Patent ID: 6940054

Claim:
A production/injection line assembly for subsea transportation of hydrocarbons, the assembly comprising: a production/injection tube; means for active heating of the tube; and continuous thermal insulation disposed along the production/injection line, over at least 100 m to control the heat transfer from the means for heating in towards the production/injection tube wherein the insulation comprises: prefabricated inner channel members having longitudinal channels, which inner channel members are laid around the production/injection tube in a continuous production line with the channels of the inner channel members facing outwardly, and prefabricated outer channel members having longitudinal channels, which outer channel members are laid flush with the channels of the inner channel members in a continuous production line wherein the means for heating are laid in the longitudinal channels of the inner channel members and enclosed by the outer channel members, wherein the inner and outer channel members accommodate the means for heating and wherein the inner channel members have higher heat transfer properties than the outer channel members so as to facilitate transfer of heat from the means for heating in towards the production/injection tube and to inhibit heat transfer outwards from the production/injection line assembly.