Least-squares Inversion for Imaging the Full Seismic Wavefield
S. Lu, F. Liu, N. Chemingui and M. Orlovich
Event name: 80th EAGE Conference and Exhibition 2018
Session: Multiple Attenuation and Manipulation / Imaging I
Publication date: 11 June 2018
Info: Extended abstract, PDF ( 873.01Kb )
Price: € 20
We present a Least-Squares inversion solution for depth migration of the full seismic wavefield including both primaries and high-order reflections. Conventional seismic processing uses only primary reflections for imaging. It treats high-order reflected events as noise and removes them before migration. Separated Wavefield IMaging (SWIM) takes advantage of the extended illumination provided by surface-multiple energy and delivers high-resolution images of the subsurface. Primary and high-order reflections are complementary, and can augment the overall imaging results when properly combined. However, imaging the full wavefield of both primaries and multiples in a standard migration has been challenging for balancing the contribution of each component. In addition, imaging of the full wavefield includes a blending process, which produces crosstalk. Inversion automatically weighs the primary and multiple reflection energy and directly estimates the earth reflectivity that explains boundary data without matching the crosstalk. Successful applications to both synthetic and field data examples demonstrate that Least-Square Full Wavefield Migration (LS-FWM) resolves the crosstalk issue in FWM and greatly improves the imaging illumination and resolution compared to conventional migration.