Adaptive Least-squares RTM for Subsalt Imaging
C. Zeng, S. Dong, B. Wang and Z. Zhang
Event name: 78th EAGE Conference and Exhibition 2016
Session: Seismic Imaging Theory - Advances in Least Squares Migration
Publication date: 31 May 2016
Info: Extended abstract, PDF ( 1.99Mb )
Price: € 20
We propose an adaptive solution for subsalt imaging using least-squares reverse time migration (LSRTM). We aim to address the typical problems in subsalt imaging such as minor velocity errors and salt related migration artefacts. We first demonstrate the modelling based noise cancellation capability of LSRTM with the field data from the Gulf of Mexico (GoM). LSRTM distinctly enhances signals and removes migration artefacts even when their characteristics are similar on seismic images. We also propose a crosscorrelation based confidence level to control the quality of data matching. The application on the GoM field data shows improved termination of sediments toward salt boundaries in the shadow zone. The strong salt halo artefacts are also suppressed effectively after the adaptive LSRTM updating.