Drilling head for reboring a stuck valve

摘要

The present invention relates to a drilling head (2) for reboring a stuck valve (35) or drilling into the formation downhole (36). The invention furthermore relates to a drilling tool (1) comprising the drilling head and a driving unit (9). The drilling head comprises a hole saw (28) beside a drill bit for cutting out a piece (37) from the stuck valve. Furthermore, the invention relates to a drilling system comprising the drilling tool and a driving tool for moving the drilling tool downhole; a method of drilling; and a use of the drilling head.