A Comprehensive Review of Geophysical Survey Techniques for Offshore Wind Farm Projects

Emissions of greenhouse gases in the atmosphere by burning fossil fuels to generate electric energy has become a major environmental concern. In this scenario, alternative clean sources, such as wind energy, are becoming the top substitute option for supplying electricity and reducing gases emissions. Brazil has huge potential for offshore wind energy. The main challenge, however, is to guarantee the proper installation of these facilities, minimizing risks and ensuring safe operation during its lifetime. To achieve that goal, extensive investigations regarding several geological, engineering and environmental factors must be conducted. Marine geophysical tools have proven to be a reliable, fast and cost-effective way to map the seafloor. This paper provides a review of how different countries are gathering data to map, manage and mitigate seabed features and risks on their offshore wind farm projects. It is shown that, despite many common characteristics, each country has specific rules regarding the survey design. The goal is to provide an overview of the "best practices", and to serve as a baseline for Brazilian regulatory agencies and other stakeholders to design effective hydrographic and geophysical surveys extracting maximum value and knowledge, minimizing geological risks and environmental impacts, keeping cost efficiency for all stakeholders in the operation.