APPARATUS AND METHOD FOR ACOUSTICALLY INVESTIGATING A BOREHOLE BY USING A PHASED ARRAY SENSOR

摘要

A tool for investigating a borehole comprises one or two matrices of acoustical transducer elements organised on respective cylindrical surfaces. Each transducer element of the respective matrices may be individually excited or measured. The tool allows for generation of a number of type of beams, e.g. focused or unfocused on the inner wall of the borehole, in directions normal or non normal to the inner wall. Methods for compensating eccentricity of the tool and for determining fluid velocity are presented.