3D Elastic Full Waveform Inversion - A Random Medium Example

3D elastic full waveform inversion (FWI) has the potential to resolve complex 3D structures and to offer multiparameter images with high resolution. In this work we describe the implementation of our 3D elastic FWI code and show first results. The code is based on the adjoint method and optimized by using a combined time-frequency domain FWI. The performance is shown for a random medium model in transmission geometry, hereby inverting for the seismic velocities. Using a 3D acquisition geometry, the differently sized, complex structures of the random medium can be well resolved. In a second test, a typical borehole geometry with lines of sources and receivers was employed. Within the plane between the boreholes, it was possible to resolve the main features, however resolution and quality is less than for the 3D acquisition geometry. Nevertheless, by using a 3D FWI instead of a 2D FWI, 3D structures can be taken into account.