Patent ID: 8009059
Filing Date: 2011-08-30
Classification: E21B

Abstract:
1. A method to periodically communicate with a sensor installed downhole in a completed well, the method comprising periodically and repeatedly: activating a surface pressure wave generator to transmit pressure waves to excite a downhole energy converter, wherein said energy converter comprises one of a magnetostrictive material or a single crystal piezoelectric; storing electrical energy from said downhole energy converter in a downhole energy storage device; after storing electrical energy in the device, powering up the sensor and a downhole control module both powered by electrical energy from the device; accumulating data received from said downhole sensor in the downhole control module; transmitting said data from said downhole control module to a surface signal processing unit, wherein the step of transmitting said data from said downhole control module to said surface signal processing unit comprises said module controlling a pressure wave telemetry unit to modify and reflect the pressure waves back to the surface location; and deactivating the surface pressure wave generator, allowing electrical energy remaining in the storage device to be consumed and shutting down the sensor and control module.