The key to combating an oil spill like the Macondo disaster could be high above you, circling the earth in orbit, not on a vessel.
Speakers at Interspill 2018 in London in March had a fascinating message for companies engaged in oil spill response. They said assets in the sky, not on the sea, could dramatically enhance the effectiveness of response efforts.
David Hamersley, a remote sensing consultant at NPA Satellite Mapping, a CGG company, said a revolution in remote sensing using satellites “is taking place above us.”
Mr Hamersley said satellites can provide a wide field of view and noted that slicks can cover thousands of square kilometres. Satellites can acquire imagery before response teams get to a site and provide valuable intelligence – they can help understand the size and direction of an oil spill.
Remote sensing using satellites has several advantages, he said. They have potential applications for monitoring spills from vessels and massive oil spills such as the Deepwater Horizon incident.
Mr Hamersley noted that different operators charge different amounts for the use of remotely sensed data from satellites. There are a growing number of open access satellites and microsatellites that are inexpensive to manufacture. This makes them ideal to monitor offshore operations, he said.
Statoil principal engineer Richard Hall said another advantage of using satellite imagery was that digitalisation of the workflow can integrate multiple observations into one summary, taking advantage of an increased number and frequency of observations.
Nowadays, he said, there are an ever-growing number of satellites, and it is important to find the right balance between using the right resources and having an up-to-date picture without being overwhelmed with choice.
In future, he said, it would be possible to ‘synergise’ multiple data streams into an integrated data layer combining different delivery times, observation times and observation capabilities. “A single sensor cannot detect all of the objects all of the time,” he said, “but all objects can be delivered by a system of sensors over a period of time.”
Synthetic aperture radar can provide a synoptic overview of an area, he explained, it has all-weather imaging capability and is independent of daylight. However, its use is not without complications: in low wind the backscattered signal is weak and there is little contrast between oil slicks and water; moderate winds are favourable for oil slick detection, with oil slicks appearing as dark features; but in high winds some of the useful signal can become lost in ambient noise.”
“The role of satellite imagery is to provide input to the collection of more data from other platforms,” he said, “and play an important role in the overall response plan.”
Back in 2010, when the Macondo incident occurred, NASA mobilised its remote sensing assets – including satellite observations – to help assess the spread and impact of the oil spill in the Gulf of Mexico. Nowadays, there are many more such assets to take advantage of.