Actuator assembly and method for actuating downhole assembly

An actuator for actuating a device, comprising:

• a housing having a chamber adapted for containing fluid, said chamber having first and second portions;
• a piston disposed in one of said portions;
• and
• a bi-directional pump member disposed between said portions within said chamber and communicating with said portions to pump fluid between said one of said portions and the other of said portions causing said piston to move within said one of said portions;
• wherein said pump is driven by an electric motor and includes a rotor disposed within a stator and wherein said rotor is supported by a bearing pack and is threaded for threading engagement with a nut that retains said bearing pack within said housing.

An actuator for actuating a downhole member from the surface of a well, comprising:

• a housing having a chamber adapted for containing fluid;
• a moineau pump disposed within said chamber and dividing said chamber into a low pressure chamber and a high pressure chamber;
• a piston disposed in said high pressure chamber movable between an actuation position and a non-actuation position;
• said moineau pump in communication with said low and high pressure chambers to pump fluid therebetween;
• and
• said moineau pump adapted to pump fluid from said low pressure chamber to said high pressure chamber to move said piston and actuate the downhole member in said actuation position and to pump fluid from said high pressure chamber to said low pressure chamber to allow said piston to move to said non-actuation position.

A method for actuating a downhole assembly comprising:

• activating a motor to rotate a rotor of a moineau pump disposed between a low pressure chamber and a high pressure chamber;
• pumping a predetermined volume of fluid from said low pressure chamber to said high pressure chamber;
• increasing pressure within said high pressure chamber,
• applying the increased pressure against u piston disposed within said high pressure chamber;
• and
• moving the piston associated with the downhole assembly to actuate the assembly.

A method for actuating a downhole assembly comprising:

• activating a motor to rotate a rotor of a moineau pump disposed between a low pressure chamber and a high pressure chamber;
• pumping a predetermined volume of fluid from said low pressure chamber to a said high pressure chamber;
• increasing pressure within said high pressure chamber;
• applying the increased pressure against a piston disposed within said high pressure chamber;
• moving the piston associated with the downhole assembly to actuate the assembly;
• pumping fluid from said high pressure chamber into said low pressure chamber. and
• moving said piston to a non-actuation position.

An actuator for driving a downhole assembly member, said actuator comprising:

• a housing disposed internally of said downhole assembly;
• a reservoir containing hydraulic fluid disposed internally of said housing:
• a hydraulic enclosure in fluid communication with said reservoir disposed internally of said housing;
• a bi-directional pump assembly disposed internally of said hydraulic enclosure between a low-pressure chamber and a high-pressure chamber;
• an electric motor for driving said bi-directional pump;
• a piston assembly disposed in said high-pressure chamber;
• and
• a repositioning assembly disposed internally of said downhole assembly offset from said housing, and in a different axial plane than said housing.

An apparatus for displacing a piston comprising:

• a chamber containing said piston and a bi-directional pump;
• a motor adapted to rotate a rotor of sad pump in both directions;
• and
• each rotation of said pump corresponding to a precise displacement of said piston.

A method for positioning a piston comprising:

• disposing a piston in a first position within a chamber;
• disposing a pump within the chamber;
• rotating a rotor of the pump in a direction to pump a predetermined volume of fluid into the chamber;
• displacing the piston to a predetermined position;
• and
• maintaining the piston in said predetermined position.

An actuator for actuating a device, comprising:

• a housing having a chamber adapted for containing fluid, said chamber having first and second portions;
• a piston disposed in one of said portions;
• a pump member disposed between said portions within said chamber and communicating with said portions to pump a specific volume of fluid between one of said portions and the other of said portions causing said piston to move a predetermined distance within said one of said portions;
• and
• a reservoir in communication with said chamber;
• wherein said chamber and said reservoir form a closed system for containing fluid.