Patent ID: 9121970
Filing Date: 2015-09-01
Classification: G01V

Abstract:
1. A LWD logging tool acoustic transmitter comprising: a transmitter comprising a plurality of arc segments of piezoelectric material alternately and rigidly bound to a plurality of arc segments of non-piezoelectric material to form a segmented ring; wherein said segmented ring is disposed within a transmitter ring assembly, said transmitter ring assembly being disposed within an insert comprising a flow conduit, said insert being disposed within a drill collar rather than into a wall of the drill collar of said logging tool; the normal of said ring is essentially coincident with the major axis of said logging tool; and said plurality of arc segments of said piezoelectric material are polarized and configured electrically to emit a pressure pulse perpendicular to said normal upon application of a voltage to said plurality of arc segments of piezoelectric material; and said non-piezoelectric material is selected to increase or decrease output frequency of the transmitter to a desired value.