SIGNAL OPERATED ISOLATION VALVE

A method of drilling a wellbore includes drilling the wellbore through a formation by injecting drilling fluid through a drill string and rotating a drill bit. The drill string includes a shifting tool, a receiver in communication with the shifting tool, and the drill bit. The method further includes retrieving the drill string from the wellbore through a casing string until the shifting tool reaches an actuator. The casing string includes an isolation valve in an open position and the actuator. The method further includes sending a wireless instruction signal to the receiver. The shifting tool engages the actuator in response to the receiver receiving the instruction signal. The method further includes operating the actuator using the engaged shifting tool, thereby closing the isolation valve and isolating the formation from an upper portion of the wellbore.