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Towards Robust Acoustic Full Waveform Inversion
- Publisher: European Association of Geoscientists & Engineers
- Source: Conference Proceedings, 77th EAGE Conference and Exhibition - Workshops, Jun 2015, Volume 2015, p.1 - 5
Abstract
Summary
Seismic full waveform inversion (FWI) is a powerful method for obtaining high resolution subsurface images, but the objective function of FWI algorithms typically contains many local minima, which may lead to erroneous solutions. This can be avoided by choosing an initial model that is close to the true model, and by incorporating only low frequencies at an early stage of an inversion run. Here, we demonstrate that the local minima problem can be mitigated by removing, at each iteration, all data that have more than half a cycle mismatch in the traveltimes compared with those predicted for the current model. Using a simple two parameter example, we show that filtering waveform data by this traveltime criterion can successfully circumvent local minimum trapping. Inversions of synthetic 2D acoustic data show that our novel traveltime-directed FWI approach is more robust and far less dependent on having an accurate starting model.
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