The journey towards the realization of the subsea factory is well on its way, promising the benefits of subsea processing and production. This "Grand Challenge" places extreme demands on the reliability, uptime and safety of the technology for distributing, delivery and control of the power system.
ABB Oil & Gas is running a Joint Industry project together with Statoil, Total and Chevron to develop technologies for subsea power transmission, distribution and conversion at greater distances, in deeper waters, and in harsher environments. The project started up in 2013 and is targeting a 3000-hour shallow-water system test in 2018, including the qualification of pressure tolerant medium voltage switchgear, medium voltage drives, as well as supporting controls and auxiliary supplies.
The project budget is in excess of 100 MUSD, funded by ABB, Statoil, Total, Chevron as well as The Research Council of Norway. The target environment is water depths up to 3000 meters, transmission distances up to 600 km, and power levels up to 100 MW.
The project follows the TRL development stages for technology qualification applied to components, sub-assemblies and equipment. This is a systematic approach ensuring that the technology will function reliably within specified limits, and it provides a common understanding and terminology of technology status and risk management. Qualification includes extensive testing of components subjected to test conditions derived from a common understanding of realistic component/equipment specific stresses throughout an agreed life-cycle mission profile, with particular emphasis on learning the behavior and limits of different designs. Comprehensive confirmation of the desired function as well as reliability testing is primarily conducted at the level of the component where a functional failure can be defined and accelerated conditions applied. Further, we perform sub-assembly testing mainly geared toward confirming the overall function, design margins, and the thermal and high-current performance. Formal qualification of key components and sub-assemblies is planned for 2017. Based on qualified components, final prototypes will be assembled in 2018 for a 3000 hour shallow-water endurance test and system demonstration.
The project passed a decision gate milestone in April 2015, having verified technology concepts as well as TRL2 for key components. Prototypes under development include full-scale subsea drives and switchgear with supporting controls and LV auxiliaries and functional verifications in key ABB factories. During 2016 key prototype designs have been tested and functionally demonstrated over a limited operating range. This paper provides a summary of the current status of the project highlighting the most critical areas for success, such as designing for modularity and the demanding reliability and availability targets, and utilizing the best experts and experience across ABB as well as the participating oil companies.