It is half a century old, although there is not much to celebrate. It is deserted. The Soviet Union started building the world's deepest well 50 years ago. He called it the Kola Super Deep Well (KSDB) or SG-3. It was a scientific prospecting project to study the Earth's crust directly.
It is located 12 kilometers west of the city of Zapoliarni near the Norwegian border. Its depth is 12,226 meters. There is no oil to look for. The purpose of SG-3 was only to study the lithosphere.
Kola drilling penetrates a third of the Baltic continental crust. Its thickness is calculated at 35 kilometers. It exposes 2.7 billion year old rocks on the ground to light. The project was the site of extensive geophysical studies.
Drilling began on May 24, 1970 on the Kola Peninsula. They used drills that opened several wells from the central branch. The deepest is SG-3. It was completed in 1989 and created a 12,262 meter deep well. The deepest fountain in the world.
For the scientists, this meant a number of fascinating results. For example, during the hypothetical transition from granite to basalt at the bottom of the metamorphic rock layer, no change in the seismic speeds was found. It extends about 5 to 10 km below the surface.
Water and hydrogen
Surprisingly, the rock there is broken and saturated with water. Water that, in contrast to the superficial, must come from the minerals of the deep crust. Due to the impermeable layer of rock, it could not reach the surface.
Another unexpected discovery was the large amount of hydrogen. It is mixed with the sludge flowing out of the hole, which is called "boiled with hydrogen". The deepest active level was SG-5, which was 8,578 meters deep. It has a diameter of 21.4 centimeters.
In mid-2008, due to financial constraints and lack of support, the project was finally finalized. It is a lonely well now. But it continues to scratch the depths of the earth's crust.