Siemens and Statoil have jointly developed and qualified a subsea hydraulic power unit for use in offshore oil and gas fields in order to provide hydraulic power right at the well site. The subsea hydraulic power unit (SHPU) supplies low-pressure and high-pressure control fluid to the subsea control modules. The subsea control module operates the hydraulic valves, the downhole safety valve and downhole chock/sliding sleeve. The hydraulic power unit can be used in the event that the umbilical fails and also as an alternative to the hydraulic lines in the umbilical. The power unit has successfully completed the qualification process, in which it has passed function tests under hyperbaric pressure equal to a water depth of 500m.
The SHPU is an important building block in the industry-wide vision for a subsea factory, where the process plant is placed on the seabed. This unit was developed to be used as a contingency for an umbilical failure on a field in the North Sea. In addition to a repair function, the SHPU can also be used to extend the lifetime of existing (brown) fields. For new (green) field developments, especially on deep water and long step-outs, the SHPU can be a cost-efficient alternative to complex umbilical lines.
