Patent ID: 6257549
Filing Date: 2001-07-10
Classification: E21B,H02J

Abstract:
An actuation module for actuating a device in a subsea wellhead assembly, the device comprising an element movable between a first safe operating position and a second operating position, the module comprising:a housing containing a rotatable actuator arranged to be coupled to a rotatable part of the device, whereby when the actuator is coupled to the rotatable part of the device rotation of the rotatable part by the actuator causes the element of the device to move between the first and second operating positions;an electric motor for rotating the actuator;an input for receiving primary power from an external source for energizing the motor;a back-up secondary power source; anda controller for responding to a loss of primary power and thence, when the actuator is coupled to the rotatable part of the device, causing the motor to be energized from the back-up secondary power source if the element is in the second operating position so that the motor causes the element to move to the first operating position;wherein the primary power source is connected through the back-up secondary power source to maintain the back-up secondary power source fully charged, any surplus power being available to energize the motor.