Abstract

In the coming decade, many kilometers of subsea pipelines will be constructed in the South East Asian region. A large portion of these lines will be in moderate to shallow water. The installation methods adopted makes a major contribution to the cost of construction these pipelines. The traditional lay barge, though very effective in deeper waters, is not a very cost effective way of installing pipes in moderate to shallow water depths. Various tow techniques are currently being used to lay pipelines in these conditions. Such tow methods complimented by a tie-in technique using a small barge will considerably reduce the cost of installation of subsea pipelines in shallow waters.

Such installation and tie-in methods are very non-linear in behaviour, hence needs special analytical techniques to analyze and design such systems. This paper describes the Rentis method of pipe lay and single point lift for tie-in. It also overviews the non-linear analytical techniques used to design such pipelines. It is believed that these installation methods backed by specialized analytical methods will provide a safe, as well as a cost effective subsea pipeline systems.