METHOD AND APPARATUS FOR ACOUSTIC DOWNHOLE TELEMETRY AND POWER DELIVERY SYSTEM USING TRANSVERSE OR TORSIONAL WAVES

摘要

Methods and apparatus for transmitting power and data along a metal pipe using wideband acoustic waves. Arrangements use shear-horizontal waves, transmitting narrowband signals for power applications and wideband signals for communications having a bandwidth greater than the coherence bandwidth of the acoustic-electric channel. Chirp wave signals, direct sequence spread signals, and on-off keying are used. Acoustic-electric channels include wedges fixed to a pipe or other substrate, transducers fixed to the wedges, and electronics linked to each transducer for sending and receiving power and signals. Matching networks, rectification circuits, and non-coherent signal reception methods may be used.

主权项

1. A method of transmitting binary data axially along a length of metal pipe, the method comprising:
providing an acoustic-electric channel, the acoustic-electric channel comprising:
a metal pipe, the pipe being a substrate;a first assembly coupled to the pipe, and a second assembly coupled to the pipe and axially spaced apart from the first assembly;wherein the first assembly comprises: a first transition piece coupled to the pipe, a first transducer coupled to the first transition piece, and first electronics communicatively linked to the first transducer;wherein the second assembly comprises: a second transition piece coupled to the pipe, a second transducer coupled to the second transition piece, and second electronics communicatively linked to the second transducer;wherein the acoustic-electric channel has a coherence bandwidth (CB); the method further comprising: the first transducer generating wideband shear-horizontal waves, the shear-horizontal waves being modulated to form a series of Chirp signals comprising binary data, wherein each Chirp signal has a varied frequency over the course of the Chirp signal, each Chirp signal has an initial frequency fi and each Chirp signal has a value fΔmax which is a maximum frequency deviation from the starting frequency fi ; wherein fΔmax is greater than the coherence bandwidth (CB) of the acoustic-electric channel; said shear horizontal waves generated by the first transducer propagating through the first transition piece, into the pipe, thence into the second transition piece and the second transducer; the second transducer turning received shear horizontal wave energy into received electrical energy; and demodulating the received electrical energy as binary data, wherein the presence and absence of Chirp signals over time are interpreted as binary data by the second electronics.