Construction of the X100 Operational Trial Pipeline at Spadeadam, Cumbria, UK

As part of an ongoing pipeline technology programme for BP Alaska, a 0.8 km, 48-inch diameter, X100 demonstration pipeline was constructed and operated for a period of two years. The pipeline was constructed using largely conventional techniques, with the exception of the mainline welding process, where a high productivity system was used. Mainline welding on X100 pipe was accomplished using a single tandem wire GMAW system offered by Serimax. Tie-in and fabrication welding was accomplished using vertical-down STT root pass and a vertical-up mechanised FCAW system. This paper discusses key features of the welding specification, presents key weld qualification results, reflects on the field welding experience and makes some general remarks about the construction experience.