METHOD FOR CONNECTING UNDERWATER PIPELINES PARTICULARLY SUITABLE FOR GREAT DEPTHS AND BIG DIAMETERS

摘要

Method for connecting underwater pipelines characterised by the following steps: installation of a pipeline (7) on a seabed fixed frame (2); laying of an outboard pipeline (10) by a lay barge; installation of a subsea winch (28) within the frame; actuation of the winch by a ROV (26A) to unwind the cable (33) of the winch, aided by a second ROV (26B) bringing and connecting the end of the cable to the outboard pipeline; winding of the cable and following deflection of the outboard pipeline up to the frame; installation of a metrology system (38) to define the distance and angular misalignment between the two pipelines ends to be connected; assembly of a connection system (50) with telescopic capabilities using the measurements of the metrology system and using a dedicated frame installed on board the support ship; installation of the connection system on the seabed fixed frame and connection of the connection system with the pipelines ends.