Integrating High-Resolution Seismic Inversion with Geotechnical Data to Assess Subsurface Soil Profile in Offshore Wind Farms

Summary Europe has ambitions of adding 20GW/yr of offshore wind energy by 2030 to achieve its 2050 Net Zero targets. This requires faster and cost-effective ways for assets to deliver first power, without compromising on reliable characterization and development of sites. Before offshore wind farms are constructed, it is critical to assess the subsurface soil profile and understand ground stability. In this paper, the geotechnical data was integrated with the ultra-high resolution seismic 2D lines, to delineate the soil stratigraphy and provide valuable geological information on the seabed and near surface rocks, on which the foundation will stand. Sand waves were observed on the interpreted seabed, which are potential threat to the turbine foundations. High-resolution seismic inversion was performed, and the generated acoustic impedance property was correlated with the interpreted soil profile in the boreholes. Subsurface features and discontinuous clay zones were mapped, which can guide the placement of wind turbine locations, in case they are high risk to the foundation. The high-resolution acoustic impedance property can be further used to guide the interpolation of the soil profile to build the geological ground model. The workflows discussed in this paper can be applied to other wind farms for successful site characterization.