Patent ID: 7522471

Claim:
A method for imaging a description of a zone behind a casing of a well, the method using a logging tool positionable inside the casing, the logging tool carrying a plurality of acoustic transducers, the method comprising: a. insonifying ( 72 ) the casing with a first acoustic wave using a first acoustic transducer for transmitting among the plurality of acoustic transducers, the first acoustic wave having a first mode that may be any mode of a set of modes defined as follows: extensional mode, thickness mode, flexural mode; b. selecting ( 71 ) at least a first acoustic transducer for receiving among the plurality of transducers, the first acoustic transducer for receiving having a location adapted to receive a first echo corresponding to the first acoustic wave; c. receiving ( 73 ) at the first acoustic transducer for receiving the first echo, and producing a first signal; d. extracting ( 76 ) from the first signal a first measurement; e. insonifying ( 74 ) the casing with a second acoustic wave using a second transducer for transmitting among the plurality of acoustic transducers, the second acoustic wave having a second mode that may be any mode of the set of modes and is distinct from the first mode; f. selecting ( 79 ) at least a second acoustic transducer for receiving among the plurality of transducers, the second acoustic transducer for receiving having a location adapted to receive a second echo corresponding to the second acoustic wave; g. receiving ( 75 ) at the second acoustic transducer for receiving the second echo and producing a second signal; h. extracting ( 77 ) from the second signal a second measurement; i. evaluating ( 78 ) from a combination of the first measurement and the second measurement the description of the zone behind the casing of the well.