Researchers from the Iceland Deep Drilling Project (IDDP) are drilling 5km down into the heart of volcano to bring steam up from the deep well to the surface. This will provide an important source of energy.
The volcano last erupted 700 years ago but 5km down temperatures are expected to exceed 500C.
A huge rig stands out on the lava fields and the drill inside has been operating 24 hours a day since August. The borehole is expected to be completed any day now but latest reports had it at 4,254m deep, making it the deepest hole in Iceland.
A borehole taps into underground stores of water or steam to run power plants to produce clean, renewable electricity.
At the moment, these boreholes are only drilled down to two or three kilometres to harness the steam but the team behind the project in the Reykjanes region want to see if the resources go deeper than that. As well as being an important energy project, the team has also been bringing up core samples to see what kind of rock is hidden that far under the surface.
At 5km the team expects to find molten rock mixed with water but with the extreme heat and pressure at this depth, the water becomes what is known as supercritical steam. This is neither a liquid nor a gas but it holds far much more than either state. It’s this steam the team wants to bring back up to convert into electricity. This steam has the potential to produce up to 10 times as much energy as that from conventional geothermal sources.
If this works, we’ll have to drill fewer holes for the same amount of energy, which means less environmental impact and lower costs.
When drilling into a volcano there are obvious risks. Back in 2009 the IDDP drilled just 2,100m into a shallow reserve of magma. Hitting these kinds of temperatures meant the drill was destroyed and black smoke billowed up from the well.
There’s a chance that if the drill does hit magma it’ll bubble straight up to the surface thanks to the enormous amounts of pressure at that depth. This would cause huge problems for the drilling operation although the researchers don’t believe they’ll hit any magma at the 5km depth.
At this stage the IDDP is drilling blind with no rock fragments coming up on the drill. It’s instead being absorbed into the surrounding rock. This means the researchers can’t exactly be sure what they’re drilling into without having these samples to study.
With just a few hundred metres to go, the team is optimistic the world’s hottest borehole is within their reach.