitude focusing can occur in migration images. In addition, background noise is often very interfering, and reflectors smear in migration images. It has been shown that along drifts that have directional changes and thus corners or chambers, the signal-to-noise ratio is low due to scattered waves. We have incorporated directional and polarization filters into the workflow for pre-processing subsurface seismic data before starting Fresnel Volume Migration (FVM). This significantly reduces background noise and geometrically induced amplitude focusing as well as migration amplitude smearing effects. By applying directional and polarization filters beforehand, we improve the 3D seismic imaging. This allows us to highlight previously hidden or smeared reflectors when calculating migrations of reflected P and S waves and suppress amplitude focusing effects along drifts. In this paper, we present step-by-step this novel methodological approach that improves 3D seismic imaging for large-scale structure exploration in mining.