Impact of the Topography of the Acquisition Surface on Preprocessing and Subsequent Free Surface Multiple Elimination and Depth Migration: Examining the Issue and Providing a Preprocessing Response That Accommodates a Variable Topography - Thereby Allowing Subsequent Multiple Removal and Imaging Methods to Deliver Their Promise and Potential

This dissertation studies the influence of the topography of the seismic acquisition surface on seismic processing. This is important because in real off-shore and on-shore acquisition, there are many cases in which seismic data have to be acquired along a surface that can be far from horizontal. This dissertation provides three advances and contributions. The first examines the issues in preprocessing when the acquisition surface is assumed to be horizontal and it is actually non-horizontal. To address and solve those issues, a new preprocessing formula is derived which accommodates the topography of the measurement surface. Numerical examples compare the preprocessing results that ignore the acquisition topography, and the preprocessing results that accommodate the acquisition topography. The second investigates the effectiveness of inverse scattering series (ISS) free surface multiple elimination that requires deghosted data, where the deghosted data is input with and without the assumption of horizontal acquisition. Comparison with numerical examples demonstrates that effective deghosting, that includes and accommodates the acquisition surface, is a prerequisite for free surface multiple elimination to deliver its capability. The third looks at the subsequent effectiveness of depth imaging, that uses different free surface multiple elimination results from the second advance as input. Quantitative analysis is provided that defines the positive effect of accommodating acquisition topography in preprocessing steps on depth imaging results.