Downhole device employing an electromagnet assembly and permanent magnet assembly to actuate a movable feature

A method, comprising:

• accessing a downhole device located within a wellbore extending through one or more subterranean formations, wherein the downhole device includes:
• a member having a first member end and a second opposite member end;
• a movable element positioned about the member, the movable element having a first movable element end and a second opposite movable element end, the movable element configured to move a stroke distance (D) from a first position to a second position;
• a permanent magnet assembly fixed to one of the member or the movable element, the permanent magnet assembly producing an inherent magnetic field having a magnetic polarity (X), the permanent magnet assembly generating a magnetic coupling force that biases the movable element toward the first position;
• and
• an electromagnet assembly fixed to an other of the movable element or the member;
• and
• supplying electric power to the electromagnet assembly to produce an electromagnetic field having an electromagnetic polarity (Y) similar in direction to the magnetic polarity (X), the electromagnetic field generating an opposite electromagnetic coupling force greater than the magnetic coupling force to actuate the movable element from the first position towards the second position.

A well system, comprising:

• a wellbore extending through one or more subterranean formations;
• and
• a downhole device located within the wellbore, the downhole device including:
• a member having a first member end and a second opposite member end;
• a movable element positioned about the member, the movable element having a first movable element end and a second opposite movable element end, the movable element configured to move a stroke distance (D) from a first position to a second position;
• a permanent magnet assembly fixed to one of the member or the movable element, the permanent magnet assembly producing an inherent magnetic field having a magnetic polarity (X), the permanent magnet assembly generating a magnetic coupling force that biases the movable element toward the first position;
• and
• an electromagnet assembly fixed to an other of the movable element or the member, the electromagnet assembly operable to receive electric power to produce an electromagnetic field having an electromagnetic polarity (Y) similar in direction to the magnetic polarity (X), the electromagnetic field configured to generate an opposite electromagnetic coupling force greater than the magnetic coupling force to actuate the movable element from the first position towards the second position when the electromagnet assembly receives the electric power.