3D High-Resolution Imaging Using Separated Wavefields

Abstract

Conventional wave equation migration extrapolates upcoming boundary data generated from primary reflections to image the subsurface. In marine seismic data processing, sea surface related multiples are a major challenge. Particularly, when the water bottom is shallow, short period multiples are difficult to deal with. Acquisition footprint of seismic imaging is another issue for shallow water bottom geology, where the primary reflections do not have the complete illumination coverage to the shallow targets, including the water bottom. In this paper, we review a method of separated wavefield imaging using sea surface related multiples. We present a data processing work flow of separated wavefield imaging including up and down-going wavefield separation using dual-sensor data, wave equation migration of wavefield extrapolation and imaging condition, and a post processing step of amplitude balancing. A shallow water example from Asia-Pacific is tested, where the separated wavefield imaging generates remarkable high resolution 3D images. The separated wavefield image has greater area of subsurface illumination, which mitigates the strong acquisition footprint. The method and results can be useful to reduce well drilling geohazards.