Well bore communication pulser

摘要

A well communication pulser is solenoid controlled but energized by an actuator responsive to the pressure drop across the signal valve. The signal valve is spring biased toward a closed state but the actuator urges it toward an open state with a force proportional to the pressure drop. When in the off-pulse state the spring is sized to yield an operating pressure for the pulser. A servo valve controls pressure admitted to the actuator to cause it to move to the on-pulse state to develop signal pressure. The servo valve is spring biased open to cause a pressure signal to be generated but it has a second actuator responsive to the pressure drop which will overcome the servo opening spring and move the servo to the off-pulse, or closed, state. The pulser would oscillate continually between the two states but a solenoid controlled latch automatically secures the servo when it arrives at either state. The latch will release the servo valve in response to signals from the down hole instrument allowing the instrument to encode time distributed changes of state detectable at the surface to decode the information from the instrument.