Reverse-time migration using wavefield decomposition

Reverse-time migration using wavefield decomposition

Kittinat Taweesintananon

Abstract:

Reverse-time migration (RTM) is capable of imaging very steeply dipping reflectors and overhangs. However, it usually produces strong artifacts that contaminate the shallow parts of the migrated images. These artifacts can be suppressed using an imaging condition with appropriate decomposed source and receiver wavefields. In this paper, such a technique is applied and examined. This imaging condition keeps only energy at the points where strong backscattering originates. The results show that RTM using wavefield decomposition is a promising remedy for attenuating artifacts compared to the implementation of a low-cut filter. However, some artifacts still remain in the decomposed RTM image. These residual artifacts are caused by the cross-correlation between the upgoing component of the direct source wavefield and the backscattered component of the receiver wavefield.