USING HIGHER ORDER HARMONICS TO DETERMINE ACOUSTIC IMPEDANCE OF MATERIAL BEHIND BOREHOLE CASINGS

摘要

An acoustic logging tool emits a wideband acoustic pulse toward an inside surface of a borehole casing and an acoustic response is received. The acoustic response is analyzed at one or more higher order harmonics of the thickness mode resonance of the casing to determine the acoustic impedance of the material behind the casing.