Method for connecting underwater pipelines particularly suitable for great depths and big diameters

摘要

PCT No. PCT/NO96/00058 Sec. 371 Date Jan. 26, 1998 Sec. 102(e) Date Jan. 26, 1998 PCT Filed Mar. 14, 1996 PCT Pub. No. WO96/29532 PCT Pub. Date Sep. 26, 1996A method of connecting underwater pipelines by installation of a pipeline on a seabed fixed frame; laying of an outboard pipeline by a lay barge; installation of a subsea winch with the frame; actuation of the winch by a ROV to unwind the cable of the winch, aided by another ROV 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 to define the distance and angular misalignment between the two pipelines' ends to be connected; assembly of a connection system with telescopic capabilities using the measurements of the metrology system and using a dedicated frame installed on board a support ship; installation of the connection system on the seabed fixed frame and connection of the connection system with the pipeline ends.