Patent ID: 6388577
Filing Date: 2002-05-14
Classification: E21B

Abstract:
A method of actuating a controllable device that is at a remote location from a source station and disposed within a tubular system containing mobile fluid media which may comprise hydrocarbon liquids and gases, water, process fluids, and various combinations of such media, the method comprising the steps of:launching a gas shock impulse into the tubular system at the source station, the shock impulse initially having abrupt leading and trailing edge transitions less than Â½ second apart, and an energy level calculated in accordance with the distance to the remote location and the media characteristics to travel through the media within the tubular system but retain predetermined impulse characteristics at the remote location; sensing at the remote location, a local physical perturbation in the media that is created by the passage of the shock impulse to the remote location; converting the sensed physical perturbation to a signal variation; determining if the signal variation is, in amplitude and duration characteristics, that intended for actuating the controllable device; and actuating the controllable device thereafter in response to the determination.