Title | Elastic full-waveform inversion with extrapolated low-frequency data |
Publication Type | Conference Paper |
Year of Publication | 2020 |
Authors | Sun, H, Demanet, L |
Conference Name | SEG Technical Program Expanded Abstracts 2020 |
Publisher | Society of Exploration Geophysicists |
Conference Location | Virtual |
Abstract | Full waveform inversion (FWI) strongly depends on an accurate starting model to succeed. This is particularly true in the elastic regime: The cycle-skipping phenomenon is more severe in elastic FWI compared to acoustic FWI, due to the short S-wave wavelength. In this note, we extend our work on extrapolated FWI (EFWI) by proposing to synthesize the low frequencies of multi-component elastic seismic records, and use those ”artificial” low frequencies to seed the frequency sweep of elastic FWI. By leveraging deep learning technologies, we separately train two neural networks to extrapolate the low frequencies of elastic data (vertical and horizontal components of particle velocity), respectively. Numerical example on the Marmousi2 model shows that the 2-4Hz low frequency data extrapolated from band-limited data above 4Hz provide good starting models for elastic FWI of P-wave and S-wave velocities. Additionally, we study the generalization ability of the proposed neural network over different physical models. For elastic test data, collecting the training dataset by elastic simulation shows better extrapolation accuracy than acoustic simulation, i.e., a smaller generalization gap. |
URL | https://library.seg.org/doi/abs/10.1190/segam2020-3428087.1 |
DOI | 10.1190/segeab.3910.1190/segam2020-3428087.1 |