Georgina Lockham, Geoscientist & Eleanor Oldham, Senior Geophysicist
In order to further develop Merlin’s capability in wind energy subsurface support, Merlin’s Geoscientist Georgina Lockham, and Senior Geophysicist Eleanor Oldham have recently attended a course and conference dedicated to this net zero energy solution. Read below for their learnings.
Georgina Lockham attended the ‘Offshore Wind Geophysical and Geotechnical Training’ course run by the American Offshore Wind Academy. The course was held online over two half days and a few things struck her from the offset. Despite the small numbers on the course, the attendee list was hugely international. Not only was nearly everyone attending a different nationality, but their active projects were based all over the globe. Secondly, the majority of participants were actively working in the wind sector, with just herself from Merlin as a relative newcomer to the industry.
So, what did she learn?
First off, a big take-home was just how important the Quality Assurance and Quality Control (QA/QC) measures are throughout the project lifecycle. At every stage, the data gathered and methods used need to be checked for consistency and accuracy. Even before data acquisition can commence, it is very important to check the accuracy of the ships GPS and tie it in with the dimensional control survey of ship. After data gathering, areas with data gaps or poor quality information should be re-surveyed, and data sets that contain anomalies should be checked to understand the cause. Merlin is very aware of the importance of QA/QC through their existing work, particularly in terms of location accuracy. Loading of historic seismic and well data requires a clear understanding of the coordinate reference systems used. Merlin have found that in a large number of cases, limited information is available and significant investigation is required to confirm true locations.
Another key aspect is understanding what the project objectives are and designing the geotechnical surveys and workflows to match. Throughout the project lifecycle, the level of survey detail will naturally change, so understanding what resolution is necessary at the current project stage is important. Initially, during the desktop study, only high-level information is required, enough to make sure the site is viable and to help tailor the subsequent geotechnical studies. As the project continues, investigations get more detailed and therefore expensive. However, the more money spent and the more information gathered, the more the risk of costly unforeseen construction issues reduces later down the line.
Further along the project lifecycle, engineering plays a large role. In order to be able to anchor floating turbines or place monopiles on the sea floor, an understanding of the shallow rock strength is vital. Models are run to test turbine stability using geotechnical surveys characterising seabed soil and geology. In situ tests (e.g. cone penetration tests (CPT)) add more detailed information on rock strength and additional laboratory tests can be run to help further understand the stresses present at that location.
Overall, mitigation of risk is the element that underpins all geotechnical activities. The studies objectives are not just to gather as much information as possible about the site, but to use this information to assess whether the site has the right characteristics to support the construction of a wind farm and its maintenance for years to come.
As for the course, the instructors and attendees were all extremely friendly with lots of questions asked and interesting discussions had. Georgina personally learnt a lot from the course and she looks forward to using this new skillset in future projects here at Merlin.
Continuing our development in the wind sector and as part of our busy conference season, Merlin’s Senior Geophysicist, Eleanor Oldham, attended the Geological Society’s first symposium on Ground Modelling for Offshore Wind Developments on 21st-22nd November.
This was a new event and it proved highly popular with geoscientists and geotechnical engineers from across the UK and Europe.
Eleanor is a relative newcomer to the world of offshore wind, so she was eager to learn more about the geoscience requirements and chat with people who are already active in this field. Fortunately, the first sessions were dedicated to seismic inversion so she immediately felt at home (although several of the geotechnical specialists looked discomfited!).
One of the key messages to come out of the conference was to highlight the importance of geology in the ground model. Ground models collate all information pertinent to the project and allow risk conscious engineering decisions to be taken. However, often ground models become a simple repository for all the data acquired in the screening process, but they can become much more powerful simply by maintaining the integration back to the underlying geology. This allows data acquisition and risk mitigation to be focused on the risks more likely to be encountered in that geological environment.
Eleanor came away from the conference with a much clearer understanding of how her skills as a geophysicist could be adapted for the offshore wind sector. Hopefully the event’s success will mean it becomes a regular fixture on the Geological Society’s calendar.
