Kevin Erickson

Velocity-independent redatuming A new approach to the near-surface problem in land seismic data processing

It is well known that a complex near surface—encountered in areas such as desert, mountainous, and glacial till environments—can significantly distort primary reflections from deeper horizons of interest. This has been and remains a major problem in seismic data processing.

Velocity‐independent datuming of seismic data

Processing techniques aiming at full prestack datuming of seismic data require a detailed knowledge of the velocitydepth model. They are usually based on wave theoretical principles and are successfully employed in marine datasets where both the water depth and velocity are readily available. In land datasets however, particularly those with a complicated near surface, a detailed knowledge of the velocity-depth model is always questionable and thus the application of conventional datuming methods produces unreliable results. In this paper we employ the concept of Common Focus Point (CFP) technology and develop a novel, full prestack datuming methodology for seismic reflection data. The main advantage of our approach is that it requires no knowledge of the velocity-depth model. Instead, the velocity-depth model is expressed in terms of propagation operators which can be easily updated.

CFP-based redatuming: Synthetic and Field data examples

Summary Using the CFP technology, any near surface complexities can be described in terms of propagation operators which can be easily updated. With these fully data driven updated operators, a one-way time image can be constructed and a complete wavefield redatuming can be applied to the seismic data by simply defining one of the sub-weathering reflectors as the new acquisition datum.