J-Lay

Today's pipe-laying processes, S-Lay processes for low and medium-sized and J-Lay processes for great water depths

J-Lay is a special method for laying pipelines in bodies of water by means of specially equipped work boats , the so-called pipe layers . The name of the process is based on the characteristic J- shaped course - similar to a chain line - of the pipeline during laying (English. Lay (ing) ).

The J-Lay method is mainly used in deep and very deep (so-called deep and ultra-deep ) waters. With the equipment available today, depths of up to 3000 m and distances of up to 4000 m per day can be reached. At shallow water depths, the S-Lay method is usually used, with the current depth record of 2,775 m being achieved with the Solitaire in S-Lay.

Laying method

Tiltable-flex-lay tower of the Seven Phoenix

During the laying operation, pipeline segments are usually automatically pivoted from the horizontal to the - somewhat inclined - vertical position in the J-Lay tower . The individual pipeline pieces or prefabricated segments, which can consist of up to four individual pieces (therefore also called quadruple joints or quadjoints ) and then reach a length of up to 48.8 m, are welded together in the J-Lay tower and then tested non-destructively . The weld seam is then given a plastic coating to improve corrosion protection.

Once coated, the pipeline segment will continue to lower as the pipe-lay vessel proceeds. The - locked - beginning of the pipeline is either pulled by a tug against the laying direction or simply laid on the ground, which results in the typical J-shaped course.

Records with the J-Lay method

• A 24-inch pipeline was laid for the Blue Stream project in the Black Sea from the Saipem 7000 using the J-Lay method at a depth of up to 2150 m.
• The record was broken by DCV Balder in 2005 when it laid parts of a pipeline at a depth of 2200 m in the J-Lay as part of the Mardi Gras project in the Gulf of Mexico.
• The laying of parts of the Langeled Pipeline , the longest underwater pipeline in the world, to develop the Ormen-Lange gas field in the North Sea was also largely carried out in the J-Lay .

Web links

• Gusto website with explanations of the J-Lay (accessed on April 13, 2009) (PDF file; 612 kB)

Individual evidence

1. ↑ Report on Marinebuzz about the Solitaire (accessed May 31, 2010)
2. ↑ ^{a b} Data on the Blue Stream and the pipelines on the Saipem website (English, PDF file, 6.13 MB, accessed on April 13, 2009) ( Memento of the original from April 24, 2009 in the Internet Archive ) Info : The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. 
3. ↑ Report in Offshore Magazine about the Mardi Gras project (accessed April 13, 2009)
4. ↑ information for laying the pipeline on Langeled Hydro.com (engl.) . Hydro. Archived from the original on January 8, 2009. Info: The archive link was automatically inserted and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. Retrieved June 24, 2009. 
5. ↑ Floatingproductionzone.com with data on the Langeled Pipeline . Floating production zone. Archived from the original on April 13, 2014. Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. Retrieved June 24, 2009.