Imaging Vertical Interfaces Using Acoustic Time-reversal
S. Singh and A. Curtis
Event name: 80th EAGE Conference and Exhibition 2018
Session: Poster: Seismic Imaging - Least Squares and Migration
Publication date: 11 June 2018
Info: Extended abstract, PDF ( 1.13Mb )
Price: € 20
Previous methods to image near-vertical interfaces or faults using migration methods all require prior information about small-scale details in the seismic velocity model in order to infer the locations of multiply-scattering wave interactions, or highly accurate velocity models to predict the paths of long-offset refracted waves. We present a novel approach to image vertical structures with multiply-scattered waves without the need for such prior information. We use waves that have their last scattering interaction at near-vertical interfaces, while their other scattering points may be anywhere in the Earth, including at the free surface. Our algorithm images the final scattering point using a time reversed imaging condition. Artifacts in the image have clear causes and can be filtered out. We call this imaging method Time Reversed Migration. The requirements for our method are similar to standard migration: data recorded at the acquisition surface with or without free surface multiples present, and a smooth version of the velocity model. Our numerical examples include a section of the Marmousi model, and demonstrate the successful application of the method.