Engineers also discovered, as they plowed past the first 14,800 feet (4,511 meters) that the rock had much more porosity and permeability. That, paired with the extremely high temperatures, made the rock behave more like a plastic than a solid, rendering drilling virtually impossible.
These temperatures were beyond the capabilities of their drilling equipment, but the Soviets pressed on until 1992, but never got any deeper than the depth reached in 1989. Drillers had no choice but to discontinue the effort, falling short of their 9.3 miles (15 kilometers) goal. The drill site was officially
shut down and the hole sealed in 2005.