This paper focuses on the interference between pipelines and fishing gear such as clump weights. The objective is to examine the clump weight behavior as it is pulled across pipelines. Numerical analyses which simulate the integrated response between clump weight and pipelines are performed [1] and compared with actual tests performed by Statoil during 2004 for the Kristin field development. The experiments involved scaled down pull-over tests over idealized free spanning pipelines.
A detailed model of the experimental model setup is established using the nonlinear finite element software SIMLA. Simulations are carried out for trawl gear interference with pipelines in various idealized free-span conditions. In each case the models force-displacement responses are compared with normalized test results.
Finally, trawl interference with a full scale 1000 m pipeline section resting on uneven seabed is studied. The interaction forces from fully integrated pipeline-trawl analyses are compared directly with design interference loads from DNV-RP-F111, [2]. The objective of this is to quantify the potential safety margin provided by DNV-RP-F111.