Which is the best way to install an offshore pipeline?
After the pipeline is reeled onto the drum of the pipelaying vessel, it is taken to the offshore location for installation. The reeled pipeline can be installed in an S-lay method or J-lay method depending on the design of the reel vessel and the depth of water. Reel vessels can have vertical reels or horizontal reels.
How does the J lay pipeline installation work?
Overcoming some of the obstacles of S-lay installation, J-lay pipeline installation puts less stress on the pipeline by inserting the pipeline in an almost vertical position. Here, pipe is lifted via a tall tower on the boat, and inserted into the sea.
What are the different methods of pipe laying?
In the second step in controlled horizontal drilling, the pilot hole is widened. Finally, the pipe string is pulled in from the exit point into the widened borehole. Offshore pipe-laying on the sea bed poses its own challenges, especially in very deep water. Three methods have established themselves: S-Lay, J-Lay and R-Lay.
How is a pipe laid in deep water?
Finally, the pipe string is pulled in from the exit point into the widened borehole. Offshore pipe-laying on the sea bed poses its own challenges, especially in very deep water. Three methods have established themselves: S-Lay, J-Lay and R-Lay. The J-lay process is particularly well-suited for pipe-laying in very deep water.
How big are the pipelines installed by Allseas?
Pipeline installation. Allseas has installed over 20,000 km of subsea pipeline worldwide using S-lay technology, with diameters ranging from 2” to 48”. S-lay is characterised by its fast installation process and its application in all water depths. The “S” refers to the shape the pipe forms between the vessel and the seabed as it is laid.
How are reeled pipelines installed in the seabed?
The reeled pipeline can be installed in an S-lay method or J-lay method depending on the design of the reel vessel and the depth of water. Reel vessels can have vertical reels or horizontal reels. The pipe is unreeled, straightened, de-ovalized, and connected to the wire rope from the seabed pre-installed hold back anchor.
How is a pipeline towed to the seafloor?
Once on location, the buoyancy modules are removed or flooded with water, and the pipe floats to the seafloor. There are four main forms of tow-in pipeline installation. The first, the surface tow involves towing the pipeline on top of the water.