Crucial issues for deep water rigid jumper design

Abstract

Subsea Rigid Jumpers (SRJ) are used in Ultra Deep Water (UDW) projects to connect well heads, manifolds and riser bases with Intra-field and Export Pipeline End Terminations. Short and flexible pipe sections are assembled in a variety of spatial configurations to accommodate fabrication and installation tolerances (design for installation) and to withstand the end loads and displacements caused by flow/temperature and pressure fluctuations, as well as riser base oscillations (design for operation).Two main criticalities are recognised in Subsea Rigid Jumper design: the bending strength and deformation capacity of induction bends during installation and operation; and the fatigue resistance under the cyclic loads from flow fluctuations and dynamic response to environmental loads.The scope of this paper is twofold: 1) to present the FE model developed to quantify the strength and deformation capacity of induction bends subject to typical deep water installation and operational loads; 2) to describe how the Vortex Induced Vibrations phenomenon in complex 3D Subsea Rigid Jumpers can be treated to assess the fatigue damage at potential stress intensification. Both issues are pertinent to Subsea Rigid Jumper design, at the moment partially covered by specific project/company guidelines.