| 20100089570 | METHOD FOR SIGNALLING A DOWNHOLE DEVICE IN A WELL - A method and apparatus for controlling the operation of a well which is not flowing or in which fluid is pumped or injected into the well utilising a downhole located pressure monitoring device which is operative to monitor a characteristic pressure profile of the well, and to respond and generate a triggering output when a significant deviation to the pressure profile is introduced into the well as a control signal to the monitoring device by comparing two separate pressure profiles within a certain time span, the device only generating a triggering output when the same pressure profile is monitored twice within the time span; and an actuator which is initiated into operation to control any required operation of the well when the monitoring device responds to the control signal and generates the triggering output. | 04-15-2010 |