Abstract: The present invention provides an insulated fluid conduit useful in facilities in which a hot fluid susceptible to one or more deleterious phase changes in response to heat loss to a cold environment is transported. Such conduits may be particularly well suited to improve thermal control in subsea hydrocarbon production operations. The fluid conduit includes an inner first insulating layer containing a first polymer matrix, and a first phase change material undergoing a phase change at T1. The fluid conduit includes an outer second insulating layer containing a second polymer matrix, and a second phase change material undergoing a phase change at T2, wherein T1 is greater than T2. One or more barrier layers inhibit migration of the phase change material from the insulation layers and into the environment. In one or more embodiments, the phase change material is present as a microencapsulated phase change material.

Abstract: The present invention provides an insulated fluid conduit useful in facilities in which a hot fluid susceptible to one or more deleterious phase changes in response to heat loss to a cold environment is transported. Such conduits may be particularly well suited to improve thermal control in subsea hydrocarbon production operations. The fluid conduit includes an inner first insulating layer containing a first polymer matrix, and a first phase change material undergoing a phase change at T1. The fluid conduit includes an outer second insulating layer containing a second polymer matrix, and a second phase change material undergoing a phase change at T2, wherein T1 is greater than T2. One or more barrier layers inhibit migration of the phase change material from the insulation layers and into the environment. In one or more embodiments, the phase change material is present as a microencapsulated phase change material.