Subsea jumpers are subjected to a variety of loads during operation. The corresponding analyses include stress and fatigue. The fatigue in jumpers can be induced due to vortex-induced vibration (VIV), thermal cyclic load from flowline, and fluid-induced vibration, including slugging. The jumper stress and fatigue analyses can be performed using piping analysis tools such as AutoPIPE, general finite element analysis (FEA) tools such as ABAQUS, and code-based tool DNV FATFree or Shear 7 depending on the load conditions. It is important to consider the misalignment and other tolerances introduced during manufacturing and installation for these analyses but such considerations can make the analysis more complex and time consuming. Therefore, it is essential to adopt an efficient jumper analysis procedure that not only ensures all static and fatigue issues are captured but also minimize unnecessary calculations. In absence of a proper planning of the analyses, it is possible to miss a critical issue or, on the other hand, the number of analyses to be performed can be overwhelming. This paper provides an efficient jumper analysis methodology under various load conditions. The methodology is aimed at achieving a golden means of computational efficiency and accuracy. This methodology will serve as a guideline for future jumper assessment analysis in Kenny's projects.
Jumpers are the connecting elements of a subsea flowline system such as those introduced between the wells and manifolds and/or manifolds and pipeline end terminations (PLET). Jumpers are made up of a series of pipes connected in a Z-, M- or W-shaped form. Such shapes accomodate for any pipeline layout misalignments and stresses due to thermal expansion. Depending on its geometry, a jumper is subjected to a variety of loading conditions and jumper design must take into account all the possible modes of failure.
