Average oil will 4000 feet or .7 miles. 10 Kilometers 6.2 miles The Kola Superdeep Borehole (Russian: Кольская сверхглубокая скважина, romanized: Kol'skaya sverkhglubokaya skvazhina) SG-3[a] 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.

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.[1] 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 2023.