Kola Superdeep Borehole: Well That's a Deep Subject

Photo: Jouko Vanne, Geological Survey of Finland

The race to the moon had been won in a come-from-behind victory by the United States and the Cold War was in full swing, fueled by widespread political and ideological differences. The time period is wrapped in mystery and intrigue, and there are hundreds of thousands of projects, agendas, and events that took place that lie outside the Space Race. In fact, I want to focus in the opposite direction: straight down, to the deepest artificial point in the world - the forty thousand foot deep SG-3 branch of the Kola Superdeep Borehole.

Captain Nemo might claim 20,000 leagues under the sea, but the USSR managed to reach forty thousand feet into the Earth's solid granite crust using a series of metal tubes strung together with a pointy bit on the end. That's like using a wire coat hanger to drill top-to-bottom through the Washington Monument. After nearly 20 years of intermittent drilling with multiple problems, delays, and a twistoff that resulted in a sidetrack of 16,000 feet of drill pipe left in-hole, drilling was called finished. At that depth, the ambient temperature reached 360º F, simply from the sheer pressure of  seven miles of planet Earth weighing down on it. To put this in perspective, the Baltic continental crust is estimated at 22 miles thick, the age of the rocks unearthed projected to be 2.5 billion years old.

It's important to note that the SG-3 hole was drilled to a total vertical depth of 40,230 feet below the surface. While the total measured depth (linear hole made) of the well has been exceeded since the well was finished, no other well penetrates as far down into the crust. The United States attempted a super-deep well bore to match the Soviet achievement, but lack of funds resulted in the same fate as the USSR lunar program - mothballed.

Quick Reference: Kola Superdeep Borehole - Wikipedia

Journals: Kola Borehole on ICDP

Kola Borehole - Oilfield Review