On thin ice - Oil spill planning for the Arctic

Materials World magazine
,
26 Nov 2012

The hustle is on for the Arctic’s vast mineral reserves, but is industry fully equipped to deal with the environmental consequences of extracting oil from here?  

According to the US Geological Survey, the Arctic Circle has an estimated 90 billion barrels of undiscovered, technically recoverable oil in 25 geologically defined areas. Of the estimated totals, more than half of the undiscovered oil resources are estimated to occur in just three geologic provinces, Arctic Alaska, the Amerasia Basin and the East Greenland Rift Basins. Despite its clear wealth of resources, drilling the Arctic has its vices, mainly because environmental and extraction conditions have not been widely studied. The constraint makes it a costly and challenging field, and extends the time to exploration.  

The Arctic Ocean system is still considered the most vulnerable to climate change, and oil spills created by tankers, subsea pipelines, gravity-based structures and floating drilling units can lead to a chain reaction of contamination. And, being a remote and relatively untapped area, lack of technology remains a problem.  

At a recent Arctic Oil Spill event in London, UK, Stephen Potter of SL Ross Environmental Research Ltd, based in Ontario, Canada, said that the problem lies in changing drilling trends. ‘We used to drill close to the shelf using ships – now there is more of a deep-water trend, going 1,000 metres down – as seen with the Gulf of Mexico.’  

The presence of ice has a great effect on an oil spill. For instance, if there is a solid sheet of ice on the sea surface, the response measures will depend on whether the oil has been spilled on or under the ice. If there is only a partial ice cover on the sea surface, the response is affected by the quantity and properties of the ice. Another issue is that there is limited understanding on how mobile oil is in ice areas. On the plus side, Potter explained, ‘it takes quite a current to move oil in ice...as ice has the ability to modify a spill’s behaviour by damaging waves, reducing natural dispersion, emulsification, equilibrium thickness and slowing evaporation’.  

Window of opportunity  
A £20 million collaboration project conducted by SINTEF’s Materials and Chemistry Division has so far provided the most extensive research into oil spill contingency in the Arctic area. The four-year Joint Industry Program for Arctic and Ice-covered Waters project (www.sintef.no/Projectweb/JIP-Oil-In-Ice/Publications) involved two large-scale field experiments carried out in the Norwegian part of the Barents Sea east of Svalbard archipelago. Tests were conducted in ice with oil concentrations ranging from 50–90%, examining countermeasures such as mechanical recovery, chemical dispersants and in-situ burning (ISB).  

SINTEF’s findings, which were presented at the event, confirmed that ISB of oil and chemical dispersion is the quickest and most effective method of removal. The main limitations, however, lie in the stages before selecting a clean-up method.  

Sea ice extent and oil weathering measurement and detection must be carried out due to changes in properties. For example, after a period of time the oil will no longer be ignitable due to water uptake. The time before this is the ‘window of opportunity’.  

The report also highlights that the presence of ice can retard the rate of spreading for spilled oil in comparison to ice-free conditions. For that reason, the seasonal cycle of freezing and melting of ice has practical implications on the selection of oil spill response method. Prime threats, for example, would be fast ice and deformed ice. Although, ‘what happens in old ice or multi-year ice is still unknown,’ noted Potter.  

The main technologies used to monitor oil in ice are SAR satellite systems, IR sensors and ground-penetrating radars (GPR). Furthermore, to even use sensing equipment you typically need a platform of some type, for example an aircraft or vessel. But due to the large opening angle of the antenna, planes must be flown at very low altitudes. ‘In the Arctic, routinely remote sensing with manned aircrafts is nearly impossible as between Denmark, Canada, Norway, the UK and the USA, there is low availability of suitable aircrafts’. If you do manage to get one, you can be up there for eight hours and you have to monitor and carry a whole crew. Also, ‘you don’t want to fly an aircraft below 20m in that weather. It has to be a very brave pilot that does that,’ said Dr Rune Storvold of the Northern Research Institute, Tromsø, Norway. He added, ‘GPRs are of great assistance, but there is an urgent need for better and higher resolution imaging of oil spills in order to measure thickness and damage’.  

Limited daylight is also an issue. ‘There’s a lot of cloudiness in the Arctic. 90% of the time you can’t even see anything unless you fly through. We need to make more powerful GPR systems so that you can go down in frequency, even if you get a lower resolution’, he added.  

Another disabling factor, said Storvold, is that ‘oil detectors work at 250nm resolution and are often too poor to note contaminated ice’.  

Yet technology is evolving in the field. Unmanned aircrafts (UAS), autonomous underwater vehicles and NMR could now offer a viable solution to detection problems and reduce both time and costs of monitoring the Arctic, due to sparse population and low GA traffic. UAS could also bridge the gap between satellite and in-situ measurements, noted Storvold.  

However, he added that ‘remote sensing alone for finding oil spills in ice is like finding a needle in a haystack’ and that GPR should be used in combination with other instruments, an unmanned vehicle and optical imaging. Adding to this, consultant Kirsten Taylor of Oil Spill Response Ltd, headquartered in London, UK, highlighted that international collaboration in generating modelling data and response would reduce overall costs.  

Out in the field  
In light of SINTEF’s report, Dr Kenneth Lee of Canadian Dept of Fisheries and Oceans echoed the importance of field trials as being a ‘real advantage point’ for creating better response techniques and technologies. However, public opinion against mock spill scenarios is strong. ‘We collect the data but don’t transmit it to the public, so often when the media ask questions they look to people who don’t necessarily know the answer.’ Lee also stated that the area of oil impact in a release is quite small and that test spills used in experiments are often blown out of proportion. He noted that, through experimental field-testing, industry could share real-time knowledge and validate each other’s work. ‘There is [also] a need to collect data on toxicity, as many groups are not testing within the typical exposure regimes in a real environment, and so often they are not relevant to a moving or diluted oil spill,’ added Lee.  

Delegates asked if the science community would do better to focus on prevention rather than response technology and why oil spill field tests were not being conducted in real-life scenarios. But Taylor said that often there is not enough time to plan and set up adequate testing equipment for a disaster area, and you also have to wait for data. ‘Also, as found in the case of the Exxon Valdez site, you need to be careful of rocky sea area and water levels,’ Lee warned. On a more controversial note, Taylor said, ‘Cleaning up straight after an oil spill is not always the best thing to do. We sometimes need to wait and learn what happens, and monitor that area of damage. The public perception is that we should get right in there and clean up.’  

Anchoring the debate while keeping environmental groups at bay, Director of Pöyry Management Consultancy, Ole Njærheim, said, ‘More than 500 wells have been drilled offshore in Alaska, Canada, Norway and Russia in Arctic conditions in the last 40 years with no problems’, but admitted that if offshore production increases, so could spills, due to limited infrastructure and ‘low proximity to equipment and people’.  

Drawing parallels with the exploration of shale gas, Njærheim noted that much of our understanding is still limited in terms of long-term effects. ‘Black oil on white snow makes such a dramatic image, it can provoke media attention and public concern.’ Instead, he added, the focus should be on improving infrastructure and tackling the ‘large technological unknowns’, of which there are many.    

 

Russians on-board 
The Russian Ministry of Transport is developing technology for the Arctic area by funding the first oblique icebreaking multi-purpose emergency oil spill and rescue vessel, Arctech N508. Project engineer Toni Kuusisto added that the vessel will have an in-built oil-recovery system with a recovered oil capacity of 900m3. The vessel (see below) is able to move sideways to tackle a larger surface area and will be delivered in December 2013. The vessel is being built with shipyard Yantar and is suitable for operation in heavy waves. It will be used in the Gulf of Finland, Baltic area and northern parts of Russia in icebreaking operations, floating facilities and oil combatting.