The Middle East to India Deepwater pipeline calls for line-pipe to be installed in water depths approaching 3500m. Design of the wall thickness suitable for such depths has utilised DNV OS-F101 (2010) design code, modified to included an enhanced fabrication factor αfab of 1.0, based on the heat soaking effect during a standard 3 layer coating process. In 2011 and 2012 two Indian pipe mills, manufactured line-pipe to MEIDP diameter, wall thickness and specification by JCOE method. In order to facilitate testing of line-pipe joints during production, a ring test rig and methodology have been developed that facilitates ring tests on full scale ring slices 50mm in length in the pipe mills within a few hours, thus allowing its inclusion in the line-pipe ITP as a standard production test.
This paper presents the basic wall thickness design requirements and tracks the production and subsequent ring collapse testing of the MEIDP line-pipe by the JCOE method. The test program showed that the ring testing method was well suited to being performed on a production basis and was capable of achieving consistently repeatable collapse capacity results. The ring tests also clearly demonstrated the positive effect on the collapse capacity of heat soaking the pipeline at simulated coating 3LPP coating temperatures. Detailed results of the ring collapse testing both before and after heat soaking will be presented.