A Land Example of Full Waveform Inversion and Distance Separated Simultaneous Sweeping

Simultaneous or blended shooting has been developed to reduce the acquisition cost while keeping a dense coverage. The processing and imaging are complicated by the cross-talks between the simultaneous sweeps. A compromise can be achieved with distance separated simultaneous sweeping when we are primarily interested in reflected events since by design, the interferences at the target are avoided and the shots can be easily separated. At large offsets which are relevant when full waveform inversion is used to construct the background velocity, cross-talks occur. Based on the single shot, single receiver land data set recorded in Inner Mongolia, China, we simulated a 2D distance separated simultaneous sweeping acquisition. We then carried out several full waveform inversions to evaluate the effects of the cross-talks. By adapting the offset weighting traditionally applied, a multi-scale full waveform inversion of the blended data produces a background velocity model that is very similar to the model obtained with the original unblended data.