Pipe-laying ship
Encyclopedia
Subsea
Subsea is a general term frequently used to refer to equipment, technology, and methods employed in marine biology, undersea geology, offshore oil and gas developments, underwater mining, and offshore wind power industries.- Oil and gas :...
infrastructure. It serves to connect oil production platforms with refineries on shore. To accomplish this goal a typical pipelaying vessel carries a heavy lift
Heavy lift
- Definition :The transportation, handling and installation of heavy items which are indivisible, and of weights generally accepted to be in the range of 1 ton to over 1000 tons and of widths/heights of more than 100 meters that are too large to fit into normal containers or onto conventional...
crane, used to install pumps and valves, and equipment to lay pipe between subsea structures.
Lay methods consist of S-lay and J-lay and can be reel-lay or welded length by length. Pipe-laying ships make use of dynamic positioning
Dynamic positioning
Dynamic positioning is a computer controlled system to automatically maintain a vessel's position and heading by using its own propellers and thrusters...
systems or anchor spreads to maintain the correct position and speed while laying pipe.
Recent advances have been made, with pipe being laid in water depths of more than 2,500 metres.
The term "pipelaying vessel" or "pipelayer" refers to all vessels capable of laying pipe on the ocean floor. It can also refer to "dual activity" ships. These vessels are capable of laying pipe on the ocean floor in addition to their primary job. Examples of dual activity pipelayers include barges, modified bulk carriers, modified drillship
Drillship
A drillship is a maritime vessel that has been fitted with drilling apparatus. It is most often used for exploratory offshore drilling of new oil or gas wells in deep water or for scientific drilling. The drillship can also be used as a platform to carry out well maintenance or completion work such...
s semi-immersible laying vessels among others .