DEVICE FOR A TOP DRIVE DRILLING MACHINE FOR CONTINUOUS CIRCULATION OF DRILLING MUD

摘要

A device for a top drive drilling machine, in which a drive shaft (14), which is arranged for releasable connection to a drive (12) and to a first end portion (51) of a drill pipe (5), is provided with a centre bore (141) extending therethrough and arranged for fluid communication between the drilling mud plant (6) and a fluid bore (53) in the drill pipe (5). First and second releasable, drive-shaft-surrounding, respectively drill-string-surrounding, pressure seals (1311c, 1321) and a valve (133) which is arranged to provide, in an open position, a passage (1331) for the drill pipe (5) or drive shaft (14), form a first and a second chamber. A drilling mud inlet (1323) is arranged for the second chamber (132) and is arranged for fluid communication between the drilling mud plant (6) and connection housing (13). A method for the continuous supply of drilling mud to a drill string (4) by the use of the drilling machine.