Graded Insulation to Improve High Pressure Resistance in Deepwater Flowlines: a Closed Form Analytical Elastic Solution

In this paper, an insulated pipe system comprising the inner pipe, insulation and outer jacket is investigated in the context of elasticity theory with the view to establish whether introducing stiffness gradient in the insulation would improve performance of the pipe under external pressure. Closed form analytical solutions are derived for stresses and displacements in the pipe system. Comparative analysis of pipes with homogeneous and graded insulation is performed and beneficial effect of graded insulation on stresses and displacements in the pipe is established.