cement bond log
A log that uses the variations in amplitude of an acousticsignal traveling down the casing wall between a transmitter and receiver to determine the quality of cement bond on the exterior casing wall. The fundamental principle is that the acoustic signal will be more attenuated in the presence of cement than if the casing were uncemented. The measurement is largely
Detailed Explanation
qualitative, as there is no indication of azimuthal cement variations such as channeling, and as it is sensitive to the effect of a microannulus.