Marine seismic imaging: the key to robust wind farm foundations

Seismic Acquisition

Accurate seismic imaging begins with meticulous data acquisition. Choosing the right specifications and equipment setup is essential for capturing high-quality seismic data.

Key elements of seismic acquisition in the UUHR domain include:

• High sample rates: Up to 16 kHz, offering high fidelity data sets.

• Short group interval streamers: Equipped with point receivers for an unbiased frequency response.

• Consistent, repeatable sources: Wide-band, high frequency sources with stable and repeatable signatures.

• Consistent spread geometry: Ensures tight acquisition bin sizes and efficient data collection.

• Deeper towing: Extends weather workability limits.

Seismic Navigation

Precise and transparent navigation is crucial to maximise the potential of a UUHR seismic data set. Achieving navigation solutions with absolute accuracies of greater than 20 cm is possible through technologies such as real time kinematic GNSS receivers and acoustic positioning networks.

Enhanced processing solutions can be developed by incorporating in-water compasses, fixed geometry points, and native navigation inputs. Quality control is maintained by ensuring a consistent fit between solutions and cross-correlating the navigation data with the seismic data.

This comprehensive approach guarantees accurate positioning of seismic data, leading to improved subsurface imaging.

Processing and Imaging 

In the rapidly evolving field of offshore wind energy, the ability to process UUHR seismic data is crucial for high-resolution structural mapping, hazard identification, and innovative seismic inversion techniques. Meeting these demands requires advanced workflows that prioritize bandwidth and amplitude preservation, ensuring compliance with stringent client requirements.

For example, we leverage our proprietary seismic processing software, developed by a dedicated R&D team, to push boundaries of UUHR seismic data processing. Our geophysicists bring extensive experience to the table, ensuring that we deliver high-quality results swiftly, keeping foundation design projects on track.

Our integrated solution involves seamless communication with acquisition teams for real-time data validation and close collaboration with interpretation groups. This synergy allows us to customise our solutions to meet specific project needs, delivering efficient and precise results.

Patrick Burn, Fugro’s Seismic Technical Manager, shares insights into the challenges and innovations in UUHR data processing: “High-resolution structural mapping, hazard identification, and advanced seismic inversion techniques rely heavily on our data. To meet these demands, our workflows prioritise bandwidth and amplitude preservation, aligning with client requirements. Key areas where processing can make a significant impact include understanding weather tolerance and managing statics associated with the sea surface. We have optimised our designature, deghosting, and demultiple tools to address these challenges and continue to refine our technology”. 

Mapping Geo-hazards

When planning wind turbine locations, accurately imaging geo-hazards such as boulders, shallow gas, faults, harder layers, outcrops, and channel features is critical to mitigate risks in the design and installation of foundations.

Success in geo-hazard mapping relies on a combination of precise acquisition, navigation, processing, and imaging. High-resolution seismic data acquisition ensures that even the smallest features are captured. Accurate navigation guarantees that the data is correctly positioned, while advanced processing techniques enhance the clarity and detail of the images. Finally, expert imaging interprets the data to provide a comprehensive understanding of the subsurface conditions.

By integrating these elements, we can create detailed maps that highlight potential hazards, enabling engineers to design foundations that are both safe and efficient. This proactive approach not only reduces risks but also optimises the overall development process, ensuring the long-term stability and success of offshore wind projects.

Operational Efficiency

In the quest for operational efficiency in geophysical surveys, minimising in-water noise and optimising data collection are paramount. We operate a global fleet of specialised, acoustically quiet vessels designed to achieve these goals. These vessels not only reduce our carbon footprint but are also equipped to deliver a comprehensive range of geophysical services. 

Each survey design is meticulously tailored to our clients' specific needs, offering options from 2D UUHR and 3D micro-siting to full-scale 3D UUHR campaigns. By prioritising schedule advancements through operational efficiency, we ensure that project timelines are met without compromising data quality or environmental responsibility. Our dedicated in-house teams support every phase of the survey process, from planning and acquisition to processing, ensuring seamless execution and superior results.

Commitment to Environmental Responsibility

In the pursuit of advanced seismic imaging for offshore wind projects, safeguarding marine life and the environment is paramount. Effective mitigation strategies, such as Passive Acoustic Monitoring and soft start procedures, are essential to minimise the impact of seismic acquisition activities on marine ecosystems.

We prioritise environmental responsibility in all marine operations. We continuously invest in and collaborate on research to understand the effects of seismic sources on marine life. Through innovation, we strive to further reduce our environmental footprint, ensuring that our operations contribute to a safe and sustainable world.

By integrating these practices, we are committed to protecting marine ecosystems while delivering high-quality seismic data for offshore wind projects. This approach not only supports the well-being of marine life but also aligns with our vision of creating a safe and liveable world for future generations.

Project Success

In the dynamic field of offshore wind farms, precise and reliable seismic imaging is crucial for successful project development. Understanding the unique challenges faced by developers, we provide the data and insights needed to make informed decisions.

Jelte Offringa, Fugro’s Global Seismic Solution Manager, emphasises: “Our advanced seismic imaging techniques ensure you have a clear understanding of subsurface conditions, reducing risks and optimising project outcomes. By partnering with Fugro, you gain access to a comprehensive suite of services, including survey planning and execution, seismic processing and interpretation, as well as ground model development and foundation engineering”. 

For wind developers navigating the subsurface complexities of offshore projects, ensuring safety, efficiency, and success is paramount. Partner with a proven leader committed to innovation and excellence.

* ISO 19901-10:2021(en) - Petroleum and natural gas industries — Specific requirements for offshore structures — Part 10: Marine geophysical investigations