An acoustic logging system for detecting anomalies in formations surrounding a borehole. The system can be used for evaluating the formation for fractures or the bond between a well casing and the cement used to seal the space between the casing and the formation. The system utilizes at least one rotating...http://www.google.de/patents/US4992994?utm_source=gb-gplus-sharePatent US4992994 - Borehole televiewer for fracture detection and cement evaluation
