Patent attributes
A casing annulus is remediated by inserting a hose into a casing annulus, the hose having a nozzle on its lower end. An acoustic signal is directed into the annulus. A sensor in the hose receives the acoustic signal and transmits data from the sensor to the surface. The data represents the acoustic signal arrival time to the sensor, and an analyzer estimates the sensor depth based on the data. The hose is inserted from a reel into a wellhead above the annulus. An electrical transducer mechanically coupled to the hose creates the acoustic signal. The signal is propagated along the hose and transferred to the fluid in the annulus, where it then propagates further into the annulus. The transducer can be installed on a hose roller along which the hose is fed into the wellhead.