ACTIVE ATTENUATION OF VIBRATIONS RESULTING FROM FIRING OF ACOUSTIC SOURCES

摘要

An acoustic logging tool is provided with a first acoustic source that generates an acoustic signal primarily directed into the formation, the acoustic signal including a noise signal carried axially along the tool, a second acoustic source adapted to generate a noise canceling signal along the tool that actively and significantly cancels the noise signal, and a plurality of acoustic sensors axially spaced from each other along the tool and spaced from the first acoustic source and the second acoustic source. The acoustic sensors receive and record indications of pressure signals resulting from the acoustic signal and the noise canceling signal. The pressure signal indications may be processed in order to generate information regarding the formation.