Patent ID: 8270251

Claim:
An acoustic isolator for use with tubular assemblies comprising an acoustic wave transmitter, the acoustic isolator comprising, in series connection: a first tubular member of a first acoustic impedance connectable adjacent to the acoustic wave transmitter and having a length that is an odd multiple of a quarter wavelength (λ/4) of a representative acoustic wave; a second tubular member of a second acoustic impedance that is less than the first acoustic impedance and having a length that is an odd multiple of a quarter wavelength (λ/4) of the representative acoustic wave; and a third tubular member of a third acoustic impedance that is greater than the second acoustic impedance; whereby a first wave propagated by the transmitter toward the first tubular member is reflected back substantially in phase with a second wave propagated at the same time by the transmitter away from the first tubular member; wherein the tubular assemblies are a part of a downhole drill-string, the acoustic wave transmitter is for acoustic telemetry, the first tubular member is a tuning bar, the second tubular member is a reflector tube, and the third tubular member is a snubber.