Complex topography and highly variable weathering layers in the near surface can severely degrade the quality of seismic data and result in a distorted structural image of the deeper subsurface reflectors. The objective of this work is to compare seismic image quality after application of the Common Focus Point (CFP) redatuming with images generated using more conventional static techniques. The CFP method resolves near surface effects on seismic data by considering the wave propagation phenomena, based on data-driven focusing operators, independent of any velocity model.

Focusing operators are required to describe the kinematic phenomena of the wave field as it passes through the near surface. The focusing operators are automatically estimated using a parametric inversion procedure that assumes the focusing operators can be described with a smooth parameterization. Using these operators, a complete wave field redatuming can be performed moving the data recorded at the surface to a new datum underneath the complex near surface. The results represent data as it would have been measured underneath the complex near surface, with the sources and receivers on the datum reflector. In a second step, these focusing operators can be input to a tomographic inversion process to obtain a velocity-depth model. This model can then be used for converting the redatumed results to depth.

The results from the CFP-based redatuming showed significant improvements over results from traditional statics methods for both synthetic and real data. The continuity of the deeper reflection events was improved and a more reliable time image was obtained of the deeper structure.

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