A DRILL STRING INCORPORATING AN ACOUSTIC TELEMETRY SYSTEM EMPLOYING ONE OR MORE LOW FREQUENCY ACOUSTIC ATTENUATORS AND AN ASSOCIATED METHOD OF TRANSMITTING DATA

摘要

A drill pipe (134) forms an acoustic transmission channel for data to betransmitted from a downhole transceiver (136) to a surface transceiver (132).By positioning a first low frequency acoustic attenuator (154) between a drillbit (156) and the downhole transceiver (136), acoustic noise generated by thedrill bit is attenuated. Similarly, by positioning the surface transceiver(132) between the top of the drill pipe (134) and a second low frequencyacoustic attenuator (130), acoustic noise generated by surface equipment isattenuated. In this manner, the first and second low frequency acousticattenuators (130, 154) serve as terminators for the acoustic transmissionchannel. Finally, by combining a third low frequency acoustic attenuator (138)positioned between first and second sections of the drill pipe with first andsecond acoustic transceivers (136, 140) acoustically isolated from one anotherby the third low frequency acoustic attenuator (138) and non-acousticallycoupled to one another for bi-directional exchanges of signals, an acousticrepeater is provided for the transmission channel.