Patent ID: 7934562
Filing Date: 2011-05-03
Classification: E21B

Abstract:
1. An electro-hydraulic process control system in a sub-sea production installation, comprising: a top-side hydraulic power unit driven and controlled to generate and supply hydraulic power to a process control unit of the sub-sea production installation at a steady-state operation mode; a sub-sea hydraulic power unit driven and controlled to generate and supply hydraulic power to the process control unit of the sub-sea production installation at a transient-state operation mode; an umbilical comprising small bore tubing feeding hydraulic power from the top-side hydraulic power unit, and cables feeding electric power for operation of the sub-sea hydraulic power unit, and a control unit configured to control the sub-sea hydraulic power unit between a stand-by mode and an operative mode wherein the sub-sea hydraulic power unit comprises a pump driven by an electric motor, the pump being operable and controlled in the transient-state operation mode to boost a pressure of hydraulic fluid returning from the process control unit to a pressure required for operating process and safety valves of the process control unit.