A goal of reflection seismic imaging is to reduce risk in exploration and development ventures. Within that context it is used to identify and define new prospects, to extend known prospects, and to monitor exploitation activities. As society's energy demands are ever increasing, and the Earth's resources are diminishing, these exploration and development activities are being applied with greater regularity in more difficult areas. Exploration objectives are more complicated, and data acquisition, processing, and interpretation is more challenging in many of the parts of the world where the search for frontier prospects is undertaken. In many of these areas, the imaging challenge is to compensate for the effects of rugged topography properly, or to image complex structures with complex subsurface velocity distributions. Both of these effects, together and separately, present some of the greatest imaging challenges to geophysicists.
In this dissertation, I investigate two of the most complicated factors affecting reflection seismic structural imaging: the effects of rugged acquisition topography, and complex velocity structure. When these effects are present, standard processing, imaging, and velocity estimation methods often fail. The reason they fail is that most standard methods are based on certain simplifying assumptions that may not be valid under the given circumstances.
I present methods based on wavefield extrapolation that result in improved imaging in regions of rugged topography and complex velocity structure. The two major contributions that I present in this dissertation are