摘要:
An apparatus for venting an annular space between a liner and a pipeline of a subsea riser (2) for conveying hydrocarbons, said apparatus comprising permeate recovery means for recovering permeate passing through the liner into said annular space. Preferably said permeate recovery means comprises a first- vent port (10) provided in a wall of the pipeline at or adjacent a lower region of the pipeline and communicating with a permeate recovery line (11) defining a flow path between said annular space and a permeate collection vessel (12). Preferably a one-way valve is associated with said permeate recovery line for preventing flow from said permeate recovery line (11) into said annular space.
摘要:
This method comprises connecting a downstream point (40) of a pipe (24) to a buoy (26) and completely submerging the buoy (26). It comprises deploying in the body of water (12) an intermediate section (30) of the pipe (24) from the downstream point (40) to at least as far as an upstream point (38), anchoring the upstream point (38), and tensioning the intermediate section (30) to keep it vertical. The height of the buoy (26) is less than 1.5 times its greatest transverse dimension. The method comprises moving the buoy (26) between a remote position and an installed position in line with an anchoring region, keeping the buoy (26) partly submerged on the surface (16) of the body of water.