Resolving the Near-Surface Complexities, Helping Reservoir Imaging – Complex Geological Settings Onshore and Offshore Case Studies

This paper investigates the impact of near-surface geological complexities on seismic imaging challenges encountered at deeper reservoir levels. It highlights how heterogeneity within near¬surface layers significantly influences the accuracy and effectiveness of deeper seismic interpretations. Through a comprehensive analysis of various onshore and offshore 3D seismic surveys, the paper discusses strategies employed to address these near-surface imaging obstacles. The findings underscore the importance of understanding near-surface dynamics in enhancing seismic imaging techniques, obtaining more accurate subsurface models and demonstrate improvements in the clarity and reliability of seismic data at deeper reservoir levels. We develop a refined velocity model that enhances the understanding of the geometrical features. Through advanced modeling techniques, we analyse how these geological features influence seismic wave propagation, thereby improving imaging accuracy. The findings provide critical insights into the subsurface characteristics associated with the complex geology, facilitating better exploration and characterization of underlying geological formations. We elaborate on fundamental full waveform inversion quality control steps and methodologies. The examples are showing improvement in structural definition, signal to noise ratio and reflection continuity with preserved relative amplitudes.