Experimental Study on the Buckling of Subsea Pipe-in-Pipe Systems

Global buckling often occurs in high-temperature and high-pressure subsea pipe-in-pipe (PIP) systems. However, only a few studies, especially experimental studies, have been conducted on the lateral buckling of PIP systems. An experimental study on the lateral buckling of a PIP system was carried out in this article. The experimental device for the global buckling of oil temperature-loaded PIP system was designed, and the lateral buckling experiment was carried out for nine groups of PIP systems. The working mechanism of the PIP system was obtained through the experiment, and the critical point for pipeline buckling was determined according to the sum of the axial forces of the outer and inner pipes. The experimental results indicated that the lateral buckling response were related to the wavelength l(0), whereas the effect of amplitude V-m was relatively small.