System for acoustically determining the quality of the cement bond in a cased borehole

摘要: The present invention is directed to an apparatus and method for obtaining azimuthally dependent measurements evaluating the casing cement bond quality and, more particularly, detecting specifically locating channels or fissures between cement. of behind one arcs known location on determinable by invention. employ a plurality sonic transducers disposed in near contact with defined segmented locations about around exterior surface downhole tool. are arranged arrays, each array comprising four transducers, two transmitting receiving along single arc so that adjacent perform same function similarly functioning determined. sets arrays provide determinations continuous complete loop casing. determined measuring attenuation compression wave from pulsed acoustic traveling helices. also useful making hard formations detect fractures uncased boreholes. When fractures, shear rather than measured.