Acoustic Waveform Inversion Applicability on Elastic Data

Full Waveform inversion is a computer intensive process, especially for 3D seismic data. After a tremendous number of synthetic examples, finally real 3D data sets have been undertaken by the industry. As field data is dominated with P waves, one feasible approach is to use the acoustic approximation. The Full Waveform Inversion described above is acoustic and real data is more accurately described by an elastic model. It is common practice to apply acoustic inversion, especially for 3D data sets because the elastic modeling is prohibitively expensive. Although the long offsets may suffer from elastic effects our experiment shows that the velocity field obtained using acoustic inversion vs. elastic data are reasonable in spite of the difference between the modeling and mother Earth. Although the elastic propagation would provide a better match to the acquired data the cost is still prohibitive compared to the acoustic propagation especially if large 3Ds are under consideration.