From S-lay to J-lay
- McDermott Inc., New Orleans, LA (United States)
A brief historical review of offshore pipelining with emphasis on the technical improvements made over the years is presented. A discussion of the development of McDermott`s J-Lay System, with a description of the equipment is followed by highlights of the use of the equipment on the Shell Auger 12-3/4 inch pipeline. Emphasis will be on the development and performance of the J-Lay equipment rather than details of the laying of the pipeline. The presentation closes with a look at the future of offshore pipelaying. The recent completion of the Shell ``Auger`` pipelines ushered in a new era in offshore pipelaying -- J-Laying. An event that has been anticipated by pipeliners for over a quarter of a century. In fact, some of the earlier marsh and bay pipelaying barges utilized inclined ramps in an attempt to lessen the effect of the overbend at the barge stem. These inclined ramps were in effect the first J-Lay barges. As the authors moved into deeper water, other methods were introduced to offset the effect of the overbend at the stem of the barges. Inclined ramps made pipehandling and alignment difficult, which definitely impacted productivity. Stingers were utilized to help support the pipe through the overbend and horizontally laid pipelines became the norm for ease of pipehandling. As they moved into even deeper water, the stingers became larger and longer. Some of the ``rigid stingers`` built in the mid-sixties were 1,000 ft. (305 m) long. They had a series of ballastable tanks which by selective ballasting allowed the stinger to be bent into a long ``S``. The rigid stingers were hard to control and were frequently damaged in rough weather, but they provided a method for getting the pipe to the seafloor.
- OSTI ID:
- 55765
- Report Number(s):
- CONF-940230--; ISBN 0-7918-1268-5
- Country of Publication:
- United States
- Language:
- English
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