Patent ID: 6422324
Filing Date: 2002-07-23
Classification: E21B

Abstract:
Apparatus for sinking bore holes, in the sea bed, having a drill string which is suitable for transmitting a torque and of which the top end is mounted on a floating platform and of which the bottom end bears a rotationally driveable drill head and which comprises a plurality of drill-string parts which can be displaced with low friction in the axial direction of the drill string relative to one another, characterized in that there is provided an air inlet which is in connection with the drill-string interior and through which it is possible to blow in compressed air fed via a pressure line;characterized in that the drill string comprises an outer and an inner drill-string part, wherein the inner drill-string part engages in the outer drill-string part, and wherein the outer drill-string part comprises an inner tube and an outer tube defining an annular gap between an internal diameter of the outer tube and an external diameter of the inner tube.