Seabed investigations performed for route selection and design of submarine pipelines offshore Norway

SYNOPSIS. The present article presents the èxtent of pipeline surveying and the methods adopted in the Norwegian Sector of the -North Sea. Modern instrument packages are being utilized to gain high quality information from difficult sea bottom conditions and during a relatively short summer season. Very stable vessels, abundant instrument spreads and back-up systems, on-board interpretation for programme adjustments, and extensive post-survey data interpretation — these are the main factors characterizing pipeline surveys offshore Norway. At the Asian Institute of Technology Symposium, the lecture was supplemented by a series of data examples showing the degree of accuracy with which seabed features can be depicted by surface vessel instrumentation and the kind of morphological and geotechnical problems encountered in North Sea pipeline design and construction. It is believed that some of the experience gained in the North Sea may be of interest in pipeline planning in South East Asia and other regions.