Streamer Cable Resilience To Shark Attacks

Abstract

In the search for new subsea oil fields, WesternGeco uses vessels to tow streamer cables, which collects important geological data. Bull sharks are attracted to the magnetic streamer fields and tend to bite through the streamer cables, causing major losses and delays. A master thesis by Axel Hagen and Tarald Hagen, studied the response of two different streamer cables, Nessie 5 and Nessie 6, when subjected to a typical shark attack. The results displayed that Nessie 5 is more exposed to critical damage from shark attacks. The mentioned master thesis and their CAD- and FE-models have been studied in detail to gain knowledge concerning the problem. Some improvements have been made to the simulation setup. The objective of this project is to propose and evaluate design improvements to enhance bite resilience on Nessie 5. The majority of proposed concepts are based on research and own ideas regarding material changes, dimensional/geometrical changes and adding new components to the cable. New designs were modeled and tested using the mentioned simulation setup in order to compare results with the original design. Several concepts displayed improved resilience against shark attacks, according to the simulation results. An overall evaluation of given requirements and results from simulations was done with WesternGeco, and one final design with improved bite resilience is proposed.