We present a methodology to invert seismic data for a localized area by combining source-side wavefield injection and receiver-side extrapolation method. Despite the high resolving power of seismic full waveform inversion (FWI), the computational cost for practical scale elastic FWI remains a heavy burden. This can be much more severe for time-lapse surveys, which require real-time seismic imaging on a daily or weekly basis. Besides, structure changes during time-lapse surveys are likely to occur in a small area rather than the whole region, such as oil reservoir. We thus propose an approach that allows to image effectively the localized structure changes far deep from both source and receiver arrays. We perform both forward and back propagation only inside the target region. We present 2D and 3D elastic numerical examples of the proposed method and quantitatively evaluate the inversion errors, in comparison to those of conventional full-model inversions. The results show that the proposed localized waveform inversion is not only efficient and robust but also accurate even under the existence of errors in baseline models.

Presentation Date: Wednesday, September 27, 2017

Start Time: 11:25 AM

Location: 361F

Presentation Type: ORAL