Biofouling: Not A Load of Barnacles

Emma Learmonth Commercial Director
Biofouling or ‘biological fouling’ is the accumulation of microorganisms, plants, algae, or animals on wetted surfaces.
The offshore oil and gas industry are responsible for a multitude of different assets underwater which these organisms grow on, but why do they become an issue and how does the industry solve this? Emma Learmonth, Director of Aquasign, highlights the problem of this serious issue and tells Oil and Gas Vision how by mimicking fish skin, they are combatting this problem for their clients:
Biofouling causes a raft of serious issues for companies working in subsea environments. Being a subsea marker provider, we look at this issue from a visibility and safety perspective, when personnel have to identify underwater assets and as a result of the biofouling cannot do so. As these organisms attach and grow on subsea markers, making it very difficult and sometimes impossible to view, a divers job becomes much more taxing.
Other serious issues due to biofouling include:
1 Additional weight load and drag: FPSO boat hulls can become covered in biofouling making them heavier to power, and consequently this uses more fuel which has an environmental impact.
2 Safety of personnel: Biofouling makes it difficult to identify specific equipment. If equipment has been subsea for some time, marine growth will have settled here. Divers need to work in safety critical environments and need to be able to identify which asset to inspect easily and, for example, if a valve is in the critical ‘open’ or closed’ position. If a structure is covered in marine life this impacts their time, performance and safety.
3 Corrosion: Barnacles and other organisms may be small but they can erode the surfaces of offshore equipment. Barnacles have their own ‘glue’ they can stick to almost any surface, while other marine life can rust or chip away at surfaces after attaching.
4 Non-identification of damaged areas: When conducting scheduled operations or condition monitoring, any maintenance issues may not be reported as they could be hidden under a thick fouling layer. External cracks and damaged constructive elements become difficult to identify.
The above reasons are largely related to the safety of workers in the industry and the environment at large: while a few organisms here and there might not sound like a lot of disruption, biofouling is a huge issue that can fluctuate between countries, water depths and water temperatures.
  aaf, power industry, generators, north sea, offshore, oil and gas  
What can stop biofouling?
While the easiest remedy might be to kill off marine growth, is that a process operators are willing to pay for and schedule time, staff and resources for periodically?
Biofouling never goes away permanently, it will simply build up again once removed.
Traditional ways to remove fouling also bear no sustainable or eco-friendly attributes, and it can be extremely tough to remove fouling and there is a requirement for machinery to be used in most cases.
Our research and development into our flagship product meant that we could test what technology and materials would combat biofouling. With our subsea markers, we managed to mimic fish skin and create an oil-exuding silicone which can prevent any marine growth. How you ever seen a fish covered in coral, seaweed or mussels?!
Our smart silicone releases no harmful chemicals into the water, is 100% environmentally friendly and contains no copper which was traditionally used to kill marine life. They also have a 60-year anti-fouling performance.
When our clients remove their offshore equipment from the sea, while the structure has biofouling already present, the marker remains clear of growth. Our manufacturing process ensures that the marker face achieves the critical surface tension required to maximise the products hydrophobic properties. This is the primary mechanism for preventing fouling attaching to the marker and theoretically gives the product an infinite lifespan. Silicones have a relatively low shore hardness which makes them susceptible to minor imperfections. Mould substrates are regularly replaced to minimise blemishes in the marker surface however minor pitting damage may accidentally occur subsea e.g. debris in water from nearby jet wash operations. Damage to the marker face can then cause anchor points for marine growth to attach.
We are pro-sustainability and eco focussed and understand that companies in the industry need a long lasting, safety conscious solution.
For further information on Aquasign please visit https://www.aquasign.com/subsea-markers/ or call (01224) 897060.
  ogv - Oil and gas vision publications