Acoustic Telemetry For Monitoring An Annulus Between The Production Casing And The Next Outer Casing Of A Well

A tool is positioned inside a production casing in a well such that at least one acoustic telemetry device provided in an extendable arm of the tool is located less than six inches away from at least another acoustic telemetry device provided in a casing module. Such proximity can ensure that the acoustic signals can be transmitted between acoustic telemetry devices through the production casing. The tool identifies a condition in the well that is measured in the B-annulus between the production casing and a next outer casing. In turn, the tool broadcasts the measured condition in the well to the Earth's surface where the measurement can be used to inform a decision about the well.