Methods and systems for communicating data through a pipe

Abstract

An acoustic telemetry system includes a piezoelectric stack at least partially disposed within a segment of pipe, and electrical circuitry for controlling the piezoelectric stack. In response to a signal from the electrical circuitry, the piezoelectric stack generates a plurality of acoustic signals for transmission through the pipe at different frequencies spanning multiple regions of a frequency response for the pipe.

1 : A method for communicating data through a drill string in a drilling system, the drilling system (i) including a downhole unit and a surface unit, and (ii) extending from the downhole unit to the surface unit, the method comprising:
 receiving an electrical signal comprising data indicative of at least one system parameter;   deriving a plurality of acoustic signals based on the electrical signal, each acoustic signal representing at least a portion of the data; and   transmitting the plurality of acoustic signals through the drill string at different frequencies spanning multiple regions of a frequency response for the drill string.   
   
   
       2 : The method of  claim 1  wherein the plurality of acoustic signals are transmitted from the downhole unit towards the surface unit. 
   
   
       3 : The method of  claim 2 , further comprising receiving, at the surface unit, at least a portion of the plurality of acoustic signals. 
   
   
       4 : The method of  claim 3 , further comprising decoding the data from the received acoustic signals. 
   
   
       5 : The method of  claim 4  wherein decoding the data comprises selecting a subset of the received acoustic signals, each acoustic signal in the subset having an amplitude greater than a pre-determined value. 
   
   
       6 : The method of  claim 4 , further comprising:
 identifying a discrepancy in the decoded data; and   resolving the discrepancy with at least one of a majority rule decoding technique and a maximal ratio combining decoding technique.   
   
   
       7 : The method of  claim 1 , further comprising measuring, at a segment of the drill string proximate to an origin for the transmission, at least one parameter of the plurality of transmitted acoustic signals. 
   
   
       8 : The method of  claim 7 , further comprising:
 comparing the measured parameter with an anticipated value therefor; and   adjusting at least one of the plurality of acoustic signals.   
   
   
       9 : The method of  claim 1 , further comprising sensing a noise signal in the drill string at least one noise frequency, each acoustic signal of the plurality of acoustic signals being transmitted at a frequency different from the at least one noise frequency. 
   
   
       10 : A method for noise cancellation during data communication through a pipe, the method comprising:
 receiving an electrical signal;   deriving an acoustic signal based on the electrical signal;   sensing a noise signal in the pipe;   generating a corrective signal to counteract the noise signal; and   transmitting the acoustic signal and the corrective signal through the pipe.   
   
   
       11 : The method of  claim 10  wherein the acoustic signal and the corrective signal are each imparted to the pipe through a common transducer. 
   
   
       12 : The method of  claim 10  wherein the acoustic signal and the corrective signal are each imparted to the pipe through different transducers. 
   
   
       13 - 33 . (canceled) 
   
   
       34 : A method for communicating data through a pipe, the method comprising:
 receiving an electrical signal comprising data indicative of at least one parameter;   deriving a plurality of acoustic signals based on the electrical signal, each acoustic signal representing at least a portion of the data; and   transmitting the plurality of acoustic signals through the pipe at different frequencies spanning multiple regions of a frequency response for the pipe.   
   
   
       35 : The method of  claim 34 , further comprising receiving at least a portion of the plurality of acoustic signals. 
   
   
       36 : The method of  claim 35 , further comprising decoding the data from the received acoustic signals. 
   
   
       37 : The method of  claim 34 , further comprising measuring, at a segment of the pipe proximate to an origin for the transmission, at least one parameter of the plurality of transmitted acoustic signals. 
   
   
       38 : The method of  claim 37 , further comprising:
 comparing the measured parameter with an anticipated value therefor; and   adjusting at least one of the plurality of acoustic signals.   
   
   
       39 : The method of  claim 34 , further comprising sensing a noise signal in the pipe at least one noise frequency, each acoustic signal of the plurality of acoustic signals transmitted at a frequency different from the at least one noise frequency.