The drilling of the world’s deepest geothermal well has been completed on Reykjanes Peninsula in Iceland, according to the Iceland Deep Drilling Project (IDDP).
Geologists have penetrated 4,659 metres down, creating the deepest-ever volcanic borehole.
Their aim is to tap into the steam at the bottom of the well to provide a source of geothermal energy.
It took the team 176 days with recorded temperatures of 427°C.
The IDDP team also collected 21m of cores, which is now to be analysed.
Guðmundur Ómar Friðleifsson, from Icelandic energy company HS Orka, the lead funder of the scheme, said: “We got some beautiful samples – everyone is very pleased.”
As the geologists neared their 5,000m target, the drilling became more difficult, and the team decided to halt the operation once it reached 4,659m.
However at this depth, the scientists did find the pressure was high enough to see the supercritical steam they were expecting.
Friðleifsson said: “We knew we had reached our goal, so we decided it was the right time to stop drilling. Mission accomplished.”
Over the coming months, the next stage will be to pump cold water into the well, in order to open it up.
The team will then see whether it generates as much energy as they hope.
Friðleifsson added: “We will start measuring and getting fluid chemistry from the deep samples. We have three more years to go before we conclude the mission.”
The scheme also gives scientists an unprecedented look into the depths of a volcano, and could help them to better understand how these systems work.
The IDDP project is funded by energy companies, including HS Orka, Statoil, Landsvirkjun and Orkuveita Reykjavíkur), Orkustofnun (the National Energy Authority of Iceland), the International Continental Scientific Drilling Program (ICDP), the National Science Foundation and Horizon 2020.