Apparatus for rotating a transducer assembly of a borehole logging tool in a deviated borehole

摘要

A borehole logging tool having a dipole acoustic energy source and at least one spaced-apart dipole acoustic energy receiver is lowered into a deviated borehole. A motor rotates the source and receiver about the axis of the borehole tool. A first signal is produced representing source and receiver rotational position relative to a vertical direction. A second signal is produced representing a fixed reference level. A comparator produces a third signal of the difference between the first and second signals. The motor rotates so as to minimize such third signal, thereby maintaining the focus of the source and receiver in a horizontal direction that is perpendicular to the direction of eccentricity of the borehole tool with respect to the borehole axis.