DEVICE AND METHOD FOR DRILLING WITH CONTINOUS TOOL ROTATION AND CONTINOUS DRILLING FLUID SUPPLY

摘要

There is described a device for a drilling rig for forming of a bore hole (6) in a subterranean structure (63), wherein the drilling rig comprises a first, top driven drilling machine (1) arranged vertically displaceable along a guide track (21), where a second drilling machine (3) is arranged between the first drilling machine (1) and the bore hole (6) vertically displaceable along a guide track (41) and provided with a rotary table (31) arranged to be able to take the weight of a pipe string (5), a rotary drive unit (32) arranged for continuous rotation of the pipe string (5), a fluid chamber (34) arranged to in a fluid communicating way to be able to connect a pipe string end portion (51) with a drilling liquid plant (7), as the fluid chamber (34) is provided with pipe string ports (341, 343) comprising means (342, 344, 345) arranged to in a fluid sealing way to be able to close the pipe string ports (341, 343), and a power tong (33) arranged for continuous rotation of an element (12, 52) connected to the pipe string (5), as the power tong (33) is arranged in the fluid chamber (34). Also described is a method for drilling with continuous tool rotation and continuous drilling liquid supply.