Kola Superdeep Borehole
The Kola Superdeep Borehole (Russian: Кольская сверхглубокая скважина, romanized: Kol'skaya sverkhglubokaya skvazhina) SG-3 is the result of a scientific drilling project of the Soviet Union in the Pechengsky District, near the Russian border with Norway, on the Kola Peninsula. The project attempted to drill as deep as possible into the Earth's crust.
Superstructure of the Kola Superdeep Borehole, 2007 | |
| Location | |
|---|---|
Kola Superdeep Borehole Location of the borehole in Murmansk Oblast, Russia Kola Superdeep Borehole Kola Superdeep Borehole (Murmansk Oblast) | |
| Location | Pechengsky District |
| Province | Murmansk Oblast |
| Country | Russia |
| Coordinates | 69.3965°N 30.6100°E |
| Production | |
| Type | Scientific borehole |
| Greatest depth | 12,262 metres (40,230 ft) |
| History | |
| Opened | 1965 |
| Active |
|
| Closed | 1995 |
Drilling began on 24 May 1970 using the Uralmash-4E, and later the Uralmash-15000 series drilling rig, and it became the deepest manmade hole in history in 1979. The 23-centimetre-diameter (9 in) boreholes were drilled by branching from a central hole. The deepest reached 12,262 metres (40,230 ft; 7.619 mi) in 1989, the deepest human-made hole on Earth, and remains so as of 2024.
In terms of true vertical depth, it remains the deepest borehole in the world. For two decades, it was also the world's longest borehole in terms of measured depth along the well bore (that is, borehole length) until it was surpassed in 2008 by the 12,289-metre-long (40,318 ft; 7.636 mi) Al Shaheen Oil Well in Qatar.