A New Buckle Arrestor for Reeled Pipe-in-Pipe

摘要

A new buckle arrestor for pipe-in-pipe (PIP) was developed and tested by Coflexip Stena Offshore Group, one of the most experienced in rigid reeled and deepwater technologies. It allows reeled installation, giving a time advantage over other installation methods, and allows design against propagation buckling. It consists of a local injection of a material in the PIP annulus. Material injection on the vessel ramp during laying is base case. Experiments on epoxy and full scale injections were performed to optimize the cure time, a critical parameter. Buckle tests were performed and proved the high performance of the arrestor. Comparison with Finite Element analysis is made. The effect of the arrestor on the PIP thermal performance is detailed. Extensive developments such as waterstop and bulkhead functions as well as pre-reeling installation are discussed.