Downhole communication system

Abstract

A downhole communication system includes a rebroadcaster. The rebroadcaster includes a receiver configured to receive signals from a surface location. A processor on the rebroadcaster demodulates and converts the signal into a pressure pulse pattern. The pressure pulse pattern is transmitted to a downhole tool as a pressure pulse signal using a mud pulse generator.

What is claimed is: 
     
         1 . A method for downhole communication, comprising:
 receiving a signal at a rebroadcaster;   converting the signal to a pressure pulse pattern; and   transmitting the pressure pulse pattern with a pressure pulse generator located downhole.   
     
     
         2 . The method of  claim 1 , wherein transmitting the pressure pulse pattern includes transmitting the pressure pulse pattern from a pressure pulse generator located in a bottomhole assembly. 
     
     
         3 . The method of  claim 1 , wherein converting the signal to the pressure pulse pattern includes directly converting the signal to the pressure pulse pattern. 
     
     
         4 . The method of  claim 1 , wherein receiving the signal at the rebroadcaster includes receiving the signal at a measurement while drilling tool. 
     
     
         5 . The method of  claim 1 , further comprising receiving the pressure pulse pattern at a rotary steerable system. 
     
     
         6 . The method of  claim 1 , further comprising transmitting the signal downhole via a wired connection. 
     
     
         7 . The method of  claim 1 , wherein converting the signal includes interpreting the signal and converting the signal into one of a plurality of pre-determined pressure pulse patterns. 
     
     
         8 . The method of  claim 1 , comprising receiving the pressure pulse pattern at a plurality of downhole tools. 
     
     
         9 . The method of  claim 8 , wherein the pressure pulse pattern includes an identifier, the identifier indicating a target downhole tool of the plurality of downhole tools to which the pressure pulse pattern is directed. 
     
     
         10 . The method of  claim 1 , wherein the signal includes instructions for a downhole tool. 
     
     
         11 . The method of  claim 1 , comprising receiving the pressure pulse pattern at a surface location and checking the pressure pulse pattern against the signal. 
     
     
         12 . A method for downhole communication, comprising:
 transmitting a signal downhole;   receiving the signal at a rebroadcaster;   converting the signal to a pressure pulse pattern; and   generating pressure pulses downhole in the pressure pulse pattern.   
     
     
         13 . The method of  claim 12 , comprising receiving the pressure pulse pattern at a downhole tool. 
     
     
         14 . The method of  claim 13 , comprising changing at least one drilling parameter based on the received pressure pulses. 
     
     
         15 . The method of  claim 12 , wherein the rebroadcaster is located within 200 feet of a pressure pulse generator that transmits the pressure pulse pattern. 
     
     
         16 . The method of  claim 12 , wherein transmitting the signal downhole includes transmitting the signal via electromagnetic downlink. 
     
     
         17 . The method of  claim 12 , wherein the signal is transmitted downhole while the surface pumps are turned off and wherein pressure pulses are generated downhole in the pressure pulse pattern when the surface pumps are turned on. 
     
     
         18 . A system for downhole communication, comprising:
 a rebroadcaster, including:
 a receiver configured to receive a signal from a surface location; 
 a processor configured to convert the signal to a pressure pulse pattern; and 
 a pressure pulse generator configured to transmit the pressure pulse pattern. 
   
     
     
         19 . The system of  claim 18 , wherein the rebroadcaster is configured to operate only in a rebroadcast mode. 
     
     
         20 . The system of  claim 18 , wherein the receiver is configured to receive electromagnetic downlink signals. 
     
     
         21 . The system of  claim 18 , wherein the pressure pulse generator is a low amplitude, high frequency pressure pulse generator.