The WL Drilling System, imported from MICON GmbH & Co. KG, Celle, has never performed its functions. The inner core barrel assemble is not able to pass through the drill pipes. That cost CCSD about 3 months to search the causes of this kind of problems because almost all engineers working in drilling site thought that Products from Germany would not occurred quality problem. Finally the engineers find out that there are some flanges existing in the welding area which stop the inner core barrel pass through the pipes. The red color in the photo stands for the flange.