High-Resolution 3D Site Characterization

We present the results of a novel method for high-resolution 3D site characterization. The strategy is based on using 3D seismic data as the framework for integrating geochemical, geophysical and geotechnical data. The end-results are 3D volumes with various attributes relevant for improved site characterization and ultimately geohazard assessment (i.e. identification of shallow gas, boulders, faults and fractures, leakage, spatial variability, soil strength …). We further show that geochemical data integrated with current high-resolution 3D seismic data can be used to constrain fluid migration pathways to the seafloor. In addition, re-processing focusing on the higher frequencies of 3D seismic data increases the resolution, resulting in a data volume displaying more details on the geology and geomorphology of the sub-surface when compared to data processed for deeper imaging. Finally, we configured an optimized 3D seismic acquisition system, which is fine-tuned for imaging the top 150 m of overburden with a meter-scale lateral and vertical resolution. Such a high-resolution 3D seismic system would provide data volumes that allow well-constrained integration of various type of data.