Velocity-independent time-domain seismic imaging using local event slopes

Abstract

By estimating local event slopes in prestack seismic reflection data, it is possible to accomplish all common time-domain imaging tasks, from normal moveout to prestack time migration, without the need to estimate seismic velocities or any other attributes. Local slopes contain complete information about the reflection geometry. Once they are estimated, seismic velocities and all other moveout parameters turn into data attributes and are directly mappable from the prestack data domain into the time-migrated image domain. I develop an analytical theory, which defines the transformation from data and local slopes to the image space for different time-domain imaging operators. Computational experiments with synthetic and field data examples confirm theoretical expectations and demonstrate practical effectiveness of the proposed method.