The present invention relates to a completion assembly for running into a borehole in a formation through a well head or blowout preventer, comprising a casing string having a first end and a second end, and a drill pipe having a first end and a second end and extending through the well head or the blowout preventer and being releasably connected at the first end with the casing string. Furthermore, the invention relates to a completion method for completing a casing string. Moreover, the invention relates to a completion kit for making a completion assembly according to the present invention.