SEMI-SUBMERSIBLE ARCTIC WATERS DRILLING VESSEL AND METHOD

摘要

A semi-submersible arctic waters drilling vessel, said vessel comprising a deckbox structure (2), a ring pontoon (3), and multiple columns (5) extending upward from the ring pontoon and supporting thereon the deckbox structure. The vessel is provided with at least one ROV system, comprising a subsea remotely operated vehicle (ROV) (15), a dedicated ROV moonpool shaft (20,22), which extends from a bottom end opening (21) of the moonpool shaft upwards to an above waterline ROV maintenance garage (25), and an ROV system winch (30). The ROV moonpool shaft (20,22) is provided with a side opening (23) that is located in the inner circumferential wall (3c) of the ring pontoon, so that the ROV can be launched and recovered via said side opening, e.g. in case the bottom end opening is closed due to the vessel sitting with the bottom (3a) of the ring pontoon on a seabed (9)..