In total, four drilling sections are planned for the 800 meters deep observation well. In the end the well will look telescope-like and becomes narrower downwards.
Therefore, tubes with a diameter of 9 5/8" were installed down to 160 m on 24/8/2012. Subsequently, the space between tube and rocks was filled with cement.
This completed the second drilling period. Now drilling continues down to ~ 580 m.