Drill string incorporating an acoustic telemetry system employing one or more low frequency acoustic attenuators and an associated method of transmitting data

Abstract

A drill pipe forms an acoustic transmission channel for data to be transmitted from a downhole transceiver to a surface transceiver. By positioning a first low frequency acoustic attenuator between a drill bit and the downhole transceiver, acoustic noise generated by the drill bit is attenuated. Similarly, by positioning the surface transceiver between the top of the drill pipe and a second low frequency acoustic attenuator, acoustic noise generated by surface equipment is attenuated. In this manner, the first and second low frequency acoustic attenuators serve as terminators for the acoustic transmission channel. Finally, by combining a third low frequency acoustic attenuator positioned between first and second sections of the drill pipe with first and second acoustic transceivers acoustically isolated from one another by the third low frequency acoustic attenuator and non-acoustically coupled to one another for bi-directional exchanges of signals, an acoustic repeater is provided for the transmission channel.