The present invention relates to apparatus and methods for remotely
actuating a downhole tool. In one aspect, the present invention provides
an apparatus for activating a downhole tool in a wellbore, the downhole
tool having an actuated and unactuated positions. The apparatus includes
an actuator for operating the downhole tool between the actuated and
unactuated positions; a controller for activating the actuator; and a
sensor for detecting a condition in the wellbore, wherein the detected
condition is transmitted to the controller, thereby causing the actuator
to operate the downhole tool. In one embodiment, conditions in the
wellbore are generated at the surface, which is later detected downhole.
These conditions include changes in pressure, temperature, vibration, or
flow rate. In another embodiment, a fiber optic signal may be transmitted
downhole to the sensor. In another embodiment still, a radio frequency
tag is dropped into the wellbore for detection by the sensor.