1. A method for torsional wave logging in a borehole of a subterranean formation, comprising: obtaining a torsional wave measurement of the borehole, wherein the torsional wave measurement represents characteristics of a torsional wave propagating within a cylindrical layered structure associated with the borehole, wherein the cylindrical layered structure comprises the subterranean formation and a completion of the borehole; analyzing, by a computer processor, the torsional wave measurement to generate a quality measure of the completion; and displaying the quality measure of the completion.