Pipe in Pipe Technology

Installing a second pipeline around the product pipeline isolates the carrier pipeline from the seawater surrounding it and creates a dry chamber around the pipeline that can be engineered to accommodate a range of advanced insulation techniques.

Pipe in pipe systems allow a range of advanced and highly efficient insulation materials to be used to achieve Overall Heat Transfer Coefficients less than 1 W/m2 K. These systems are important components of subsea 

developments where untreated well fluids may have to be transported large distances and wax and hydrate problems have to be managed. 

However, as a result of this efficient insulation, thermal expansion challenges are increased and techniques such as probabilistic analysis, upheaval buckling design, snake lay or cooling spools employed to mitigate high expansion loads.

Insulation Capabilities:

Reference:

http://www.jpkenny.com/SiteCollectionDocuments/PIPE%20IN%20PIPE%20REV%2001.pdf

http://www.deepsea-eng.com/sites/deepsea-eng.com/files/media/DeepSea%20Pipe-in-Pipe%20technical%20presentation.pdf