Subsea Production

An advanced subsea control system will relay continual real-time information from the SPS via fibre optic cable to the control room of the Shetland Gas Plant. More than 50 instruments will provide detailed readings on the temperature and pressures within the multi-phase fluid stream, all of which will be fed back to the shore via the control umbilical.

The control umbilicial consists of a bundle arrangement, providing two-way fibre optic communication, high voltage electricity supply and hydraulic power to the SPS.

Manufacturing and installing a single, continuous bundle, more 140km in length, pushes the boundaries of modern umbilical technology. The sheer weight of the umbilical cable can easily exceed the load capacity of most flexible pipelay vessels.

“The SPS is being designed to be fault tolerant, with designed-in redundancy. We’re looking at both quality and reliability over the whole life cycle of the system,” adds Jerome. “We’ve also designed-in additional spare capacity to accommodate up to seven additional wells – up to a distance of 15km from the existing Laggan-Tormore development. We hope to be able to tie-in future new discoveries to the SPS.”

Safety too is paramount. At 600m, the SPS lies beyond the reach of conventional commercial fishing activities, but even the smallest risk of damage from deep-water pelagic trawlers has been taken into consideration. Robust protection has been pre-engineered into the design, in some cases doubling the weight of subsea components.

The resulting system will rely on a global supply chain, with SPS components sourced from Scotland, Texas, California, Singapore, China, Norway, The Netherlands and Italy.

Overseeing the system's developement is a 25-strong TOTAL E&P UK team, currently divided between Norway and UK with the main SPS project office in Kongsberg, Norway, the Template/Manifold fabrication yard in Tonsberg, Norway,  the Xmas Tree System Engineering & Manufacturing in Dunfermline, Scotland and some project services in Aberdeen, UK.

Once completed in summer 2012, each component will be extensively tested onshore prior to installation offshore.