Extreme Heat Halted Soviet Kola Borehole at 12,262 Meters

The Soviet Union’s SG-3 Kola Superdeep Borehole reached 12,262 meters, setting a world record for drilling depth. Launched in 1970, the project had aimed to descend 15 kilometers beneath the surface.

According to Bitcoin.com News, extreme heat and pressure proved to be the limiting factors. At those depths, the rock behaved plastically, deforming and squeezing the borehole closed.

Specialized drilling equipment could not overcome those conditions, and the effort ended in 1992. The project stopped roughly 2.7 kilometers short of its original goal.