drill rig with a drill rig, and methods for constructing a riser column and for providing a riser column insert

摘要

A drilling vessel with a drilling deck includes a drilling vessel floor structure defining the drilling deck and a tubular support assembly that is recessed in the drilling floor structure. The assembly includes a support frame and at least two support tables, wherein the tables have a top surface that forms part of the drilling deck. The tables are each guided by the support frame to allow displacement along a line between an active position for supporting a tubular and a retracted position for passing an object. The tables and the adapters segments supported thereby are coupled, for example via a clamp or a shape-coupling, such that when the tables move from their active position into their retracted position each segment moves with the respective table it is coupled with and the bushing is opened up for passing through an object through the opening between the at least two support tables and the adapter segments they support.