Detachable electrical actuator
AssigneeVetco Gray Inc.
InventorRobert K. Voss
Life of this patent
Estimating the term…
Abstract
A removable module for actuating elements, such as valves, within a subsea production tree. The module can include a motor, a drive shaft, and a ball screw. Embodiments exist where only the motor is removable, optionally the motor and drive shaft and/or all module elements are removable. A fail safe system is included that moves the production tree element into a pre-designated fail safe position.
Claims17
A subsea system for producing hydrocarbons comprising:
- a subsea production member in fluid communication with a wellbore;
- an element in the production member linearly moveable between at least a first position and a second position;
- a cylindrical actuation housing having an inner end mounted to and extending from the production member and an open outer end:
- a stem coupled to the element for linear movement therewith and protruding concentrically into the actuation housing;
- an electrically powered motor having a motor housing assembly and a rotatable drive member extending therefrom;
- a motion translator located within the actuation housing, having a rotatable end linked with the rotatable drive member and a linearly moveable opposite end connected with the stem;
- a fastening assembly connected between the motor housing assembly and the actuation housing to secure the motor housing assembly to the actuation housing with the rotary drive member inserted into the actuation housing, the fastening assembly having cooperative elements on the motor housing and on the actuation housing adjacent the open end of the actuation housing;
- and
- wherein releasing the fastener assembly enables the motor housing assembly to be retrieved while the actuation housing remains subsea.
A subsea wellhead assembly for producing hydrocarbons from a subsea wellbore comprising:
- a subsea valve having a valve element linearly moveable between first and second positions, and a valve stem extending therefrom;
- a cylindrical actuation housing mounted to the valve and having an open end opposite the valve, the stem extending concentrically within the actuation housing;
- an electric motor having a rotatable shaft and a motor housing having a portion that inserts into the open end of the actuation housing;
- a pin and slot arrangement on an exterior portion of the motor housing and an interior portion of the actuation housing for releasably latching the motor housing to the actuation housing, enabling the motor to be retrieved while the actuation housing remains subsea;
- a motion translator linkage with a rotatable end selectively coupled with the rotatable shaft from the electric motor and a linearly moveable end connected to the valve stem;
- a reaction plate connected to the linearly moveable end of the linkage and movable in unison therewith:
- and
- a coil spring coaxially disposed in the actuation housing and having an outer end in contact with the reaction plate for urging the reaction plate and the valve stern toward the open end of the actuation housing.
A method of operating a subsea production member having a linearly moveable element therein and a stem extending from the moveable element, the method comprising:
- mounting a cylindrical actuation housing to the production member with the stem extending concentrically inside the actuation housing;
- connecting a linear movably end of a motion transfer linkage to the stem such that the linkage is enclosed by the actuation housing;
- providing an electrical motor with a motor housing assembly, lowering the motor subsea, inserting a rotary drive member of the motor into engagement with a rotatable end of the linkage;
- releasably securing the motor housing assembly to the actuation housing;
- energizing the motor to drive the linkage;
- linearly moving the moveable element with the linkage;
- and
- releasing the motor housing assembly from the actuation housing, and retrieving the motor housing assembly.
The method of claim, 11 wherein releasably securing the motor housing assembly to the actuation housing comprises clamping the motor housing assembly to the actuation housing.
Dependencies are inferred from the claim text.