A new multi-scale signed direct envelope inversion with more accurate amplitude polarity information

Abstract

Subsurface parameter reconstruction using full waveform inversion is highly nonlinear with nonunique solutions. When the initial model with high precision is missing, the cycle skipping problem will be encountered, especially for the strong scattering media like salt structures. In order to adapt to the inversion of strong scattering media, direct envelope inversion (DEI) using directly the envelope Frechet derivatives was proposed to avoid the weakly nonlinear assumption for the model updating. In the original DEI method, the envelope polarity is not considered. To further improve the effectiveness of DEI, signed envelope inversion with polarity detection can be used. In this work, we develop a new polarity detection technique on the basis of seismic attributes, which can provide more accurate polarity information for the seismic envelope. Based on the above technique, the new multi-scale signed DEI method is proposed. The new technique is applied to the SEG/EAGE salt model. The numerical examples verified the effectiveness of this method.