Question

the longest drilled in the earth by a personal​

Answer 1

Answer:

Kola Superdeep Borehole

Answer 2

Kola Superdeep Borehole

The Kola Superdeep Borehole on the Kola peninsula of Russia reached 12,262 metres (40,230 ft) and is the deepest penetration of the Earth's solid surface. The German Continental Deep Drilling Program at 9.1 kilometres (5.7 mi) has shown the earth crust to be mostly porous.

Kola Superdeep Borehole

Known as the Kola Superdeep Borehole, the deepest hole ever dug reaches approximately 7.5 miles below the Earth's surface (or 12,262 kilometers), a depth that took about 20 years to reach.