ABSTRACT

The Daisy Chain subsea termination of umbilical breaks out the services housed through it, distributing them to the onward equipment (X-Trees, Manifolds, SDUs) by means of infield flying leads.

An innovative subsea umbilical termination design has been developed by GE Oil&Gas in order to meet the ultra-deep-water field requirements in a competitive market scenario, where the oil price downturn requires to be focused on the cost reduction. The innovative subsea umbilical termination is to be installed with the conventional umbilical installation steps [1], while housing the functionality required by a daisy chain field architecture which does not provide the usage of additional distribution blocks. The new family of subsea umbilical termination is suitably designed for water depths up to 3000 m, for umbilical transition spools [1] up to Class 300 – 20 inches Nominal Pipe Size as per ANSI B16.5 –, for connecting together up to six off infield flying leads allowing chemical/hydraulic power distribution and twelve off flying lead allowing the electrical/optical power distribution.

From a structural point of view, the new family of subsea umbilical termination includes a main frame made up of tubular beams and a secondary frame of plates welded / bolted to the main frame itself. Fully designed to meet the requirements of the DNV-2.7-3 [2], it guarantees a Payload up to 80000 Kg. The Installation methodology can vary according to the Customer requests: horizontal tensioner and over boarding system, horizontal tensioner with vertical over boarding system, closed vertical lay system and open vertical laying system [1] can be adopted. The first UTA of this new family has been successfully installed at the beginning of 2016 in the Indonesian seas and it is currently working: this means that the new design philosophy has got a technology readiness level of six, in accordance with the API 17N [3]. A further subsea field will be provided within the middle of 2017: a fully daisy chain architecture with the "new" GE subsea umbilical termination as key element. Future is changing: GE is adapting its technology to drive this change providing to our Customer the way to win.

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