The virtual source method for imaging steeply dipping structures using a walk-away VSP Acquisition geometry

Abstract

Seismic interferometry is a recently developed geophysical technique that has been used almost exclusively to solve imaging problems in petroleum environments. It is a method that has a broad range of applications, however one of the most well-known is the ability of the technique to create virtual sources at the location of buried receivers, without knowledge of the subsurface velocity between the true surface sources and the receivers. This research focuses on a problem in a minerals environment, in which a shallow, steeply dipping sub-surface feature is to be illuminated using the virtual source method, a form of seismic interferometry. The research presented here uses both a ray tracing analysis and 2D synthetic seismic modelling to understand the implementation issues associated with the virtual source method. The ultimate aim is to understand the acquisition and processing requirements to image optimally a shallow, steeply dipping sub-surface feature in a hard rock environment.