Reflection multi‐scale envelope inversion

• Published in: Geophysical Prospecting 2018-09, Vol.66 (7), p.1258-1271
• Main Authors: Chen, Guo‐Xin, Wu, Ru‐Shan, Chen, Sheng‐Chang
• Format: Article
• Language: English
• Subjects: Acoustics; Components; Dependence; Full waveform; Inversion; Mathematical models; Migration; Reflected waves; Reflection; Reflectors; Seismic data; Wave reflection; Wavelength
• ISSN: 0016-8025; 1365-2478
• DOI: 10.1111/1365-2478.12624

ABSTRACT Sufficient low‐frequency information is essential for full‐waveform inversion to get the global optimal solution. Multi‐scale envelope inversion was proposed using a new Fréchet derivative to invert the long‐wavelength component of the model by directly using the low‐frequency components contained in an envelope of seismic data. Although the new method can recover the main structure of the model, the inversion quality of the model bottom still needs to be improved. Reflection waveform inversion reduces the dependence of inversion on low‐frequency and long‐offset data by using travel‐time information in reflected waves. However, when the underground medium contains strong contrast or the initial model is far away from the true model, it is hard to get reliable reference reflectors for the generation of reflected waves. Here, we propose a combination inversion algorithm, i.e., reflection multi‐scale envelope inversion, to overcome the limitations of multi‐scale envelope inversion and reflection waveform inversion. First, wavefield decomposition was introduced into the multi‐scale envelope inversion to improve the inversion quality of the long‐wavelength components of the model. Then, after the initial model had been established to be accurate enough, migration and de‐migration were introduced to achieve multi‐scale reflection waveform inversion. The numerical results of the salt‐layer model and the SEG/EAGE salt model verified the validity of the proposed approach and its potential.