Multiscale seismic-envelope inversion for salt structures using a new direct-envelope Fréchet derivative

Abstract

For strong-nonlinear FWI involved with salt structures or other strong-contrast structures, the standard envelope inversion does not work well. We introduce multi-scale window-averaged envelope (WAE) data and derive a new envelope Frechét derivative (sensitivity operator) based on energy pulse scattering physics without using the chain rule of differentiation. This new envelope Frechét derivative (EFD) does not depend on the weak nonlinearity assumption and can be applied to the case of strong-nonlinear inversion. In this paper we show the features of the new Frechét and its related adjoint source and gradient fields. Then the inversion results for the SEG 2D salt model is shown to prove the theory and method. Presentation Date: Thursday, September 28, 2017 Start Time: 11:00 AM Location: 361F Presentation Type: ORAL