Overtrawlability and Mechanical Damage of Pipe-in-Pipe

ZHENG JIEXIN

Publication

Overtrawlability and Mechanical Damage of Pipe-in-Pipe

ZHENG JIEXIN

Abstract

Pipe-in-pipes are widely used in the offshore industry. Traditionally, mechanical design of these systems with regards to fishing gear interaction has used the same approach as for single pipe systems. However, this approach is likely to result in a conservative design as the outer pipe is not required to resist internal pressure and can accommodate a greater level of indentation than a single, pressure containing pipe. Eliminating conservatism in this aspect of design has the potential to eliminate the need for trenching in areas of high fishing activity and can therefore have considerable economic benefits. The objective of this research is to develop the methods to estimate the overtrawlability of pipe-in-pipes, meanwhile review the existing methods for single wall pipes. Experiments are conducted, and FE models and semi-empirical relationships are developed and validated. The model test and scaling law are reviewed and improved.