Quantitative Interpretation and Imaging of Walkaway VSP Data: Navigating Rough Terrain and Complex Subsurface

An integrated quantitative approach utilizing walkaway vertical seismic profiling (WAVSP) has successfully imaged subsurface targets with high resolution in a complex environment characterized by rough terrain and highly dipping geology. By acquiring WAVSP data in a deep well and applying a comprehensive methodology encompassing pre-processing, earth model building, rock physics studies, and inversion, we overcame the limitations of traditional surface seismic imaging. The resulting images revealed detailed structures that were poorly illuminated on surface seismic data, enabling accurate delineation of the targets’ lateral extent through post-stack inversion for acoustic impedance. This study underscores the importance of combining WAVSP imaging with quantitative analysis for enhanced subsurface understanding in challenging settings, paving the way for future refinements, including improvements to the earth model and the application of advanced imaging techniques like reverse time migration (RTM) and full wavefield migration (FWM).