ACOUSTIC BOREHOLE LOGGING

摘要

An acoustic borehole logging system employs an acoustic transmitter excited by a sweep frequency tone burst to produce an acoustic output having a free-field frequency spectrum of at least one resonant frequency of vibration. A closely-spaced acoustic receiver detects a borehole frequency spectrum that is representative of the acoustic transmitter free-field frequency spectrum altered by the effects of the properties of the subsurface formation materials comprising the borehole wall. Such detected borehole frequency spectrum is recorded in correlation with depth as a log of the material properties of the subsurface formations surrounding the borehole.