Infrastructure which interacts with the seabed, that is, foundations and subsea cables, accounts for a very significant portion of CAPEX spend, sometimes as much as 40 percent. This infrastructure depends on diligent design, robust ground model and seabed risk management to reduce CAPEX, ensuring constructability and to reduce long term OPEX spend. The quality, reliability and type of data characterising the seabed is critical to this process. Optimising something as simple as sample type and subsequent control on laboratory testing specifications can very positively impact CAPEX for foundations.
A ‘right from the start’ attitude taken by the project team can ensure overall risk and cost reduction; an approach which can only be realised by engaging consultancy with experience in the end-use of the data. Selecting the right consultant to provide good survey management, technical support and offshore representation can add value and achieve a significant ROI for a project.
Client representatives who are specialists in the work undertaken, with genuine technical onshore support allow the survey to be bespoke and targeted, on the fly, which secures value for the client. The key to unlocking value at the survey stage is in having staff offshore who have experience of the end-use of the data, enabling real-time geotechnical parameter selection, pile capacity calculations, jackup LPA’s or subsea cable routing, for example. The risk of not having the ability to react offshore can have real cost implications. In addition to the demanding technical role, client representatives must be able to lead by example on matters of HSE. Do consider specific HSE and first aid training for your representatives to ensure that they can deliver this critical part of their role.
The cost of a client rep is relatively fixed, around 2 percent of the Geotechnical survey and 5 percent of the Geophysical survey, being controlled by the comparatively large cost of the survey vessel and operations. However, the client gains value with a detailed knowledge of the end use of the data, from a design perspective. This de-risks the data collection, allows informed real-time decisions and targets survey spend towards what actually matters. Given the relative expense of survey operations and inexpense of quality survey consultancy, this is where value can be gained from a good survey management service.
As an example, Cathie Associates was appointed by EDF Renewables in 2016 to support the Blyth offshore demonstrator wind farm off the North-East coast in the UK in the geotechnical aspects of the design and development phase, following project involvement dating back to 2012. The project comprised the installation of five wind turbines located around 5.7 km off the coast at a water depth ranging from 36 to 39 metres.
A bespoke approach to the seabed data acquisition at early project phases resulted in a staged approach to survey and reduced exposure to ‘at-risk’ spend whilst still managing seabed risk to an appropriate level. This approach saved the client over £200,000 on site characterisation geophysical survey. At the detailed geotechnical stage, optimised sample collection and targeting of advanced laboratory testing delivered critical information for the design of the novel gravity base foundations. Bespoke advanced laboratory testing procedures ensured that the foundation design was properly informed and that risk was identified and managed.
Our engagement throughout the project development and construction phase delivered continuity of care from the earliest stages of project definition through to the installation of the GBS’, scour protection and subsea cabling. This holistic approach to seabed risk management, design and installation delivered tangible value to our client resulting in lower LCOE and project risk.
Cathie Associates is committed to providing end-to-end, integrated geospatial, geophysical and geotechnical support to the project to mitigate risk, reduce cost and ensure delivery on offshore wind projects.
To learn how we supported the Blyth Offshore Demonstrator Wind Farm, download our case study now!
If you are looking for a survey consultant for your offshore or nearshore project, contact us now!