Wireless communication between tools

Abstract

The present invention relates to a downhole tool system for being submerged into a casing, comprising at least three tools having a tool axis. Furthermore, the present invention relates to a downhole tool system for being submerged into a casing, comprising at least three tools, and finally the invention relates to communication methods for communicating wirelessly between a first and a third tool separated by a second tool.

1 . A downhole tool system ( 100 ) for being submerged into a casing ( 10 ), comprising at least three tools having a tool axis:
 a first tool ( 1 ) having a first ( 11 ) and a second end ( 12 ) and comprising a first communication device ( 13 ) arranged at the second end,   a second tool ( 2 ) having a first end ( 21 ), which is connected with the second end of the first tool, and a second end ( 22 ), the second tool comprising a housing ( 23 ), and   a third tool ( 3 ) comprising a second communication device ( 33 ) and a first end ( 31 ), the first end of the third tool being connected with the second end of the second tool,   
       the first and second communication devices comprising an antenna for communicating with each other by sending and receiving radio waves. 
     
     
         2 . A downhole tool system according to  claim 1 , wherein the antennas transmit radio waves having a wavelength which is lower than 200 m, preferably lower than 1 m, more preferably lower than 10 cm, even more preferably lower than 2.5 cm. 
     
     
         3 . A downhole tool system according to  claim 1  or  2 , wherein the antenna comprises one or more ferrite rods. 
     
     
         4 . A downhole tool system according to any of the preceding claims, wherein the antenna is wound around one or more ferrite rods. 
     
     
         5 . A downhole tool system according to any of  claims 3 - 4 , wherein the ferrite rods extend parallel to the tool axis. 
     
     
         6 . A downhole tool system according to any of  claims 3 - 5 , wherein the ferrite rods are arranged in a circular loop. 
     
     
         7 . A downhole tool system according to any of the preceding claims, wherein orthogonal frequency-division multiplexing (OFDM) modulation is used for transmitting encoding digital data on multiple carrier frequencies between the antennas. 
     
     
         8 . A downhole tool system according to any of  claims 3 - 7 , wherein the antenna sends and receives at different frequencies with one frequency for each rod. 
     
     
         9 . A downhole tool system according to any of the preceding claims, wherein the antenna is a loop antenna. 
     
     
         10 . A downhole tool system according to any of the preceding claims, wherein the antenna is a small loop antenna. 
     
     
         11 . A downhole tool system according to any of the preceding claims, wherein the antenna is a loop stick antenna. 
     
     
         12 . A downhole tool system according to any of the preceding claims, wherein the waves are transmitted at a frequency of 520-1610 kHz. 
     
     
         13 . A downhole tool system ( 100 ) for being submerged into a casing ( 10 ), comprising at least three tools:
 a first tool ( 1 ) having a first ( 11 ) and a second end ( 12 ) and comprising a first communication device ( 13 ) arranged at the second end,   a second tool ( 2 ) having a first end ( 21 ), which is connected with the second end of the first tool, and a second end ( 22 ), the second tool comprising a housing ( 23 ), and   a third tool ( 3 ) comprising a second communication device ( 33 ) arranged at a first end ( 31 ), the first end of the third tool being connected with the second end of the second tool,   
       the first and second communication devices being a first and a second acoustic device, respectively, 
       wherein the second tool is arranged between the first tool and the third tool, and the first acoustic device arranged at the first end of the second tool sends and receives acoustic signals to and from the second acoustic device which is arranged at the first end of the third tool. 
     
     
         14 . A downhole tool system according to  claim 13 , wherein the first and second acoustic devices comprise means ( 4 ) for converting data parameters into electric signals and transducers ( 5 ) for receiving the electrical signals and generating acoustic signals propagating along the housing of the second tool. 
     
     
         15 . A downhole tool system according to  claim 14 , wherein the transducers abut the ends of the second tool. 
     
     
         16 . A downhole tool system according to any of the preceding claims, wherein the transducers of the first and second acoustic devices face the second tool, causing the acoustic signals to propagate axially along the housing of the second tool. 
     
     
         17 . A downhole tool system according to any of the preceding claims, wherein the first and second communication devices are antennas instead of acoustic devices, sending and receiving radio waves. 
     
     
         18 . A downhole tool system according to any of the preceding claims, wherein the third tool is a logging tool. 
     
     
         19 . A downhole tool system according to any of the preceding claims, wherein the first tool comprises an electronic motor ( 14 ). 
     
     
         20 . A downhole tool system according to any of the preceding claims, wherein the first and/or second communication device(s) comprise(s) a memory ( 6 ). 
     
     
         21 . A downhole tool system according to any of the preceding claims, wherein the first and/or second communication device(s) comprise(s) a processing unit ( 7 ) for processing data before converting the data into acoustic signals. 
     
     
         22 . A downhole tool system according to any of the preceding claims, wherein the transducer is a magnetostrictive transducer. 
     
     
         23 . A downhole tool system according to any of the preceding claims, wherein the communication device comprises a battery ( 8 ). 
     
     
         24 . A downhole tool system according to any  claims 13 - 23 , wherein the acoustic devices comprise mechanical or electronic filters ( 9 ). 
     
     
         25 . A communication method for communicating wirelessly between a first and a third tool separated by a second tool, comprising the steps of:
 connecting the first tool with the second tool, the first tool comprising a first communication device having an antenna and the second tool comprising a tool housing,   connecting the third tool with the second tool, the third tool comprising a second communication device having an antenna,   sending radio waves from the first communication device to the second communication device.   
     
     
         26 . A communication method according to  claim 25 , further comprising the step of using orthogonal frequency-division multiplexing (OFDM) modulation for transmitting encoding digital data on multiple carrier frequencies between the antennas. 
     
     
         27 . A communication method for communicating wirelessly between a first and a third tool separated by a second tool, comprising the steps of:
 connecting the first tool with the second tool, the first tool comprising a first acoustic device and the second tool comprising a tool housing,   connecting the third tool with the second tool, the third tool comprising a second acoustic device,   sending acoustic signals from the first acoustic device to the second acoustic device, the signals propagating along the housing of the tool.   
     
     
         28 . A communication method according to  claim 27 , further comprising the step of converting data parameters into electric signals.