SPWLA Glossary

A well-logging system wherein a pulsed, narrow acoustic (sonar) beam scans the borehole wall in a tight helix as the tool moves up the borehole. A display of the amplitude of the reflected wave on a cathode ray tube (television screen) is photographed yielding a picture of the borehole wall. The picture is a representation of the wellbore wall as if it were split vertically along magnetic north and laid out flat. Physical discontinuities such as fractures, vugs, etc. are detailed on the log. The tool may be used for casing inspection, without the magnetic orientation for location of perforations or damage.