Isolation thermique des conduites sous-marines

Thermal insulation coatings for underwater pipelines

Total - Compagnie Française des Pétroles

Abstract

In order to avoid deposits of wax in subsea pipelines, it is often necessary, when developping an offshore oilfield, to unsulate thermically the oil flowlines between wellheads and platforms. Approximately twenty different solutions for thermal insulation are available.

On the North Alwyn Field (British Sector of the North Sea), currently under development by Total, a subsea wellhead will be connected to central platform by a 6” flowline coated with a heat insulating coating. For this project, a thick coating system has been selected. Before making a final decision the operator had tests of the different coatings run both in an independant laboratory and on the pipelaying barge. The data collected during these tests made it possible :

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  to compare these data with the results given by the coating contractors,

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  to incorporate the data in a production specification for quality control purposes,

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  to compare the data with other well known coating materials,

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  to compare values measured before and after reeling operations.

Fifteen technical properties of the thermal coatings have been examined in various conditions.