2D Acoustic Full Waveform Tomography of Marine Streamer Data - Problems and Data Preprocessing

In recent years many synthetic studies showed the great resolution potential of full waveform tomography (FWT), nevertheless application to field data is not a common standard yet. This study discusses some of the problems related with the inversion of conventional single sensor marine streamer data in the 2D acoustic approximation. The lack of low frequency information makes the waveform tomography strongly depending on the initial model. In particular, density information should be considered in the inversion process to obtain reliable P-wave velocity models. The directivity of marine airguns and wave propagation effects, that cannot be reproduced by the forward modeling code require a certain amplitude calibration and scaling of amplitude with offset. Swell noise caused by time variant sea surface topography may significantly reduce the field data quality. Therefore, the noise subtraction algorithm that mutes noise and preserves the useful seismic signal must be applied. The effects of the sea surface topography can be reduced by data de-ghosting. However, this procedure may require additional measurements of pressure and particle velocities using dual-sensors.